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A Twin Study of the Relationships among Inattention, Hyperactivity/Impulsivity and Sluggish Cognitive Tempo Problems

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We investigated the etiological relationships between the three ADHD dimensions of Inattentive Problems (INP), Hyperactivity-Impulsivity Problems (HIP) and Sluggish Cognitive Tempo (SCT) as measured by the CBCL 6-18 questionnaire. Multivariate models were applied to 398 twin pairs (374 boys and 422 girls) aged 8 to 17 years (M = 13.06, SD = 2.59) belonging to the population-based Italian Twin Registry. The INP, HIP and SCT problem scores were moderately-to-substantially (range 0.29-0.47) intercorrelated. The best fitting model showed that these 3 dimensions are correlated both at the genetic (correlations' range: 0.65-0.83) and the environmental (correlations: 0.29 and 0.44) levels, but they are also distinct. While SCT showed moderate heritability and large non-shared environmental influences, variance for both INP and HIP was substantially explained by genetic influences. We also found evidence of negative sibling interaction for INP, implying that a given behavior in one twin leads to an opposite behavior in the co-twin. Our results support at the etiological level the findings of previous psychometric and longitudinal studies of ADHD, which yielded evidence of the 3 distinct-albeit correlated-problem dimensions of inattentiveness, hyperactivity-impulsivity, and sluggish cognitive tempo.

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... Nevertheless, at present, there are very few twin studies that have been concerned with analyzing this pattern by including CDS within the research design. Regarding the co-occurrence of CDS with internalizing disorders, the only twin study that has been carried out so far is the one conducted by Scaini et al. in 2023 [73] . More specifically, this work focused on the analysis of the underlying causes of comorbidity between CDS and various anxiety-related phenotypes in a sample of 400 pairs of Italian twins aged 8 to 18 years. ...
... From a preliminary analysis, the authors found a significant association between CDS and only two types of anxiety, namely somatic and generalized anxiety. Therefore, they tested the goodness of fit to the data of the different multivariate models specific to the twin methodology, finding that the one with the best fit was a Common pathway model [73] . This model indicated that the associations between CDS and the two anxiety phenotypes were influenced by a unique latent susceptibility factor whose variance was, in turn, significantly determined by both genetic and environmental common factors. ...
... The results of this work thus highlighted that although CDS and anxiety-related problems represent distinct phenomena at the clinical level, they possess many common etiological factors, consisting of both life experiences and biological predisposition [73] . ...
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Twin studies are cutting-edge design methodologies proper to behavioral genetics that aim to investigate how the interplay between genetic and environmental factors can concur to explain individual differences in psychopathology, temperamental traits, and behavior. This particular research design has been widely applied to the study of comorbidity between internalizing (INT) and externalizing (EXT) symptoms, especially in childhood and adolescence. Notably, the high co-occurrence of symptoms of both these diagnostic domains has led to the hypothesis that at their basis, there might be one single latent common susceptibility factor, namely p factor. Twin studies have contributed to marking a relevant turning point in this regard by highlighting the consistent genetic nature of this factor. In light of these premises, the present narrative review aims to outline the path for future twin studies in investigating the comorbidity between Cognitive Disengagement Syndrome (CDS) and INT-EXT disorders, examining the evidence supporting this need and its clinical implications. Since CDS has not been recognized as a stand-alone syndrome until very recently, research on this condition is still in its infancy and the etiological factors at the basis of its comorbidity with INT-EXT are still unclear. Being aware of the causal factors underneath the comorbidity between INT-EXT might pave the way for improving assessment diagnostic procedures as well as setting up preventive interventions for CDS.
... • Con respecto las medidas externalizadas, los resultados indican que tanto SCT como TDAH-IN correlacionan con sintomatología externalizada, como la hiperactividad/impulsividad (HIM), problemas de conducta (PC) o síntomas del Trastorno Negativista Desafiante (TND), aunque dicha correlación es más elevada en TDAH-IN que en SCT. Lo curioso de esta asociación es que, mientras el TDAH-IN predice elevadas puntuaciones de sintomatología externalizada, elevadas puntuaciones de SCT ofrecen relaciones nulas o incluso negativas con los comportamientos externalizados, incluso tras controlarse la influencia mutua de TDAH-IN y SCT Becker & Langberg, 2013;Becker, Luebbe, Fite et al., 2014;Bernad et al., 2014;Burns et al., 2013;Fenollar-Cortés et al., 2015;Khadka et al., 2015;Langberg, Becker & Dvrosky, 2014;Lee et al., 2014;Leopold, Bryan, Pennington, & Willcutt, 2014;Moruzzi et al., 2014;Saxbe & Barkley, 2014;). • Niños con TDAH con elevados síntomas de SCT muestran menores puntuaciones de comportamientos externalizados, como agresiones, en comparación con niños TDAH sin síntomas SCT (Carlson & Mann, 2002;. ...
... Uno de los avances más notables se ha dado en el campo de la validez discriminante y predictiva puesto que, como era ya conocido de hace tiempo, las conductas y elementos definitorios del SCT solapan con las conductas y síntomas de inatención, tal y como se han definido en el TDAH. Ha sido necesario aplicar complejos análisis factoriales confirmatorios en muestras clínicas y normales, a través tanto de diseños transversales como longitudinales, para poder concluir lo que hasta ahora parece una de las resoluciones más sólidas: efectivamente el SCT se relaciona de forma moderada con el TDAH e incluso de forma elevada con la medida de inatención de este trastorno; sin embargo, al controlar el efecto mutuo entre SCT e inatención, cada una de ellas mantiene de forma significativa un patrón de relación con otras variables comportamentales, de interacción y de rendimiento, que incluso en algunos casos es opuesto (Araujo et al., 2015;Becker, Ciesielski et al., 2014;Becker & Langberg, 2013;Becker, Luebbe et al., 2015;Becker, Luebbe, Fite et al., 2014;Bernad et al., 2014;Burns et al., 2013;Camprodon et al., en prensa;Fenollar-Cortés et al., 2015;Khadka et al., 2015;Lee et al., 2014;Leopold, et al., 2015;Marshall et al.;Moruzzi et al., 2014;. Pero no queremos dejar de hacer notar que a veces el tamaño del efecto de tales diferencias no ha sido especialmente elevado. ...
... Mientras, la dimensión SCT lo hace en mucho menor grado, de forma no significativa e incluso, en algunas ocasiones, de modo inverso. En este sentido cabe destacar que en algunos aspectos, como la medida de psicopatía, el SCT puede ser un factor protector, puesto que la correlación es negativa y significativa Becker & Langberg, 2013;Becker, Luebbe, Fite et al., 2014;Bernad et al., 2014;Burns et al., 2013;Carlson & Mann, 2002;Fenollar-Cortés et al., 2015;Khadka et al., 2015;Lee et al., 2014;en prensa;Leopold et al., 2015;Moruzzi et al., 2014;. ...
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El Sluggish Cognitive Tempo (SCT) se presenta como una posible entidad psicopatológica caracterizada por inatención, enlentecimiento, tendencia a soñar despierto, hipoactividad, olvidos frecuentes y letargia, que muestra alta comorbilidad con el Trastorno por Déficit de Atención con Hiperactividad (TDAH) subtipo predominantemente inatento, y aunque comparten varios de los criterios diagnósticos, se muestran estudios que revelan la posibilidad de ser una entidad independiente. Esto no está plenamente comprobado debido a que algunos resultados son contradictorios en las investigaciones realizadas, especialmente en cuanto a etiologías, prevalencias, diferencias por género, características familiares, edad de aparición, estudios por neuroimagen y de neurotransmisores, los cuales se asemejan de manera importante a las características del TDAH. El SCT, además de mostrar gran variabilidad en los resultados expuestos, presenta a la fecha características similares a varios trastornos de los llamados internalizantes, coincidiendo en la sintomatología y dificultando su diagnóstico. Aquí se muestra una mirada crítica sobre el artículo-objetivo Sluggish Cognitive Tempo: realidades y controversias (Bernard & Servera, 2016) y se deja abierta la posibilidad sobre una entidad nosológica independiente o un subtipo de TDAH que necesita más sustento teórico que permita dar respuesta a los interrogantes planteados, los cuales no son pocos, cuando se evalúa este constructo.
... share some genetic risk factors, SCT appears to be less heritable than ADHD (Moruzzi et al., 2014). The correlation between SCT and ADHD symptoms and numerous environmental factors (such as demographics, comorbidities, and impairments) varies. ...
... In this study, we investigated whether there are differences between SCT and ADHD in terms of oxidative stress, DNA damage, and inflammatory biomarkers. Since SCT is diagnosed later than ADHD (Barkley, 2013;Barkley, 2012) and shows less genetic transmission (Moruzzi et al., 2014), we hypothesized that neuroinflammatory mechanisms and oxidant/antioxidant imbalance may be an important reason for the development of SCT. Therefore, we aimed specifically to test the assumption that there might be differences between oxidative stress, DNA damage, and inflammatory biomarkers of SCT and ADHD. ...
Article
Background: There has been a debate on whether sluggish cognitive tempo (SCT) differs from attention-deficit/hyperactivity disorder (ADHD). Although there have been many studies on metabolic parameters in relation to ADHD, no similar studies have been conducted on patients with SCT. We investigated whether there are differences between SCT and ADHD in terms of these factors. Subjects and Methods: Sixty-two participants with ages ranging from 11 to 18 who have diagnosis of ADHD (33 subjects) and SCT (29 subjects) were included in this study. The parents of all participants completed the 48-item Conners' Parent Rating Scale (CPRS) and the Barkley Child Attention Scale (BCAS) forms, and all participants' blood was taken to compare metabolic, oxidative stress, and antioxidant status of the SCT and ADHD groups. A child and adolescent psychiatrist interviewed the parents and children to assess the diagnosis of SCT and ADHD using standard diagnostic procedures. Results: In the comparison between the SCT and ADHD groups in terms of metabolic parameters, statistically significant differences were found in terms of total oxidant status, total antioxidant status, Oxidative Stress Index, total thiol, native thiol, disulfide, interleukin (IL)-1β, IL-6, and DNA damage (p < 0.05), but not in terms of tumor necrosis factor-α (p > 0.05). Conclusions: Our data showed that these two disorders may be different, but we believe that the data that indicate their differences remain inconclusive overall, but this study may be a potential pathway for future research.
... They also found that a lack of a positive family environment, meaning not only the presence of negative factors but also the absences of positive factors (i.e., lacking high levels of warmth, praise and positive emotion) strengthened the relationship between SCT and depression. Moruzzi, Rijsdijk, and Battaglia (2014) conducted the first SCT-related study of genetic heritability and found SCT to be comparatively less heritable than ADHD in a sample of monozygotic and dizygotic twins. SCT also had significantly larger non-shared environmental influences. ...
... The study findings are also limited by the SCT measure used. SCT score was based on a 4-item subscale derived from the CBCL, which includes low energy, slow-movement, staring and daydreaming (e.g., Moruzzi et al., 2014). Given the evolving symptom set associated with SCT, the content validity of this CBCL-based measure may be limited. ...
Article
Background: Childhood adversity has been suggested, but not yet empirically examined, as a factor in sluggish cognitive tempo (SCT) in childhood. Objective: This study was an examination of SCT in relation to childhood adversity, and its association with exposure to non-interpersonal and interpersonal trauma. Method: Caregivers (N = 161) and a sub-sample of children, 8–17 years old, were recruited from mental health and pediatric practices/programs and interviewed. Results: SCT was positively associated with interpersonal trauma but not non-interpersonal trauma. Two hierarchical regression analyses revealed that interpersonal trauma exposure was associated with SCT score over and above symptoms of other psychopathologies. Conclusion: Results suggest that SCT is associated with interpersonal trauma exposure in children. Further research is needed to examine the association between SCT and interpersonal trauma exposure, and trauma-related biopsychosocial impairments.
... First, genetic factors probably contribute to the high rate of SCT in ASD. Moderate heritability of SCT was found in a population-based twin study and SCT shared over half of its genetic contribution with ADHD (Moruzzi, Rijsdijk & Battaglia, 2014). Taking into account that ASD is highly heritable and also shares genetic contribution with ADHD (Rommelse, 2010), it is plausible that genetic factors are associated with the high rates of SCT in ASD. ...
... Finally, environmental factors may also be contributing to SCT symptoms in ASD. There is an indication that in addition to genetic factors, environmental factors influence considerably the presentation of SCT symptoms in ADHD (Moruzzi et al., 2014). However, the specific environmental factors affecting SCT are not known . ...
Article
Sluggish cognitive tempo (SCT) was introduced in 1980s in the field of attention deficit hyperactivity disorder (ADHD). Studies indicate that symptoms of SCT are separate from symptoms of ADHD and independently associated with multiple domains of functioning in clinical groups and in typical development. We assessed whether similar pattern would apply to higher functioning autism spectrum disorders (ASD). Children with higher functioning ASD (N = 55; 5−15 years) were divided into the ASD+High SCT (n = 17), the ASD+Medium SCT (n = 18) and the ASD+Low SCT (n = 20) groups based on parent-rated daydreaming and slowness on the Five to Fifteen questionnaire (FTF). The groups were compared on SCT-related impairments found in previous studies: social skills, academic functioning, psychiatric symptoms, and processing speed. Assessment methods were the FTF, the Development and Well-Being Assessment, and the Coding subtest of the WISC-III. The ADHD symptoms were statistically controlled due to the overlap between SCT and ADHD. The ASD+High SCT and ASD+Medium SCT groups were significantly more likely to have the most pronounced social impairments, and the ASD+High SCT group had significantly higher rate of internalizing disorders compared to the ASD+Low SCT group. Our results suggest that children with higher functioning ASD and high or medium levels of SCT symptoms could be at higher risk for psychosocial impairments than children with higher functioning ASD with low levels of SCT symptoms. Co-occurring ADHD symptoms do not explain the finding. Recognizing SCT symptoms in higher functioning ASD would be important to targeting preventive support.
... Uno de los avances más notables se ha dado en el campo de la validez discriminante y predictiva puesto que, como era ya conocido de hace tiempo, las conductas y elementos definitorios del SCT solapan con las conductas y síntomas de inatención, tal y como se han definido en el TDAH. Ha sido necesario aplicar complejos análisis factoriales confirmatorios en muestras clínicas y normales, a través tanto de diseños transversales como longitudinales, para poder concluir lo que hasta ahora parece una de las resoluciones más sólidas: efectivamente el SCT se relaciona de forma moderada con el TDAH e incluso de forma elevada con la medida de inatención de este trastorno; sin embargo, al controlar el efecto mutuo entre SCT e inatención, cada una de ellas mantiene de forma significativa un patrón de relación con otras variables comportamentales, de interacción y de rendimiento, que incluso en algunos casos es opuesto (Araujo et al., 2015;Barkley, 2012;Bauermeister et al., 2012;Becker, 2014;Becker et al., 2016;Becker, Ciesielski et al., 2014;Becker & Langberg, 2013;Becker, Luebbe et al., 2015;Becker, Luebbe, Fite et al., 2014;Belmar et al., 2015;Bernad et al., 2014;2015;Burns et al., 2013;Camprodon et al., en prensa;Fenollar-Cortés et al., 2015;Khadka et al., 2015;Lee et al., 2014;Leopold, et al., 2015;Marshall et al.;McBurnett et al, 2014;Moruzzi et al., 2014;Penny et al., 2009;Servera et al., 2015;Willcutt et al., 2014,). Pero no queremos dejar de hacer notar que a veces el tamaño del efecto de tales diferencias no ha sido especialmente elevado. ...
... Mientras, la dimensión SCT lo hace en mucho menor grado, de forma no significativa e incluso, en algunas ocasiones, de modo inverso. En este sentido cabe destacar que en algunos aspectos, como la medida de psicopatía, el SCT puede ser un factor protector, puesto que la correlación es negativa y significativa (Barkley, 2012;Becker et al., 2016;Becker & Langberg, 2013;Becker, Luebbe, Fite et al., 2014;Belmar et al., 2015;Bernad et al., 2014;2015;Burns et al., 2013;Carlson & Mann, 2002;Fenollar-Cortés et al., 2015;Garner et al., 2013;Khadka et al., 2015;Lee et al., 2014;en prensa;Leopold et al., 2015;Marshall et al., 2014;McBurnett et al., 2014;Moruzzi et al., 2014;Penny et al., 2009;Servera et al., 2015;Willcutt et al., 2014). ...
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valorarán aquellos estudios que traten de averiguar las impli-caciones a nivel neuropsicológico del SCT, especialmente en cuanto a las alteraciones en funciones ejecutivas. Algunas de las conclusiones más interesantes son que el estudio del SCT se extiende a poblaciones de distintas condiciones clínicas (principalmente pacientes con sintomatología TDAH), que se encuentran escalas de medida válidas y fiables para evaluar la presencia de la sintomatología SCT (algo que permite au-mentar la comprensión de esta dimensión), y que se aportan datos suficientes para afirmar que SCT conforma un construc-to distinto a la Inatención del TDAH, con correlatos internos y externos diferenciados. Por todo ello sería recomendable incluir una medida SCT en protocolos de evaluación psico-patológica infantil (especialmente ante sospecha de TDAH-IN), así como proponer tratamientos especializados para in-dividuos con esta sintomatología. Palabras clave: revisión, Sluggish Cognitive Tempo (SCT), Tras-torno por Déficit de Atención con Hiperactividad (TDAH) Sluggish Cognitive Tempo: Facts and controversies Abstract Lately it has grown a considerably interest in a dimension known as Sluggish Cognitive Tempo (SCT), which refers to individuals who have a different inattentive pattern as the one described for inattention (IN) in Attention Deficit and Hyperactivity Disorder (ADHD), and slowed thinking. SCT has always been a controversial dimension, mostly because of its high association with ADHD-IN. It is therefore the aim of this paper to review the current situation of the SCT construct, as well as its historical evolution. The various existing definitions of SCT, the measuring instruments that have been used over Resumen En los últimos años ha crecido notablemente el interés por una dimensión conocida como Sluggish Cognitive Tempo (SCT), que se refiere a aquellos individuos que presentan una sintomatología inatenta, diferente a la descrita para la Inaten-ción (IN) en el Trastorno por Déficit de Atención e Hiperacti-vidad (TDAH), y una conducta y un pensamiento enlenteci-dos. Esta dimensión SCT no se encuentra exenta de controversias, la mayoría relacionadas con su elevada asocia-ción con el TDAH-IN. Es por ello, que el objetivo del presente trabajo consiste en revisar la situación actual en que se en-cuentra el constructo SCT, así como realizar un recorrido a lo largo de la historia sobre esta dimensión. Se comentarán las distintas definiciones existentes de SCT, los instrumentos de medida que se han venido utilizando a lo largo de los años por distintos investigadores, los primeros datos epidemioló-gicos del constructo, y, sobre todo, las implicaciones que supone la presencia de esta sintomatología a distintos niveles.
... Interest in this topic has surged recently, perhaps due to the fact that many researchers now view sluggish tempo as a symptom cluster that exists independent of ADHD (Barkley 2013a(Barkley , b, 2014Bauermeister et al. 2012; & Elizabeth K. Lefler elizabeth.lefler@uni.edu Becker andLangberg 2013, 2014;Becker et al. 2014bBecker et al. , c, 2016Garner et al. 2010;Lee et al. 2014;Moruzzi et al. 2014;Willcutt et al. 2014). Today, SCT is defined by the following behavioral characteristics: daydreaming, drowsiness, sluggishness, slow moving, mental confusion, spacey or ''in a fog,'' lethargy, withdrawal, hypoactivity, difficulty processing information quickly and accurately, and difficulty staying awake or alert (Barkley 2013a(Barkley , b, 2014Lee et al. 2014;Penny et al. 2009). ...
... Although a review of the current research by Becker et al. (2016) provides significant evidence for the internal and external validity of SCT, the authors conclude that there is not currently enough evidence to support the diagnostic validity of SCT at this time. Despite this, there is evidence that children are struggling with SCT symptoms and that these symptoms are causing significant impairment (Barkley 2013a(Barkley , b, 2014Bauermeister et al. 2012;Becker et al. 2014bBecker et al. , c, 2016Becker andLangberg 2013, 2014;Garner et al. 2010;Lee et al. 2014;Moruzzi et al. 2014;Willcutt et al. 2014). Perhaps then, it is less important for teachers to be able to identify specific disorders or sets of symptoms by name; rather, it may be the teacher's responsibility to recognize when a problem is present and alert these other stakeholders. ...
Article
Sluggish cognitive tempo (SCT) is characterized by a passive form of inattention that may not overtly disrupt classroom goals. Due to the nature of these symptoms, children with SCT may be "falling through the cracks" in schools. The current study examined pre-service teachers' perceptions of SCT in the classroom. Undergraduate education majors (n = 161) read vignettes describing fictitious fourth-grade boys presenting with symptoms of SCT, attention-deficit/hyperactivity disorder (ADHD), or a non-ADHD-related control: social anxiety disorder (SA), and rated each of the vignettes in terms of their perceptions of the boy described. Results were analyzed using repeated measures ANOVAs and paired-sample t tests. Pre-service teachers viewed all three sets of symptoms as concerning, but viewed ADHD behaviors as the most problematic. These results are promising, as they suggest that pre-service teachers are concerned about both hyperactive (i.e., ADHD) and non-hyperactive behavioral problems (i.e., SCT and SA). Implications and future directions are discussed.
... It is possible that the parents of our sample show SCT symptoms. Our results follow the same lines as previous studies (Barkley, 2013(Barkley, , 2014Becker, Langberg, Luebbe, Dvorsky, & Flannery, 2014;Marshall et al., 2014;Moruzzi, Rijsdijk, & Battaglia, 2014) in showing that psychosocial problems have a greater influence on SCT symptoms than on ADHD symptoms. As concluded in the only twin study that examined genetic and environmental contributions to SCT and ADHD, SCT symptoms are somewhat more influenced than either inattention or hyperactivity-impulsivity by non-shared environmental factors (Moruzzi et al., 2014). ...
... Our results follow the same lines as previous studies (Barkley, 2013(Barkley, , 2014Becker, Langberg, Luebbe, Dvorsky, & Flannery, 2014;Marshall et al., 2014;Moruzzi, Rijsdijk, & Battaglia, 2014) in showing that psychosocial problems have a greater influence on SCT symptoms than on ADHD symptoms. As concluded in the only twin study that examined genetic and environmental contributions to SCT and ADHD, SCT symptoms are somewhat more influenced than either inattention or hyperactivity-impulsivity by non-shared environmental factors (Moruzzi et al., 2014). More research is needed to elucidate the etiology of SCT, attending to biologically based contributions as well as possible environmental factors. ...
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Objective: The aims of the present study were to examine the presence of sluggish cognitive tempo (SCT) symptoms in children; associations of the symptoms with sociodemographic characteristics of the children; and relationships between SCT symptoms and symptoms of ADHD, dyslexia, academic performance, and behavioral problems. Method: We evaluated Catalan schoolchildren aged 7 to 10 years in Barcelona, 2012-2013. Parents filled out the SCT–Child Behavior Checklist (SCT-CBCL), the Strengths and Difficulties Questionnaire (SDQ), and a questionnaire concerning sociodemographic characteristics. Teachers completed the ADHD criteria of Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV) (ADHD-DSM-IV), a list of dyslexia symptoms, and evaluated the children’s academic performance. SCT symptoms were studied as a continuous and dichotomous variable. Results: In all, 11% of the children in our sample scored above the clinical cut-off on the SCT-CBCL scale. We observed a higher rate of SCT symptoms in boys, children whose father was unemployed, those whose maternal educational level was lower, children with a high socioeconomic vulnerability index at home, those who reported maternal smoking during pregnancy and current second-hand smoke exposure at home, and children with an ADHD diagnosis. More SCT symptoms were associated with inattention symptoms, symptoms of dyslexia, academic problems, and emotional and peer relationship problems. Conclusion: We observed a higher prevalence of SCT symptoms in our sample than expected in the general population. While girls are less prone to SCT symptoms, some socioeconomic indicators, dyslexia, and inattention symptoms as well as exposure to smoking at home increase the risk of SCT and must be taken into account during assessments.
... Two twin studies have examined the genetic and environmental influences on SCT symptoms in children (Willcutt et al., unpublished material, 2015). 78 Both studies found SCT to be significantly heritable, with between approximately one-to two-thirds of the total variance in SCT accounted for by genetic influences. Both studies also found SCT symptoms to be less heritable than ADHD symptoms. ...
... 6. Family Environmental Factors. The 2 twin studies that demonstrated significant heritability of SCT also found that shared and nonshared environmental factors influence the presence of SCT (Willcutt et al., unpublished material, 2015) 78 Although this finding will need to be replicated, it points to an important direction for future research. Identification of potential environmental factors that contribute to SCT, such as socioeconomic status and psychosocial stress, as well as parenting styles and behaviors, parent-child interactions, and parent psychopathology may provide potential avenues for intervention or prevention. ...
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OBJECTIVE To conduct the first meta-analysis evaluating the internal and external validity of the sluggish cognitive tempo (SCT) construct as related to or distinct from attention-deficit/hyperactivity disorder (ADHD) and as associated with functional impairment and neuropsychological functioning. METHOD Electronic databases were searched through September 2015 for studies examining the factor structure and/or correlates of SCT in children or adults. The search procedures identified 73 papers. The core SCT behaviors included across studies, as well as factor loadings and reliability estimates, were reviewed to evaluate internal validity. Pooled correlation effect sizes using random effects models were used to evaluate SCT in relation to external validity domains (i.e., demographics, other psychopathologies, functional impairment, and neuropsychological functioning). RESULTS Strong support was found for the internal validity of the SCT construct. Specifically, across factor analytic studies including over 19,000 individuals, 13 SCT items loaded consistently on an SCT factor as opposed to an ADHD factor. Findings also support the reliability (i.e., internal consistency, test-retest reliability, inter-rater reliability) of SCT. In terms of external validity, there is some indication that SCT may increase with age (r = 0.11) and be associated with lower socioeconomic status (r = 0.10). Modest (potentially negligible) support was found for SCT symptoms being higher in males than females in children (r = 0.05) but not adults. SCT is more strongly associated with ADHD inattention (r = 0.63 in children, r = 0.72 in adults) than with ADHD hyperactivity-impulsivity (r = 0.32 in children, r = 0.46 in adults), and it likewise appears that SCT is more strongly associated with internalizing symptoms than with externalizing symptoms. SCT is associated with significant global, social, and academic impairment (rs = 0.38-0.44). Effects for neuropsychological functioning are mixed, although there is initial support for SCT being associated with processing speed, sustained attention, and metacognitive deficits. CONCLUSION This meta-analytic review provides strong support for the internal validity of SCT and preliminary support for the external validity of SCT. In terms of diagnostic validity, there is not currently enough evidence to describe SCT in diagnostic terms. Key directions for future research are discussed, including evaluating the conceptualization of SCT as a transdiagnostic construct and the need for longitudinal research.
... In the etiology of CDS, prenatal alcohol exposure, prenatal and postnatal tobacco exposure [7,8], low socioeconomic status, maternal low educational level [1,9,10], negative emotional environment, and high emotional expression within the family [11] have been identified as influential factors. Unlike ADHD, genetic involvement is more moderate and may be caused more by environmental factors [12,13], the 7-repeat allele in the DRD4 gene is more frequent in CDS [14], thyroid-stimulating hormone levels were found to be more associated with CDS [4], and the theta/delta wave ratio in the frontal region in ADHD was found to be unrelated to CDS [15]. ...
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Background In the past, cognitive disengagement syndrome (CDS) and attention deficit hyperactivity disorder (ADHD) were considered similar concepts. However, many differences have recently been identified between the two disorders, and they have been separated from each other. This study aims to investigate balance and vestibular function in individuals at high risk for ADHD and CDS. Materials and methods This study involved 60 college students. Participants were given the Adult ADHD Self-Report Scale and the Adult Concentration Inventory. Using the applied indices, participants with high and low risk for CDS and ADHD were identified. Every participant underwent static posturography, the video head impulse test (vHIT), and cervical vestibular myogenic-evoked potentials (cVEMP). Results People with low and high risk for CDS did not differ in terms of static posturography or cVEMP ( p > 0.05). Similarly, no differences were found in ADHD ( p > 0.05). While right ear lateral vHIT responses were worse in individuals with high-risk CDS ( p > 0.05), bilateral posterior vHIT rates were worse in individuals with high-risk ADHD ( p > 0.05). Conclusion The fact that individuals at high risk for CDS and ADHD show different vestibular involvement strengthens the fact that there are different clinical pictures.
... Studies demonstrated that CDS remains associated with increased anxiety and depression (Becker et al., 2020;Fredrick et al., 2022;Smith et al., 2020), social withdrawal and loneliness Yung et al., 2021), and to a less clear extent, executive functions (Barkley, 2013;Bauermeister et al., 2012;Wåhlstedt & Bohlin, 2010) after controlling ADHD. Also, some studies showed that CDS is related to environmental factors (Fredrick et al., 2022;Moruzzi et al., 2014). Therefore, CDS is of clinical and research interest due to its association with other psychological issues. ...
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Objective The study aims to examine family functionality, emotion regulation difficulties, preference for loneliness, social exclusion, internalizing and externalizing disorders, and executive functions in children with Attention Deficit Hyperactivity Disorder (ADHD) and Cognitive Disengagement Syndrome (CDS) and compare with ADHD, and ADHD+ Oppositional Defiant Disorder (ODD). Method This study included 842 children aged 8–12 years. The subjects were categorized according to DSM-V as ADHD (n = 246), ADHD + ODD (n = 212), ADHD + CDS (n = 176), and Control group (n = 207). The solitude and social exclusion, difficulties in emotion dysregulation and Barkley SCT scales, Child Behavior Checklist, family assessment device, and Central Vital Signs (CNSVS) test were used. Results According to the study, children with ADHD + CDS had higher rates of internalizing disorders. They also preferred being alone and experienced more difficulty communicating with their parents and solving problems within the family. Additionally, these children had difficulty recognizing and understanding the emotional reactions of others. The ADHD + ODD group presented a poorer performance on CNSVS domain tests except for the psychomotor speed test than other groups. Also, ADHD + CDS children had the lowest psychomotor speed scores and lower scores on reaction time and cognitive flexibility than pure ADHD children. Conclusion This study will contribute to the etiology, treatment, and clinical discrimination of ADHD + CDS.
... Studies demonstrated that CDS remains associated with increased anxiety and depression (Becker et al., 2020;Fredrick et al., 2022;Smith et al., 2020), social withdrawal and loneliness Yung et al., 2021), and to a less clear extent, executive functions (Barkley, 2013;Bauermeister et al., 2012;Wåhlstedt & Bohlin, 2010) after controlling ADHD. Also, some studies showed that CDS is related to environmental factors (Fredrick et al., 2022;Moruzzi et al., 2014). Therefore, CDS is of clinical and research interest due to its association with other psychological issues. ...
Article
Objective: The study aims to examine family functionality, emotion regulation difficulties, preference for loneliness, social exclusion, internalizing and externalizing disorders, and executive functions in children with Attention Deficit Hyperactivity Disorder (ADHD) and Cognitive Disengagement Syndrome (CDS) and compare with ADHD, and ADHD+ Oppositional Defiant Disorder (ODD). Method: This study included 842 children aged 8-12 years. The subjects were categorized according to DSM-V as ADHD (n = 246), ADHD + ODD (n = 212), ADHD + CDS (n = 176), and Control group (n = 207). The solitude and social exclusion, difficulties in emotion dysregulation and Barkley SCT scales, Child Behavior Checklist, family assessment device, and Central Vital Signs (CNSVS) test were used. Results: According to the study, children with ADHD + CDS had higher rates of internalizing disorders. They also preferred being alone and experienced more difficulty communicating with their parents and solving problems within the family. Additionally, these children had difficulty recognizing and understanding the emotional reactions of others. The ADHD + ODD group presented a poorer performance on CNSVS domain tests except for the psychomotor speed test than other groups. Also, ADHD + CDS children had the lowest psychomotor speed scores and lower scores on reaction time and cognitive flexibility than pure ADHD children. Conclusion: This study will contribute to the etiology, treatment, and clinical discrimination of ADHD + CDS.
... As research on CDS has advanced, there is a clear need for additional studies to examine possible underlying causes and associations of CDS . Of note, CDS symptoms may be less heritable than ADHD symptoms, with CDS symptoms showing moderate heritability and larger non-shared environmental influences (Moruzzi et al., 2014;Willcutt, 2020). However, remarkably few studies have examined environmental factors that may be related to CDS symptoms (for a recent review, see Fredrick et al., 2023). ...
Article
Approximately 13.8 million U.S. households face food insecurity, which severely affects child development, with more than half of these households including children. Research links food insecurity to cognitive deficits and mental health challenges, highlighting the need for thorough understanding and intervention. Although existing studies have explored the association between food insecurity and internalizing symptomatology, less research has examined food insecurity in relation to attention-deficit/hyperactivity disorder (ADHD) symptoms. Further, no studies have explored the connection between food insecurity and cognitive disengagement syndrome (CDS) symptoms, closely related to ADHD symptoms. Despite extant research linking CDS to environmental factors, empirical attention to its potential association with food insecurity is notably lacking. Additionally, adolescents, almost twice as likely as younger children to experience household food insecurity, are likely more aware and respond differently to challenges during this developmental period. Accordingly, this study investigated the unique associations of parent-, teacher-, and youth self-reported ADHD dimensions and CDS symptoms in relation to parent-reported food insecurity in early adolescents (N = 136, ages 10–12). Controlling for age, sex, race, and medication use, no informant’s ratings of ADHD symptom dimensions were uniquely related to food insecurity. In contrast, higher parent-, teacher-, and youth self-reported CDS symptoms were uniquely associated with greater food insecurity. This finding was robust to additional control of family income for teacher- and youth self-reported CDS symptoms. These findings highlight the complex link between food insecurity and mental health, suggest a connection with CDS symptoms, and stress the need to address food insecurity as a public health priority, especially in early adolescence.
... Although many studies focused on the relationships between ADHD þ CDS, the underlying psychological mechanisms of ADHD with high CDS symptoms and their effect on other problems such as the social or emotional need to be clearer. Studies demonstrated that CDS remains associated with increased anxiety and depression (Becker et al., 2020;Fredrick et al., 2022;Smith et al., 2020), social withdrawal and loneliness (Yung et al., 2021), and to a less clear extent, executive functions (Barkley, 2012;;Wåhlstedt & Bohlin, 2010) after controlling ADHD and CDS is caused more by environmental factors (Becker et al., 2023;Fredrick et al., 2022;Moruzzi et al., 2014). Also, a few studies showed that there was a relationship between CDS and psychological factors such as low income and education level (Barkley, 2013;Becker, 2013;Dvorsky et al., 2021, Barkley, 2012, negative family environment (Fredrick et al., 2019 and peer victimization). ...
Article
This study aims to investigate the predictive and mediating relationships between emotion dysregulation, internalizing disorders, family functionality, loneliness preference, and executive functions (EF) in children with attention deficit hyperactivity disorder and cognitive disengagement syndrome (ADHD + CDS). This study included 176 children and adolescents (92 boys, 84 girls) who were diagnosed with ADHD + CDS according to the Diagnostic and Statistical Manual of Mental Disorders, the Fifth Edition criteria by a fellowship-trained child and adolescent psychiatrist, between ages 8 -12 (M = 10, SD = 1.52) with a convenience sampling method. The solitude scale for children, difficulties in emotion dysregulation scale, Child Behavior Checklist, Barkley Sluggish Cognitive Tempo Scale, Family assessment device, and CNS Vital Signs test were used. The results showed that difficulty in emotion regulation, preference for loneliness, internalizing disorders and CDS symptom severity did not have a mediating effect between family functionality and EF. Still, emotion dysregulation mediates the relationship between EF and internalizing disorders by itself and through loneliness preference. Also, preference for loneliness and emotion dysregulation had a mediating effect between family functionality and internalizing disorders. Finally, it was found that the effect of emotion regulation difficulty, loneliness preference, and internalizing disorders had a mediating role between CDS symptom severity and family functionality. In conclusion, the information obtained from this study on the etiology of CDS may guide future studies.
... In studies assessing the relationship between CDS symptoms and age, there may be a modest association between CDS symptoms with increasing age . In the very few studies examining potential etiologies, it was observed that genetic (Moruzzi et al., 2014) and prenatal factors (East et al., 2023;Graham et al., 2013) may play a role, and CDS symptoms may be associated with low socioeconomic status and low educational level in the family (Barkley, 2013). ...
Article
Objective The internal (structural) and external validity of a self‐report measure of cognitive disengagement syndrome (CDS, formerly sluggish cognitive tempo) relative to a self‐report measure of attention‐deficit/hyperactivity disorder‐inattention (ADHD‐IN) was evaluated with adults from university outpatient psychiatric clinics in Turkey. Methods A total of 274 outpatients (75.9% women; ages 18–64 years; M age = 31.06; SD age = 10.84; 50.4% anxiety disorders; 41.6% depressive disorders; 2.9% ADHD; 1.5% sleep disorders; 0.7% eating disorders; 2.9% no mental disorder) completed self‐report measures of CDS, ADHD‐IN, ADHD‐hyperactivity/impulsivity (HI), sleep problems, depression, and stress. Results All 15 CDS symptoms measured by the Adult Concentration Inventory (ACI) showed convergent (moderate to high loadings on the CDS factor) and discriminant (loading close to zero on the ADHD‐IN factor) validity. CDS also showed stronger first‐order and unique associations than ADHD‐IN with sleep problems, depression, anxiety, and stress, whereas ADHD‐IN showed stronger first‐order and unique associations than CDS with ADHD‐HI. Conclusion This is the first study to provide support for the scores from this 15 item self‐report measure of CDS by the ACI in a clinical sample of adults, with findings consistent with previous studies examining parent and teacher rating scale measures with the same 15 CDS symptoms. These findings provide additional support for usefulness of these 15 CDS symptoms as measured by the ACI to study CDS across various cultures.
... Furthermore, the causal origins of CDS can be characterized as complex and multidimensional. Initial studies indicate that the condition arises from an interplay between genetic predispositions and external stressors, with a particular emphasis on dysfunctional family interactions (Fredrick et al., 2019;Moruzzi et al., 2014). In addition, twin studies indicate that genetic factors have a role in the development of CDS, yet there is also evidence to suggest that environmental factors such as prenatal exposure to alcohol or tobacco are influential . ...
Article
This study aims to explore trends and principal research areas in the literature on Cognitive Disengagement Syndrome (CDS) in children aged 0–17 from a macro perspective. A total of 236 studies, selected based on inclusion and exclusion criteria from the Web of Science and Scopus databases, formed the data source for this research. We conducted a bibliometric analysis to examine the growth of CDS literature and to identify the most productive countries, relevant journals and publications, and trending topics. Additionally, through content analysis, we identified general research themes, sample trends, and methodologies used in these studies. Our findings reveal that the relatively new field of CDS research is expanding. Our thematic analysis shows that the literature on CDS covers a broad spectrum of research topics, addressing various facets of the syndrome and identifying current research themes. The existing studies highlight the complex nature of CDS and its diverse cognitive, psychological, and neurological impacts. Our results also suggest that while research is more prevalent in certain age groups, there is a need to encompass a wider demographic range, considering CDS's potential impact across different life stages. This bibliometric analysis offers a comprehensive review of the current knowledge in the CDS field, providing a valuable resource for researchers. Our analyses and findings can guide future research in this area and suggest approaches for broader study frameworks. It is anticipated that ongoing and future research in the CDS field will incorporate these insights to more effectively address the syndrome's varied aspects and consequences.
... Cognitive disengagement syndrome (CDS) (1) is characterized by a cluster of symptoms, including excessive daydreaming, slow actions, and loss of train of thought (2)(3)(4)(5)(6)(7)(8). Although CDS has not yet been included in the Diagnostic and Statistical Manual of Mental Disorders (DSM) classification system, recent neuroimaging and genetic studies provide strong evidence suggesting that it should be evaluated as a separate category (9)(10)(11)(12)(13)(14). Studies determining its prevalence have reported rates as high as 11% in the general population aged 7-10 years (15), and 20.8% in a clinical sample (16). ...
... La exposición prenatal al alcohol y la sensibilidad al castigo constituyen otros de los factores investigados con el propósito de establecer su posible relación con la dimensión aquí estudiada. La investigación con gemelos (Moruzzi, Rijsdijk, & Battaglia, 2014) ha revelado que la influencia genética del SCT es menor que la del TDAH, observándose que Sluggish Cognitive Tempo se ve influenciado por factores ambientales propios, no compartidos con el trastorno hiperactivo-atencional. No obstante, se reconoce el estatus aún provisional de estos resultados, anticipándose el desarrollo de la investigación en este ámbito. ...
Article
Se describen los ámbitos científicos y hallazgos acumulados en los últimos años sobre la dimensión Sluggish Cognitive Tempo (SCT). Se analiza la realidad actual atendiendo a aspectos conceptuales; instrumentales; implicaciones clínicas, académicas, sociales; y la relación que mantiene el SCT con factores biológicos y conductuales. Los hallazgos revisados permiten comprender y situar esta dimensión en el contexto de la investigación sobre los individuos que, con sintomatología inatenta, se diferencian de aquellos que cumplen con los criterios diagnósticos para la presentación inatenta. Se concluye subrayando las limitaciones actuales en el conocimiento de esta dimensión y los ámbitos de desarrollo en el futuro.
... Regarding SCT, twin studies have evidenced that SCT could be explained by environmental factors more prominently than neurocognitive factors, highlighting its partially distinct etiological patterns to ADHD 29 . Therefore, it is reasonable to hypothesize that LE and PRB would affect patients with ADHD and SCT differently. ...
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Although sluggish cognitive tempo (SCT) symptoms are often observed in children with attention deficit hyperactivity disorder (ADHD), an increasing number of studies have highlighted its uniqueness. Nevertheless, no national survey on SCT among children and adolescents has been conducted in China. Hence, this research aims to study SCT in China and to evaluate the differences between SCT and ADHD symptoms by comparing their risk factors in terms of life events (LE) and parental rearing behaviors (PRB). This cross-sectional study used data from a survey on 71,929 children and adolescents in 5 province-level regions in China to study the incidence and demographic information of SCT in the Chinese population. Subsequently, the study investigated the comorbidity of ADHD and SCT, and conducted three logistic regressions on the LE and PRB scores to predict whether participants develop symptoms of ADHD or SCT, or neither symptom. 6658 participants were allocated into the SCT group, and the weighted point prevalence of SCT was 9.78%. 36.34% of participants with ADHD (n = 676) were found to demonstrate SCT symptoms, whereas no statistically significant difference was observed in its comorbidity to the three ADHD subtypes (χ² = 1.668, p > 0.05, Δ = 2). The regression results on the presence or absence of ADHD revealed paternal excessive-interference and rejection, and maternal favoring were associated with ADHD diagnosis, whereas paternal punishment and favoring and maternal emotional warmth was related to the absence of ADHD symptoms. Academic stress and maternal excessive-interference were associated with SCT symptoms, and maternal emotional warmth associated with SCT absence. Concerning the presence of ADHD-only or SCT-only symptoms, LE adaptation was found to relate to SCT-only symptoms, while PRB paternal rejection and maternal favoring were associated with ADHD-only symptoms. While evidencing the high prevalence of SCT in China, our findings supported that although ADHD and SCT were highly comorbid, they may be considered two independent disorders with different risk factors. Specifically, participants with SCT symptoms are more vulnerable to stress from LE and tend to face more maladjustment than ADHD and normally-developing participants, and maternal rearing behaviours are the key factors to SCT symptoms. SCT brings global challenges in its diagnosis and treatment, and the challenge is more severe in a mentally stressful environment. Therefore, stress management and SCT etiology studies are recommended.
... Finally, there has been growing interest in understanding the etiology of the CDS phenotype, especially given somewhat less heritability and greater environmental influence on CDS compared to ADHD-I (Moruzzi et al., 2014;Willcutt, 2020). Similar to the equifinality of etiological causes of ADHD, which include genetic underpinnings, prenatal complications, and environmental risk/injury (e.g., secondary ADHD from TBI) (Narad et al., 2018;Willcutt, 2020), biological and medical factors may contribute to CDS. ...
Article
Cognitive disengagement syndrome (CDS, previously referred to as sluggish cognitive tempo) is a unique set of symptoms distinct from ADHD inattentive symptoms that appear to be independently associated with neuropsychological and psychosocial outcomes in community and ADHD-specific samples of youth. However, our understanding of CDS in individuals with chronic or complex medical conditions is limited. The current systematic review is the first to summarize the literature on CDS prevalence rates and associations with neurocognitive and functional outcomes in youth with medical conditions, and to discuss areas of future research to guide clinical intervention. We conducted literature searches across four major databases and included studies assessing prevalence estimates, associations with neuropsychological and/or psychosocial functioning, or predictors of CDS in individuals with chronic or complex medical conditions. Twenty-five studies were identified and retained. Fifteen of sixteen studies reported elevations in CDS symptoms, though findings were mixed in studies comparing mean differences to typically developing youth. Seven studies provided inconsistent evidence for CDS being associated with neuropsychological or academic functioning, with six studies demonstrating consistent effects on psychosocial functioning. Finally, nine studies identified biological and sociodemographic factors associated with CDS, though almost all await replication. CDS symptoms are significantly elevated in youth with medical conditions and appear to be particularly linked with psychosocial functioning. Future research is needed to identify prevalence of CDS across a range of medical conditions, examine associations with neuropsychological and psychosocial functioning, and examine whether CDS impacts self-management.
... For the last 10 years, interest in SCT in developmental psychopathology has been steadily increasing. Research initially focused on empirical evidence of a clear difference between SCT and Attention-Deficit /Hyperactivity Disorder (ADHD); as a matter of fact, some studies investigating the psychometric and genetic variance of these constructs demonstrated a possible overlap between SCT symptoms and ADHD-predominantly inattentive presentation (Moruzzi et al., 2014;Saxabe & Barkley, 2014). Although these two dimensions appear to be significantly correlated during the developmental age, some research has suggested that SCT could be considered to be an independent psychopathological dimension, with its own set of symptoms. ...
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Sluggish Cognitive Tempo (SCT) is a neuropsychiatric construct including lethargy, behavioral sluggishness, and confusion. A growing number of studies in the literature suggest that this set of symptoms refers to neuropsychological constructs such as sustained attention. However, studies focusing on SCT and its neuropsychological correlates in developmental age are scarce. The present study aims to fill this gap. The Child and Adolescent Behavior Inventory (CABI – Teacher and Parent versions, also including the school functioning scale, and the Child Concentration Inventory (CCI-2) were administered to a sample of 128 Italian primary-school children (57.6% F, mean age 8.81, SD 1.07); the neuropsychological constructs involved in the study were sustained attention and reaction times to two computerized tasks. Bivariate non-parametric correlation analyses yielded significant negative associations between teacher-referred SCT and measures of sustained attention (e.g., the Attentional Network Test and the Hearts and Flowers task) as well as CABI-T school-functioning scale; a small-to-moderate positive correlation was found between CABI-T SCT scores and mean reaction times, as a measure of the slowness of behavioral responses on the Attentional Network Test: this result would appear to represent a fine operationalization of the SCT-characteristic of behavioral sluggishness. Implications of these results for operationalizing the SCT construct in developmental age are discussed.
... higher levels of peer difficulties and have fewer friends , likely due to low social engagement and withdrawal from social situations . Previous studies suggest SCT is frequently comorbid with Internalising disorders including anxiety, depression, shyness, and withdrawn behaviours (Barkley, 2013;Başay et al., 2021;Becker & Langberg, 2012;Belmar et al., 2017;Carlson & Mann, 2002;Hartman et al., 2004;Lee et al., 2018;Moruzzi et al., 2013; but see, Becker et al., 2016). Considerable overlap between ADHD and SCT has also been noted, with co-occurrence rates ranging from 39-59% (Barkley, 2013). ...
Article
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Language disorders are frequently comorbid with attention-deficit/hyperactivity disorder (ADHD). Sluggish cognitive tempo (SCT), a second attention disorder, may potentially explain some of the links between language disorders and ADHD. In this study we examined the psycholinguistic abilities of 207 children (mean age 7;10) with and without clinically significant levels of SCT symptoms to determine the degree to which symptoms of language disorder co-occur in cases of SCT. Analyses of children's tense-marking, nonword repetition, and sentence recall indicated that deficits in these areas were not associated with SCT. Instead, SCT appears to be more closely aligned with features of social (pragmatic) communication disorder.
... This was seen in a twin study, where individual differences in the SCT subtype were mostly explained by non-shared environmental factors, while genetic factors mostly influenced the variability in the HYP and IN subtypes. This finding indicates that, when we disregard SCT, it may cause greater ADHD heterogeneity and diminished diagnostic clarity among children belonging to the ADHD inattentive group [60]. ...
Article
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Controversy around the association between celiac disease (CeD) and attention deficit hyperactive disorder (ADHD) was addressed by a systematic review in 2015, ultimately showing no association. Since 2015, there have been several studies showing an association between celiac disease and attention deficit hyperactive disorder. This is an updated systematic review. Background: Most experts agree on the recommendation to not screen as part of the standard of care for ADHD in persons with CeD or vice versa. Simultaneously, they propose that untreated patients with CeD and neurological symptoms such as chronic fatigue, inattention, pain, and headache could be predisposed to ADHD-like behavior, namely inattention (which may be alleviated by following a gluten-free diet). The inattentive subtype of ADHD that encompasses the symptoms of inattention is phenotypically heterogeneous, as it includes the clinical construct of sluggish cognitive tempo (SCT). SCT symptoms overlap with the neurological manifestations of CeD. Methods: A systematic search (PRISMA) of PubMed, Google Scholar, EMBASE, Web of Science, Stanford Lane, SCOPUS, and Ovid was conducted for articles up to 21 February 2022. Of these, 23 studies met the criteria. Results: Out of the 23 studies, 13 showed a positive association between ADHD and CeD. Most studies that showed a positive association had been published in the last five years. Inconsistencies in the results remain due to the heterogeneous methodology used, specifically for ADHD and the outcome questionnaires, as well as a lack of reporting on ADHD subtypes. Conclusion: There is an association between ADHD and celiac disease. The current methodological limitations will be lessened if we examine the subtypes of ADHD.
... Additionally, above and beyond ADHD-IN, SCT symptoms remain associated with academic, emotional, and social impairments (Becker & Barkley, 2018). Furthermore, although the etiology of ADHD is largely genetic, initial research suggests that SCT symptoms are less heritable and may be affected by environmental characteristics (Moruzzi et al., 2014), including forms of psychosocial adversity (Barkley, 2012;Fredrick et al., 2019;Fredrick et al., 2021;Musicaro et al., 2020) or shortened sleep . Despite advancements in the study of SCT, several limitations remain. ...
Article
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The Adult Concentration Inventory (ACI) is an adult self-report measure of sluggish cognitive tempo (SCT) developed following a meta-analysis identifying items distinguishing SCT from attention-deficit/hyperactivity disorder (ADHD) inattention. To date, only one study conducted in college students has examined the structural and external validity of the ACI. The current study evaluated the convergent and discriminative validity of the ACI in a community sample of adults, in addition to testing unique associations with internalizing symptoms, daily life executive functions, and sleep. Adults (N = 286; Mage = 44.45; 83.6% female) completed ratings of SCT, ADHD symptom dimensions, and external correlates. An a priori two-factor model with cross-loadings found 10 of the 16 SCT items to have high loadings on the SCT factor and low loadings on the ADHD inattention factor. SCT was uniquely associated with higher internalizing symptoms, time management and self-organization difficulties, poorer sleep quality, shorter sleep duration, lower sleep efficiency, and more daytime sleepiness. These findings replicate and extend support for the ACI in assessing SCT in adults.
... Despite the established link between peer difficulties and SCT symptoms, very few studies have investigated environmental factors that may help to explain this association further. Environmental factors are important to consider within a developmental psychopathology framework, particularly as SCT symptoms have lower heritability than ADHD-IN symptoms (Moruzzi et al., 2014). The current study tested school support, a component of school climate, as a possible moderator of the association between peer difficulties and SCT symptoms in a sample of adolescents with and without ADHD. ...
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Objective: Although peer difficulties and sluggish cognitive tempo (SCT) are related, studies have yet to examine environmental factors that may advance further understanding of this association. The current study tested whether peer difficulties, specifically social competence and peer victimization, interacted with school support, a component of school climate, in relation to adolescents’ SCT symptoms. Further, we explored whether these relations would be differentially associated with SCT in adolescents with and without attention-deficit/hyperactivity disorder (ADHD). Method: Adolescents (N = 288; Mage = 14.08, 45% female, 82.6% White; 52% with ADHD) completed measures of social competence, peer victimization, school climate support, and SCT and ADHD inattentive (IN) symptoms. Parents also reported on adolescents’ social competence, SCT, and ADHD-IN symptoms. Results: Results indicated that adolescent and parent ratings of lower social competence were both associated with higher adolescent-reported SCT symptoms in the context of low, but not high, school support. Relational and nonphysical victimization were associated with higher self-reported SCT symptoms in the context of low school support. Lower adolescent- and parent-reported social competence were also related to higher parent-reported SCT symptoms, with these associations not moderated by school support. These results remained after controlling for demographics and ADHD-IN symptoms and were similar across adolescents with and without ADHD. Conclusions: Findings from the current study are the first to provide evidence that peer difficulties and school climate are jointly related to adolescents’ self-reported SCT and underscore the importance of continued research investigating social adversity and environmental factors in relation to SCT.
... 9 Kalıtsallık düzeyini araştıran bir ikiz çalışmasında hiperaktivite/dürtüsellik semptomlarının en fazla kalıtsallık gösteren semptom grubu olduğu, dikkat eksikliğinin 2. sırada olduğu ve YBT bulgularının en az kalıtsallık gösteren grup olduğu vurgulanmıştır. 11 YBT semptomlarının DEHB semptomlarına göre daha az kalıtsallık gösterdiği ve daha çok çevresel faktörlerden etkilendiği Moruzzi ve ark. 11 tarafından bildirilmiş olmakla birlikte, literatürde YBT semptomları ile ilişkisi bildirilen çevresel faktörler prenatal alkol maruziyeti, beyin tümörü ya da akut lenfoblastik lösemi tedavisi almış olmak olarak bildirilmiştir. ...
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Objectives:Sluggish cognitive tempo (SCT) is characterized by daydreaming, staring blankly, mental confusion, and hypoactivity. The most important question is how we should evaluate its relationship with the diagnosis of attention deficit hyperactivity disorder (ADHD). Our aim in this study is to determine the behavioral and emotional differences between ADHD and SCT cases.Materials and Methods:The cases included in the study were evaluated using the Atilla Turgay DSM‐IV‐based child and adolescent disruptive behavioral disorders Screening and Rating scale, child behavior checklist, Barkley child attention survey and teacher rating form. Among 4 groups (145 cases in the only ADHD group, 23 cases in the only SCT gorup, 71 cases in the ADHD + SCT group, 92 cases in the healthy controls), Rating scale scores evaluated by families and teachers were compared.Results:The ADHD group had more symptoms in the evaluation of symptoms of hyperactivity/impulsivity and conduct disorder in both family and teacher scores (p
... This supports the differentiation between SCT and ADHD. In addition, Moruzzi et al. (2014) found that a small set of SCT items were genetically and environmentally correlated to ADHD symptom domains, but were distinct domains. From the little evidence gathered about the etiology of SCT, it is clear there are distinctions between SCT and ADHD as constructs, though further work is needed to not only understand these distinctions, but to also further understand SCT. ...
Article
Sluggish cognitive tempo (SCT) is characterized by behavioral symptoms reflecting slowness and lethargy (e.g., sluggishness, appearing sleepy) and inconsistent alertness/mental confusion (e.g., daydreaming, fogginess). SCT is substantially correlated with the inattentive symptoms of attention-deficit/hyperactivity disorder (ADHD) and may be part of that domain, but in cross-sectional data, SCT is also strongly associated with both inattention and depression. To date, no study has examined the prospective associations of SCT symptoms in childhood/adolescence with symptoms of ADHD and internalizing problems in adulthood. Using a sample of 449 twin children and adolescent pairs, prospective multiple regression analyses examined whether self- and parent-reported SCT, depression, and parent-reported symptoms of ADHD predicted symptoms in adulthood 12 years later. SCT and depression at time one were strongly correlated (self-reported SCT and depression r = 0.84; parent-reported SCT and depression r = 0.78). When adult outcomes were separately regressed on each youth symptom dimension, self-reported SCT (β = 0.26, p < 0.0001) and depression (β = 0.13, p < 0.0001) each predicted adult symptoms of depression and self-reported SCT predicted inattention (β = 0.12, p = 0.0026). Parent-reported depression, but not parent-reported SCT, predicted self-reported adult depression symptoms (β = 0.17, p = 0.0003). In contrast, when each adult outcome was regressed simultaneously on youth self-reported SCT and depression, neither predicted adulthood inattention or depression. These findings indicate that SCT in childhood and adolescence is strongly associated concurrently and predictively with both inattention and depression. Theoretical and clinical applications of the construct of SCT must take its robust association with both inattention and depression into account.
... 19 However, we are not aware of any genetic study comparing SCT and ADHD subjects to understand potential different etiologic pathways, except for a twin study which detected SCT symptoms as less heritable than ADHD symptoms. 20 The main aim of this study was to investigate the prevalence of two VNTRs (located within the 3 0 UTR region of DAT1 and in exon 3 of DRD4) and neuropsychological findings among four groups: SCT without ADHD, ADHD without SCT, SCT + ADHD, and typically developing (TD) controls. ...
Article
Objective:Studies to reduce the heterogeneity of attention-deficit/hyperactivity disorder (ADHD) haveincreased interest in the concept of sluggish cognitive tempo (SCT). The aim of this study wasto investigate if the prevalence of two variable-number tandem repeats (VNTRs) located within the30-untranslated region of theDAT1gene and in exon 3 of the dopamine D4 receptor (DRD4) genediffer among four groups (31 subjects with SCT but no ADHD, 146 individuals with ADHD but no SCT,67 subjects with SCT+ADHD, and 92 healthy controls).Methods:We compared the sociodemographic profiles, neurocognitive domains, and prevalence oftwo VNTRs in SCT and ADHD subjects versus typically developing (TD) controls.Results:The SCT without ADHD group had a higher proportion of females and lower parentaleducational attainment. Subjects in this group performed worse on neuropsychological tests, exceptfor psychomotor speed and commission errors, compared to controls. However, the ADHD withoutSCT group performed significantly worse on all neuropsychological domains than controls. We foundthat 4R homozygosity for theDRD4gene was most prevalent in the ADHD without SCT group. TheSCT without ADHD group had the highest 7R allele frequency, differing significantly from the ADHDwithout SCT group.Conclusion:The 7R allele ofDRD4gene was found to be significantly more prevalent in SCT casesthan in ADHD cases. No substantial neuropsychological differences were found between SCT andADHD subjects.
... 19 However, we are not aware of any genetic study comparing SCT and ADHD subjects to understand potential different etiologic pathways, except for a twin study which detected SCT symptoms as less heritable than ADHD symptoms. 20 The main aim of this study was to investigate the prevalence of two VNTRs (located within the 3 0 UTR region of DAT1 and in exon 3 of DRD4) and neuropsychological findings among four groups: SCT without ADHD, ADHD without SCT, SCT + ADHD, and typically developing (TD) controls. ...
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Objective: Studies to reduce the heterogeneity of attention-deficit/hyperactivity disorder (ADHD) have increased interest in the concept of sluggish cognitive tempo (SCT). The aim of this study was to investigate if the prevalence of two variable-number tandem repeats (VNTRs) located within the 3′-untranslated region of the DAT1 gene and in exon 3 of the dopamine D4 receptor (DRD4) gene differ among four groups (31 subjects with SCT but no ADHD, 146 individuals with ADHD but no SCT, 67 subjects with SCT + ADHD, and 92 healthy controls). Methods: We compared the sociodemographic profiles, neurocognitive domains, and prevalence of two VNTRs in SCT and ADHD subjects versus typically developing (TD) controls. Results: The SCT without ADHD group had a higher proportion of females and lower parental educational attainment. Subjects in this group performed worse on neuropsychological tests, except for psychomotor speed and commission errors, compared to controls. However, the ADHD without SCT group performed significantly worse on all neuropsychological domains than controls. We found that 4R homozygosity for the DRD4 gene was most prevalent in the ADHD without SCT group. The SCT without ADHD group had the highest 7R allele frequency, differing significantly from the ADHD without SCT group. Conclusion: The 7R allele of DRD4 gene was found to be significantly more prevalent in SCT cases than in ADHD cases. No substantial neuropsychological differences were found between SCT and ADHD subjects.
... For example, more educated parents may be more likely to focus on promoting children's cognitive development, and more educated parents may themselves be more organized in their daily routines allowing them to more effectively achieve parenting goals (Duncan & Magnuson, 2012). Of note, twin studies have reported nonshared environmental factors influence the presence of SCT more than the presence of ADHD symptomatology (Moruzzi, Rijsdijk, & Battaglia, 2014). Further research is warranted to explore the nuances of the association between socioeconomic variables, familylevel factors, and SCT. ...
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Previous studies have demonstrated that sluggish cognitive tempo (SCT) behaviors are empirically distinct from inattentive (IN) behaviors that are used to define attention-deficit/hyperactivity disorder. However, most studies used cross-sectional designs during middle childhood. Using parent and teacher ratings from the Family Life Project (N = 1,173), we investigated the factor structure, longitudinal measurement invariance, developmental trajectories, and predictors of developmental change in SCT and IN from age 3 years through Grade 5. SCT and IN were dissociable but correlated constructs that exhibited longitudinal invariance for both informants. Mean levels of SCT increased modestly with age, becoming more prominent between age 5 years and first grade, while IN was more stable. Lower parental education was associated with higher parent- and teacher-reported SCT, male sex was associated with higher teacher-reported IN, and African American race was associated with higher teacher-reported IN but lower teacher-reported SCT. These findings support the validity of SCT starting in early childhood.
... As SCT and ADHD partially overlap in presentation of symptomology, EF deficits, and genetic etiology (Moruzzi, Rijsdijk, & Battaglia, 2014), it is possible that interventions created to target ADHD symptoms will also alleviate SCT symptoms. If psychosocial interventions for adolescents with ADHD do improve SCT symptoms, it will be important to determine which factors are associated with change in SCT. ...
Article
Background: Sluggish cognitive tempo (SCT) is a construct that includes symptoms of slowness, excessive daydreaming, and drowsiness. SCT is often comorbid with attention-deficit/hyperactivity disorder (ADHD), and SCT symptoms are associated with significant academic impairment above the influence of ADHD. Despite the overlap between ADHD and SCT and associated impairments, no studies have evaluated how evidence-based psychosocial interventions for adolescents with ADHD impact symptoms of SCT. Methods: This study examined whether SCT symptoms improved in a sample of 274 young adolescents with ADHD who were randomly assigned to an organizational skills intervention, homework completion intervention, or to a waitlist control. SCT intervention response was evaluated broadly in all participants and, specifically, for participants in the clinical range for SCT symptom severity at baseline. Change in ADHD symptoms of inattention, executive functioning, and motivation were examined as potential predictors of improvement in SCT. Results: The two intervention groups were collapsed together for analyses because there were no significant differences in change in SCT symptoms. Multilevel modeling results indicate that parent-reported SCT symptoms significantly decreased when comparing the intervention group to waitlist control (d = .410). For adolescents with parent-reported clinical levels of SCT, the decrease in symptoms was more pronounced (d = .517). Self-reported SCT symptoms produced null results, though effect size calculations showed small improvement for the full sample (d = .313) and for the high-SCT group (d = .384). Change in behavior regulation executive functioning (d = .247), metacognitive executive functioning (d = .346), and inattention (d = .230) predicted change in parent-reported SCT symptoms. Conclusions: Although not specifically designed to decrease SCT symptoms, the ADHD interventions evaluated in this study resulted in significant improvements in parent-reported SCT with small to moderate effect sizes. Clinical implications and future directions are discussed, including development of interventions for adolescents with high levels of SCT.
... The limited studies that have been completed regarding the etiology of SCT suggest that SCT, similar to ADHD, has multiple etiologies. It is possible that SCT has neurobiological and genetic factors that contribute to its etiology, with one study finding SCT to be moderately heritable (Moruzzi, Rijsdijk, & Battaglia, 2014), but less strongly heritable or determined by genetic factors than ADHD. ...
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Sluggish cognitive tempo (SCT) consists of symptoms of slowness, sluggishness, daydreaming, and low motivation. SCT has been linked to attention-deficit/hyperactivity disorder (ADHD), internalizing symptoms, and daytime sleepiness. Although there is clear evidence that SCT and ADHD symptoms are distinct constructs, the distinction between SCT, anxiety/depression, and daytime sleepiness is less clear. Prior research has largely relied upon parent-report to evaluate potential overlap between SCT, sleep, and anxiety/depression, despite best practice suggesting that self-report should be used to assess internalizing symptoms. The present study used adolescent self-report to evaluate whether SCT was distinct from daytime sleepiness, anxiety, and depression. Participants were 285 middle school students comprehensively diagnosed with ADHD. Ten confirmatory factor analyses were conducted: four 1-factor models, three 2-factor models, one 3-factor model, one 4-factor model, and a higher order model. Results showed that SCT was indeed distinct from all tested constructs, with the four-factor model including self-report of SCT, anxiety, depression, and daytime sleepiness meeting adequate model fit criteria. All models including SCT as its own factor had improved model fit over models with SCT in a combined factor with another construct. Implications for the assessment and treatment of SCT are discussed.
... YBT'nin etyolojisine yönelik kısıtlı sayıda çalışma vardır. Bu çalışmalardan bazıları YBT'nin kalıtılabilir olduğunu belirtmektedir (25). YBT'nin tedavisine yönelik yapılan çalışma sayısı da oldukça kısıtlıdır. ...
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Objective: The purpose of this study is to examine the psychometric properties of the Barkley Child Attention Scale (BCAS) for 6- to 12-year-old children. Method: This study was conducted with 291 children (of an age of 6-12 years) with a clinically normal level of intelligence and a diagnosis of attention-deficit/hyperactivity disorder (ADHD). The structure validity of the scale was studied by exploratory and confirmatory factor analyses. In order to evaluate the measuredependent validity of the scale, Child Behavior Checklist for ages 6-18 and Swanson, Nolan and Pelham Questionnaire (SNAP-IV) parental form were used. Reliability of the scale was measured by Cronbach's alpha coefficient. Results: As a result of the exploratory factor analysis, the scale consists of two factors called "daydreaming" and "sluggish," as is the case in its original form. Confirmatory factor analysis indicated that the fit indices of the scale were at an acceptable level. The correlation analysis study for the criterion-related validity study of the scale revealed that Sluggish Cognitive Tempo (SCT) had a positive correlation with ADHD-IN and internalization problems, a negative correlation with attention deficit hyperactivity disorder/hyperactivityimpulsivity (ADHD-HI), and no correlation with externalization problems. Cronbach's alpha coefficient of the BCAS is 0.86 and the scale is seen to be reliable. Conclusion: It can be said that the BCAS is a valid and reliable scale that can measure sluggish cognitive tempo symptoms of 6- to 12-year-old children. © 2018 Yerkure Tanitim ve Yayincilik Hizmetleri A.S..All right reserved.
... 8). While biological factors likely contribute to SCT (Moruzzi et al., 2014), environmental and lifestyle factors (e.g., poor sleep habits, substance use) may also contribute to SCT. ...
Article
We evaluated sluggish cognitive tempo (SCT) symptoms in relation to personality as assessed via both the Reinforcement Sensitivity Theory (BIS/BAS) and Five Factor (Big 5) Model of personality. 3,172 students from five universities completed psychopathology, BIS/BAS, and Big 5 measures. Correlations and path models with SCT, attention-deficit/hyperactivity disorder (ADHD) dimensions, and anxiety/depression in relation to personality were examined. SCT evidenced a different pattern of relations to adult personality than ADHD and anxiety/depression. SCT was significantly uniquely associated with higher BIS and Neuroticism, as well as higher BAS Fun-Seeking. SCT was uniquely associated with lower Extraversion and Conscientiousness. This study provides the first evidence linking SCT to adult personality and underscores the importance of differentiating SCT from both ADHD and anxiety/depression.
... ADHD is heterogeneous and some form of subtyping is likely to eventually be useful, but this will probably entail revision if not overhaul of the existing presentations. In part, there remains considerable concern in the field about how to describe a group of children who appear inattentive and underactive, sometimes referred to as children with sluggish cognitive tempo (Barkley, 2013;Moruzzi, Rijsdijk, & Battaglia, 2013). Many of these children are likely included in the ADHD inattentive presentation, but some experts suspect they have a distinct syndrome unlike other children in that presentation grouping. ...
Chapter
Self-regulation and self-control of attention and impulse (emotion and behavior) are fundamental to adaptation and closely intertwined. Accordingly, disturbances in regulation of attention and impulse are ubiquitous in developmental psychopathology, but attention-deficit/hyperactivity disorder (ADHD) comprises a paradigmatic neurodevelopmental condition for examining typical and atypical functioning and development of these abilities at multiple levels of analysis. It is described. Then a two-process model of regulation is used as heuristic for organizing both the functioning of attention and impulse control and the related literature on ADHD pathophysiology. For both inattention and impulsivity, type 1 (bottom-up) and type 2 (top-down) regulatory processes, their corresponding formal measurement, and corresponding neural instantiation are described to the extent the literature allows. Impulsivity can be linked to temporal discounting of reward, here presented as a bottom-up process that intersects particularly, but not exclusively with emotion regulation. It can also be linked with response inhibition or response suppression, here presented primarily in its top-down aspect. However, it can also occur in a bottom-up fashion via emotional arousal. Therefore, integration of cognition and emotion is conceptually essential for understanding self-control, impulsivity, and inattention. Additional processes accordingly are contained with these heuristic type 1 and type 2 manifestations and are elaborated to add nuance to the general framework proposed. In each section, typical functioning is described and findings in relation to ADHD are highlighted including behavioral, neuropsychological, and neuroimaging findings. Developmental etiology is discussed in relation to molecular genetic approaches, gene by environment interplay, and epigenetic emergence of function and dysfunction. Conclusions and future directions are proposed, highlighting the emerging tractability of revised neurobiologically based nosology for ADHD, the importance of adding contextual nosology to biological nosology, and the integrative potential of an epigenetic model.
... Of note, previous studies have found SCT to be strongly associated with ADHD-IN , although SCT is somewhat less strongly associated with ADHD-IN in psychiatrically hospitalized children . There is some indication that SCT is associated with lower socioeconomic status and less genetically heritable than ADHD symptoms (Moruzzi, Rijsdijk, & Battaglia, 2014). We thus tentatively posit that SCT and ADHD-IN may be less strongly associated in high-risk samples such as ours that are characterized by adversities (e.g. ...
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Background Although identified as a significant public health concern, few studies have examined correlates of suicide risk in school-aged children. Recent studies show a relation between sluggish cognitive tempo (SCT) symptoms and a range of adverse outcomes linked to suicidal ideation, including depression, emotion dysregulation, lowered self-esteem, and peer problems/social withdrawal, yet no study to date has examined SCT in relation to suicide risk. Methods We tested the hypothesis that SCT would be associated with suicide risk in a sample of 95 psychiatrically hospitalized children (74% male; 62% black) between the ages of 8 and 12 (M = 10.01, SD = 1.50). Parents completed measures of their child's psychiatric symptoms, including SCT and depression, as well as a measure of their own psychopathology. Children completed measures assessing loneliness and depression. Both parents and children completed measures of suicide risk. Results White children reported greater suicide risk than nonwhite children. After controlling for demographic characteristics, loneliness, parental psychopathology, and correlated psychiatric symptoms, including both parent- and child self-reported depressive symptoms, SCT remained uniquely associated with children's suicide risk. Results were consistent across both parent and child measures of suicide risk. Conclusions This multi-informant study provides strong preliminary support for an association between SCT symptoms and suicide risk in psychiatrically hospitalized children, above and beyond loneliness, depression, and demographic characteristics. Findings are discussed in the context of the interpersonal theory of suicide. Additional studies are needed to replicate and extend these findings, with a particular need for studies that examine the cognitive processes and daydreaming content of individuals displaying elevated SCT symptomatology.
... Little is known regarding the aetiology of SCT, but again, there is emerging evidence for the separateness of SCT from ADHD. The only published twin study to date found SCT to be substantially heritable, although SCT symptoms were less heritable than ADHD and more strongly influenced by shared and non-shared environmental factors (25). The one neuroimaging study of SCT found an association between SCT symptom severity and hypoactivity in the left superior parietal lobe during a cued flanker task, suggestive of deficits in reorientating or shifting of attention (26) that is different from the attention networks implicated in ADHD (27). ...
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Sluggish cognitive tempo (SCT) is characterized by excessive daydreaming, mental confusion and fogginess, and slowed behavior/thinking. A brief history of the SCT construct is provided, followed by a review of the current research supporting SCT as distinct from attention-deficit/hyperactivity disorder (ADHD) and other psychopathologies. SCT is positively associated with ADHD inattentive symptoms, depression, anxiety, and daytime sleepiness, but unassociated or negatively associated with externalizing behaviors such as hyperactivity-impulsivity, oppositionality, and aggression. A growing body of research also demonstrates that SCT is uniquely associated with poorer functioning in various domains of major life activities, including academic difficulties (including poor organization, homework problems, and lower grade point average), social problems (especially peer withdrawal and isolation), and emotion dysregulation. SCT is less clearly associated with most neuropsychological performance outcomes with the possible exceptions of sustained attention, processing speed, and motor speed. SCT is more consistently related to deficits in daily life executive functioning, though perhaps more so in adults than in children. Key directions for future research are offered, and issues related to terminology are discussed.
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Purpose Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial disorder that has been linked to increased risk for behavioral, academic, and interpersonal problems. Developmental language disorder (DLD) has also been linked to poor outcomes in these areas. The presence of co-occurring disorders in children's profiles is generally associated with poorer outcomes relative to profiles consisting of only one disorder. This study investigated the extent to which co-occurring DLD in children already identified with ADHD presented increased risk for severity of their primary ADHD symptoms, the presence of secondary behavioral problems, and/or increased problems in the tertiary areas of academic performance and interpersonal interactions. Method Data from 90 children from combined community-based and clinically based study samples were used in this retrospective study. Behavioral, academic, and social attributes were assessed from parent ratings on the Child Behavior Checklist. Results Results indicated primary symptoms of ADHD and related tertiary interpersonal consequences were not increased when co-occurring DLD was present. However, the co-occurrence of DLD on ADHD resulted in increased risk for secondary externalizing problems and deficits in academic performance. Conclusions Outcomes highlight the need for high-quality collaborations among clinical professionals, school-based professionals, and parents to ensure the complex needs of children with ADHD are adequately addressed. Children with ADHD who have elevated externalizing behaviors and who are struggling academically should be tested for possible co-occurring DLD.
Article
Objective: To study the clinical and neurophysiological features of children with low cognitive tempo (NCT), as well as the effectiveness of the drug Pantogam in the treatment of this pathology. Material and methods: A total of 90 children aged 8 to 10 years were examined. Of these, the main study group consisted of 30 children with NCT, the comparison group consisted of 30 children with a combined type of attention deficit hyperactivity disorder ADHD (ADHD-K), the control group consisted of 30 children without neuropsychiatric disorders. The study used clinical, neurophysiological (electroencephalography (EEG)) and parametric methods. The CMAS scale of apparent anxiety (The Children's Form of Manifest Anxiety Scale), the SNAP-IY scale (assessment of the degree of inattention, hyperactivity and impulsivity), the TOVA computer test (the Test of Variables of Attention), the scale «SCT» (Sluggish Cognitive Tempo) for assessing manifestations of low cognitive tempo, the «RAM» technique for quantifying working memory. Pantogam was used to treat patients at a dose of 750 mg per day for 8 weeks. Results: Patients with NCT are characterized by more pronounced attention disorders compared with healthy peers and with children with ADHD-K, and they have a decrease in mainly not selective attention, but the overall level of functional activity. Also, the group of children with NCT has an increased level of anxiety compared to the group of children with ADHD. A comparative analysis of the level of impulsivity showed that children with NCT are less characterized by a deficit in inhibition processes. According to the quantitative analysis of the EEG, specific changes in functional activity in the frontal and central regions of the cerebral cortex were revealed (a statistically significant increase in the ratio of absolute theta rhythm to beta1 rhythm, compared with other groups), reflecting insufficient cortical arousal and less focused neural states. When re-evaluating the condition of children with NCT after a course of therapy with Pantogam, an improvement in the form of a decrease in the degree of inattention, the severity of memory impairment and a decrease in reaction time was recorded in 60% of cases. According to quantitative EEG analysis, there was a significant decrease in the ratio of absolute theta rhythm to beta1 rhythm in the central leads of both hemispheres and in the parietal-temporal leads of the left hemisphere, indicating an increase in the level of overall activation of the cerebral cortex after a course of treatment. Conclusion: Clinical and neurophysiological differences were revealed in patients with NCT and with combined ADHD. It has been shown that the use of Pantogam for the treatment of children with NCT leads not only to a decrease in the main manifestations of this disorder, but also to an improvement in the functional state of the brain.
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Background Slow cognitive tempo (SCT) is a disorder characterized by two symptomatic dimensions: motor symptoms such as sluggishness and slow movement, and such cognitive problems as daydreaming, appearing sleepy, slowed behavior/thinking, and confusion. Albeit its unclear etiology, SCT is considered multifactorial, as in attention deficit hyperactivity disorder (ADHD). Here, we aimed to investigate the relationship between vitamin B12 deficiency, one of the conditions causing neurodevelopmental retardation, and SCT. Methods Diagnosed with vitamin B12 deficiency, 52 patients without additional vitamin deficiency and psychiatric diseases, and 52 controls without vitamin deficiency and any diseases were included in the study. While the Conners' Parent Rating Scale-Revised Long (CPRS-R:L) and the Barkley Child Attention Scale (BCAS) were performed with cases’ parents, their teachers underwent the Conners' Teacher Rating Scale-Revised Long (CTRS-R:L) and BCAS. The scores were also evaluated statistically. Results Among B12 deficiency patients, parental education was found lower, and the number of siblings was higher than controls. The risk of patients’ daydreaming scores with vitamin B12 deficiency was 1.4 times higher than that of the controls. Given the investigation of SCT concerning sluggishness and daydreaming scores, a significant difference was detected in terms of sex difference (p = 0.008), and girls were seen to have a higher total score. Conclusion In families with a higher number of siblings and a lower level of parental education, vitamin B12 deficiency is more commonly witnessed, and the symptoms of SCT should be considered to develop in those with B12 deficiency, without severe neurological and hematological findings.
Article
Data on the etiological factors underlying the co-occurrence of Cognitive Disengagement Syndrome (CDS) with anxiety symptoms are very limited. The present study investigated the nature of latent shared etiological elements in 400 Italian twin pairs aged 8-18, explaining the covariation between CDS and anxiety symptoms. Preliminary analysis demonstrated significant correlations between Child Behaviour Checklist/6-18 Sluggish Cognitive Tempo Scale and two (Somatic Anxiety, Generalized Anxiety) out of five Screen for Child Anxiety Related Disorders anxiety subscales. Results from causal analysis seem to exclude the hypothesis that co-occurrence between CDS and Anxiety Symptoms could be due to a direct phenotypic effect of one trait upon the other. Model fitting-analysis indicated that the aforementioned associations were partially explained by shared genetic and environmental factors influencing a common liability factor. A latent variable capturing the covariation between CDS and anxiety problems can be considered as a unifying (patho)physiological mechanism/system common to these constructs. Our results support the adoption of a broader view of the relationships between CDS and anxiety phenotypes in childhood and adolescence for both clinicians and educators.
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Objective (1) Evaluate current knowledge and identify key directions in the study of sluggish cognitive tempo (SCT) and (2) arrive at a consensus change in terminology for the construct that reflects the current science and may be more acceptable to researchers, clinicians, caregivers, and patients. Method Convened an international Work Group that in early 2021 compiled an online archive of all research studies on SCT and summarized the current state of knowledge, noted methodological issues, and highlighted future directions, and met virtually on ten occasions in 2021 to discuss these topics and terminology. Results Major progress has been made over the last decade in advancing our understanding of SCT across the following domains of inquiry: construct measurement and stability; genetic, environmental, pathophysiologic, and neuropsychological correlates; comorbid conditions; functional impairments; and psychosocial and medication interventions. Findings across these domains are summarized, and potential avenues to pursue in the next generation of SCT-related research are proposed. Following repeated discussions on terminology, the Work Group selected cognitive disengagement syndrome (CDS) to replace “SCT” as the name for this construct. This term was deemed to best satisfy considerations that should apply when selecting terms for a condition or syndrome, as it does not overlap with established terms for other constructs, is not offensive, and reflects the current state of the science. Conclusion It is evident that CDS (SCT) has reached the threshold of recognition as a distinct syndrome. Much work remains to further clarify its nature (e.g., transdiagnostic factor, separate disorder, diagnostic specifier), etiologies, demographic factors, relations to other psychopathologies, and linkages to specific domains of functional impairment. Investigators are needed with interests and expertise spanning basic, clinical, and translational research to advance our understanding and improve the lives of individuals with this unique syndrome.
Article
Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children worldwide, and also the recognition of its persistence into adulthood is increasing. While ADHD in childhood is highly heritable and mostly driven by familial factors, during adulthood it appears to show a lower heritability, even if there is not total agreement on this yet. This disorder often co-occurs with many other conditions, which also vary across the different stages of development, and several studies have used the twin design to investigate these comorbidities, giving valuable insights into the origins of the observed co-occurrence. This review aims to summarize the main results of twin research, according to the following domains: individual traits, cognitive impairment, behavioral manifestations, clinical conditions and psychosocial risk factors. Individual features seem to play a role in this symptomatology and include personality traits such as negative emotionality, personality disorders and temperamental dimensions with a predominance of novelty seeking. At a lower level, ADHD is associated with both functional and anatomic brain characteristics. ADHD is also associated with some forms of cognitive impairment, such as sluggish cognitive tempo, and learning disabilities, with a specific predisposition to reading disability. In addition, ADHD is strongly associated with externalizing disorders such as conduct disorder and oppositional defiant disorder, and some behavioral outcomes, particularly substance use and abuse both in adolescence and adulthood. Moreover, ADHD symptoms often overlap with other psychological disorders, namely affective and internalizing disorders, as well as autism spectrum disorder and autistic-like traits in a wider sense. Notably, a genetic overlap has been found between asthma and ADHD, particularly with respect to hyperactivity/impulsivity dimensions. ADHD also appears to represent a risk factor for disordered eating, and, more specifically, for binge eating and bulimia nervosa. Finally, among psychosocial factors, an association has been proposed between childhood maltreatment and ADHD symptoms.
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A nationally representative sample of U.S. children was used to determine the empirical and clinical differentiation of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) symptoms using both categorical and dimensional approaches. Mothers of children (N = 2,056, M± SDage = 8.49 ± 2.15 years, 49.3% girls) completed measures of SCT, ADHD, oppositional defiant disorder (ODD), anxiety, depression, sleep difficulties, daily life executive functioning, conflicted shyness, friendship difficulties, and social and academic impairment. Scores greater than the top 5% on SCT and ADHD measures were used to create SCT-only (n = 53, 2.58%), ADHD-only (n = 93, 4.52%), SCT+ADHD (n = 49, 2.38%), and comparison (n = 1,861, 90.52%) groups. Fifty-two percent of the SCT group did not qualify for the ADHD group, whereas 65% of the ADHD group did not qualify for the SCT group. The SCT-only group had higher levels of anxiety, depression, conflicted shyness, and sleep difficulties than the ADHD-only group. In contrast, the ADHD-only group had greater executive functioning deficits and higher ODD than the SCT-only group. SCT-only and ADHD-only groups showed similar levels of friendship, social, and academic impairment. Similar findings emerged when using structural regression analyses to determine the unique clinical correlates of SCT and ADHD dimensions. This is only the second study to examine the distinction of clinically-elevated SCT from ADHD in a national sample of children and extends previous findings to a broader array of functional outcomes. Normative information on the SCT scale also provides a validated rating scale to advance research and clinical care.
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Objective: Sluggish cognitive tempo refers to a constellation of symptoms that include slowed behavior/thinking, reduced alertness, and getting lost in one’s thoughts. Despite the moniker “sluggish cognitive tempo,” the evidence is mixed regarding the extent to which it is associated globally with slowed (sluggish) mental (cognitive) information processing speed (tempo). Method: A well-characterized clinical sample of 132 children ages 8–13 years (M = 10.34, SD = 1.51; 47 girls; 67% White/non-Hispanic) were administered multiple, counterbalanced neurocognitive tests and assessed for sluggish cognitive tempo symptoms via multiple-informant reports. Results: Bayesian linear regressions revealed significant evidence against associations between sluggish cognitive tempo and computationally modeled processing speed (BF01 > 3.70), and significant evidence for associations with slower working memory manipulation speed. These findings were consistent across parent and teacher models, with and without control for attention-deficit/hyperactivity disorder inattentive symptoms and IQ. There was also significant evidence linking faster inhibition speed with higher parent-reported sluggish cognitive tempo symptoms. Conclusions: These findings provide strong evidence against characterizing children with sluggish cognitive tempo symptoms as possessing a globally sluggish cognitive tempo. Instead, these symptoms appear to be related, to a significant extent, to executive dysfunction characterized by working memory systems that are too slow and inhibition systems that are too fast. Behaviorally, these findings suggest that requiring extra time to rearrange the active contents of working memory delays responding, whereas an overactive inhibition system likely terminates thoughts too quickly and therefore prevents intended behaviors from starting or completing, thereby giving the appearance that children are absent-minded or failing to act when expected.
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Background: Although multiple cross-sectional studies have shown symptoms of sluggish cognitive tempo (SCT) and attention-deficit/hyperactivity disorder (ADHD) to be statistically distinct, studies have yet to examine the temporal stability and measurement invariance of SCT in a longitudinal sample. To date, only six studies have assessed SCT longitudinally, with the longest study examining SCT over a 2-year period. The overall goals of this study were to assess the 10-year longitudinal stability and interfactor relationships of ADHD and SCT symptoms among a community sample of children. Methods: Confirmatory factor analysis was used to assess the temporal invariance of ADHD and SCT symptoms in a large population-based longitudinal sample (International Longitudinal Twin Study of Early Reading Development) that included children assessed at preschool and after kindergarten, first, second, fourth, and ninth grades (n = 489). Latent autoregressive models were then estimated to assess the stability of these constructs. Results: Results demonstrated invariance of item loadings and intercepts from preschool through ninth grades, as well as invariance of interfactor correlations. Results further indicated that both ADHD and SCT are highly stable across these years of development, that these symptom dimensions are related but also separable, and that hyperactivity/impulsivity and SCT are both more strongly correlated with inattention than with each other and show differential developmental trajectories. Specifically, even in the presence of latent simplex analyses providing support for the developmental stability of these dimensions, linear comparisons indicated that that mean levels of hyperactivity/impulsivity decreased with time, inattentive ratings were generally stable, and SCT tended to increase slightly across development. Conclusions: This study adds to the current literature by being the first to systematically assess and demonstrate the temporal invariance and stability of ADHD and SCT across a span of 10 years.
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This study investigated 3 broad classes of individual-differences variables (job-search motives, competencies, and constraints) as predictors of job-search intensity among 292 unemployed job seekers. Also assessed was the relationship between job-search intensity and reemployment success in a longitudinal context. Results show significant relationships between the predictors employment commitment, financial hardship, job-search self-efficacy, and motivation control and the outcome job-search intensity. Support was not found for a relationship between perceived job-search constraints and job-search intensity. Motivation control was highlighted as the only lagged predictor of job-search intensity over time for those who were continuously unemployed. Job-search intensity predicted Time 2 reemployment status for the sample as a whole, but not reemployment quality for those who found jobs over the study's duration. (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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In psychological research, it is desirable to be able to make statistical comparisons between correlation coefficients measured on the same individuals. For example, an experimenter (E) may wish to assess whether 2 predictors correlate equally with a criterion variable. In another situation, the E may wish to test the hypothesis that an entire matrix of correlations has remained stable over time. The present article reviews the literature on such tests, points out some statistics that should be avoided, and presents a variety of techniques that can be used safely with medium to large samples. Several numerical examples are provided. (18 ref) (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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While there have been significant advances in both the behaviour genetics and molecular genetics of Attention Deficit Hyperactivity Disorder (ADHD), researchers are now beginning to develop hypotheses about relationships between phenotypes and genetic mechanisms. Twin studies are able to model genetic, shared environmental and non-shared environmental influences on aetiol-ogy. The present review describes recent behaviour genetic and latent class findings in relation to ADHD and its subtypes, including rater effects, comorbidity, and developmental effects, which have an impact on findings of high heritability. Molecular genetic studies have predominantly focused on dopamine genes, including dopamine receptor and transporter genes, because of animal and human studies indicating the importance of dopaminergic attention systems. The recent clinical use of noradrenergic reuptake inhibitors has also increased interest in noradrenergic genes. Adult ADHD and age-related genetic effects, in addition to "reading" genes, are reviewed in relation to comorbidity and developmental effects.
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Attention deficit hyperactivity disorder (ADHD) is characterized by symptoms of inattention, and/or hyperactivity-impulsivity. Inattention symptoms are present when an individual fails to pay attention and has difficulty in concentrating. Children or adults who are hyperactive fidget, squirm and move about constantly and can not sit still for any length of time. Impulsivity can be described as acting or speaking too quickly without first thinking of the consequences. Children with ADHD face developmental and social difficulties. As adults, they may face problems related to employment, driving a car, or relationships (Barkley, 2002). As is the case for many other psychiatric disorders, the diagnosis of ADHD is not based on a specific pathological agent, such as a microbe, a toxin, or a genetic mutation, but instead on the collection of signs and symptoms that occur together more frequently than expected by chance (Todd, Constantino, & Neuman, 2005). Genetic studies of psychiatric disorders are complicated by this lack of clear diagnostic tests (Hudziak, 2001). Heritability estimates in epidemiological genetic studies and the results of gene-finding studies may vary as a consequence of the instrument that is used to assess ADHD, and of other factors such as the specific population that is investigated. In the current chapter we will focus on behavioral measures of ADHD, and not on endophenotypes (i.e., phenotypes that form a link between the biological pathway and the behavioral outcome, for example, executive functioning). An excellent overview of endophenotypes for ADHD can be found in Castellanos and Tannock (2002). In this overview, we will first present epidemiological studies on the prevalence of ADHD (Section Prevalence of ADHD). Next, the results of studies reporting the heritability of ADHD and related phenotypes will be discussed (Section Genetic Epidemiological Studies on ADHD in Children). We concentrate on variation in these statistics as a result of the specific characteristics of the samples (e.g., age and sex of the children) and as a result of variation in the assessment methods and informants. Finally, we give an overview of studies reporting on the agreement between questionnaire data and diagnostic interviews (Section The Relation Between Questionnaire Data and Diagnostic Interviews).
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The Child Behavior Checklist for Ages 6–18 (CBCL/6-18) possesses newly developed DSM-Oriented Scales, constructed through expert clinical judgment to match selected categories for behavioral/emotional problems as described in the DSM-IV. The present investigation examined the basic psychometric properties for all six DSM-Oriented Scales (i.e., Affective, Anxiety, Somatic, Attention-Deficit/Hyperactivity, Oppositional, and Conduct Scales) in a large clinical sample of children and adolescents (N = 673). Findings from the present study provide strong evidence for the reliability, as well as convergent and discriminative validity, of these scales. It appears that the DSM-Oriented Scales may provide accurate supplementary information that may be considered when formulating clinical diagnoses.
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Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria for attention deficit/hyperactivity disorder (ADHD) specify two dimensions of inattention and hyperactivity-impulsivity symptoms that are used to define three nominal subtypes: predominantly hyperactive-impulsive type (ADHD-H), predominantly inattentive type (ADHD-I), and combined type (ADHD-C). To aid decision making for DSM-5 and other future diagnostic systems, a comprehensive literature review and meta-analysis of 546 studies was completed to evaluate the validity of the DSM-IV model of ADHD. Results indicated that DSM-IV criteria identify individuals with significant and persistent impairment in social, academic, occupational, and adaptive functioning when intelligence, demographic factors, and concurrent psychopathology are controlled. Available data overwhelmingly support the concurrent, predictive, and discriminant validity of the distinction between inattention and hyperactivity-impulsivity symptoms, and indicate that nearly all differences among the nominal subtypes are consistent with the relative levels of inattention and hyperactivity-impulsivity symptoms that define the subtypes. In contrast, the DSM-IV subtype model is compromised by weak evidence for the validity of ADHD-H after first grade, minimal support for the distinction between ADHD-I and ADHD-C in studies of etiological influences, academic and cognitive functioning, and treatment response, and the marked longitudinal instability of all three subtypes. Overall, we conclude that the DSM-IV ADHD subtypes provide a convenient clinical shorthand to describe the functional and behavioral correlates of current levels of inattention and hyperactivity-impulsivity symptoms, but do not identify discrete subgroups with sufficient long-term stability to justify the classification of distinct forms of the disorder. Empirical support is stronger for an alternative model that would replace the subtypes with dimensional modifiers that reflect the number of inattention and hyperactivity-impulsivity symptoms at the time of assessment. (PsycINFO Database Record (c) 2012 APA, all rights reserved).
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Objective: This study investigated the role of sluggish cognitive tempo (SCT) in relation to externalizing and internalizing mental health problems, academic functioning, and social functioning among young adolescents with attention-deficit/hyperactivity disorder (ADHD). Method: In all, 57 youth ages 10 to 14 participated in the study. Parents rated SCT, internalizing, and externalizing symptoms, as well as social and academic impairment. Teachers rated academic and peer impairment, and intelligence and academic achievement also were assessed. Results: Above and beyond ADHD and conduct problem symptoms, SCT was associated with internalizing mental health symptoms and social problems. The association between SCT and externalizing problems or academic functioning was not significant when accounting for ADHD symptomatology and intelligence. Conclusion: SCT is consistently associated with internalizing symptoms and is also associated with young adolescents’ general social difficulties. When controlling for important related constructs, SCT is not associated with externalizing symptoms or academic impairment among young adolescents with ADHD.
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The aims of this study were the Italian standardization of the Child Behavior Checklist (CBCL/4-18) and the Teacher's Report Form (TRF), the analysis of the internal consistency of the two instruments, and the evaluation of the agreement between parents' and teachers' ratings. A group of 1423 parents and 1464 teachers of children and adolescents aged 4 to 18 years, from three different provinces of Northern Italy, were randomly recruited. Boys scored higher than girls on the Externalizing scales on both CBCL and TRF, while there were no significant differences between the two sexes on the Internalizing scales. In general, internalizing problems increased with age, whereas externalizing behaviors decreased, mainly through a reduction of aggressive problems in older subjects. For most scales, low socioeconomic status was associated with high problem scores. Most scales of the CBCL and the TRF showed a satisfactory internal consistency, with higher a coefficients for overt behaviors. A low-to-moderate parents' and teachers' agreement was found, with the higher correlation found for the Attention Problems scale. Overall, the figures of this first standardization are in line with the results of most studies carried out in Western and Eastern countries, evidencing a good... (PsycINFO Database Record (c) 2012 APA, all rights reserved)
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This study examined the latent structure and validity of inattention, hyperactivity-impulsivity, and sluggish cognitive tempo (SCT) symptomatology. We evaluated mother and teacher ratings of ADHD and SCT symptoms in 140 Puerto Rican children (55.7% males), ages 6 to 11 years, via factor and regression analyses. A three-factor model (inattention, hyperactivity-impulsivity, and SCT) provided the best fit for both sets of ratings. Inattention was the strongest correlate of lower scores on neuropsychological, achievement, and psychosocial measures. Externalizing problems were most strongly associated with hyperactivity-impulsivity, and internalizing problems were most strongly associated with parent-rated SCT and teacher-rated Inattention. SCT was not associated with executive function but was negatively associated with math. Inattention accounted for a disproportionate amount of ADHD-related impairment, which may explain the restricted discriminant validity of DSM-IV types. The distinct factors of hyperactivity-impulsivity and SCT had unique associations with impairing comorbidities and are roughly equivalent in predicting external correlates of ADHD-related impairment.
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Researchers who study subtypes of attention-deficit/hyperactivity disorder (ADHD) in children have identified a subset having a sluggish cognitive tempo (SCT) typified by symptoms of daydreaming, mental confusion, sluggish-lethargic behavior, and hypoactivity, among others who differ in many respects from ADHD. No studies have examined the nature and correlates of SCT in adults. This study sought to do so using a general population sample in which those having high levels of SCT symptoms were identified (≥95th percentile) and compared to adults having high levels of ADHD symptoms and adults having both SCT and ADHD symptoms. From a representative sample of 1,249 U.S. adults 18-96 years four groups were created: (a) high levels of SCT but not ADHD (N = 33), (b) high levels of ADHD but not SCT (N = 46), (c) high levels of both SCT and ADHD (N = 39), and (d) the remaining adults as a control group (N = 1,131). As in children, SCT formed a distinct dimension from ADHD symptoms that was unrelated to age, sex, or ethnicity. Adults in both ADHD groups were younger than those with SCT only or control adults. The SCT-only group had less education than the control group, whereas both SCT groups earned less annual income than the control or ADHD-only group. More individuals in the combined group were out of work on disability. In their EF, both SCT groups reported greater difficulties with self-organization and problem solving than controls or the ADHD-only group. Otherwise, the SCT + ADHD group reported significantly greater problems with all other domains of EF than the other groups. But both the SCT-only and ADHD-only groups had significantly more EF difficulties than controls though not differing from each other. A similar pattern was evident on most ratings of psychosocial impairment, except in work and education where SCT was more impairing than ADHD alone and in driving where ADHD was more impairing. SCT contributed unique variance to EF deficits and psychosocial impairment apart from ADHD inattention and hyperactive-impulsive symptoms. Results further suggested that a symptom threshold of 5 or more out of 9 along with a requirement of impairment would result in 5.1% of the population as having SCT. It is concluded that SCT may be a separate disorder from ADHD yet with comorbidity occurring in approximately half of all cases of each. (PsycINFO Database Record (c) 2011 APA, all rights reserved).
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DSM-IV distinguishes two symptom domains of attention deficit hyperactivity disorder (ADHD): inattentiveness and hyperactivity-impulsivity. The present study examines the aetiologies and developmental relations underlying the associations between inattentiveness and hyperactivity-impulsivity over time, based on a representative population sample from the United Kingdom of approximately 7,000 twin pairs. ADHD symptoms were assessed as continuous dimensions using the DSM-IV items from the Conners' Parent Rating Scale at two ages: middle childhood (age 1) and early adolescence (age 2). Quantitative genetic cross-lagged analyses showed that the association of the ADHD dimensions over time is influenced by stable as well as newly developing genetic factors. Moreover the longitudinal relationship between the ADHD dimensions appears to be unidirectional, with hyperactivity-impulsivity in middle childhood predicting the presence of inattentiveness in early adolescence, but not vice versa. Thus, hyperactivity-impulsivity may serve to exacerbate inattentiveness over time. Findings are discussed in the context of developmental changes in ADHD symptoms.
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While social impairment, difficulties with communication, and restricted repetitive behaviors are central features of Autism Spectrum Disorders, physical clumsiness is a commonly co-occuring feature. In a sample of 398 twin pairs (aged 8-17 years) from the Italian Twin Registry we investigated the nature of the co-variation between a psychometric index of Clumsiness and the Child Behavior Checklist (CBCL) Autistic scale. Bivariate twin analyses showed that a genetic etiological overlap, rather than direct causation, is a plausible explanation for the association between clumsiness and autistic-like traits, as measured by indices derived from the parent-rated CBCL scale. Additive genetic influences that impinge upon clumsiness/motor problem and autistic-like traits coincided remarkably, with a genetic correlation of 0.63.
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A previous paper in this journal revealed substantial genetic overlap between the ADHD dimensions of hyperactivity-impulsivity and inattentiveness in a sample of 8-year old twins drawn from a UK-representative population sample. Four years later, when the twins were 12 years old, more than 5,500 pairs drawn from the same sample were rated again on the DSM-IV based Revised Conners' Parent Rating Scale to assess symptoms on both ADHD dimensions. Heritabilities were high (around 70%) for both hyperactivity-impulsivity and inattentiveness and evidence for etiological sex differences was absent. The critical finding was a genetic correlation of 0.55, indicating that hyperactivity-impulsivity and inattentiveness are substantially influenced by the same genes but that the two dimensions also show large and significant unique genetic effects. These results in early adolescence confirm our findings in middle childhood, providing evidence for substantial genetic overlap as well as genetic heterogeneity of the ADHD dimensions. Future genetic studies should investigate the ADHD dimensions separately.
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The present study examined Sluggish Cognitive Tempo (SCT) in relation to ADHD symptoms, clinical diagnosis, and multiple aspects of adjustment in a clinical sample. Parent and teacher reports were gathered for 322 children and adolescents evaluated for behavioral, emotional, and/or learning problems at a university clinic. Confirmatory factor analyses (CFA) supported the presence of three separate, but correlated factors (SCT, inattention, and hyperactivity/impulsivity) in both parent and teacher ratings. As expected, SCT symptoms were greatest in youth with ADHD Inattentive type, but were also found in non-ADHD clinical groups. SCT symptoms were related to inattention, internalizing, and social problems across both parent and teacher informants; for parent reports, SCT was also related to more externalizing problems. Findings support the statistical validity of the SCT construct, but its clinical utility is still unclear.
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The aim of the present study was to investigate the independent relations of DSM-IV-defined inattention and behaviors characteristic of sluggish cognitive tempo (SCT) to neuropsychological factors and problem behaviors often comorbid with attention deficit/hyperactivity disorder (ADHD). By controlling for symptoms of DSM-IV-defined inattention, unique relations to SCT could be ascertained. Additionally, interactive relations of DSM-IV-defined inattention and SCT were of interest. A community-based sample of school children (N = 209; the higher end of the ADHD-symptom range was oversampled) completed neuropsychological tasks designed to measure executive function (EF), sustained attention, and state regulation. Behavioral symptoms were measured using parental and teacher ratings of the DSM-IV criteria for ADHD and Oppositional Defiant Disorder (ODD). The results showed that these two domains of inattention, DSM-IV-defined inattention and SCT, have neuropsychological processes and comorbid behavioral problems in common. However, when controlling for the overlap, DSM-IV-defined inattention was uniquely related to EF and state regulation, while SCT was uniquely related to sustained attention. In addition, the results showed an interactive relation of DSM-IV-defined inattention and SCT to ODD. Findings from the present study support the notion that DSM-IV-defined inattention constitutes a somewhat heterogeneous condition. Such results can further our theoretical understanding of the neuropsychological impairments and comorbid behavioral problems associated with ADHD symptoms.
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Attention Deficit Hyperactivity is a childhood-onset disorder that can persist into adult life. Traditional family, twin and adoption studies have shown that ADHD defined both categorically and dimensionally is familial and heritable. Twin studies are now being used to examine ways of defining the ADHD phenotype, to investigate gender differences, the effects on genes on continuity and comorbidity and to consider gene-environment interplay. Molecular genetic findings on ADHD have mainly arisen from functional candidate gene association studies and a number of pooled and meta-analyses have now been conducted. There is consistent evidence of association between ADHD and a dopamine D4 receptor gene VNTR and a dopamine D5 receptor gene microsatellite marker. More recent evidence from different studies and a pooled analysis suggests that conduct problems in those with ADHD is influenced by the COMT val158/108 met variant. Linkage studies suggest that there are no genes of moderate effect size and findings from large scale whole genome association studies are currently awaited. Overall the evidence to date, suggests that examining gene-phenotype links and testing whether gene variants have modifying effects on the ADHD phenotype are important. The contribution of gene-environment interplay (G x E) to psychopathology is becoming increasingly recognised, although for ADHD little is known on causal environmental risk factors.
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Twin studies described a strongly heritable component of attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. However, findings varied considerably between studies. In addition, ADHD presents with a high rate of comorbid disorders and associated psychopathology. Therefore, this literature review reports findings from population-based twin studies regarding the influence of subtypes, assessment instruments, rater effects, sex differences, and comorbidity rates on ADHD heritability estimates. In addition, genetic effects on the persistence of ADHD are discussed. By reviewing relevant factors influencing heritability estimates more homogeneous subtypes relevant for molecular genetic studies can be elicited. A systematic search of population-based twin studies in ADHD was performed, using the databases PubMed and PsycInfo. Results of family studies were added in case insufficient or contradictory findings were obtained in twin studies. Heritability estimates were strongly influenced by rater effects and assessment instruments. Inattentive and hyperactive-impulsive symptoms were likely influenced by common as well as specific genetic risk factors. Besides persistent ADHD, ADHD accompanied by symptoms of conduct or antisocial personality disorder might be another strongly genetically determined subtype, however, family environmental risk factors have also been established for this pattern of comorbidity.
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Behavioral genetic investigations have consistently demonstrated large genetic influences for the core symptom dimensions of attention-deficit/hyperactivity disorder (ADHD), namely inattention (INATT) and hyperactivity (HYP). Yet little is known regarding potential similarities and differences in the type of genetic influence (i.e., additive vs. nonadditive) on INATT and HYP. As these symptom dimensions form the basis of the current Diagnostic and Statistical Manual of Mental Disorders subtype classification system, evidence of differential genetic influences would have important implications for research investigating causal mechanisms for ADHD. The current meta-analysis aimed to investigate the nature of etiological influences for INATT and HYP by comparing the type and magnitude of genetic and environmental influences each. A comprehensive literature search yielded 79 twin and adoption studies of INATT and/or HYP. Of these, 13 samples of INATT and 9 samples of HYP were retained for analysis. Results indicated that both dimensions were highly heritable (genetic factors accounted for 71% and 73% of the variance in INATT and HYP, respectively). However, the 2 dimensions were distinct as to the type of genetic influence. Dominant genetic effects were significantly larger for INATT than for HYP, whereas additive genetic effects were larger for HYP than for INATT. Estimates of unique environmental effects were small to moderate and shared environmental effects were negligible for both symptom dimensions. The pattern of results generally persisted across several moderating factors, including gender, age, informant, and measurement method. These findings highlight the need for future studies to disambiguate INATT and HYP when investigating the causal mechanisms, and particularly genetic influences, behind ADHD.
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Sluggish cognitive tempo (SCT) is a construct that some researchers believe may be extremely useful in understanding the inattentive subtype of attention-deficit/hyperactivity disorder, and may even help define a completely new disorder. However, the construct of SCT is as yet inadequately operationally or theoretically defined. The authors took the first steps toward developing an empirically supported measure of SCT in children. In Study 1, potential items to measure SCT were identified from a literature review, content validity of the items was evaluated by a group of experts, and a preliminary set of SCT items were selected. In Study 2, ratings completed by parents and teachers of 335 children (ages 4-13) were used to further develop and evaluate the SCT items by computing factor analyses, item-level analyses, reliability analyses, and preliminary validity analyses. The final SCT scale (14 items) produced a total scale score and 3 subscale scores: Slow, Sleepy, and Daydreamer. These scales were constructed with good content validity and were found to have strong reliability. Future directions include replication, extension into a clinical population, and further examination of validity.
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Attention deficit hyperactivity disorder and oppositional behaviours frequently co-occur, We aimed to study the etiology of this overlap in a general population-based twin sample, assessing the symptom domains of hyperactivity-impulsivity and inattentiveness separately for their overlap with oppositionality. We further aimed to investigate whether rater bias may contribute to the overlap in previous data which used one rater only. Using parent and teacher ratings on hyperactivity-impulsivity, inattentiveness and oppositionality, and actigraph measurements of activity level, for 668 7-9-year-old twin pairs, oppositionality showed a higher overlap with hyperactivity-impulsivity (r = 0.95) than with inattentiveness (r = 0.52) and all etiological influences on hyperactivity-impulsivity were shared with those on oppositionality, indicated by a genetic correlation of 0.95 and a child-specific environmental correlation of 0.94. Actigraph data did not show an overlap with ratings of oppositionality. In middle childhood, symptoms of hyperactivity-impulsivity and oppositional behaviour may represent the same underlying liability, whereas the inattentive domain is more distinct.
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The biases resulting from missing information were examined in three psychiatric epidemiological studies. In each study, cases with missing information could be compared with the main sample because data were available from several sources or at several points in time through a longitudinal study. In almost all instances, cases with missing data differed systematically in terms of variables crucial to the questions being studied. In general, they tended to include a higher proportion with problems of various kinds--such as, behavioural deviance, reading backwardness, child or adult psychiatric disorder, and marital discord. The characteristics or circumstances of those giving information were generally more strongly associated with co-operation in testing or interviewing than the characteristics of those about whom information was sought. In some situations, the nature and degree of distortion resulting from missing information could lead to biased results.
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Optimal diagnostic thresholds were determined for DSM-IV attention deficit hyperactivity disorder, and the psychometric properties were compared to alternative definitions. Structured diagnostic interviews of multiple informants for 380 clinic-referred youths aged 4-17 years were conducted. In addition, standardized clinicians' validation diagnoses of attention deficit disorder were obtained to assess agreement with clinical judgment. Measures of impairment were obtained to assess the accuracy of identifying youth with an impairing condition. Three subtypes of attention deficit hyperactivity disorder (predominantly inattentive, predominantly hyperactive-impulsive, and combined types) were distinguished on the basis of the degree of deviance on separate dimensions of inattention and hyperactivity-impulsivity. These three subtypes were found to differ in terms of types of impairment, age, and sex ratio, but not ethnicity. In terms of case identification of attention deficit hyperactivity disorder, DSM-IV was found to be very similar to DSM-III-R, except that DSM-IV identified more impaired girls and preschool children. These results support the decision to subdivide the heterogeneous category of DSM-III-R attention deficit hyperactivity disorder into three subtypes. The resulting DSM-IV definition appears to be somewhat less biased toward the symptom pattern typical of elementary school boys.
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The unique opportunity given by the “fiscal code”, an alphanumeric identification with demographic information on any single person residing in Italy, introduced in 1976 by the Ministry of Finance, allowed a database of all potential Italian twins to be created. This database contains up to now name, surname, date and place of birth and home address of about 1,300,000 “possible twins”. Even thought we estimated an excess of 40% of pseudo-twins, this still is the world's largest twin population ever collected. The database of possible twins is currently used in population-based studies on multiple sclerosis, Alzheimer's disease, celiac disease, and type 1 diabetes. A system is currently being developed for linking the database with data from mortality and cancer registries. In 2001, the Italian Government, through the Ministry of Health, financed a broad national research program on twin studies, including the establishment of a national twin registry. Among all the possible twins, a sample of 500,000 individuals are going to be contacted and we expect to enrol around 120,000 real twin pairs in a formal Twin Registry. According to available financial resources, a sub sample of the enrolled population will be asked to donate DNA. A biological bank from twins will be then implemented, guaranteeing information on future etiological questions regarding genetic and modifiable factors for physical impairment and disability, cancers, cardiovascular diseases and other age related chronic illnesses.
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In a variety of situations in psychological research, it is desirable to be able to make statistical comparisons between correlation coefficients measured on the same individuals. For example, an experimenter may wish to assess whether two predictors correlate equally with a criterion variable. In another situation, the experimenter may wish to test the hypothesis that an entire matrix of correlations has remained stable over time. The present article reviews the literature on such tests, points out some statistics that should be avoided, and presents a variety of techniques that can be used safely with medium to large samples. Several illustrative numerical examples are provided.
Book
Preface. List of Figures. List of Tables. 1. The Scope of Genetic Analyses. 2. Data Summary. 3. Biometrical Genetics. 4. Matrix Algebra. 5. Path Analysis and Structural Equations. 6. LISREL Models and Methods. 7. Model Fitting Functions and Optimization. 8. Univariate Analysis. 9. Power and Sample Size. 10. Social Interaction. 11. Sex Limitation and GE Interaction. 12. Multivariate Analysis. 13. Direction of Causation. 14. Repeated Measures. 15. Longitudinal Mean Trends. 16. Observer Ratings. 17. Assortment and Cultural Transmission. 18. Future Directions. Appendices: A. List of Participants. B. The Greek Alphabet. C. LISREL Scripts for Univariate Models. D. LISREL Script for Power Calculation. E. LISREL Scripts for Multivariate Models. F. LISREL Script for Sibling Interaction Model. G. LISREL Scripts for Sex and GE Interaction. H. LISREL Script for Rater Bias Model. I. LISREL Scripts for Direction of Causation. J. LISREL Script and Data for Simplex Model. K. LISREL Scripts for Assortment Models. Bibliography. Index.
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Although attention deficit - hyperactivity disorder (ADHD) has a distinct developmental progression and a substantial genetic component, very little is known about the genetic contribution to its development and the question of whether the same genes contribute to ADHD throughout childhood and into adolescence. Data from one of the most extensive twin databases, the Australian Twin ADHD Project (ATAP) have shown that ADHD is inherited as a behavioural dimension rather than as a discrete disorder. Behavioural genetic analysis is used in this study with both cross-sectional and longitudinal analyses of inattention and hyperactivity - impulsivity symptoms of ADHD to demonstrate that much of the consistency in behaviour during childhood and early adolescence is due to genetic influences. Genetic analyses hel