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Relative age within the school year and diagnosis of attention-deficit hyperactivity disorder: A nationwide population-based study
Abstract
Background:
Findings are mixed on the relationship between attention-deficit hyperactivity disorder (ADHD) and younger relative age in the school year. We aimed to investigate whether relative age is associated with ADHD diagnosis in a country where prescribing rates are low and whether any such association has changed over time or relates to comorbid disorders (eg, conduct disorder [CD], oppositional defiant disorder [ODD], or learning disorder [LD]).
Methods:
We used nationwide population-based registers to identify all Finnish children born between Jan 1, 1991, and Dec 31, 2004, who were diagnosed with ADHD from age 7 years onwards (age of starting school). We calculated incidence ratios to assess the inter-relations between relative age within the school year, age at ADHD diagnosis, and year of diagnosis (1998-2003 vs 2004-11).
Findings:
Between Jan 1, 1998, and Dec 31, 2011, 6136 children with ADHD were identified. Compared with the oldest children in the school year (ie, those born between January and April), the cumulative incidence of an ADHD diagnosis was greatest for the youngest children (ie, those born between September and December); for boys the incidence ratio was 1·26 (95% CI 1·18-1·35; p<0·0001) and for girls it was 1·31 (1·12-1·54; p=0·0007). The association between relative age and age at ADHD diagnosis reflected children diagnosed before age 10 years, and the strength of this association increased during recent years (2004-11). Thus, compared with children born between January and April, for those born between May and August, the ADHD incidence ratio was 1·37 (95% CI 1·24-1·53; p<0·0001) and for those born between September and December, the incidence ratio was 1·64 (1·48-1·81; p<0·0001). The relative age effect was not accounted for by comorbid disorders such as CD, ODD, or LD.
Interpretation:
In a health service system with low prescribing rates for ADHD, a younger relative age is associated with an increased likelihood of receiving a clinical diagnosis of ADHD. This effect has increased in recent years. Teachers, parents, and clinicians should take relative age into account when considering the possibility of ADHD in a child or encountering a child with a pre-existing diagnosis.
Funding:
Academy of Finland, Finnish Medical Foundation, Orion Pharma Foundation, Finnish Cultural Foundation.
... O ver the last decade, many studies have associated younger relative age within a school year with an increased risk of being diagnosed with, and medicated for, attention-deficit/ hyperactivity disorder (ADHD) (Sayal et al. 2017;Caye et al. 2019;Whitely et al. 2019). The reported risk was about 30%-40% higher in the youngest, than oldest, children in a classroom (Caye et al. 2019;Whitely et al. 2019). ...
... The reported risk was about 30%-40% higher in the youngest, than oldest, children in a classroom (Caye et al. 2019;Whitely et al. 2019). Swedish and Finnish population-based studies have shown that the relative age effect was stronger in children during their early school years (Halldner et al. 2014;Brikell et al. 2016;Sayal et al. 2017;Vuori et al. 2020). Other studies have demonstrated that the effect of having a birthday late in the school year peaked in the fourth and fifth grades when the children were 10-11 years of age (Whitely et al. 2019). ...
... Other studies have demonstrated that the effect of having a birthday late in the school year peaked in the fourth and fifth grades when the children were 10-11 years of age (Whitely et al. 2019). In general, empirical evidence has indicated that relative age plays a more important role in middle childhood in patients with ADHD (Halldner et al. 2014;Sayal et al. 2017;Whitely et al. 2019). The prevalence of ADHD medication use varies significantly across countries (Raman et al. 2018). ...
Objective: The youngest children in a classroom have a higher risk of attention-deficit/hyperactivity disorders (ADHDs) and depression than their relatively older peers. However, there has been a lack of research on how relative age is related to second-generation antipsychotic (SGA) medication use. Methods: This study used the Finnish National Prescription Register data and comprised all 669,726 Finnish children and adolescents aged 7-17 in 2018. We extracted data for those who were dispensed SGAs (risperidone, quetiapine, aripiprazole, and olanzapine) and ADHD medication (methylphenidate, atomoxetine, dexamphetamine, and lisdexamfetamine). Odds ratios (OR) and 95% confidence intervals (CI) were calculated for medication dispensed to schoolchildren born from January to April (the relatively oldest), May to August, and September to December (the relatively youngest). Dispensed prescriptions were a proxy for medication use. Results: SGAs were dispensed to 9146 (1.4%) individuals in 2018. Their use was lower among girls aged 12-17 years born from September to December than January to April (OR 0.89; 95% CI 0.83-0.97), with no association between SGA use and birth month among boys. However, younger relative age was associated with combined SGA and ADHD medication, which was used by 2556 (0.4%) of the cohort: 2074 (0.6%) boys and 482 (0.1%) girls. The OR was 1.27 for boys aged 12-17 born from September to December (95% CI 1.10-1.46), compared with January to April. The OR for girls born from May to August was 1.35 (95% CI 1.04-1.76) and from September to December it was 1.33 (95% CI 1.02-1.74), compared with January to April. Conclusions: A novel discovery of this study was that using both SGA and ADHD medication at the age of 12-17 years was more common among the youngest subjects in a school year than their relatively older peers.
... 10 One line of research suggests that RAE may represent a situation in which the more immature behavior of younger children is treated as ADHD. [11][12][13] There is empirical evidence of the RAE from countries with high prescription rates, such as Iceland, 14 the United States, 15 Canada, 16 and Sweden, 17 but also from countries with moderate rates, such as Norway 18 and Taiwan. 19 The strength of the RAE may vary within countries across time. ...
... 24 Our purpose with this study was to examine the extent to which relative age is associated with ADHD medication use among children in Finland born in 2005 to 2007. Importantly, we were able to use the study by Sayal et al, 13 which examined the association between relative age and an ADHD diagnosis among Finnish children (born between 1991 and 2004) as a baseline. Altogether, with our study, we add to the global understanding of the RAE in ADHD by providing a more-complete picture of the phenomenon from a single jurisdiction where the rates of children with ADHD have increased somewhat rapidly and delayed school entry has decreased. ...
... Altogether, with our study, we add to the global understanding of the RAE in ADHD by providing a more-complete picture of the phenomenon from a single jurisdiction where the rates of children with ADHD have increased somewhat rapidly and delayed school entry has decreased. 13,26 First, we hypothesized that with delayed school entry being somewhat rare in Finland, there would be at least a modest RAE in prescribing ADHD medication for children. Second, given that difference in maturity is more extreme at young ages, we expected that the RAE in ADHD medication use would be stronger at ages 6 to 7, when children start primary education. ...
Objectives:
The youngest children in a classroom are at increased risk of being medicated for attention-deficit/hyperactivity disorder (ADHD). We examined the association between children's birth month and ADHD medication rates in Finland.
Methods:
Using a population-based study, we analyzed ADHD medication use among children born in 2005 to 2007. Cases (n = 7054) were identified from the first purchase of medication for ADHD. Cox proportional hazard models and hazard ratios (HRs) were examined by birth month and sex. Finnish children start first grade in the year of their seventh birthday. The cutoff date is December 31.
Results:
Risk of ADHD medication use increased throughout the year by birth month (ie, January through April to May through August to September through December). Among boys born in September to December, the association remained stable across cohorts (HR: 1.3; 95% confidence interval [CI]: 1.1-1.5). Among girls born in September to December, the HR in the 2005 cohort was 1.4 (95% CI: 1.1-1.8), whereas in the 2007 cohort it was 1.7 (95% CI: 1.3-2.2). In a restricted follow-up, which ended at the end of the year of the children's eighth birthday, the HRs for boys and girls born in September to December 2007 were 1.5 (95% CI: 1.3-1.7) and 2.0 (95% CI: 1.5-2.8), respectively.
Conclusions:
Relative immaturity increases the likelihood of ADHD medication use in Finland. The association was more pronounced during the first school years. Increased awareness of this association is needed among clinicians and teachers.
... Eleven countries (Canada, Denmark, Finland, Germany, Italy, Norway, South Korea, Sweden, Taiwan, Turkey, and the United States of America) on three continents (Asia, Europe, and North America) are represented in the studies. Researchers extracted data exclusively from healthcare and insurance databases in nine out of the 14 studies included in this review (Boland et al. 2018;Bonati et al. 2018;Chen et al. 2016;Dalsgaard et al. 2012;Evans, Morrill, and Parente 2010;Karlstad et al. 2017;Morrow et al. 2012;Sayal et al. 2017;Schwandt and Wuppermann 2016) (see Table 1). Halldner et al. (2014) used a combination of findings from databases, parent reports and self-reports. ...
... Twelve out of the 14 studies (Boland et al. 2018;Bonati et al. 2018;Chen et al. 2016;Elder 2010;Elder and Lubotsky 2009;Evans, Morrill, and Parente 2010;Gökçe et al. 2017;Halldner et al. 2014;Karlstad et al. 2017;Morrow et al. 2012;Sayal et al. 2017;Schwandt and Wuppermann 2016) found a clear positive association between relative age and the probability of being diagnosed with ADHD compared to peers, thus showing that younger-in-class children are more likely to be diagnosed with ADHD (Table 1). In 11 out of 12 of these studies, researchers extracted their data from databases or past cohorts and thus relied on objective, retrospective data (Boland et al. 2018;Bonati et al. 2018;Chen et al. 2016;Elder 2010;Elder and Lubotsky 2009;Evans, Morrill, and Parente 2010;Halldner et al. 2014;Karlstad et al. 2017;Morrow et al. 2012;Sayal et al. 2017;Schwandt and Wuppermann 2016). ...
... Twelve out of the 14 studies (Boland et al. 2018;Bonati et al. 2018;Chen et al. 2016;Elder 2010;Elder and Lubotsky 2009;Evans, Morrill, and Parente 2010;Gökçe et al. 2017;Halldner et al. 2014;Karlstad et al. 2017;Morrow et al. 2012;Sayal et al. 2017;Schwandt and Wuppermann 2016) found a clear positive association between relative age and the probability of being diagnosed with ADHD compared to peers, thus showing that younger-in-class children are more likely to be diagnosed with ADHD (Table 1). In 11 out of 12 of these studies, researchers extracted their data from databases or past cohorts and thus relied on objective, retrospective data (Boland et al. 2018;Bonati et al. 2018;Chen et al. 2016;Elder 2010;Elder and Lubotsky 2009;Evans, Morrill, and Parente 2010;Halldner et al. 2014;Karlstad et al. 2017;Morrow et al. 2012;Sayal et al. 2017;Schwandt and Wuppermann 2016). It is notable that this tendency is consistent across the several diagnostic cultures, diagnostic manuals and educational systems represented in the data. ...
Attention deficit hyperactivity disorder (ADHD) is a debated phenomenon and the link between schooling and the occurrence of ADHD diagnoses is worth critical scrutiny. This paper contributes to the academic debate by providing a literature review of the evidence on the influence of relative age effect (RAE) on being diagnosed with ADHD. Firstly, the review presents a general cross-national trend of a positive association between relative age and the probability of being diagnosed with ADHD compared with peers, thus showing that the younger-in-class children are more likely to be diagnosed with ADHD. Secondly, this paper outlines and presents discussion on the suggested explanations of the phenomenon as depicted in the literature reviewed. Finally, the paper proceeds to provide alternative frameworks for the explanation of the RAE on ADHD diagnosis that consider the broader social, cultural and political contexts in which the phenomenon takes place.
Free e-prints: https://www.tandfonline.com/eprint/6RSIYSNDC2KARKZED3NN/full?target=10.1080/14681366.2019.1624599
... A growing number of studies suggest that in this signaling function the relatively 'young behavior' of early pupils gives them a much greater likelihood of being diagnosed with a a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 disorder, including Attention Deficit Hyperactivity Disorder (ADHD) [7,8,9,10,11,12,13,14,15,16,17]. This so-called 'relative age effect' [18] has also been demonstrated to increase the likelihood of pupils having special educational needs [8,19], be diagnosed with lower intelligence [20] and learning difficulties [21], attain lower physical education achievements [22,23,24], lower performance during the school career [25,26], and being bullied [27]. ...
... The international literature has demonstrated a relative age effect in relation to outcome measures that range from the likelihood of learning problems [21] to the likelihood of success in playing hockey [41]. For pupil behavior problems, the association between relatively young pupils and the likelihood of receiving an ADHD diagnosis in particular is well documented [9,10,11,12,13,14,15,16,17], although some published studies did not find an association [26,42]. ...
... The body of evidence demonstrating the relative age effect in the context of ADHD is very large, with studies in many different countries around the world, and with very different methodologies [9,10,11,12,13,14,15,16,17]. Hence, on the basis of our relatively small-scale study we cannot conclude that this concerns a spurious rather than a real association. ...
A growing number of studies suggest that relatively young behavior of pupils gives them a much greater likelihood of being diagnosed with a disorder such as ADHD. This ‘relative age effect’ has also been demonstrated for special educational needs, learning difficulties, being bullied, and so on. The current study investigated the relationship between relative age of pupils in primary education and teachers’ perception of their behavior. The study sample included 1973 pupils, aged between 6 and 12. Six linear mixed models were carried out with birth day in a year as predictor variable and ‘total problem score’, ‘problems with hyperactivity’, ‘behavioral problems’, ‘emotional problems’, ‘problems with peers’ and ‘pro-social behavior’ as dependent variables. Random intercepts were added for school and teacher level. Cluster-mean centering disaggregated between-school effects and within-school effects. We found no associations between relative age of pupils and teacher perceptions of their behavior. Several explanations are postulated to account for these findings which contradict prior studies on relative age effects.
... The Finnish study (Sayal, Chudal, Hinkka-Yli-Salomaki, Joelsson, & Sourander, 2017) examined the birth month distribution of 870,695 children aged 7-19, of whom 6,136 (0.7%) were ever diagnosed with ADHD. The chances of a child being diagnosed before age 10 were 64% higher (95% CI: 1.48-1.81) ...
... They reported across diverse age ranges. Most reported medication rates, but some included only stimulants, while others included the less commonly prescribed atomoxetine, with the proportion of children medicated/diagnosed ranging from a high of 6.3% (aged 7-14 medicated with stimulants in the Icelandic study; Zoega et al., 2012) to a low of 0.7% (aged 7-19 diagnosed in the Finnish study; Sayal et al., 2017). The Dutch study (Krabbe et al., 2014) reported only methylphenidate use. ...
... Some compared the last 3 months with the first 3 months (Karlstad et al., 2016;Pottegard et al., 2014). Four compared the last third (4 months) with the first third (Evans et al., 2010;Hoshen et al., 2016;Sayal et al., 2017;Zoega et al., 2012), and two compared the first half of the year with the second half (Elder, 2010;Librero et al., 2015). ...
Background
Multiple studies have found that the youngest children in a classroom are at elevated risk of being diagnosed with, or medicated for, ADHD. This systematic review was conducted to investigate whether this late birthdate effect is the norm and whether the strength of effect is related to the absolute risk of being diagnosed/medicated.
Methods
A literature search of the PubMed and ERIC databases and snowball and grey literature searching were conducted.
Results
A total of 19 studies in 13 countries covering over 15.4 million children investigating this relationship were identified. Three other studies exploring related topics were identified. The diversity of methodologies prevented a meta‐analysis. Instead a systematic review of the 22 studies was conducted.
A total of 17 of the 19 studies found that the youngest children in a school year were considerably more likely to be diagnosed and/or medicated than their older classmates. Two Danish studies found either a weak or no late birth date effect. There was no consistent relationship between per‐capita diagnosis or medication rates and the strength of the relative age effect, with strong effects reported in most jurisdictions with comparatively low rates.
Conclusions
It is the norm internationally for the youngest children in a classroom to be at increased risk of being medicated for ADHD, even in jurisdictions with relatively low prescribing rates. A lack of a strong effect in Denmark may be accounted for by the common practice of academic ‘redshirting’, where children judged by parents as immature have a delayed school start. Redshirting may prevent and/or disguise late birthdate effects and further research is warranted. The evidence of strong late birthdate effects in jurisdictions with comparatively low diagnosis/medication rates challenges the notion that low rates indicate sound diagnostic practices.
... It has been argued that the relative age effect may represent the more immature behaviour of younger children being diagnosed and treated as ADHD and, therefore, more relaxed school entry policies may be able to offset this [15,17]. This systematic review aims to investigate the strength of evidence for a relative age effect, distinguishing countries known to have higher and lower prescribing rates [19,20]. It addresses three key questions-Is there an association between younger relative age, defined as being in the second half of the academic year, and: (1) the presence of high levels of ADHD symptoms, (2) receiving a clinical diagnosis of ADHD and (3) Abstracts were screened independently by JH and KS with 100% agreement, and then full text assessments were conducted by JH. ...
... Twenty studies were assessed for the review and data extraction, the characteristics of these studies are shown in Table 1. Six of these could not be included in the quantitative synthesis initially due to: information not being presented on the total number of children, with and without a diagnosis/ medication receipt [8,19,22,24,25] or comparisons only being made between the starting school age not age within the school year [26]. However, following communications with the authors, data were provided for three studies [8,20,25] and were therefore included. ...
... This suggests the possibility of misdiagnosis in relation to children with young relative age. However, this explanation does not fit with findings from a study using data from Finland, a country with low diagnosis and prescription rates but with evidence of a relative age effect [19]. Second, linked to the above, there are differences in diagnostic practice across countries, for example, which professionals are able to give a diagnosis [15,17]. ...
There is a growing international literature investigating the relationship between attention-deficit/hyperactivity disorder (ADHD) and younger relative age within the school year, but results have been mixed. There are no published systematic reviews on this topic. This study aimed to systematically review the published studies on the relative age effect in ADHD. Systematic database searches of: Medline, Embase, PsycINFO, Web of Science, ERIC, Psychology and Behavioral Sciences Collection and The Cochrane Library were conducted. Studies were selected which investigated the relative age effect in ADHD in children and adolescents. Twenty papers were included in the review. Sixteen (of 20) papers reported a significantly higher proportion of relatively younger children being diagnosed with ADHD and/or receiving medication for this. Meta-analyses involving 17 of these 20 papers revealed a modest relative age effect in countries with higher prescribing rates, risk ratio = 1.27 (95% CI 1.19–1.35) for receipt of medication. The relative age effect is well demonstrated in countries with known higher prescribing rates. Amongst other countries, there is also increasing evidence for the relative age effect, however, there is high heterogeneity amongst studies. Further research is needed to understand the possible reasons under-pinning the relative age effect and to inform attempts to reduce it.
... For example, the prevalence of ADHD is estimated at 12.2% in the Midwest, 11.1% in the South, 10.3% in the Northeast, and 7% in the West (Barkley, 2014). ADHD is a major impediment to the child's adaptation to a new environment and learning progression (Catalá-López & Hutton, 2018;Sayal et al., 2017;Wolraich et al., 2019). Normally, the severity of ADHD manifestations decreases by age 15. ...
... Normally, the severity of ADHD manifestations decreases by age 15. However, the symptoms do not disappear completely, and attention deficits become more pronounced (Cabral et al., 2020;Sayal et al., 2017). Importantly, subclinical manifestations of this disorder persist throughout life in almost 20% of patients (Solanto, 2017). ...
The present article used a pilot study to determine the effectiveness of digital cognitive mindfulness training developed based on dialectical behavioral therapy (DBT) in reducing attention deficit hyperactivity disorder (ADHD) symptoms in children. The sample consisted of 90 children (8–10 years old) diagnosed with ADHD. The participants were randomized into two groups: an experimental group (n = 45) and a control group (n = 45). Results were assessed at three time points: before, after the study, and one month after the end of the study. Regarding ADHD symptoms, the ANCOVA results showed that there were no statistically significant differences between the study groups for inattention and hyperactivity/impulsivity after testing. One month after completion of the program, there was a significant alleviation in symptoms of inattention, executive functioning, learning problems, aggression, and peer relationships. Hyperactivity was the only variable that showed a decrease both post-test and during follow-up. These results suggest that a DBT-based mindfulness program is a promising method of reducing ADHD symptoms in children.
... Compared with their older classmates, younger students have been found to be more at risk of being diagnosed with and taking medication for ADHD. This phenomenon has been observed in various regions worldwide, including North and South America (e.g., [18,[20][21][22]), Europe (e.g., [23][24][25]), the Middle East [26], Asia, and Australia [15,27]. ...
... Various dimensions of immaturity are associated with ADHD, including emotional, intellectual, behavioral, cognitive, neurocognitive, and brain immaturity [20,23,27]. The expression of immaturity encompasses a rather broad array of childish behaviors, including impulsivity; hyperactivity; inattention; and difficulties settling down, focusing in school, and meeting school demands [15,25]. This confusion between ADHD symptoms and immaturity could result from teachers using the group as a comparative benchmark when forming an opinion of a student. ...
Diagnosis and pharmacological treatment of ADHD are more common among the youngest children in a classroom, born in the months immediately preceding the school entry cutoff date. The mechanisms behind this phenomenon, called the relative age effect (RAE), are not yet well understood. Nearly all hypotheses involve the school system, various teachers’ actions, and concern children’s immaturity. However, most previous studies have been based on reports of health professionals’ diagnoses and prescriptions found in official databases rather than on reports of teachers’ behavior identification or suspicion of ADHD, despite their being at the first stages of the medicalization process. Our study overcomes this limitation by using reports of parents’ and teachers’ behavior identification or suspicion of ADHD within a three-level multilevel survey design, comprising 1294 children, 130 teachers, and 17 elementary public schools. The goal of our study was to investigate whether RAE stems (1) from adults’ judgement of the child’s expression of immaturity or (2) from the consequences associated with the child’s double burden of being immature and exhibiting ADHD behaviors. Our multilevel analyses put forward the first hypothesis only, supporting the medicalization of immaturity. RAE in ADHD seems mostly initiated by teachers’ pre-diagnostic actions toward younger children.
... Because of cut-off birthdates for entry into school, children within the same grade may be almost 1 year apart in terms of age; in other words, the youngest students with birthdates just before the cut-off date are much younger and less mature than their classmates born at other times of the year, particularly those born in the first month of the academic year [1][2][3]. Such a birthdate effect, also known as the relative age effect, represents a within-grade relative maturity disadvantage in a child's performance (cognitive performance, academic performance, and sport performance) in school [1]. ...
... Evidence suggests the crucial effect of relative age on many conditions and variables, such as cognitive development, academic performance, and diagnosis of and medication prescription for attention deficit hyperactivity disorder (ADHD) [1][2][3][4][5]. Navarro et al. analyzed 15,234 eighth graders in the National System of Quality Assessment in Education Survey from Chile and revealed significant effects of relative age on global academic performance as well as on each measure of different academic domains, including reading, mathematics, social studies, and science [5]. ...
Background
The annual cut-off birthdate for entry into school in Taiwan is August 31. Thus, children and adolescents born in August are typically the youngest in their grades. The potential effect of relative age on the diagnosis of autism spectrum disorder (ASD) remains uncertain.MethodsA total of 9,548,393 individuals aged 3–17 years during the study period (from September 1, 2001, to August 31, 2011) identified from the Taiwan National Health Insurance Research Database were enrolled into our study. Logistic regression analysis was used to examine the likelihood of receiving ASD diagnosis for those who were born in August (the youngest) compared with those who were born in September (the oldest).ResultsBoth boys and girls born in August had a higher likelihood of being diagnosed with ASD (odds ratio [OR]: 1.24, 95% confidence interval [CI]: 1.16–1.32; OR: 1.23, 95% CI 1.06–1.42) than did those born in September. Sensitivity analysis conducted over different periods revealed consistent findings.DiscussionRelative age, as an indicator of neurocognitive maturity, is a crucial contributor to the risk of being diagnosed with ASD among children and adolescents. Our findings highlight the importance of considering the age of a child within a grade when diagnosing ASD.
... There is increasing evidence from similar studies, reporting that the younger children within the same school year are at an increased risk for the development of ADHD-related outcomes during primary school, and authors suggest that this association represents a causal relationship [14][15][16]. However, the relationship between the persistence of ADHD symptoms and the age of entry into primary school has yet to be adequately examined, due to a lack of longitudinal studies. ...
... Based on the findings of the previous research, we postulated that any relative age effect would be strongest for younger ages and that a relative age effect would exist in the earlier but not in the later study period [15,16,31,32]. ...
Background
Attention-deficit hyperactivity disorder (ADHD) is the most common neurodevelopmental disorders among school-age children worldwide. In a more recent follow-up study, Biederman et al. found that 78% of children diagnosed with ADHD between the ages of 6–17 years continued to have a full (35%) or a partial persistence after eleven years.
Objective
In this study, it was aimed to identify the factors contributing to the persistence of ADHD symptoms in elemantary school children who were prospectively assessed both in their earlier and upper grades.
Methods
The sample was drawn from a previous community-based study where ADHD symptoms in 3696 first/or second graders were examined in regard to their school entry age. Two years after, the families of the children that participated in the initial study were called by phone and invited to a re-evaluation session. Among those who were reached, 154 were consequently eligible and were assessed with Swanson, Nolan and Pelham questionnaire (SNAP-IV), Conners’ rating scales (CRS) and the Kiddie schedule for affective disorders and schizophrenia (K-SADS).
Results
Of the 154 children, 81 had been evaluated to have “probable ADHD” by the initial interview. Among these 81 children, 50 (61.7%) were indeed diagnosed with ADHD after two years. Initial scores of the teacher reported SNAP-IV inattention subscale predicted the ADHD diagnosis after two years, with an odds ratio of 1.0761 (p = 0.032, Wald: 4.595).
Conclusions
Our results suggest that high inattention symptom scores reported by the teacher in the earlier grades, might predict an ADHD diagnosis in upper grades.
Keywords: Attention deficit hyperactivity disorder, Age, Children, Elementary school, Persistence
https://authors.elsevier.com/c/1cRRS1OAg2736S
... The result that occurred most often (57.1%) was that the RAE on ADHD diagnosis or medication was similar for both sexes (Chen, Fortin, & Phipps, 2015;Chen et al., 2016;NHIS sample: Evans et al., 2010;Cohort 1: Halldner et al., 2014;Hoshen et al., 2016;Karlstad, Furu, Stoltenberg, Håberg, & Bakken, 2017;Morrow et al., 2012;Zoëga et al., 2012). One alternative conclusion reached (35.7%) was that the pattern of RAE on ADHD was stronger for boys (Bonati et al., 2018;MEPS sample: Evans et al., 2010; private insurance sample: Evans et al., 2010;Librero et al., 2015;Sayal et al., 2017). However, one study found that the RAE on ADHD was significant for girls but not for boys (Dee & Sievertsen, 2018). ...
... One study reported a consistent lack of RAE on ADHD regardless of the child's age (Dalsgaard et al., 2014). Four studies (40%) reported the hypothesized trend, wherein a stronger effect was observed in younger children (e.g., preschool and school-aged children) than older children (e.g., adolescents; Chen et al., 2016;NHIS sample: Evans et al., 2010;Cohort 1: Halldner et al., 2014;Sayal et al., 2017). However, three studies (30%) reported the opposite trend, wherein older children had a stronger RAE than younger children (MEPS sample: Evans et al., 2010;Karlstad et al., 2017;Pottegård et al., 2014). ...
One potential source contributing to the misdiagnosis and inappropriate treatment of attention deficit hyperactivity disorder (ADHD) could be as simple as a child’s age in relation to others in their grade. Studies indicate that children who are youngest in their grade are at greater risk of being diagnosed with, and medicated for, ADHD. The relative age effect (RAE), wherein younger people are described as less proficient relative to older members of the group, may explain these findings. This meta-analysis explored the overall effect of the RAE on ADHD in school-aged children. Twenty-six studies met eligibility criteria and 24 were included in the quantitative analysis. Results indicated that there is evidence that children who are the youngest in the class are significantly more likely to be diagnosed with ADHD and to be prescribed medication, SE = 0.09, t(8.87) = 16.0, p < .001. Implications of these findings on diagnostic and treatment practices for ADHD and school policy are discussed.
... Several studies show that children who are relatively younger compared to their classmates have a higher likelihood of receiving a diagnosis of ADHD. [4][5][6][7][8][9][10][11] These reports primarily reflect three types of data: epidemiological samples gathering registers of ADHD diagnosis; 4-6 epidemiological samples using registers of ADHD medication; 8,9 and clinical samples assessing relative immaturity within diagnosed children and adolescents; 10,11 With few exceptions, regardless of methodological differences, all those studies agree that being relatively younger within the school year is a risk factor for an ADHD diagnosis, but the estimates are variable, with risk ratios ranging from 0.96 to 2.43. Recent systematic reviews have confirmed that the effect of relatively younger age is consistently observed across different settings and methodologies. ...
... Overall, 25 studies with 30 samples were included in the meta-analysis (see Figure S1 and Table S2, available online). [4][5][6][8][9][10][11][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41] The main characteristics of the included studies are outlined in Table S3 (available online). ...
Objective:
To investigate the effect of relatively younger age on attention-deficit/hyperactivity disorder (ADHD) symptoms and diagnosis through three population-based cohorts and a meta-analysis.
Method:
This study included participants of three community-based cohorts in Brazil: 1993 Pelotas Cohort (N = 5,249), 2004 Pelotas Cohort (N = 4,231), and Brazilian High-Risk Study for Psychiatric Disorders (HRC study) (N = 2,511). We analyzed the effect of relatively younger age on ADHD symptoms and diagnosis. For the meta-analysis, we searched MEDLINE, PsycINFO, and Web of Science from inception through December 25, 2018. We selected studies that reported measures of association between relative immaturity and an ADHD diagnosis. We followed the Meta-analysis Of Observational Studies in Epidemiology guidelines. The protocol for meta-analysis is available on PROSPERO (CRD42018099966).
Results:
In the meta-analysis, we identified 1,799 potentially eligible records, from which 25 studies including 8,076,570 subjects (164,049 ADHD cases) were analyzed with their effect estimates. The summarized relative risk of an ADHD diagnosis was 1.34 (95% confidence interval 1.26-1.43, p < .001) for children born in the first 4 months of the school year (relatively younger). Heterogeneity was high (I2 = 96.7%). Relative younger age was associated with higher levels of ADHD symptoms in the 1993 Pelotas Cohort (p = .003), 2004 Pelotas Cohort (p = .046), and HRC study (p = .010).
Conclusion:
Children and adolescents who are relatively younger compared with their classmates have a higher risk of receiving an ADHD diagnosis. Clinicians should consider the developmental level of young children when evaluating ADHD symptoms.
... A recent review on over 300 published studies found convincing evidence of ADHD overdiagnosis and overtreatment in children and adolescents, especially on the milder end of the ADHD spectrum [13]. In Finland, younger relative age was associated with an increased risk of receiving a diagnosis and medication for ADHD [7,14], especially during the first school years (ages [6][7][8]. Furthermore, excessive exposure to screens [15][16][17][18][19][20] and shorter sleep duration during childhood [21] are known risk factors for inattentive or hyperactive symptoms. ...
Aims
This study examined the incidence of attention-deficit/hyperactivity disorder medication among children and adolescents by sex and age group in Finland during 2008–2019.
Methods
The data on children and adolescents aged 6–18 years receiving reimbursement for any attention-deficit/hyperactivity disorder medication was collected from the nationwide register on reimbursed purchases. The incidence was calculated as a ratio of the number of new users and the number of age and sex-matched population at risk. Negative binomial models were used to calculate rate ratios (RRs).
Results
In 2019, the incidence of attention-deficit/hyperactivity disorder medication was 13.4 per 1000 boys and 4.8 per 1000 girls. Among boys, the incidence became 3.7 times greater during the observed years (RR 95% confidence interval (CI) 2.0, 6.5, P<0.0001), whereas in girls it was 7.6 times greater (RR 95% CI 2.1, 27.4, P=0.0019). The boys had 2.8 times the incidence rate compared with the girls (RR 95% CI 2.2, 3.6, P<0.0001). The increase was associated with age only among boys ( P=0.0001). The highest incidence rate 23.4 per 1000 individuals (95% CI 22.5, 24.4) was found in 2019 among 6–8-year-old boys.
Conclusions
The incidence of attention-deficit/hyperactivity disorder medication use among children and adolescents increased significantly in Finland during the study period. Incidence was higher among boys, but the increase was greater among girls. The most common group to start attention-deficit/hyperactivity disorder medication was 6–8-year-old boys. These findings warrant critical evaluation of the diagnostic and treatment policies currently available in Finland for the treatment of attention-deficit/hyperactivity disorder and related symptoms.
... A meta-analysis of 25 studies, involving over eight million participants, revealed a distinctive pattern: children and adolescents who are relatively younger compared to their classmates are more likely of receiving an ADHD diagnosis (29). This finding is supported by other studies (30,31) highlighting the relative age effect on ADHD diagnosis, showing an increased proportion of younger children diagnosed in more recent birth cohorts. ...
The diagnosis of attention-deficit hyperactivity disorder (ADHD) is based on the presence of pervasive, persistent symptoms of inattention and/or hyperactivity/impulsivity typically emerging early in life and resulting in significant functional impairment. In contrast to a worldwide epidemiological prevalence of approximately 5% in children and 2–3% in adults, there are significant variations in the prevalence of administrative ADHD diagnoses and medication use. We assert that in order to explore the underlying dynamics of this phenomenon, a thorough understanding of the construct ADHD is necessary. We contend that ADHD is not a natural entity that unfolds within an individual and can be understood independent from societal and environmental factors, but rather that ADHD as a diagnosis can better be conceptualized as a valid and pragmatically useful social construct. Decisions to diagnose and treat ADHD should follow a person-centered approach and be focused on functional impairment within a socially constructed, context-dependent and environmentally contingent model.
... The follow-up diagnostic reassessment needed to have occurred after age 10 years (based on evidence that the relative age effect tends to decline after this age) and at least 4 years after the initial diagnostic assessment. 16 We did all statistical analyses in the R environment (version 4.1.1). To analyse the data of primary studies, we fitted, for each study, a logistic regression model assessing the association of relative age with persistence of ADHD at follow-up. ...
... The follow-up diagnostic reassessment needed to have occurred after age 10 years (based on evidence that the relative age effect tends to decline after this age) and at least 4 years after the initial diagnostic assessment. 16 We did all statistical analyses in the R environment (version 4.1.1). To analyse the data of primary studies, we fitted, for each study, a logistic regression model assessing the association of relative age with persistence of ADHD at follow-up. ...
Background The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.
... The follow-up diagnostic reassessment needed to have occurred after age 10 years (based on evidence that the relative age effect tends to decline after this age) and at least 4 years after the initial diagnostic assessment. 16 We did all statistical analyses in the R environment (version 4.1.1). To analyse the data of primary studies, we fitted, for each study, a logistic regression model assessing the association of relative age with persistence of ADHD at follow-up. ...
Background The youngest children in a school class are more likely than the oldest to be diagnosed with ADHD, but this relative age effect is less frequent in older than in younger school-grade children. However, no study has explored the association between relative age and the persistence of ADHD diagnosis at older ages. We aimed to quantify the association between relative age and persistence of ADHD at older ages.
... Girls born in the month prior to the cutoff date were 70% more likely to receive a diagnosis of ADHD than girls born in the month immediately afterwards. 13. Sayal et al. 2017 Databases (the Finnish Hospital Discharge Register and the Population Register Centre)/Finland Compared with the oldest boys in each school year (i.e., those born in the first four months after the cutoff date), the incidence ratio of ADHD diagnosis for the youngest boys in the school year (i.e., those born in the four months right before the cutoff date) was 1.26 (95% CI 1.18-1.35; p<.0001). ...
... In 50% of individuals diagnosed with ADHD, this condition persists into adulthood (Spencer et al. 2007). Manifestations related to ADHD can overwhelm the ability of affected individuals to develop social skills, to engage in school activities and to hold a job (Gallo and Posner 2016;Sayal et al. 2017). In addition, a substantial economic impact associated with ADHD has been reported. ...
Background:
This systematic review and meta-analysis aimed to answer the following question: Are children and adolescents with attention deficit hyperactivity disorder (ADHD) more likely to have gingival or periodontal disease-related outcomes than their non-ADHD peers?
Methods:
Searches were conducted in the following databases: Embase, Scopus, Web of Science, and PubMed. Google Scholar and OpenGrey were also verified. Observational studies were included in which children and adolescents with ADHD were compared with their healthy peers in terms of gingival and/or periodontal endpoints. Bias appraisal was performed using the Joann Briggs tool for case-control and cross-sectional studies. Meta-analysis was performed using R language. Results are reported as mean difference (MD) and odds ratio (OR). Statistical analyses were performed in RStudio.
Results:
A total of 149 records were identified in the searches. Seven studies were included. The meta-analysis showed that children and adolescents with ADHD had a higher mean gingival bleeding index (percentage) than their non-ADHD peers (MD = 11.25; CI = 0.08-22.41; I2 = 73%). There was no difference between groups for plaque index (MD = 4.87; CI = - 2.56 to 12.30; I2 = 63%) and gingivitis (OR = 1.42; CI = 0.22-9.21; I2 = 76%). Regarding the assessment of risk of bias, the major issue found in the articles was the absence of analyses for the control of confounding factors.
Conclusion:
Children and adolescents with ADHD had more gingival bleeding than their non-ADHD peers, but no difference regarding plaque or gingivitis was detected between groups.
Clinical registration:
CRD42021258404.
... Maternal and paternal ages were not related to hyperactivity and were not included in the final multivariable regression model Adjusted odds ratios (aORs) of ADHD as a factor of job stress were calculated, adjusting for gender, urban residence, birth order, birth season, autism spectrum disorder of the child, industry, occupation, and shiftwork schedules of the mothers' jobs occurrence of ADHD in children whose birthday was in the summer (June, July, or August). A plausible explanation for this phenomenon could be their relatively younger age within the same school year; in Taiwan, the youngest child in a school year has a birthday no later than August 31 (Chen et al. 2016;Layton et al. 2018;Sayal et al. 2017). Preterm birth and low birth weight did not be recognized as significant variables in the study. ...
Objective
Attention deficit hyperactivity disorder (ADHD) is the most common neurobehavioral disorders. Although studies have suggested relationships between ADHD in children and maternal psychosocial stress during pregnancy, little is known about the effects of work-related mental stress. Considering the increasing number of pregnant women who continue to work during the gestation period, this study investigated whether work-related stress during pregnancy is related to offspring ADHD.
Methods
The Taiwan Birth Cohort Study followed selected representative mother–infant pairs in a face-to-face interview since a child was 6 months old. A total of 10,556 working pregnant women who completed follow-up 8 years later were included. Whether the 8-year-old child had ever received a diagnosis of ADHD were inquired. Self-reported job stress during pregnant period was obtained 6 months after delivery. Factors including perinatal and socioeconomic factors as well as the mother’s job conditions were further analyzed with logistic regression.
Results
Among those who continued working during pregnancy, 3850 (36.5%) mothers reported having job stress during pregnancy, and 210 (2.0%) of the children were diagnosed as having ADHD before 8 years of age. Compared with mothers who reported no job stress, the adjusted odds ratio of child ADHD was 1.91 (95% CI 1.21–3.07) for mothers with “very stressful” jobs during pregnancy and 1.53 (95% CI 1.04–2.25) for mothers with “rather stressful” jobs.
Conclusion
Among pregnant female workers, higher levels of job stress were related to the higher occurrence of ADHD in their children.
... Current study revealed that age of the child is the significant negative predictor for their hyperactivity problems, i.e., hyperactivity decreases as child grows older. This finding is supported by studies conducted by Sayal et al. [23] and Caye et al. [24] which reported that younger children are more likely to receive a clinical diagnosis of ADHD. Study findings further reported that poor monitoring/supervision is the significant positive predictor of hyperactivity. ...
... In other words, the chance for diagnosis and treatment for ADHD of young children in the age group was greater than 19% of older children in the same age group. Researchers found similar results in other countries such as Norway (Karlstad et al., 2017) and Finland (Sayal et al., 2017). ...
... 9 These studies include very large cohort and register studies across many countries and continents, with varying ages of school entry and prescription rates. The Nordic register-based studies from Sweden, Finland, Norway, and Iceland all indicated significant relative age effects on ADHD, 4,11,13,14 but an exception is the Danish dataset that reported almost no relative age effect on medication use for ADHD. 15 The most likely explanation for the lack of a relative age effect in Denmark is the more flexible approach to school starting age, with a high proportion of relatively young children held back by 1 year. ...
Objective
Young relative age (ie, being among the youngest in a school class) and attention-deficit/hyperactivity disorder (ADHD) are both potential risk factors for adverse long-term outcomes. Young relative age also increases the risk of ADHD diagnosis. Using data from Swedish national registers, we investigate the independent and joint long-term effects of young relative age and ADHD on educational achievement, substance use disorder (SUD), criminality, and depression.
Method
We identified a national cohort of individuals with young relative age (born November−December) and a comparison group with old relative age (born January−February). Of the total sample of 297,840 individuals, 6,528 individuals had a diagnosis of ADHD in childhood. The 4 outcomes were measured at ages 15 to 23 years. We examined main, additive, and interactive effects of young relative age and ADHD on long-term outcomes.
Results
In the individuals without ADHD, young relative age was associated with increased risk of depression (odds ratio [OR] = 1.14 [95% CI =1.09−1.20]), SUD (OR = 1.14 [1.09−1.20]), and low educational achievement (OR = 1.17 [1.14−1.20]), but not criminality (OR = 1.00 [0.98−1.03]). In the individuals with ADHD, young relative age was associated with increased risk of SUD (OR = 1.23 [1.01−1.50]) and low educational achievement (OR = 1.12 [1.00−0.26]; CI included 1), but not depression or criminality (OR = 0.88 [0.73−1.07] and OR = 0.89 [0.79−1.01], respectively). An interaction emerged between young relative age and ADHD for depression (OR = 0.78 [0.64−0.95]).
Conclusion
We observed relative age effects that add to the evidence supporting a more flexible approach to school starting age and that emphasize the importance of careful age-match comparisons during assessment of childhood ADHD symptoms.
... 1,3,12,13 The effects of relative age on ADHD diagnosis and treatment have been reported in Western countries. 12,14 These reports accord with our findings based on the Taiwanese NHIRD. We further revealed the effect of relative age on DD diagnosis, which is commonly comorbid with ADHD. ...
Background
The effect of relative age on the diagnoses of attention deficit hyperactivity disorder (ADHD), disruptive behavior disorder (DD), anxiety disorder, and depressive disorder and the prescription for ADHD and antidepressant medications remains unclear.
Aim
To clarify the impact of relative age in a school year with the diagnoses of ADHD, DD, anxiety disorder and depressive disorder and the prescription for ADHD and antidepressant medications.
Methods
The annual cutoff birthdate for entry to school in Taiwan is August 31. The Taiwan National Health Insurance Research Database was used to enroll 9,548,393 children and adolescents aged 3–17 years during the study period (September 1, 2001, to August 31, 2011). The poisson regression model was performed to examine the likelihood of receiving diagnoses of ADHD, DD, anxiety disorder, and depressive disorder, as well as the prescription of ADHD and antidepressant medications among children born in August (the youngest) and September (the oldest).
Results
Both boys and girls born in August had a higher risk of being diagnosed as having ADHD (odds ratio [OR] = boys: 1.65, girls: 1.80), DD (1.29, 1.45), anxiety disorder (1.49, 1.33), and depressive disorder (1.10, 1.10). Furthermore, children born in August were more likely to be prescribed ADHD medication (1.71, 1.72) and antidepressants (1.18, 1.09) compared with those born in September.
Discussion
Relative age, as an indicator of neurocognitive maturity, is a critical factor for the likelihood of being diagnosed as having ADHD, DD, anxiety disorder, and depressive disorder among children and adolescents.
... Two population-based studies on relative age and ADHD examined the role of comorbid learning disorders. A Finnish register study (Sayal et al., 2017) found that comorbid learning and coordination disorders did not influence the relative age effect on being diagnosed with ADHD. An Italian study (The Lombardy ADHD Group, 2018) suggested similar results, but also found an increased number of neurodevelopmental and psychiatric diagnoses in children born later in the school year, regardless of whether they had comorbid ADHD. ...
Background: Being among the youngest in class has previously been associated with attention‐deficit/hyperactivity disorder (ADHD) and academic disadvantage, but the relative age effect on learning disorders is less well understood. This study examined whether relatively young children are more likely to be diagnosed with specific learning disorders than their older peers.
Methods: The setting included all 388,650 children born singleton in Finland from 1996 to 2002. Cases diagnosed with specific learning disorders in specialized health care by the age of 10 were identified from national registers. Cumulative incidences of specific learning disorders and the corresponding incidence rate ratios (IRRs) and 95% confidence intervals (CIs) were calculated for each birth month compared to January.
Results: During follow‐up, 3162 (0.8% of 388,650) children were diagnosed with a specific learning disorder. Children born in December displayed higher cumulative incidences for specific learning disorders than children born in January (IRR: 1.77, 95% CI: 1.50–2.11). The findings were similar for girls (IRR: 2.01, 1.44–2.83) and boys (IRR: 1.70, 1.39–2.08). ADHD did not explain the association, as the IRR for the youngest children with specific learning disorders and ADHD was 1.59 (1.13–2.26) compared to those without ADHD (IRR: 1.84, 1.51–2.24).
Conclusions: Relatively younger children in Finnish schools were more likely to be diagnosed with a specific learning disorder by the age of 10. Increased awareness of how relative age differences affect the likelihood for children to be diagnosed with specific learning disorders is needed among parents, clinicians, and teachers.
... This could predispose them to being bullied if they are reflected in the child's behaviour and the ability to create and maintain social relationships. It has been stated that any characteristics that set children apart from the group increases the likelihood of them being bullied. 2 The relative age effects found in mental health 10 and ADHD 12,13 have also been explained by differences in maturity 13,28,29 and cognitive and social skills 10 related to age. This is the first study which has assessed the impact that relative age had on whether children bullied others. ...
Aim
To assess whether relative age was associated with bullying involvement and whether the associations were independent of child psychiatric symptoms.
Methods
Bullying was assessed among 8576 children in the second grade, aged 8 years, by using four cross‐sectional population‐based studies with identical methodology completed by children, parents and teachers in 1989 (response rate 97%), 1999 (93%), 2005 (90%), and 2013 (86%). The main outcomes were bullying victimization and perpetration. Odds ratios (OR) and 95% confidence intervals (95% CI) were calculated with the relatively oldest as the reference group and adjusted for child psychiatric symptoms.
Results
The relatively youngest children, born September to December, were compared with the relatively oldest, born January to April. The youngest children had increased odds of being victims according to child (OR 1.2, 95% CI 1.1‐‐1.4) and parent reports (OR 1.2 95% CI 1.008‐‐1.4). The youngest also had decreased odds of being perpetrators according to child (OR 0.8, 95% CI 0.7‐‐0.96) and teacher reports (OR 0.8, 95% CI 0.7‐‐0.95). These findings were independent of psychiatric symptoms.
Conclusion
The relative age effects which were found in bullying involvement were independent of psychiatric symptoms. Considering this newly recognized risk factor for victimization is important within anti‐bullying practices.
... 7 Another identified factor in prescribing patterns is age compared to classroom peers, which has been demonstrated in Louisiana and internationally. 7,15,16 Beginning at age 6 in Louisiana, children with birthdays in September (the youngest children in the class) are 26% more likely to have an ADHD prescription than children born in October, 7 suggesting that classroom expectations influence treatment patterns. ...
Background: Attention-deficit/hyperactivity disorder (ADHD) is a common pediatric condition with significant developmental, social, educational, and safety implications. The American Academy of Pediatrics has developed guidelines to support quality care of children with ADHD, but studies demonstrate that the guidelines are variably followed.
Methods: This review highlights patterns of diagnosis and treatment of children with ADHD nationally and in Louisiana and provides examples of system- and practice-level opportunities to improve adherence to quality standards.
Results: Possible contributors to the higher prevalence of ADHD and medication use in Louisiana compared to the nation are specialty workforce shortages, factors in the educational system, and factors associated with race and geography. Innovative system approaches have been developed to address workforce shortages and training limitations. Practice-level innovations include improving the use of validated measures, offering adequate scheduling, and identifying relevant resources and sharing the information with families.
Conclusion: Despite the availability of evidence-based recommendations and resources, significant opportunities exist to provide enhanced ADHD care at the primary care level, especially in Louisiana where the high prevalence of some risk factors for ADHD and the high rates of ADHD and medication prescriptions have been noted nationally and at the state level. Attention to these factors can potentially help address these disproportionalities. Additionally, innovative models of training and collaboration in pediatrics are imperative. Pediatric clinicians, mental health providers, and families can work together to increase awareness about the needs of children and families affected by ADHD in medical, educational, and policy arenas and move the system forward for children.
... While some of this variation may be explained by differences in underlying prevalence such as boys being predisposed to ADHD or low-income settings exacerbating ADHD symptoms, it is difficult to account for most of the observed large diagnosis rate gaps. The fact that children who are young for their grade are much more likely to be diagnosed and treated for ADHD is an excellent example of the inherently subjective nature of diagnosis for this disorder (Chen et al. 2016;Elder and Lubotsky 2009;Elder 2010;Evans et al. 2010;Hoshen et al. 2016;Layton et al. 2018;Morrow et al. 2012;Karlstad et al. 2017;Sayal et al. 2017;Schwandt and Wuppermann 2016;Whitely et al. 2017). We believe we are the first to demonstrate that a non-traditional family structure is similarly associated with a much larger likelihood of diagnosis for boys and girls, a much higher medication rate for boys, and a substantially larger gender gap for both diagnosis and medication. ...
We document the large, excess male-female gap in ADHD diagnosis and treatment rates for non-traditional families. Pre-teen boys in traditional families are 2.9 percentage points more likely to have been medicated for ADHD in the past two years than girls in traditional families, while the same gap for non-traditional families is 5.4 percentage points. We also document a similar pattern of boys in non-traditional families for ADHD-related outcomes such as attention span, learning disability, emotional difficulties and unhappiness. Examining alternative pathways to family structure, we rule out typical forms of disadvantage but find that school policies may interact with family structure to increase the male ADHD diagnosis and medication gap. We also highlight an important limitation of the family fixed effects models often used in family structure research, showing that the largest effects are for only children.
... Tanto la prevalencia como el tratamiento farmacológico asociado son ampliamente heterogéneos en función de múltiples factores. Alguno, como la correlación del diagnóstico con el mes de nacimiento del individuo (3,4), sorprende y cuestiona su propia validez. También se ha descrito que entre los alumnos favorecidos desde un punto de vista socioeconómico hay mayor probabilidad de utilizar fármacos para el TDAH durante el periodo escolar (5). ...
Objective: To carry out an in-depth analysis of the evolution and current management
of ADHD, paying attention to the neurobiological model narrative, statistical
data, information on drug efficacy and safety, trends in adult population and non-pharmacological alternatives.
Methods: A bibliographical search was carried out (December 2017) on ADHD and associated trends through Medline and the Cochrane Library. Clinical practice guidelines (NICE, Spanish guideline), regulatory agencies databases (Spanish Medicines Agency, EMA, FDA) and other complementary sources of information (drug bulletins, news media, websites) were also explored. Moreover, data on drug prescription and national consumption were requested from the Health Department of Navarre and the Department of Basic Common Services Portfolio (Ministry of Health).
Results/Conclusions: ADHD is a phenomenon of variable prevalence and increasing drug consumption. The evolution of the ADHD concept has constantly changed in a substantial way and its etiology remains unknown. Arguments in favour of a biologic hypothesis lack consistency and no reliable biological markers have been found. Symptom-based scales are poorly correlated with relevant dysfunction outcomes. More and better designed research studies are expected on non-pharmacological therapies, playing behavioural therapy a lead role because of its potential usefulness. Drug treatment might provide some efficacy in the short term, with no clear improvement in long term relevant outcomes. While adults are increasingly diagnosed and treated for ADHD, methylphenidate seems to be gradually replaced by lisdexamfetamine. Cardiovascular, psychiatric and endocrine adverse events should be closely monitored. According to a prudence-based medicine approach, drugs should always be considered as a short and exceptional help.
BACKGROUND AND OBJECTIVES
Being among the youngest within a school class is linked to disadvantages in various educational and mental health domains. This study aimed to investigate whether preterm born infants are particularly vulnerable to relative age effects on mental health, not previously studied.
METHODS
We used registry data on all Norwegians born between 1989 and 1998 to compare prescription status for psychostimulants, antidepressants, hypnotics, anxiolytics, and antipsychotics per year from age 10 to 23 years (2004-2016) between exposure groups with different time of birth in the year (relative age) and different gestational age (preterm versus term).
RESULTS
Of 488 470 individuals, 29 657 (6,1%) were born preterm. For term born in November/December, the adjusted odds ratio (aORs) for psychostimulant prescription compared with peers born in January/February was 1.80 (95% confidence interval [CI], 1.69–1.91) at ages 10 to 14 years, and 1.17 (95% CI, 1.08-1.27) at ages 20 to 23 years. Within preterm born, the corresponding results were 1.39 (95% CI, 1.13-1.69) and 1.34 (95% CI, 1,00–1.78) at ages 10 through 14 and 20 through 23 years, respectively.
CONCLUSIONS
Being relatively young within the school group was associated with increased psychostimulant prescription in the preterm as well as the term population. In contrast to term peers, the relative age effect for psychostimulant prescription seemed to persist to young adulthood for the preterm population. The results suggest that preterm individuals are vulnerable to long-term effects of relative immaturity and that they require careful consideration from both health care professionals and the school system.
Background: Children who are relatively young for their school grade are more likely to receive treatment for attention-deficit/hyperactivity disorder (ADHD). It is unclear whether the phenomenon also exists across Australia or is impacted by the school enrolment policy in place. Objective: We evaluated the association between children's relative age and initiation of ADHD medicines across Australian jurisdictions with different school enrolment policies and rates of delayed school entry. Methods: We used Australia-wide dispensing data for a 15% random sample of children 4-9 years of age in 2013-2017 to create a nationwide cohort. Due to high rates of delayed school entry in New South Wales (NSW), we used linked prescribing and education data for a cohort of NSW residents starting school in 2009 and 2012. We estimated incidence rate ratios (IRRs) for ADHD medicine across children's birth month, sex, and jurisdiction. We used asthma medicines as a negative control. Results: For girls, we observed a relative age effect in three out of five jurisdictions, with an IRR ranging from 1.3 to 2.8, comparing the youngest versus oldest birth month thirds. We observed more modest effects among boys, ranging from null to 1.5-fold. In NSW, the relatively youngest boys were less likely to initiate stimulant medicines than the oldest (IRR = 0.5, 95% confidence interval 0.29-0.78). We did not observe a relative age effect for initiation of asthma medicines. Conclusions: In jurisdictions with low rates of delayed entry, relatively young children were more likely to initiate ADHD medicines than their older classmates. We observed the inverse association in NSW where delayed entry was highest, likely reflecting the characteristics and needs of children who delay school entry for 1 year and become the oldest children in the grade. Increased awareness around children's maturity differences and school readiness may enhance appropriate diagnosis and treatment of ADHD.
Background
Previous studies suggest an association between age within schoolyear and attention-deficit hyperactivity disorder (ADHD). Scotland and Wales have different school entry cut-off dates (six months apart) and policies on holding back children. We aim to investigate the association between relative age and treated attention deficit hyperactivity disorder (ADHD) in two countries, accounting for held-back children.
Methods
Routine education and health records of 1,063,256 primary and secondary schoolchildren in Scotland (2009–2013) and Wales (2009–2016) were linked. Logistic regression was used to examine the relationships between age within schoolyear and treated ADHD, adjusting for child, maternity and obstetric confounders.
Results
Amongst children in their expected school year, 8,721 (0.87%) had treated ADHD (Scotland 0.84%; Wales 0.96%). In Wales, ADHD increased with decreasing age (youngest quartile, adjusted OR 1.32, 95% CI 1.19–1.46) but, in Scotland, it did not differ between the youngest and oldest quartiles. Including held-back children in analysis of their expected year, the overall prevalence of treated ADHD was 0.93%, and increased across age quartiles in both countries. More children were held back in Scotland (57,979; 7.66%) than Wales (2,401; 0.78%). Held-back children were more likely to have treated ADHD (Scotland OR 2.18, 95% CI 2.01–2.36; Wales OR 1.70, 95% CI 1.21–2.31) and 81.18% of held-back children would have been in the youngest quartile of their expected year.
Conclusions
Children younger within schoolyear are more likely to be treated for ADHD, suggesting immaturity may influence diagnosis. However, these children are more likely to be held back in countries that permit flexibility, attenuating the relative age effect.
Background:
Attention deficit hyperactivity disorder (ADHD) is a psychiatric diagnosis increasingly used in adults. The recommended first-line pharmacological treatment is central nervous system (CNS) stimulants, such as methylphenidate, but uncertainty remains about its benefits and harms.
Objectives:
To assess the beneficial and harmful effects of extended-release formulations of methylphenidate in adults diagnosed with ADHD.
Search methods:
We searched CENTRAL, MEDLINE, Embase, nine other databases and four clinical trial registries up to February 2021. We searched 12 drug regulatory databases for clinical trial data up to 13 May 2020. In addition, we cross-referenced all available trial identifiers, handsearched reference lists, searched pharmaceutical company databases, and contacted trial authors.
Selection criteria:
Randomised, double-blind, parallel-group trials comparing extended-release methylphenidate formulations at any dose versus placebo and other ADHD medications in adults diagnosed with ADHD.
Data collection and analysis:
Two review authors independently extracted data. We assessed dichotomous outcomes as risk ratios (RRs), and rating scales and continuous outcomes as mean differences (MDs) or standardised mean differences (SMDs). We used the Cochrane risk of bias tool to assess risks of bias, and GRADE to assess the certainty of the evidence. We meta-analysed the data using a random-effects model. We assessed three design characteristics that may impair the trial results' 'generalisability'; exclusion of participants with psychiatric comorbidity; responder selection based on previous experience with CNS stimulants; and risk of withdrawal effects. Our prespecified primary outcomes were functional outcomes, self-rated ADHD symptoms, and serious adverse events. Our secondary outcomes included quality of life, ADHD symptoms rated by investigators and by peers such as family members, cardiovascular variables, severe psychiatric adverse events, and other adverse events.
Main results:
We included 24 trials (5066 participants), of which 21 reported outcome data for this review. We also identified one ongoing study. We included documents from six drug regulatory agencies covering eight trials. Twenty-one trials had an outpatient setting and three were conducted in prisons. They were primarily conducted in North America and Europe. The median participant age was 36 years. Twelve trials (76% of participants) were industry-sponsored, four (14% of participants) were publicly funded with industry involvement, seven (10% of participants) were publicly funded, and one had unclear funding. The median trial duration was eight weeks. One trial was rated at overall unclear risk of bias and 20 trials were rated at overall high risk of bias, primarily due to unclear blinding of participants and investigators, attrition bias, and selective outcome reporting. All trials were impaired in at least one of the three design characteristics related to 'generalisability'; for example, they excluded participants with psychiatric comorbidity such as depression or anxiety, or included participants only with a previous positive response to methylphenidate, or similar drugs. This may limit the trials' usefulness for clinical practice, as they may overestimate the benefits and underestimate the harms. Extended-release methylphenidate versus placebo (up to 26 weeks) For the primary outcomes, we found very low-certainty evidence that methylphenidate had no effect on 'days missed at work' at 13-week follow-up (mean difference (MD) -0.15 days, 95% confidence interval (CI) -2.11 to 1.81; 1 trial, 409 participants) or serious adverse events (risk ratio (RR) 1.43, CI 95% CI 0.85 to 2.43; 14 trials, 4078 participants), whereas methylphenidate improved self-rated ADHD symptoms (small-to-moderate effect; SMD -0.37, 95% CI -0.43 to -0.30; 16 trials, 3799 participants). For secondary outcomes, we found very low-certainty evidence that methylphenidate improved self-rated quality of life (small effect; SMD -0.15, 95% CI -0.25 to -0.05; 6 trials, 1888 participants), investigator-rated ADHD symptoms (small-to-moderate effect; SMD -0.42, 95% CI -0.49 to -0.36; 18 trials, 4183 participants), ADHD symptoms rated by peers such as family members (small-to-moderate effect; SMD -0.31, 95% CI -0.48 to -0.14; 3 trials, 1005 participants), and increased the risk of experiencing any adverse event (RR 1.27, 95% CI 1.19 to 1.37; 14 trials, 4214 participants). We rated the certainty of the evidence as 'very low' for all outcomes, primarily due to high risk of bias and 'indirectness of the evidence'. One trial (419 participants) had follow-up at 52 weeks and two trials (314 participants) included active comparators, hence long-term and comparative evidence is limited.
Authors' conclusions:
We found very low-certainty evidence that extended-release methylphenidate compared to placebo improved ADHD symptoms (small-to-moderate effects) measured on rating scales reported by participants, investigators, and peers such as family members. Methylphenidate had no effect on 'days missed at work' or serious adverse events, the effect on quality of life was small, and it increased the risk of several adverse effects. We rated the certainty of the evidence as 'very low' for all outcomes, due to high risk of bias, short trial durations, and limitations to the generalisability of the results. The benefits and harms of extended-release methylphenidate therefore remain uncertain.
Background
Attention-Deficit/ Hyperactivity Disorder (ADHD) is one of the most common childhood neurobehavioral conditions. Symptoms related to this disorder cause a significant impairment in school tasks and in the activities of children’s daily lives; an early diagnosis and appropriate treatment could almost certainly help improve their outcomes.
The current study, part of the Models Of Child Health Appraised (MOCHA) project, aims to explore the age at which children experience the onset or diagnosis of ADHD in European countries.
Methods
A systematic review was done examining the studies reporting the age of onset/diagnosis (AO/AD) of ADHD in European countries (28 European Member States plus 2 European Economic Area countries), published between January 1, 2010 and December 31, 2019. Of the 2276 identified studies, 44 met all the predefined criteria and were included in the review.
Results
The lowest mean AO in the children diagnosed with ADHD alone was 2.25 years and the highest was 7.5 years. It was 15.3 years in the children with ADHD and disruptive behaviour disorder. The mean AD ranges between 6.2 and 18.1 years.
Conclusions
Our findings indicate that there is a wide variability in both the AO and AD of ADHD, and a too large distance between AO and AD. Since studies in the literature suggest that an early identification of ADHD symptoms may facilitate early referral and treatment, it would be important to understand the underlying reasons behind the wide variability found.
Trial registration
PROSPERO registration: CRD42017070631 .
(1) Background: Attention deficit hyperactivity disorder (ADHD) constitutes one of the leading mental health and behavioral disorders in childhood and adolescence. The main objective of this study was to analyze the time trend in the incidence of ADHD diagnoses in Navarre (Spain) from 2003 to 2019 in children and adolescents from 5 to 19 years old. Additionally, the seasonal trends of ADHD incidence and ADHD prevalence were determined. (2) Methods: A population-based observational retrospective study, which included people born between 1991 and 2011 and who attended compulsory education between 2007 and 2017 in Navarre (Spain), was carried out with data from both the Education and Health Department databases. (3) Results: The incidence rate increased from 4.18 cases per 1000 person-years in 2003 to 7.43 cases per 1000 person-years in 2009, before decreasing progressively to 2.1 cases per 1000 person-years in 2019. A peak incidence rate at 7–8 years of age was observed, which is consistent across the study period and for both genders. Males were more than twice as likely to be diagnosed with ADHD than females, with similar time trends in both. A seasonal pattern in ADHD diagnosis was found, with peaks in February–March and the lowest rates in the summer months. Inattentive cases were much more frequent than hyperactive cases, whereas combined cases remained low across the study period. (4) Conclusions: In this age-period-cohort analysis, a clear period and age effect was observed. We found a decreasing trend in the ADHD incidence rate since 2015. Further research is needed to confirm whether a change of trend is occurring globally.
Objective: Relative age refers to a difference in age between peers in the same academic year. Although younger age of alcohol use is associated with a higher risk of lifetime problematic alcohol use, the potential effects of relative age are poorly understood. We hypothesized that a younger relative age would be associated with a younger chronological age of testing positive for alcohol in a medical setting. Methods: Problematic alcohol use was operationalized and identified as a positive alcohol test (PAT) in a medical setting. This was a retrospective population study of all 12 to 18-year-old residents (n = 4610) of Olmsted County, Minnesota (USA), who were tested for alcohol in a medical care setting from 1998 through 2016. Cox regression models examined the relationship between relative age and the age at testing positive for alcohol. Results: Relative age was not associated with age at first PAT. Results remained nonsignificant after stratifying by gender, and after adjusting for race, number of nonalcohol-related psychiatric comorbidities, and type of alcohol testing. Conclusions: The results did not support a relative age effect as a risk factor for alcohol use in adolescents in Olmsted County, Minnesota. These results contrast with findings from previous studies on this topic, which suggested older relative age increases risk of alcohol use in adolescence.
Importance
Reported increases in attention-deficit/hyperactivity disorder (ADHD) diagnoses are accompanied by growing debate about the underlying factors. Although overdiagnosis is often suggested, no comprehensive evaluation of evidence for or against overdiagnosis has ever been undertaken and is urgently needed to enable evidence-based, patient-centered diagnosis and treatment of ADHD in contemporary health services.
Objective
To systematically identify, appraise, and synthesize the evidence on overdiagnosis of ADHD in children and adolescents using a published 5-question framework for detecting overdiagnosis in noncancer conditions.
Evidence Review
This systematic scoping review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Extension for Scoping Reviews and Joanna Briggs Methodology, including the PRISMA-ScR Checklist. MEDLINE, Embase, PsychINFO, and the Cochrane Library databases were searched for studies published in English between January 1, 1979, and August 21, 2020. Studies of children and adolescents (aged ≤18 years) with ADHD that focused on overdiagnosis plus studies that could be mapped to 1 or more framework question were included. Two researchers independently reviewed all abstracts and full-text articles, and all included studies were assessed for quality.
Findings
Of the 12 267 potentially relevant studies retrieved, 334 (2.7%) were included. Of the 334 studies, 61 (18.3%) were secondary and 273 (81.7%) were primary research articles. Substantial evidence of a reservoir of ADHD was found in 104 studies, providing a potential for diagnoses to increase (question 1). Evidence that actual ADHD diagnosis had increased was found in 45 studies (question 2). Twenty-five studies showed that these additional cases may be on the milder end of the ADHD spectrum (question 3), and 83 studies showed that pharmacological treatment of ADHD was increasing (question 4). A total of 151 studies reported on outcomes of diagnosis and pharmacological treatment (question 5). However, only 5 studies evaluated the critical issue of benefits and harms among the additional, milder cases. These studies supported a hypothesis of diminishing returns in which the harms may outweigh the benefits for youths with milder symptoms.
Conclusions and Relevance
This review found evidence of ADHD overdiagnosis and overtreatment in children and adolescents. Evidence gaps remain and future research is needed, in particular research on the long-term benefits and harms of diagnosing and treating ADHD in youths with milder symptoms; therefore, practitioners should be mindful of these knowledge gaps, especially when identifying these individuals and to ensure safe and equitable practice and policy.
Making a diagnosis is a fundamental part of child and adolescent psychiatry that facilitates communication and provision of care. The International Classification of Diseases and the Diagnostic and Statistical Manual of Mental Disorders codify universal definitions of mental disorders and provide operationalized criteria that improve their reliability. However, diagnoses of mental disorders do not reflect distinct entities with known causes. Many mental disorders lie on a continuum and cannot be unambiguously separated from normality or from one another. Comorbidity, heterogeneity, overspecification, overdiagnosis, and stigma have emerged as major challenges to the use of current diagnostic systems. Prototypic diagnoses and dimensional systems have been proposed as alternatives. Yet, a universal categorical system is necessary to support clinical decisions and effective communication. The present systems are imperfect but useful. Appropriate diagnosis makes it more likely that patients receive treatments from which they will benefit. Universality and continuity of diagnostic systems facilitate discoveries and enable evidence-based treatment. This chapter provides a summary of knowledge supporting the use of the present diagnostic systems and provides guidance on using diagnostic categories for the benefit of patients.
The Routledge International Handbook of Global Therapeutic Cultures explores central lines of enquiry and seminal scholarship on therapeutic cultures, popular psychology, and the happiness industry. Bringing together studies of therapeutic cultures from sociology, anthropology, psychology, education, politics, law, history, social work, cultural studies, development studies, and American Indian studies, it adopts a consciously global focus, combining studies of the psychologisation of social life from across the world. Thematically organised, it offers historical accounts of the growing prominence of therapeutic discourses and practices in everyday life, before moving to consider the construction of self-identity in the context of the diffusion of therapeutic discourses in connection with the global spread of capitalism. With attention to the ways in which emotional language has brought new problematisations of the dichotomy between the normal and the pathological, as well as significant transformations of key institutions, such as work, family, education, and religion, it examines emergent trends in therapeutic culture and explores the manner in which the advent of new therapeutic technologies, the political interest in happiness, and the radical privatisation and financialisation of social life converge to remake self-identities and modes of everyday experience. Finally, the volume features the work of scholars who have foregrounded the historical and contemporary implication of psychotherapeutic practices in processes of globalisation and colonial and postcolonial modes of social organisation. Presenting agenda-setting research to encourage interdisciplinary and international dialogue and foster the development of a distinctive new field of social research, The Routledge International Handbook of Global Therapeutic Cultures will appeal to scholars across the social sciences with interests in the advance of therapeutic discourses and practices in an increasingly psychologised society.
Background
Attention-deficit hyperactivity disorder (ADHD) is one of the most common neurobehavioral disorders in childhood globally. Between the two components of ADHD, hyperactivity disorder is more prevalent than inattention during early childhood. Although some investigations have implied a relationship between childhood ADHD and gestational exposure to air pollution, the evidence is limited. The aim of this study was to investigate the association between gestational exposure to air pollution exposure and hyperactivity disorder in childhood in a population-based birth cohort.
Methods
The Taiwan Birth Cohort Study started from all deliveries of Taiwan in 2005 by the birth registry, and recruited representative 12% of all mother–infant pairs by two-stage stratified sampling. At age of 8 years in each child, their main caretaker was inquired whether the child had ever received a hyperactivity diagnosis from a physician or other specialist, like special needs educator. Exposure to air pollutants during gestation was estimated through ordinary kriging based on data from air monitoring stations of Environmental Protection Administration, Taiwan. Logistic regression was used to determine adjusted odds ratios (aORs) of hyperactivity disorder in relation to air pollutants.
Results
A total of 16,376 mother–infant pairs were included in the final analysis; 374 (2.3%) of the children had received a diagnosis of hyperactivity before 8 years of age. The occurrence of hyperactivity was significantly related to prenatal nitrogen oxide (NOx), but not to particulate matter 10 μm or less in diameter or sulfur dioxide. Further analysis to separate effects by nitrogen dioxide (NO2) and/or nitrogen monoxide (NO) showed that only NO was significantly related to hyperactivity [aOR per interquartile range (3.14 ppb): 1.26, 95% confidence interval: 1.09–1.46].
Conclusions
In conclusion, our study found childhood hyperactivity disorder to be positively associated with prenatal NO exposure. Further confirmation on potential hazardous effects of NO and investigation on potential mechanisms are warranted.
ADHD diagnoses are increasing worldwide, in patterns involving both overdiagnosis of some groups and underdiagnosis of others. The current study uses data from a national longitudinal study of Irish children (N = 8568) to examine the sociodemographic, clinical and psychological variables that differentiate children with high hyperactivity/inattention symptoms, who had and had not received a diagnosis of ADHD. Analysis identified no significant differences in the demographic characteristics or socio-emotional wellbeing of 9-year-olds with hyperactivity/inattention who had and who had not received a diagnosis of ADHD. However, by age 13, those who had held a diagnosis at 9 years showed more emotional and peer relationship problems, worse prosocial behaviour, and poorer self-concept. Further research is required to clarify the developmental pathways responsible for these effects.
A number of worldwide studies have demonstrated that children born later in the school year are more likely to receive an ADHD diagnosis than their same school-year peers. There is, however, variation in findings between countries. We aimed to confirm whether relative age is associated with ADHD diagnosis, with or without comorbidities, and to investigate whether relative age is associated with ADHD type and severity, and if this age relationship is in common with other neurodevelopmental disorder. We used the Lombardy Region’s ADHD registry. Data on children aged 6 years and older from September 1, 2011 to December 31, 2017 were considered. We calculated incidence ratios to assess the inter-relations between relative age within the school year, using age at diagnosis of ADHD or of other psychiatric disorder, year of diagnosis, and total number of children born in Lombardy during the corresponding timeframe. Data on ADHD type, severity of diagnosed disorder clinical global impressions–severity scale, and repetition of a school-grade were also considered. 4081 children, 2856 of whom with ADHD, were identified. We confirmed that the cumulative incidence of ADHD diagnosis was greatest for younger children, in particular for boys, for whom the prevalence is greater. The relative age effect was not accounted for by ADHD comorbid disorders, ADHD of combined type or severity. The relative age effect was also observed for children with other neurodevelopmental disorders (without ADHD), with a similar profile as ADHD children: the incidence ratio was 1.78 (95% CI 1.07–2.97; p < 0.0247) for boys diagnosed before age ten. The findings have a potential implication for diagnostic and therapeutic practice, educational advice, and policies, besides to better plan and organize service systems and appropriately inform parents, children, and citizens.
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common childhood behavioural disorder – systematic reviews indicate that the community prevalence of ADHD globally is between 2% to 7%, with an average of around 5%. In addition, a further 5% of children have significant difficulties with over-activity, inattention and impulsivity that are just sub-threshold to meet full diagnostic criteria for ADHD. Estimates of the administrative (clinically diagnosed and/or recorded) prevalence vary worldwide and although increasing over time, ADHD is still relatively under-recognised and under-diagnosed in most countries, particularly in girls and older children. ADHD often persists into adulthood and is a risk factor for other mental health disorders and negative outcomes including educational under-achievement, difficulties with employment and relationships, and criminality. The timely recognition and treatment of children with ADHD-type difficulties provides an opportunity to improve their long-term outcomes. This review includes a systematic review of the community and administrative prevalence of ADHD in children and adolescents; an overview of the barriers to accessing care for ADHD; a description of costs associated with ADHD; and a broad discussion of evidence-based pathways for the delivery of clinical care, including a focus on key issues for two specific age groups - pre-school children and adolescents requiring transition of care from child to adult services.
Background
Prenatal smoking exposure has been associated with attention-deficit/hyperactivity disorder (ADHD). ADHD is commonly associated with a wide spectrum of psychiatric comorbidity. The association between smoking and neuropsychiatric comorbidity of ADHD has remained understudied. The aim of this study is to examine the association between prenatal exposure to maternal smoking and offspring ADHD, and test whether the smoking-ADHD associations are stronger when ADHD is accompanied by other lifetime neuropsychiatric comorbidities. Methods
The study is based on a nested case-control design and includes all Finnish singletons born between 1991 and 2005 and diagnosed with ADHD by 2011 (n = 10,132), matched with four controls (n = 38,811) on date of birth, sex and residence in Finland. ResultsThe risk for ADHD with or without comorbidity was significantly increased among offspring exposed to maternal smoking on adjusting for potential confounders (OR = 1.75, CI 95 % = 1.65–1.86). Compared to the only ADHD cases, subjects with comorbid conduct disorder or oppositional defiant disorder had a significantly stronger association with smoking exposure (OR = 1.80, CI 95 % = 1.55–2.11). Conclusions
Prenatal smoking represents an important risk factor for the ADHD comorbid with CD/ODD. Further research on the association between prenatal smoking exposure and neuropsychiatric comorbidity of ADHD is needed considering the increased risk among these subjects of an overall poor health outcome as compared to only ADHD. In particular, studies utilizing biomarkers or including subjects with neuropsychiatric conditions with and without comorbid ADHD are needed.
Recent studies have shown an increasing incidence of attention-deficit/hyperactivity disorder (ADHD) among children diagnosed in specialized services. This study aims to describe children with ADHD in Finnish specialized healthcare by reporting the demographic characteristics, time trends in diagnosis, psychiatric comorbidity, and the validity of register-based diagnoses. All the singletons born in Finland between 1991 and 2005 and diagnosed with ADHD by 2011 were identified and their psychiatric comorbidity data was obtained from the Finnish Hospital Discharge Register (FHDR). Parents of 69 patients were interviewed via telephone for a diagnostic validation. A total of 10,409 children were identified with ADHD, with a male: female ratio of 5.3:1 and a psychiatric comorbidity rate of 76.7 %. Of the validation sample 88 % met the diagnostic criteria of ADHD for DSM-IV. There is an increasing trend of ADHD diagnosis among both males and females. Psychiatric comorbidity is common and includes a wide range of disorders among children with ADHD. There was an increase of ADHD diagnoses especially among boys. More attention is needed to detect ADHD among girls in health services. Diagnoses in the FHDR show diagnostic validity and their sociodemographic patterns are in line with previous studies.
An increasing number of studies has shown an association between parental age and psychiatric disorders. However, there are inconsistent results regarding whether age at parenthood is associated with attention-deficit/hyperactivity disorder (ADHD). The aim of this study is to examine whether low or advanced parental age is associated with ADHD.
In this nested case-control study, we identified 10,409 individuals with ADHD born in Finland during 1991 to 2005 and diagnosed with ADHD between 1995 and 2011, along with 39,125 controls matched on sex, date, and place of birth, from nationwide population-based registers. Conditional logistic regression was used to examine the association between parental age and ADHD in offspring, adjusting for potential confounding due to parental psychiatric history, maternal socioeconomic status, marital status, maternal smoking during pregnancy, number of previous births, and birth weight for gestational age.
Fathers younger than 20 years had a 1.5-fold (odds ratio [OR] = 1.55, 95% CI = 1.11-2.18, p = .01) increased risk of having offspring with ADHD as compared to fathers aged 25 to 29 years. Mothers of the same age group had a 1.4-fold (OR = 1.41, 95% CI = 1.15-1.72, p =.0009) increased risk. Advanced maternal age was inversely associated with ADHD (OR = 0.79, 95% CI = 0.64-0.97, p = .02).
ADHD was associated with young fathers or mothers at the time of birth. Health professionals working with young parents should be aware of the increased risk of ADHD in offspring. This will improve early detection; however, for the development of preventive measures and appropriate interventions, more information on the developmental pathways is needed.
Copyright © 2015 American Academy of Child and Adolescent Psychiatry. Published by Elsevier Inc. All rights reserved.
Attention-Deficit/Hyperactivity Disorder (ADHD) is a common neurodevelopmental disorder starting in childhood that may persist into adulthood. It can be managed through carefully monitored medication and nonpharmacological interventions. Access to care for children at risk of ADHD varies both within and between countries. A systematic literature review was conducted to investigate the research evidence related to factors which influence children accessing services for ADHD.
Studies investigating access to care for children at risk of ADHD were identified through electronic searches of the international peer-reviewed and grey literature. Databases were searched from inception till 30th April 2012. This identified 23,156 articles which were subjected to three levels of screening (title, abstract and full text) by a minimum of two independent reviewers. Due to the heterogeneity in the study designs, a narrative approach was used to present the findings.
Twenty-seven papers met the inclusion criteria; these were grouped into four main themes, with some papers being included in more than one. These were wider determinants (10 papers); identification of need (9 papers); entry and continuity of care (13 papers) and interventions to improve access (4 papers). Barriers and facilitators to access were found to operate at the individual, organisational and societal level. Limited evidence of effective interventions to improve access was identified.
This review explored the multilayered obstacles in the pathway to care for children at risk of ADHD and the lack of evidence-based interventions designed to address these issues, thereby indicating areas for service development and further evaluative research.
© 2015 Association for Child and Adolescent Mental Health.
Background
Previous studies from North America and Iceland have shown that the youngest children within a grade are up to twice as likely to be diagnosed and treated for attention-deficit/hyperactivity disorder (ADHD) compared with their older classmates. We aimed to investigate whether younger age in class is associated with an increased probability of being prescribed medication for ADHD among school-aged children in Denmark.Methods
We followed all Danish children between 2000 and 2012 from 1st through 6th grade (7–12 years). Among children who started school on their age-assigned grade level, we estimated the prevalence proportion ratio (PPR) of receiving ADHD medication between the youngest children in class (born in October–December) and the oldest in class (born in January–March), specified by grade level, calendar year and gender. As a sensitivity analysis, we added children not on their age-assigned grade level to the main calculations.ResultsWe identified 932,032 eligible children for the main analysis, of whom 17.3% were among the youngest and 26.5% among the oldest in class. In total, 1.2% eligible children filled at least one prescription for ADHD medication in 2000–2012. The average PPR over the study period was 1.08 (95% CI, 1.04–1.12) and remained stable across subgroups and sensitivity analyses. Overall, 40% of children born October–December had entered school a year after their age-assigned grade level.Conclusions
Contrary to previous study results, we observed almost no relative age effect on medication use for ADHD among children in Denmark. We postulate that this may be due to the high proportion of relatively young children held back by 1 year in the Danish school system and/or a generally low prevalence of ADHD medication use in the country.
Assessing whether symptoms of attention-deficit hyperactivity disorder (ADHD) in children are age-inappropriate is essential. Hence, comparing children within one school grade is problematic and the risk of applying relative standards is inherent. Being young-for-grade increases the likelihood of receiving medication in countries with high prevalence of ADHD medication. We test the same hypothesis in a cohort of 418,396 children and find no difference between children who are young-for-grade and old-for-grade. The Danish system, with its restrictive approach to medication and clear diagnostic guidelines seems to have avoided a systematic bias of ADHD medication in young children reported in other countries.
#### Summary box
Prevalence and prescribing rates for attention-deficit/hyperactivity disorder (ADHD) have risen steeply over the past decade, partly in response to concerns about underdiagnosis and undertreatment.1 2 But although clinicians have become better …
The annual cut-off date of birth for entry to school in British Columbia, Canada, is Dec. 31. Thus, children born in December are typically the youngest in their grade. We sought to determine the influence of relative age within a grade on the diagnosis and pharmacologic treatment of attention-deficit/hyperactivity disorder (ADHD) in children.
We conducted a cohort study involving 937 943 children in British Columbia who were 6-12 years of age at any time between Dec. 1, 1997, and Nov. 30, 2008. We calculated the absolute and relative risk of receiving a diagnosis of ADHD and of receiving a prescription for a medication used to treat ADHD (i.e., methylphenidate, dextroamphetamine, mixed amphetamine salts or atomoxetine) for children born in December compared with children born in January.
Boys who were born in December were 30% more likely (relative risk [RR] 1.30, 95% confidence interval [CI] 1.23-1.37) to receive a diagnosis of ADHD than boys born in January. Girls born in December were 70% more likely (RR 1.70, 95% CI 1.53-1.88) to receive a diagnosis of ADHD than girls born in January. Similarly, boys were 41% more likely (RR 1.41, 95% CI 1.33-1.50) and girls 77% more likely (RR 1.77, 95% CI 1.57-2.00) to be given a prescription for a medication to treat ADHD if they were born in December than if they were born in January.
The results of our analyses show a relative-age effect in the diagnosis and treatment of ADHD in children aged 6-12 years in British Columbia. These findings raise concerns about the potential harms of overdiagnosis and overprescribing. These harms include adverse effects on sleep, appetite and growth, in addition to increased risk of cardiovascular events.
Scientific and clinical interest in attention-deficit hyperactivity disorder (ADHD) is increasing worldwide. This article presents data from a cross-national workshop and survey related to questions of variability in diagnostic and, particularly, treatment procedures.
Representatives of nine nations (Australia, Brazil, Canada, China, Germany, Israel, the Netherlands, Norway, and the United Kingdom), plus the United States, who attended a 2010 workshop on ADHD, responded to a survey that addressed diagnostic procedures for ADHD; treated prevalence of medication approaches, as well as psychosocial interventions; types of medications and psychosocial treatments in use; payment systems; beliefs and values of the education system; trends related to adult ADHD; and cultural and historical attitudes and influences related to treatment.
Use of both medication and psychosocial treatment for ADHD varies widely within and across nations. More expensive long-acting formulations of medications are becoming more widespread. Nations with socialized medical care provide a wide array of evidence-based interventions. Economic, historical, and political forces and cultural values are related to predominant attitudes and practices. Strong antipsychiatry and antimedication voices remain influential in many nations.
There is considerable variation in implementation of care for ADHD. Recognition of the social context of ADHD is an important step in ensuring access to evidence-based interventions for this prevalent, chronic, and impairing condition.
To test the hypothesis that younger children in a school year are at greater risk of emotional and behavioural problems.
Cross sectional survey.
Community sample from England, Scotland, and Wales.
10 438 British 5-15 year olds.
Total symptom scores on psychopathology questionnaires completed by parents, teachers, and 11-15 year olds; psychiatric diagnoses based on a clinical review of detailed interview data.
Younger children in a school year were significantly more likely to have higher symptom scores and psychiatric disorder. The adjusted regression coefficients for relative age were 0.51 (95% confidence interval 0.36 to 0.65, P < 0.0001) according to teacher report and 0.35 (0.23 to 0.47, P = 0.0001) for parental report. The adjusted odds ratio for psychiatric diagnoses for decreasing relative age was 1.14 (1.03 to 1.25, P = 0.009). The effect was evident across different measures, raters, and age bands. Cross national comparisons supported a "relative age" explanation based on the disadvantages of immaturity rather than a "season of birth" explanation based on seasonal variation in biological risk.
The younger children in a school year are at slightly greater psychiatric risk than older children. Increased awareness by teachers of the relative age of their pupils and a more flexible approach to children's progression through school might reduce the number of children with impairing psychiatric disorders in the general population.
Little is known about the global use and cost of medications for attention deficit hyperactivity disorder (ADHD). Global use of ADHD medications rose threefold from 1993 through 2003, whereas global spending (2.4 billion US dollars in 2003) rose ninefold, adjusting for inflation. Per capita gross domestic product (GDP) robustly predicted use across countries, but the United States, Canada, and Australia showed significantly higher-than-predicted use. Use and spending grew in both developed and developing countries, but spending growth was concentrated in developed countries, which adopted more costly, long-acting formulations. Promoting optimal prescription and monitoring should be a priority.
Objective:
Attention-deficit/hyperactivity disorder (ADHD) has been linked to immaturity relative to peers in childhood, yet it is unclear how such immaturity is associated with ADHD across development. This longitudinal twin study examined the genetic and environmental contributions to the association between parents' perception of their child's immaturity relative to peers (RI) in childhood and ADHD symptoms across development.
Method:
1,302 twin pairs from the Swedish Twin Study of Child and Adolescent Development were followed prospectively from childhood to early adulthood. Parent ratings of RI were collected at 8 to 9 years and parent and self-ratings of ADHD symptoms were collected at 8 to 9, 13 to 14, 16 to 17, and 19 to 20 years using the Child Behavior Checklist Attention Problems scale. In addition, ADHD symptoms corresponding to DSM criteria were used for sensitivity analysis. Analyses were conducted using longitudinal structural equation modeling with multiple raters.
Results:
RI-related etiologic factors, predominantly influenced by genes, explained 10-14% of the variance in ADHD symptoms from 8 to 9 up to 16 to 17 years. The influence of these RI-related factors on ADHD symptoms attenuated to 4% by 19 to 20 years of age. The remaining variance in ADHD symptoms was primarily explained by genetic factors independent of RI, which remained relatively stable across development, explaining 19% to 30% of the variance in ADHD symptoms from 13 to 14 up to 19 to 20 years.
Conclusion:
The results show that RI is significantly associated with ADHD symptoms, particularly during childhood and adolescence, and that the association is primarily explained by a shared genetic liability. Nevertheless, the magnitude of associations across development was modest, highlighting that RI is merely one aspect contributing to the complex etiology of ADHD symptoms.
Background:
Diagnosis of children with attention-deficit/hyperactivity disorder (ADHD) is increasing. The present study sought to identify characteristics and medication treatment patterns of children with ADHD and compare them by relative age in class, sex, ethnicity, family size, sibling order, and other socioeconomic status, as well as find trends in disparity of pharmacotherapy.
Methods:
This study was based on data from 1 013 149 Clalit Health Services members aged 6-17 years during 2006-2011. Centrally acting sympathomimetic drug purchases were compared according to children's estimated relative age in class; youngest third (born August to November), middle third (born April to July), and oldest third (born December to March). Treatment trends were determined and compared according to sociodemographic and family-related factors.
Results:
The overall prevalence of stimulant use in the population was 2.6% in 2006 and 4.9% in 2011. The annual incidence of stimulant use increased from 0.75% to 1.36%, rising more sharply among children in the older age groups (≥12) than among younger ones. Moreover, the youngest third of children in class was more likely to use medication than the oldest third (risk ratio (RR) 1.17, confidence interval (CI) 1.12-1.23) or the middle third (RR 1.06, CI 1.01-1.11). Of the different ethnic sectors, incidence of stimulant use was highest among general Jewish (1.8% in 2011) and lowest among Arabs (0.37% in 2011).
Conclusions:
The use of stimulant medication is growing among children in Israel. Although the overall use does not exceed the estimated prevalence of ADHD among children, the appropriateness of prescribing to the Israeli pediatric population, especially to the youngest children in class, may be questionable. Copyright © 2016 John Wiley & Sons, Ltd.
Overdiagnosis occurs when a true abnormality is discovered, but detection of that abnormality does not benefit the patient. It should be distinguished from misdiagnosis, in which the diagnosis is inaccurate, and it is not synonymous with overtreatment or overuse, in which excess medication or procedures are provided to patients for both correct and incorrect diagnoses. Overdiagnosis for adult conditions has gained a great deal of recognition over the last few years, led by realizations that certain screening initiatives, such as those for breast and prostate cancer, may be harming the very people they were designed to protect. In the fall of 2014, the second international Preventing Overdiagnosis Conference will be held, and the British Medical Journal will produce an overdiagnosis-themed journal issue. However, overdiagnosis in children has been less well described. This special article seeks to raise awareness of the possibility of overdiagnosis in pediatrics, suggesting that overdiagnosis may affect commonly diagnosed conditions such as attention-deficit/hyperactivity disorder, bacteremia, food allergy, hyperbilirubinemia, obstructive sleep apnea, and urinary tract infection. Through these and other examples, we discuss why overdiagnosis occurs and how it may be harming children. Additionally, we consider research and education strategies, with the goal to better elucidate pediatric overdiagnosis and mitigate its influence.
Background
We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment.Methods
We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case–control designs to study 6–69 year-old individuals in Sweden from July 2005 to December 2009 (Cohort 1). Cohort 1 included 56,263 individuals diagnosed with ADHD or ever used prescribed ADHD-specific medication. Complementary population-representative cohorts provided DSM-IV ADHD symptom ratings; parent-reported for 10,760 9-year-old twins born 1995–2000 from the CATSS study (Cohort 2) and self-reported for 6,970 adult twins age 20–47 years born 1959–1970 from the STAGE study (Cohort 3). We calculated odds ratios (OR:s) for ADHD across age for individuals born in November/December compared to January/February (Cohort 1). ADHD symptoms in Cohorts 2 and 3 were studied as a function of calendar birth month.ResultsADHD diagnoses and medication treatment were both significantly more common in individuals born in November/December versus January/February; peaking at ages 6 (OR: 1.8; 95% CI: 1.5–2.2) and 7 years (OR: 1.6; 95% CI: 1.3–1.8) in the Patient and Prescribed Drug Registers, respectively. We found no corresponding differences in parent- or self-reported ADHD symptoms by calendar birth month.Conclusion
Relative immaturity compared to class mates might contribute to ADHD diagnosis and pharmacotherapy despite absence of parallel findings in reported ADHD symptom loads by relative immaturity. Increased clinical awareness of this phenomenon may be warranted to decrease risk for imprecise diagnostics and treatment. We speculate that flexibility regarding age at school start according to individual maturity could reduce developmentally inappropriate demands on children and improve the precision of ADHD diagnostic practice and pharmacological treatment.
Summer-born children perform less well academically and are more likely to receive SEN provision than those born in the spring or autumn. School studies using small samples suggest that summer-born children with learning difficulties perform no less well on age-standardised tests. This
article examines the relation between season of birth, SEN, specific learning difficulties and performance on age-standardised measures of IQ, reading and spelling, using data from a large population-based cross-sectional community survey of British children. There were more summer-born children
with SEN compared with autumn and spring-born, but no significant differences in IQ, reading ability, spelling ability or specific learning difficulties between seasons. The excess of summer-born children with special needs does not mirror age-adjusted attainment. Teachers' expectations may
not allow fully for age variation within the school year.
Background:
We evaluated whether younger age in class is associated with poorer academic performance and an increased risk of being prescribed stimulants for attention-deficit/hyperactivity disorder (ADHD).
Methods:
This was a nationwide population-based cohort study, linking data from national registries of prescribed drugs and standardized scholastic examinations. The study population comprised all children born in 1994-1996 who took standardized tests in Iceland at ages 9 and 12 (n = 11 785). We estimated risks of receiving low test scores (0-10th percentile) and being prescribed stimulants for ADHD. Comparisons were made according to children's relative age in class.
Results:
Mean test scores in mathematics and language arts were lowest among the youngest children in the fourth grade, although the gap attenuated in the seventh grade. Compared with the oldest third, those in the youngest third of class had an increased relative risk of receiving a low test score at age 9 for mathematics (1.9; 95% confidence interval [CI] 1.6-2.2) and language arts (1.8; 95% CI 1.6-2.1), whereas at age 12, the relative risk was 1.6 in both subjects. Children in the youngest third of class were 50% more likely (1.5; 95% CI 1.3-1.8) than those in the oldest third to be prescribed stimulants between ages 7 and 14.
Conclusions:
Relative age among classmates affects children's academic performance into puberty, as well as their risk of being prescribed stimulants for ADHD. This should be taken into account when evaluating children's performance and behavior in school to prevent unnecessary stimulant treatment.
To compare national use of attention-deficit/hyperactivity disorder (ADHD) drugs between five Nordic countries.
A population-based drug utilisation study based on nationwide prescription databases, covering in total 24 919 145 individuals in 2007. ADHD drugs defined according to the World Health Organization Anatomic Therapeutic Chemical classification system as centrally acting sympathomimetics (N06BA). Results: The 2007 prevalence of ADHD drug use among the total Nordic population was 2.76 per 1000 inhabitants, varying from 1.23 per 1000 in Finland to 12.46 per 1000 in Iceland. Adjusting for age, Icelanders were nearly five times more likely than Swedes to have used ADHD drugs (Prev.Ratio = 4.53, 95% CI: 4.38-4.69). Prevalence among boys (age 7-15) was fourfold the prevalence among girls (Prev.Ratio = 4.28, 95% CI: 3.70-4.96). The gender ratio was diminished among adults (age 21 +) (Prev.Ratio = 1.24, CI: 1.21-1.27).
A considerable national variation in use of ADHD drugs exists between the Nordic countries.
We exploit the discontinuity in age when children start kindergarten generated by state eligibility laws to examine whether relative age is a significant determinant of ADHD diagnosis and treatment. Using a regression discontinuity model and exact dates of birth, we find that children born just after the cutoff, who are relatively old-for-grade, have a significantly lower incidence of ADHD diagnosis and treatment compared with similar children born just before the cutoff date, who are relatively young-for-grade. Since ADHD is an underlying neurological problem where incidence rates should not change dramatically from one birth date to the next, these results suggest that age relative to peers in class, and the resulting differences in behavior, directly affects a child's probability of being diagnosed with and treated for ADHD.
We wanted to survey physicians in the Washington, DC, metropolitan area regarding the frequency with which physicians, teachers, parents, and others first suggest the diagnosis of attention-deficit/hyperactivity disorder (ADHD).
A questionnaire was mailed to all family physicians, primary care pediatricians, and child psychiatrists in greater Washington, DC. In answer to the question, "Who first suggests the diagnosis of ADHD?" respondents assigned percentages to primary care physicians, consultants, parents, teachers, etc.
Teachers were most likely to be first to suggest the diagnosis of ADHD (46.4%; 95% CI, 44.1%-48.7%), followed by parents (30.2%; 95% CI, 28.3%-32.0%), primary care physicians (11.3%; 95% CI, 9.7%-12.8%), school personnel other than teachers (6.0%; 95% CI, 4.9%-7.2%), consultants such as child psychiatrists or psychologists (3.1%; 95% CI, 2.3%-3.9%) and other specified categories (3.0%; 95% CI, 2.4%-3.6%).
Teachers and other school personnel are often the first to suggest the diagnosis of ADHD in children in the greater Washington, DC, area. Regional variations in the prescribing of medication for ADHD may be caused at least in part by variations in the likelihood of a teacher suggesting the diagnosis of ADHD.
ADHD prevalence estimates across three decades: an updated systematic review and meta-regression analysis
- G V Polanczyk
- E G Willcutt
- G A Salum
- C Kieling
- L A Rohde
Polanczyk GV, Willcutt EG, Salum GA, Kieling C, Rohde LA.
ADHD prevalence estimates across three decades: an updated
systematic review and meta-regression analysis.
Int J Epidemiol 2014; 43: 434-42.