[show abstract][hide abstract] ABSTRACT: This study examined whether (a) a genetic disposition for physical health problems increases the risk of peer victimization and (b) peer victimization interacts with genetic vulnerability in explaining physical health problems.
Participants were 167 monozygotic and 119 dizyogtic twin pairs. Physical symptoms were assessed in early childhood and early adolescence. Peer victimization was assessed in middle childhood.
Genetic vulnerability for physical health problems in early childhood was unrelated to later peer victimization, but genetic vulnerability for physical health problems during early adolescence increased the risk of victimization. Victimization did not interact with genetic factors in predicting physical symptoms. Environmental, not genetic, factors had the greatest influence on the development of physical symptoms in victims.
Genetic vulnerability for physical health problems in early adolescence increases the risk of peer victimization. Whether victims suffer a further increase in physical symptoms depends on the presence of protective environmental factors.
Journal of Pediatric Psychology 10/2013; · 2.91 Impact Factor
[show abstract][hide abstract] ABSTRACT: This study used a genetically informed design to assess the effects of friends' and nonfriends' reticent and dominant behaviors on children's observed social reticence in a competitive situation. Potential gene-environment correlations (rGE) and gene-environment interactions (GxE) in the link between (a) friends' and nonfriends' behaviors and (b) children's social reticence were examined. The sample comprised 466 twin children (i.e., the target children), each of whom was assessed in kindergarten together with a same-sex friend and two nonfriend classmates of either sex. Multilevel regression analyses revealed that children with a genetic disposition for social reticence showed more reticent behavior in the competitive situation and were more likely to affiliate with reticent friends (i.e., rGE). Moreover, a higher level of children's reticent behavior was predicted by their friends' higher social reticence (particularly for girls) and their friends' higher social dominance, independently of children's genetic disposition. Children's social reticence was also predicted by their nonfriends' behaviors. Specifically, children were less reticent when male nonfriends showed high levels of social reticence in the competitive situation, and this was particularly true for children with a genetic disposition for social reticence (i.e., GxE). Moreover, children genetically vulnerable for social reticence seemed to foster dominant behavior in their female nonfriend peers (i.e., rGE). In turn, male nonfriends seemed to be more dominant as soon as the target children were reticent, even if the target children did not have a stable genetic disposition for this behavior. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
[show abstract][hide abstract] ABSTRACT: Objectif : La Substance Use Risk Profile Scale (SURPS) est un instrument de dépistage des caractéristiques de personnalité qui représentent un risque pour le développement d'une consommation problématique de substances. La SURPS comporte 23 items évaluant 4 dimensions et permet aux intervenants en santé mentale de mieux cibler la prévention. La SURPS a été validée au Canada anglais, au Royaume-Uni, en Chine et au Sri Lanka; l'objectif de cette étude est de valider une traduction française de la SURPS pour des adolescents francophones québécois, en plus d'en tester la sensibilité dans une population clinique. Méthode : Deux cent deux jeunes de 15 ans d'un échantillon communautaire ont répondu à la SURPS et à des mesures de la personnalité et de l'utilisation de substances. La cohérence interne, la solution factorielle et la validité concomitante de l'échelle ont été évaluées. Quarante adolescents (âge moyen de 15,7 ans) présentant un diagnostic psychiatrique ont également répondu à la SURPS et les scores ont été comparés aux normes de l'échantillon communautaire. Résultats : La traduction française de la SURPS démontre une bonne cohérence interne ainsi qu'une solution factorielle à 4 facteurs semblable à la version originale. Ses 4 sous-échelles ont une bonne validité concomitante. De plus, 3 de ses sous-échelles sont corrélées avec des mesures relatives à la consommation de substances psychoactives. Finalement, 95 % des participants de l'échantillon clinique ont été identifiés à risque selon les scores limites de la SURPS. Conclusion : La version française de la SURPS paraît être une mesure valide et sensible pouvant être utilisée auprès d'une population adolescente, québécoise et francophone.
Canadian journal of psychiatry. Revue canadienne de psychiatrie 09/2013; 58(9):538-545. · 2.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: Adolescent substance use is associated with both earlier childhood behavioural problems and serious lifetime addiction problems later in life.
To examine whether, and through which mechanisms, targeting risk factors in early childhood prevents substance use across adolescence.
Disruptive kindergarten boys (n = 172) living in Montreal were randomly allocated to a preventive intervention and a control condition. The intervention was delivered over 2 years (7-9 years of age) with two main components: (a) social and problem-solving skills training for the boys; and (b) training for parents on effective child-rearing skills.
Adolescent substance use, up to 8 years post-intervention, was reduced in those who received the intervention (d = 0.48-0.70). Of most interest, the intervention effects were explained partly by reductions in impulsivity, antisocial behaviour and affiliation with less deviant peers during pre-adolescence (11-13 years).
Adolescent substance use may be indirectly prevented by selectively targeting childhood risk factors that disrupt the developmental cascade of adolescent risk factors for substance use.
The British journal of psychiatry: the journal of mental science 08/2013; · 6.62 Impact Factor
[show abstract][hide abstract] ABSTRACT: Most research linking early pubertal development to substance use has focused on the effects of pubertal timing (age at which a certain stage of pubertal development is reached or pubertal status at a particular age-related to the maturation disparity hypothesis), but little research has focused on pubertal tempo (rate of growth through pubertal stages-related to the maturation compression hypothesis). However, both timing and tempo have not only been identified as important components of pubertal development, with different predictors, but have also been shown to be independently associated with other adolescent psychopathologies. Using latent growth-curve modeling, this study examined how pubertal status at age 12 and pubertal tempo (between 11 and 13 years) related to substance use from 15 to 16 years in boys from low socioeconomic backgrounds (N = 871). Results showed that both pubertal status at age 12 and tempo were significant predictors of increased levels of substance use and problems in mid to late adolescence. In an attempt to identify mechanisms that may explain the association between pubertal development and substance use it was found that sensation seeking partially mediated the association between pubertal status at age 12 and substance use behaviors. Impulse control was found to moderate the association sensation seeking had with marijuana use frequency, with high sensation-seeking scores predicting higher marijuana use frequency only at low levels of impulse control. These findings highlight the importance of considering multiple sources of individual variability in the pubertal development of boys and provide support for both the maturational disparity and compression hypotheses. (PsycINFO Database Record (c) 2013 APA, all rights reserved).
Journal of Abnormal Psychology 08/2013; 122(3):782-96. · 4.86 Impact Factor
[show abstract][hide abstract] ABSTRACT: ‘Civicness’ may be defined as that property of the social fabric that is characterized by socio‐political commitment, solidarity and mutual trust. From a social ecological perspective it is expected that civic traditions in a given geographical area will have an impact on criminality. The aim of the present study was to test the association between level of civicness and level of juvenile delinquency among the regions of Italy. For the purpose of this study, the term ‘delinquency’ encompasses all illegal acts, from minor offences to violent crimes. We hypothesized that regions with high levels of civic commitment would be more successful in the socialization of its youth, and would thus curb its involvement in delinquent behaviour. Results generally supported the hypothesis. Significant negative correlations were observed at three different time periods (in the 1970s, the 1980s, and in the 1990s) between civicness and official records of robbery and attempted murder by minors, and murder committed by both minors and adults. Analyses using data from a large victimization survey confirmed the significant negative correlations between civicness and violent crimes, but also revealed a significant negative correlation between civicness and theft. Finally, analyses which included socio‐economic predictors revealed that they overlapped to a great extent with civicness, and thus indicated that the predominance of one over the other could not be determined. Nevertheless, it is concluded that the development of environments in which socio‐political commitment, solidarity and mutual trust abound may facilitate the social integration of children and prevent the development of criminal behaviour.
[show abstract][hide abstract] ABSTRACT: IMPORTANCE Maternal depression is a major risk factor for the development of children's mental health problems. No population-based study to date has examined whether early child care spanning the full preschool period from infancy onward is protective for children of depressed mothers. OBJECTIVE To examine whether early child care moderates associations between maternal depressive symptoms (MDSs) and child internalizing problems (emotional problems [EPs], separation anxiety symptoms, and social withdrawal symptoms [SWSs]) during the preschool period. DESIGN AND SETTING Population-based prospective cohort study within the Québec Longitudinal Study of Child Development. PARTICIPANTS Québec Longitudinal Study of Child Development participants (n = 1759) assessed repeatedly between ages 5 and 60 months. MAIN OUTCOMES AND MEASURES High-level trajectories of EPs, SWSs, and separation anxiety symptoms between ages 17 and 60 months. RESULTS Child care age at entry moderated associations between MDSs and child internalizing problems. Among children of mothers with elevated MDSs, reduced odds ratios for EPs and SWSs were found for those entering child care early (0.24; 95% CI, 0.09-0.66 for EPs and 0.29; 95% CI, 0.09-0.92 for SWSs) or late (0.29; 95% CI, 0.11-0.77 for EPs and 0.21; 95% CI, 0.07-0.65 for SWSs) compared with those remaining in maternal care. Child care type moderated the association between MDSs and child EPs; children of mothers with elevated MDSs who received group-based child care had lower odds ratios for EPs than those who remained in maternal care (0.21; 95% CI, 0.09-0.48) or those who were cared for by a relative or babysitter (0.40; 95% CI, 0.17-0.94). CONCLUSIONS AND RELEVANCE Regulated early child care services reduced the risks for internalizing problems for children of mothers with elevated MDSs. Regulated child care services may be used as a public health intervention to buffer the negative effect of maternal depression on children's internalizing problems.
[show abstract][hide abstract] ABSTRACT: BACKGROUND: Few twin studies have examined nutrition-related phenotypes among children, and none has investigated energy and macronutrient intakes. OBJECTIVE: The objective was to quantify genetic and environmental influences on variations in energy and macronutrient intakes among children aged 9years. DESIGN: We conducted a nutrition study among children participating in the Quebec Newborn Twin Study, a population-based birth cohort of twins. We derived dietary data from two multiple-pass 24-hour dietary recalls with a parent and his or her child. The analysis employed a classic twin study design and used data from 379 twin pairs. RESULTS: Univariate analyses indicate that heritability for mean daily energy (kcal) and macronutrient (g) intakes was moderate, ranging from 0.34 (95% CI: 0.22, 0.46) to 0.42 (0.31, 0.53). Genetic effects also accounted for 0.28 (0.16, 0.40) of the variance in percent of energy from lipids, while only environmental (shared and unique) effects accounted for the variance in percent of energy from proteins and carbohydrates. The shared environment did not contribute to variations in daily intakes for most of the nutritional variables under study. Multivariate analyses suggest the presence of macronutrient-specific genetic influences for lipids and carbohydrates, estimated at 0.12 (0.04, 0.19) and 0.20 (0.11, 0.29) respectively. CONCLUSIONS: The unique environment (i.e., not shared by family members) has the largest influence on variances in daily energy and macronutrient intakes in 9-year-old children. This finding underscores the need to take obesogenic environments into account when planning dietary interventions for younger populations.
[show abstract][hide abstract] ABSTRACT: OBJECTIVES:To determine the relative contributions of genetic and environmental factors on daytime and nighttime continuous sleep duration at 6, 18, 30, and 48 months of age, and to identify different subgroups of children who followed different daytime and nighttime sleep duration trajectories and to investigate their etiology.METHODS:The current study included 995 twins (405 monozygotic and 586 dizygotic) of the Quebec Newborn Twin Study recruited from the birth records of the Quebec Statistics Institute. Daytime and nighttime sleep was assessed through maternal reports at 6, 18, 30, and 48 months of age. A semiparametric modeling strategy was used to estimate daytime and nighttime sleep duration trajectories. Quantitative genetic models were used to examine to what extent genetic and environmental factors influenced daytime and nighttime continuous sleep duration.RESULTS:Genetic modeling analyses revealed environmental influences for all daytime sleep duration trajectories. In contrast, strong genetic influences were found for consolidated nighttime sleep duration (except at 18 months and for the short-increasing sleep duration trajectory).CONCLUSIONS:This is the first indication that early childhood daytime sleep duration may be driven by environmental settings, whereas the variance in consolidated nighttime sleep duration is largely influenced by genetic factors with a critical environmental time-window influence at ∼18 months.
[show abstract][hide abstract] ABSTRACT: The study examined whether reciprocal friendship quantity or quality can mitigate genetic vulnerability for depression symptoms in children. The sample comprised 168 monozygotic twin pairs and 126 same-sex dizygotic twin pairs assessed in Grade 4 (mean age = 10.04 years). Friendship participation was measured via reciprocal nominations of close friendships within the classroom. Friendship quality was measured through self-reports. Depression symptoms were measured through teacher and peer reports. Genetic vulnerability for depression symptoms was unrelated to friendship participation or the number of reciprocal friends, but it was negatively related to positive friendship quality. In line with gene-environment interaction, genetic risk effects on depression symptoms were mitigated in girls who had at least one close reciprocal friend. In boys, only moderate main effects of genetic vulnerability and friendship participation were found but no interaction between them. However, among boys with at least one reciprocal friend, a greater number of friends was related to fewer depression symptoms whereas no cumulative effect of friendship was found for girls. Finally, positive friendship quality was related to fewer depression symptoms in girls and boys even when controlling for genetic risk. The findings emphasize the importance of teaching social interactional skills that promote high-quality friendship relations to help prevent the development of depression symptoms in children.
Development and Psychopathology 05/2013; 25(2):277-89. · 4.40 Impact Factor
[show abstract][hide abstract] ABSTRACT: BACKGROUND: The experience of low socioeconomic position in childhood may increase risk for adult cardiovascular disease above and beyond the effects of current socioeconomic position. One limitation of most previous research is that childhood socioeconomic position was assessed retrospectively. METHODS: Measures of ambulatory blood pressure, heart rate, and heart rate variability were obtained from 110 young men (22 years) who were enrolled in a long-term study of child development at age 6. RESULTS: Men who had lower childhood socioeconomic position had smaller decreases in systolic blood pressure (SBP) during sleep independent of current education, daytime SBP, and body mass index (BMI). They also displayed smaller decreases in low-frequency heart rate variability during sleep. Twenty-four-hour SBP was negatively associated with childhood socioeconomic position independent of current education and BMI. CONCLUSIONS: While the mechanisms are unclear, childhood socioeconomic position may influence blood pressure in early adulthood independent of current life circumstances.
Annals of Behavioral Medicine 04/2013; · 4.20 Impact Factor
[show abstract][hide abstract] ABSTRACT: Oppositional and defiant behavior (ODB) problems are among the most important behavior problems in school children. Understanding their trajectories during elementary school and conditional risk factors at school entry is essential for implementing effective preventive and corrective interventions. Behavior problems of a population sample (958 boys, 971 girls) attending public schools were assessed annually by teachers. Three groups were identified: High Opposition (HO; 14.5%), Moderate Opposition (MO; 37.5%), and Low Opposition (LO; 48.0%). Children on the HO trajectory were found to be different from those on the MO and LO trajectories for numerous kindergarten risk factors: a) they tended to be boys with high family adversity; b) their mothers reported low warmth and high control; c) teachers rated them high on physical aggression, opposition, hyperactivity and low anxiety. Children who are likely to have chronic ODB throughout the elementary school years can be identified in kindergarten. Preventive interventions at school entry could probably help these children.
Australian Journal of Educational and Developmental Psychology 04/2013; 3:234-243.
[show abstract][hide abstract] ABSTRACT: Objective: To examine associations of teacher-rated conduct problems (CP) and hurtful and uncaring behaviours (HUB) at age 6 and 10 with criminal convictions up to age 24 among 1593 males and 1423 females, and to determine whether aggressive behaviour at age 12 mediated the associations of CP and HUB with criminal convictions. Method: Teachers assessed HUB and CP at ages 6 and 10 and ratings above the 90th percentile at each age and within each sex were used to assign participants to 1 of 4 groups. Teachers assessed proactive, reactive, indirect, and verbal aggression at age 12. Juvenile and adult criminal records were obtained. Results: High CP and HUB males, aged 6, were 4 times more likely than males with lower ratings to acquire convictions for violent crimes and 5 times more likely to acquire convictions for nonviolent crimes by age 24. High HUB and CP females, aged 6, were 5 times more likely than females with lower ratings to have a conviction for a nonviolent offence by age 24. Among males, both aged 6 and 10, high HUB without CP were associated with elevations at risk of convictions for violent and nonviolent crimes, while among females the elevations at risk were limited to convictions for nonviolent crimes. Different types of aggressive behaviour mediated associations of high HUB and CP with subsequent criminal convictions, but not the association of HUB without CP and crime. Conclusions: Teachers in elementary schools rated behaviours that, from age 6 onward, significantly predicted criminal convictions into early adulthood.
Canadian journal of psychiatry. Revue canadienne de psychiatrie 03/2013; 58(3):143-50. · 2.48 Impact Factor
[show abstract][hide abstract] ABSTRACT: Early disruptive behaviors, such as aggressive and hyperactive behaviors, known to be influenced by genetic factors, have been found to predict early school peer relation difficulties, such as peer rejection and victimization. However, there is no consensus regarding the developmental processes underlying this predictive association. Genetically informative designs, such as twin studies, are well suited for investigating the underlying genetic and environmental etiology of this association. The main goal of the present study was to examine the possible establishment of an emerging gene-environment correlation linking disruptive behaviors to peer relationship difficulties during the first years of school. Participants were drawn from an ongoing longitudinal study of twins who were assessed with respect to their social behaviors and their peer relation difficulties in kindergarten and in Grade 1 through peer nominations measures and teacher ratings. As predicted, disruptive behaviors were concurrently and predictively associated with peer relation difficulties. Multivariate analyses of these associations indicate that they were mainly accounted for by genetic factors. These results emphasize the need to adopt an early and persistent prevention framework targeting both the child and the peer context to alleviate the establishment of a negative coercive process and its consequences.
Development and Psychopathology 02/2013; 25(1):79-92. · 4.40 Impact Factor
[show abstract][hide abstract] ABSTRACT: Animal and human studies suggest that inflammation is associated with behavioral disorders including aggression. We have recently shown that physical aggression of boys during childhood is strongly associated with reduced plasma levels of cytokines IL-1α, IL-4, IL-6, IL-8 and IL-10, later in early adulthood. This study tests the hypothesis that there is an association between differential DNA methylation regions in cytokine genes in T cells and monocytes DNA in adult subjects and a trajectory of physical aggression from childhood to adolescence.
We compared the methylation profiles of the entire genomic loci encompassing the IL-1α, IL-6, IL-4, IL-10 and IL-8 and three of their regulatory transcription factors (TF) NFkB1, NFAT5 and STAT6 genes in adult males on a chronic physical aggression trajectory (CPA) and males with the same background who followed a normal physical aggression trajectory (control group) from childhood to adolescence. We used the method of methylated DNA immunoprecipitation with comprehensive cytokine gene loci and TF loci microarray hybridization, statistical analysis and false discovery rate correction. We found differentially methylated regions to associate with CPA in both the cytokine loci as well as in their transcription factors loci analyzed. Some of these differentially methylated regions were located in known regulatory regions whereas others, to our knowledge, were previously unknown as regulatory areas. However, using the ENCODE database, we were able to identify key regulatory elements in many of these regions that indicate that they might be involved in the regulation of cytokine expression.
We provide here the first evidence for an association between differential DNA methylation in cytokines and their regulators in T cells and monocytes and male physical aggression.
PLoS ONE 01/2013; 8(8):e71691. · 3.73 Impact Factor
[show abstract][hide abstract] ABSTRACT: An increasing number of animal and human studies are indicating that inflammation is associated with behavioral disorders including aggression. This study investigates the association between chronic physical aggression during childhood and plasma cytokine levels in early adulthood.
Two longitudinal studies were used to select males on a chronic physical aggression trajectory from childhood to adolescence (n = 7) and a control group from the same background (n = 25). Physical aggression was assessed yearly by teachers from childhood to adolescence and plasma levels of 10 inflammatory cytokines were assessed at age 26 and 28 years. Compared to the control group, males on a chronic physical aggression trajectory from childhood to adolescence had consistently lower plasma levels of five cytokines: lower pro-inflammatory interleukins IL-1α (T(28.7) = 3.48, P = 0.002) and IL-6 (T(26.9) = 3.76, P = 0.001), lower anti-inflammatory interleukin IL-4 (T(27.1) = 4.91, P = 0.00004) and IL-10 (T(29.8) = 2.84, P = 0.008) and lower chemokine IL-8 (T(26) = 3.69, P = 0.001). The plasma levels of four cytokines accurately predicted aggressive and control group membership for all subjects.
Physical aggression of boys during childhood is a strong predictor of reduced plasma levels of cytokines in early adulthood. The causal and physiological relations underlying this association should be further investigated since animal data suggest that some cytokines such as IL-6 and IL-1β play a causal role in aggression.
PLoS ONE 01/2013; 8(7):e69481. · 3.73 Impact Factor