The Validity of the ADHD Section of the Diagnostic Interview Schedule for Children

Self-esteem in children and adolescents with and without attention-deficit/hyperactivity disorder: A meta-analytic review

Meta-analytic methods were used to examine global and domain-specific (i.e., academic, social, behavioral) self-esteem in children and adolescents with and without ADHD. Potential moderators of effect size heterogeneity were also examined via meta-regressions within a three-level approach. Findings from 49 aggregated global self-esteem effect sizes (ADHDN = 2500, TDN = 9448), 12 academic self-esteem effect sizes (ADHDN = 386, TDN = 315), 11 social self-esteem effect sizes (ADHDN = 258, TDN = 254), and 8 behavioral self-esteem effect sizes (ADHDN = 231, TDN = 211) suggest that children and adolescents with ADHD experience moderate global (ES = 0.46, p < .001), academic (ES = 0.60, p = .009), and social (ES = 0.67, p = .001) self-esteem impairments compared to children and adolescents without the disorder. The aggregated behavioral self-esteem effect size (ES = 0.20, p = .54), however, was not significant, and the global self-esteem effect size was markedly smaller compared to effect sizes for the academic and social domains. Further, examination of potential moderators of effect size heterogeneity indicated null effects for medication status, diagnostic complexity, informant, age, sex, comorbid psychopathology, and self-esteem dimension. Collectively, findings suggest that children and adolescents with ADHD do not hold a ubiquitous negative self-perception of difficulties across academic, social, and behavioral domains of functioning, and unexamined domains that are distal to ADHD may serve to bolster global self-esteem.

The efficacy of a self-help parenting program for parents of children with externalizing behavior: a randomized controlled trial

Parenting programs are effective for children with externalizing problems, but not always easily accessible for parents. In order to facilitate accessibility, we developed a self-help parenting program, consisting of a manual and online part. The efficacy of the program in reducing children's externalizing problems was compared to waitlist in a randomized controlled trial. In addition, two versions of the program were exploratively compared, one with and one without biweekly telephonic support. Candidate moderators (child and parent factors) and parental satisfaction were also examined. We randomly assigned 110 families to one of the following three conditions: the support condition, the no support condition, or the waitlist condition. Intervention duration was 15 weeks. Outcomes were collected at baseline (T0), 8 weeks (T1), 15 weeks (T2), and 28 weeks (T3) and included daily telephonic measurements of parent-rated externalizing behavior and the Intensity scale of the parent-rated Eyberg Child Behavior Inventory (ECBI). Main analyses compared outcomes at T2, using longitudinal regressions with T0 as fixed factor. Results showed that children improved significantly more on both outcomes in the intervention condition compared to waitlist, with small to medium effect sizes. Parental satisfaction was high. Neither differences in efficacy nor in parental satisfaction were found between the support and no support condition. No moderators were detected. The newly developed self-help parenting program is effective in reducing children's externalizing behavior problems and may help improve access to evidence-based care.

Validation of the Diagnostic Interview Schedule for Children (DISC-5) Tic Disorder and Attention-Deficit/Hyperactivity Disorder Modules

Effective methods to assess mental disorders in children are necessary for accurate prevalence estimates and to monitor prevalence over time. This study assessed updates of the tic disorder and attention-deficit/hyperactivity disorder (ADHD) modules of the Diagnostic Interview Schedule for Children, Version 5 (DISC-5) that reflect changes in diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (Fifth edition, DSM-5). The DISC-5 tic disorder and ADHD parent- and child-report modules were compared to expert clinical assessment for 100 children aged 6-17 years (40 with tic disorder alone, 17 with tic disorder and ADHD, 9 with ADHD alone, and 34 with neither) for validation. For the tic disorder module, parent-report had high (>90%) sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, while the youth-report had high specificity and PPV, moderate accuracy (81.4%), and lower sensitivity (69.8%) and NPV (67.3%). The ADHD module performed less well: parent-report had high NPV (91.4%), moderate sensitivity (80.8%), and lower specificity (71.6%), PPV (50.0%), and accuracy (74.0%); youth-report had moderate specificity (82.8%) and NPV (88.3%), and lower sensitivity (65.0%), PPV (54.2%), and accuracy (78.6%). Adding teacher-report of ADHD symptoms to DISC-5 parent-report of ADHD increased sensitivity (94.7%) and NPV (97.1%), but decreased specificity (64.2%), PPV (48.7%), and accuracy (72.2%). These findings support using the parent-report tic disorder module alone or in combination with the child report module in future research and epidemiologic studies; additional validation studies are warranted for the ADHD module.

Collateral Effects of Youth Disruptive Behavior Disorders on Mothers' Psychological Distress: Adolescents with Autism Spectrum Disorder, Intellectual Disability, or Typical Development

Disruptive behavior disorders were assessed in 160 youth aged 13 years, with Autism Spectrum Disorder (ASD, n = 48), intellectual disability (ID, n = 28), or typical development (TD, n = 84). Mothers' reported collateral effects on their psychological adjustment were related to both youth disability status and clinical level behavior disorders. More youth with ASD or ID had clinical level behavior disorders than their TD peers, and their mothers reported significantly higher personal stress and psychological symptoms, as well as lower positive impact of the youth on the family. The youth's clinical level behavior disorders accounted for these differences more than the diagnostic status. Mothers high in dispositional optimism reported the lowest stress and psychological symptoms in relationship to youth behavior challenges.

A Review of the Clinical Utility of Systematic Behavioral Observations in Attention Deficit Hyperactivity Disorder (ADHD)

This review evaluates the clinical utility of tools for systematic behavioral observation in different settings for children and adolescents with ADHD. A comprehensive search yielded 135 relevant results since 1990. Observations from naturalistic settings were grouped into observations of classroom behavior (n = 58) and of social interactions (n = 25). Laboratory observations were subdivided into four contexts: independent play (n = 9), test session (n = 27), parent interaction (n = 11), and peer interaction (n = 5). Clinically relevant aspects of reliability and validity of employed instruments are reviewed. The results confirm the usefulness of systematic observations. However, no procedure can be recommended as a stand-alone diagnostic method. Psychometric properties are often unsatisfactory, which reduces the validity of observational methods, particularly for measuring treatment outcome. Further efforts are needed to improve the specificity of observational methods with regard to the discrimination of comorbidities and other disorders.

Aiding the diagnosis of AD/HD in childhood: Using actigraphy and a continuous performance test to objectively quantify symptoms

The current gold standard for the diagnosis of AD/HD is based on subjective reports from teachers, parents, and clinicians. These measures can be problematic as they are open to rater biases and also fail to account for the developmental nature of symptoms. The current study examined the diagnostic accuracy of two objective measures, a computer-based Continuous Performance Task and actigraphy (e.g. motion tracking device) in differentiating children with AD/HD (N=70) from healthy controls (N=70). It was predicted that task-unrelated movement (measured via actigraphy) during a CPT and CPT performance would have high classification accuracy in differentiating children with AD/HD from healthy controls, and that the inclusion of age would increase this accuracy. Results indicated that total energy expenditure from the task-unrelated wrist and ankle movement during the CPT was higher in children with AD/HD than controls, and that CPT performance was poorer in AD/HD than controls. Discriminant function analyses revealed that the CPT Full-Scale Response Control Quotient and wrist and ankle energy expenditure provided optimal classification accuracy - correctly classifying 86% of cases, with sensitivity of 81.4% and specificity of 91.4%. The prediction that classification accuracy would increase with the inclusion of age was not supported by the data. When taken in conjunction with other clinical assessments, these findings suggest that actigraphy during a CPT and CPT performance may increase the probability of a correct AD/HD diagnosis.

Is hyperactivity ubiquitous in ADHD or dependent on environmental demands? Evidence from meta-analysis

Hyperactivity, or excess gross motor activity, is considered a core and ubiquitous characteristic of ADHD. Alternate models question this premise, and propose that hyperactive behavior reflects, to a large extent, purposeful behavior to cope with environmental demands that interact with underlying neurobiological vulnerabilities. The present review critically evaluates the ubiquity and environmental modifiability of hyperactivity in ADHD through meta-analysis of 63 studies of mechanically measured activity level in children, adolescents, and adults with ADHD relative to typically developing groups. Random effects models corrected for publication bias confirmed elevated gross motor activity in ADHD (d=0.86); surprisingly, neither participant age (child vs. adult) nor the proportion of each ADHD sample diagnosed with the inattentive subtype/presentation moderated this effect. In contrast, activity level assessed during high cognitive load conditions in general (d=1.14) and high executive functioning demands in particular (d=1.39) revealed significantly higher effect sizes than activity level during low cognitive load (d=0.36) and in-class schoolwork (d=0.50) settings. Low stimulation environments, more rigorous diagnostic practices, actigraph measurement of movement frequency and intensity, and ADHD samples that included fewer females were also associated with larger effects. Overall, the results are inconsistent with DSM-5 and ADHD models that a) describe hyperactivity as ubiquitous behavior, b) predict a developmental decline in hyperactivity, or c) differentiate subtypes/presentations according to perceived differences in hyperactive behavior. Instead, results suggest that the presence and magnitude of hyperactive behavior in ADHD may be influenced to a considerable extent by environmental factors in general, and cognitive/executive functioning demands in particular.

Assessing Attention and Disruptive Behavior Symptoms in Preschool-Age Children: The Utility of the Diagnostic Interview Schedule for Children

Data are presented from two samples of preschool children to evaluate the reliability, concurrent validity, and predictive validity of the ADHD, ODD, and CD sections of the Diagnostic Interview Schedule for Children, Fourth Edition (DISC-IV). Information was obtained from a community sample of 128 children (M_age = 53.16 months; 63 girls) and from a sample of 72 externalizing children (M_age = 45.23 months; 31 girls) plus 25 control children (M_age = 44.51 months; 8 girls). In both studies, the DISC-IV was administered to parents along with parent and teacher behavior rating scales, and teacher rating scales were obtained again later to evaluate the predictive validity of the DISC-IV (after approximately 6 months in Study 1, and 3 years in Study 2). The ADHD and ODD sections exhibited acceptable internal consistency in both studies, and showed concurrent validity with parent behavior rating scales. In both studies, the ADHD section was also concurrent with teacher reports. In Study 2, the ADHD, ODD, and CD sections distinguished externalizing children from controls. In both studies, the ADHD section predicted future teacher ratings beyond initial teacher ratings, and beyond initial parent rating scales; the ODD section similarly predicted later teacher ratings in Study 1. Findings provide strong support for the utility of the ADHD section for preschool children and moderate support for the ODD and CD sections.

Correspondence of parent report and laboratory measures of inattention and hyperactivity in children with heavy prenatal alcohol exposure

Clinical research and practice support a multi-method approach to validating behavioral problems in children. We examined whether parent-reported symptoms of hyperactivity and inattention (using the Disruptive Behavior Disorder Rating Scale) were substantiated by objective laboratory measures [hyperactivity measured by wrist-worn actigraphy (ACT) and inattention assessed using a 20-minute continuous performance task (CPT)] in three age- and demographically-matched groups of school-age children: children with prenatal alcohol exposure (AE), non-exposed children with idiopathic ADHD (ADHD), and controls (CON). Results indicated that the clinical groups (AE, ADHD) had significantly higher parent-reported levels for both domains compared to the CON group, and did not differ from each other. On the laboratory measures, the clinical groups were more inattentive than controls on the CPT, but did not differ from each other. In contrast, the ADHD group had higher objective activity on the ACT than AE and CON, which did not differ from each other. Thus, laboratory measures differentially validated parent reports in a group-dependent manner. Actigraphy substantiated parent-reported hyperactivity for children in the ADHD group but not for children in the AE group, while the CPT validated parent-reported inattention for both clinical groups. Although the majority of children in the AE group met the criteria for ADHD, objective activity levels were not different from controls, indicating that hyperactivity may be a less prominent feature in the AE group. Thus, while there is considerable overlap between the effects of prenatal alcohol exposure and ADHD, differences in behavioral profiles may be clinically useful in differential diagnosis. Further, these data indicate that objective measures should be used to validate parent reports.

Assessment of attention in preschoolers

In the past two decades, there has been an increased interest in the assessment and treatment of preschool children presenting with concerns about attention problems. This article reviews the research and clinical literature involving assessment of attention and related skills in the preschool years. While inattention among preschoolers is common, symptoms alone do not necessarily indicate a disorder, and most often represent a normal variation in typical preschool child development. Thus, accurate identification of "disordered" attention in preschoolers can be challenging, and development of appropriate, norm-referenced tests of attention for preschoolers is also difficult. The current review suggests that comprehensive assessment of attention and related functions in the preschool child should include thorough review of the child's history, planned observations, and formal psychometric testing. The three primary methods of psychometric assessment that have been used to characterize attentional functioning in preschool children include performance-based tests, structured caregiver interviews, and rating scales (parent, teacher, and clinician). Among performance-based methods for measurement of attention in the preschool years, tests have been developed to assess sustained attention, selective (focused) attention, span of attention (encoding/manipulation), and (top-down) controlled attention--including freedom from distractibility and set shifting. Many of these tests remain experimental in nature, and review of published methods yields relatively few commercially available, nationally normed tests of attention for preschoolers, and an overall dearth of reliability and validity studies on the available measures.

Sources of continuity and change in activity level in early childhood

Actigraphs and parent and observer ratings were used to explore genetic influences on continuity and change in activity level (AL) in early childhood. Over 300 pairs of twins wore actigraphs for a 48-hr period in the home and laboratory at ages 2 and 3. AL was genetically influenced at both ages with little evidence of differential heritability across age. For all measures, genetic influences contributed to phenotypic continuity. With the exception of the actigraph measure of AL in the home, new genetic effects emerged at age 3 indicating that genetic factors influence both continuity and change in AL in early childhood. Nonshared environmental influences were also a source of change in AL across the transition from infancy to early childhood.

Objective measurement of motor activity during cognitive performance in adults with attention-deficit/hyperactivity disorder

OBJECTIVE

This study investigates whether hyperactivity, i.e. an increased level of motor activity, can be observed in adults with attention-deficit/hyperactivity disorder (ADHD).

METHOD

An infrared motion-tracking system was used to measure motor activity in 20 unmedicated adults with ADHD and 20 matched healthy controls (HC) during a 1-back working memory task.

RESULTS

Motor activity was higher in ADHD. It increased with the duration of testing and co-varied with cognitive performance in ADHD only. Subjective and objective measurements of motor activity were related in HC, but not in ADHD.

CONCLUSION

Higher levels of motor activity in ADHD are objectively measurable not only in children, but in adults as well. It is linked to cognitive performance arguing against distinguishable diagnostic subtypes. The objective measurement of motor activity seems to extend the description of ADHD symptoms derived from rating scales and might thus help to bridge the gap between psychopathological symptom description and neurobiological alterations.

Are Children Diagnosed With the Combined Form of ADHD Pervasively Hyperactive?

Diagnostic criteria specified by the Diagnostic and Statistical Manual of Mental Disorders ( DSM-IV-TR ; American Psychological Association [APA], 2000) require that motor excess be present across situations, at home and school, in order to establish that this condition is a characteristic of the child. The article discusses a study whose primary purpose was to use actigraphy to validate teacher and parent reports of hyperactivity at home and school. Continuous activity measurements were recorded for each minute of each 24-hr period (1,440 measurements per child per day) for a full 7-day week, during school and at home, on 9 children clinically diagnosed with the combined form of ADHD and 9 control children clinically examined at the same community mental health clinic and determined not to meet diagnostic criteria. The article highlights that the children with ADHD had not yet started medication, and the study findings reveal that only 1 of 9 children diagnosed with the combined form of ADHD was measurably pervasively hyperactive as DSM-IV-TR inclusion criteria require. Implications are discussed.

Is overactivity a core feature in ADHD? Familial and receiver operating characteristic curve analysis of mechanically assessed activity level

OBJECTIVE

Symptoms of overactivity form part of the DSM-IV criteria for the combined or hyperactive-impulsive subtypes of attention-deficit/hyperactivity disorder (ADHD); yet little data exist that would quantify the nature of the overactivity component. We aimed to quantify the ability of four different measures of motion sensor data, taken from actigraphs, and the intraindividual variability (IIV) in these measures, to distinguish ADHD cases from controls. Furthermore, we aimed to investigate the degree of shared familial influences on these measures and the ADHD diagnosis.

METHOD

Receiver operating characteristic analysis and multivariate structural equation modeling were used on actigraph data collected during a cognitive testing session in a sample of 116 ADHD combined-type probands, 119 of their siblings, and 218 control siblings (age range 6-18 years).

RESULTS

Three measures of actigraph data--the number of movements made, the magnitude of these movements, and the IIV in the magnitude of movement--yielded an area under the curve of up to 0.8, indicating an ability to distinguish between cases and controls. The latter two of these measures showed significant shared familial vulnerability with an ADHD diagnosis, with high ADHD-actigraph familial correlations.

CONCLUSIONS

The actigraph data support the DSM-IV conceptualization of including overactivity as one of the core features within ADHD combined subtype. The magnitude of movements made, and the IIV of these movements, may be suitable candidates for future molecular genetic studies seeking to identify polymorphisms associated with the risk for ADHD. Further research should investigate if these findings generalize to a more naturalistic, homelike setting.

High heritability for a composite index of children's activity level measures

Despite the high heritability of children's activity level, which forms part of the core symptom domain of hyperactivity-impulsivity within attention deficit hyperactivity disorder (ADHD), there has only been a limited success with identifying candidate genes involved in its etiology. This may reflect a lack of understanding about the different measures used to define activity level across studies. We aimed to study the genetic and environmental etiology across three measures of activity level: parent and teacher ratings of hyperactivity-impulsivity and actigraph measurements, within a population-based sample of 463 7-9 year old twin pairs. We further examined ways in which the three measures could be combined for future molecular studies. Phenotypic correlations across measures were modest, but a common underlying phenotypic factor was highly heritable (92%); as was a simple aggregation of all three measurements (77%). This suggests that distilling what is common to all three measures may be a good method for generating a quantitative trait suitable for molecular studies of activity level in children. The high heritabilities found are encouraging in this respect.

Personality characteristics associated with persistent ADHD in late adolescence

This study focused on the personality characteristics associated with Attention-deficit/Hyperactivity disorder (ADHD) in a longitudinal sample of youth, with a particular focus on differences between those with and without persisting ADHD symptoms. Participants with ADHD (n = 90) were initially evaluated when they were 7-11 years old, and re-assessed at 16-22 years of age. Matched control subjects (n = 80) were recruited at the time of the follow-up evaluation. At follow-up, the Kiddie-SADS-PL, a semi-structured psychiatric interview, and the NEO-PI, a self-report personality inventory, were administered. Data were analyzed using multivariate analyses of variance (MANOVA). Results indicate that childhood ADHD is associated with lower scores on the NEO Conscientiousness subscale in adolescents/young adults--irrespective of the degree of ADHD persistence. In contrast, ratings of Neuroticism and Agreeableness appear to be more closely linked to adolescent status; those with persisting symptoms only exhibited increased Neuroticism and decreased Agreeableness. These results suggest that ADHD, and the degree to which symptoms persist into adolescence, may be closely linked to personality structure.

Attention-deficit/hyperactivity disorder and behavioral inhibition: a meta-analytic review of the stop-signal paradigm

Deficient behavioral inhibition (BI) processes are considered a core feature of attention deficit/hyperactivity disorder (ADHD). This meta-analytic review is the first to examine the potential influence of a wide range of subject and task variable moderator effects on BI processes--assessed by the stop-signal paradigm--in children with ADHD relative to typically developing children. Results revealed significantly slower mean reaction time (MRT), greater reaction time variability (SDRT), and slower stop-signal reaction time (SSRT) in children with ADHD relative to controls. The non-significant between-group stop-signal delay (SSD) metric, however, suggests that stop-signal reaction time differences reflect a more generalized deficit in attention/cognitive processing rather than behavioral inhibition. Several subject and task variables served as significant moderators for children's mean reaction time.

Attention-Deficit/Hyperactivity Disorder and Behavioral Inhibition: A Meta-Analytic Review of the Stop-signal Paradigm

Deficient behavioral inhibition (BI) processes are considered a core feature of attention deficit/hyperactivity disorder (ADHD). This meta-analytic review is the first to examine the potential influence of a wide range of subject and task variable moderator effects on BI processes--assessed by the stop-signal paradigm--in children with ADHD relative to typically developing children. Results revealed significantly slower mean reaction time (MRT), greater reaction time variability (SDRT), and slower stop-signal reaction time (SSRT) in children with ADHD relative to controls. The non-significant between-group stop-signal delay (SSD) metric, however, suggests that stop-signal reaction time differences reflect a more generalized deficit in attention/cognitive processing rather than behavioral inhibition. Several subject and task variables served as significant moderators for children's mean reaction time.

Genetic influences on mechanically-assessed activity level in children

BACKGROUND

Activity level is an important component of children's temperament, as well as being part of the core symptom domain of hyperactivity-impulsivity within attention deficit hyperactivity disorder (ADHD). Yet it is poorly understood, due partly to limitations on parent and teacher ratings, which are typically used as measurements of these symptoms.

METHODS

We aimed to study the etiology of objectively-measured activity level across two situations, using actigraphs. A population-based sample of 463 7-9-year-old twin pairs were assessed individually both when apart undergoing laboratory-based cognitive testing and when together during a break in testing.

RESULTS

Heritability of activity level was estimated as 24% during the test session and at 30% during the break in testing. Shared environmental influences accounted for 27% of the variance in activity level during the test session and 42% of activity level measured during the break. A genetic correlation of 1.0 indicated that the same genes influenced activity level across the two situations, justifying the use of a composite measure of the two situations. This produced a heritability estimate of 36%.

CONCLUSIONS

Objectively-measured activity level shows a moderate degree of genetic influence, with a common set of genes influencing activity level across situations. This supports the use of actigraphs as an additional source of information in studies that aim to improve phenotype definition for molecular genetic studies of activity level and ADHD.

Sleep hygiene and actigraphically evaluated sleep characteristics in children with ADHD and chronic sleep onset insomnia

In the present study we investigated sleep hygiene and actigraphically evaluated sleep in 74 medication-naïve children, aged 6-12 years, with rigorously diagnosed attention-deficit/hyperactivity disorder (ADHD) and chronic sleep onset insomnia (ADHD-SOI) and 23 ADHD controls without insomnia (ADHD-noSOI). Between-group differences were analysed for lights out (sleep log), actigraphically evaluated sleep onset, sleep latency, total sleep duration, actual sleep time and sleep hygiene as measured with the Children's Sleep Hygiene Scale. We found a significant difference (P < 0.001) in mean (+/-SD) sleep onset between the ADHD-SOI group (21:49 +/- 0:56 h) and ADHD-noSOI groups (20:41 +/- 0:45 h). Sleep latency was significantly (P < 0.001) longer in ADHD-SOI (00:53 +/- 0:25 h) compared to ADHD-noSOI (00:26 +/- 0:25 h). The difference in total sleep duration between ADHD-SOI (9:42 +/- 0:44 h) and ADHD-noSOI (10:09 +/- 0:43 h) was not significantly different (P = 0.18). The group difference in actual sleep time was also not significant (8:43 +/- 0:52 h in ADHD-SOI versus 9:13 +/- 1:16 h; P = 0.40). There was no significant difference (P = 0.17) in mean (+/-SD) total sleep hygiene score between the ADHD-SOI (56.4 +/- 10.5) and ADHD-noSOI groups (53.0 +/- 10.6). We conclude that there were differences in sleep onset and sleep latency in ADHD children with chronic SOI and those without insomnia; however, sleep hygiene practices were similar and did not relate to sleep characteristics.

Relationship between response to methylphenidate treatment in children with ADHD and psychopathology in their families

OBJECTIVE

To compare the pattern of familial aggregation of psychopathology in children who are good responders (GR) to methylphenidate (MPH) versus those who are poor responders (PR).

METHOD

A total of 118 clinically referred children ages 6 to 12 years, diagnosed with ADHD participated in a double-blind, placebo-controlled, randomized 2-week crossover trial of MPH from 1999 to 2004. A low dose of 0.5 mg/kg of body weight of MPH divided in two equal doses was used. Family history was obtained by interviewing at least one key historian relative of each subject using Family Interview for Genetic Studies. Information was collected on 342 first-degree and 1,151 second-degree relatives of children with attention-deficit/hyperactivity disorder.

RESULTS

Forty-four subjects showed mild or no improvement (PR) and 74 showed moderate or very much improvement (GR) on MPH over placebo. First-degree relatives of GR subjects were at significantly higher risk of attention-deficit/hyperactivity disorder than the relatives of PR subjects (p<.05). Second-degree relatives of the GR were at significantly higher risk of antisocial personality disorder compared to the relatives of PR subjects (p<.05).

CONCLUSIONS

The significantly higher presence of attention-deficit/hyperactivity disorder in the first-degree relatives and of antisocial personality disorder in the second-degree relatives of GR children suggests that this group may, at least partially, be distinct from the PR group on the basis of genetic determinants.