Personality mediation of genetic effects on Attention-Deficit/Hyperactivity Disorder

Negative Parenting Mediates the Longitudinal Association between Parental Internalizing Symptoms and Child Oppositional Symptoms

Research has pointed to both cross-sectional and longitudinal associations between parental internalizing symptoms and child externalizing symptoms. This study analyzed whether the association is mediated by negative parenting behavior in view of previous reports that both parental internalizing symptoms and child externalizing symptoms are related to parenting behaviors. Longitudinal data for the current analyses were derived from a randomized controlled trial on the efficacy of a web-assisted self-help intervention for parents of children with elevated levels of externalizing symptoms. Two different mediation models were analyzed, one using attention-deficit/hyperactivity disorder (ADHD) symptoms as the dependent variable and the other using oppositional defiant disorder (ODD) symptoms. Both models included parental internalizing symptoms as the independent variable, negative parenting behavior as a mediator, and study condition as a confounder. The longitudinal analyses support the mediating role of negative parenting behavior in the association between early parental internalizing symptoms and later child ODD symptoms.

Mental health in Canadian children and adolescents during COVID-19 pandemic: the role of personality and, coping and stress responses

In December 2019, the Coronavirus Disease (COVID-19) pandemic first emerged in China and quickly spread to other countries. Previous studies have shown that the COVID-19 pandemic and the consequences have negatively impacted the mental health of adults. Individual differences such as personality could contribute to mental health. Furthermore, coping and responses to stress may affect an individual's response to the pandemic. In the past, studies have only investigated this relationship in adults. In the current study, we examine how personality traits (using the Five-Factor Model as our framework) and Coping and Response to COVID-19 stress are related to the mental health of Canadian children and adolescents during the pandemic. Using parent reports of 100 preschoolers and 607 6-18-year-old children, we performed multiple regression analysis to explore how personality traits predict the effects of COVID-19 on mental health. The results showed that personality traits are associated with the mental health of Canadian youth during the COVID-19 pandemic. In preschoolers, Neuroticism and Agreeableness predicted the most mental health problems, and in 6-18-year-old children, Extraversion negatively predicted the most mental health problems. Also, Openness to Experience was the weakest predictor of mental health status in Canadian youth. These findings could be useful in understanding children's responses to the COVID-19 pandemic and could assist public health services delivering mental health services specifically tailored to children's personalities during and after this pandemic.

Personality disorders, depression and anxiety in mothers of children with ADHD and anxiety disorders in Iran

BACKGROUND/AIM

This study aims to assess and compare personality disorders and psychiatric disorders (depression and anxiety) in mothers of children with ADHD and anxiety disorders aged 2-16 years living in Iran.

MATERIAL AND METHODS

This is a descriptive cross-sectional study. Participants were 168 mothers (100 with children having ADHD and 68 with children having anxiety disorders). The Millon Clinical Multiaxial Inventory-III, the Depression Anxiety Stress Scale (DASS-21) and the Symptom Checklist-90-Revised (SCL-90-R) were used for assessing personality disorders, depression and anxiety in mothers. Collected data were analysed in SPSS software.

RESULTS

Of 168 mothers, only 100 completed the questionnaires completely (68 having children with ADHD and 32 with anxious children). Of 100 mothers, 61 had personality disorders, where 21 had children with anxiety disorders and 40 had children with ADHD. The most common personality disorder was depressive personality disorder (n = 27) followed by compulsive personality disorder (n = 15). No antisocial, borderline and paranoid personality disorders were observed in mothers. Based on DASS-21, 72 mothers had depression, and 84 had anxiety. Based on the SCL-90-R, 86 had depression, and 81 had anxiety. We found no statistically significant difference between the two groups of mothers in terms of personality disorders, depression and anxiety.

CONCLUSION

Prevalence of depression, anxiety and personality disorders in mothers of children with anxiety disorders and ADHD in Iran is high, and there is no difference between them. It is recommended that psychiatric and psychological counseling be provided for these mothers.

Longitudinal Temperament Pathways to ADHD Between Childhood and Adolescence

The current investigation extended prior cross-sectional mapping of etiological factors, transdiagnostic effortful and affective traits, and ADHD symptoms to longitudinal pathways extending from two etiological domains: polygenic and prenatal risk. Hypotheses were (1) genetic risk for ADHD would be related to inattentive ADHD symptoms in adolescence and mediated by childhood effortful control; (2) prenatal smoking would be related to hyperactive-impulsive ADHD symptoms during childhood and mediated by childhood surgency; and (3) there would be age-related variation, such that mediation of genetic risk would be larger for older than younger ages, whereas mediation of prenatal risk would be larger in earlier childhood than at later ages. Participants were 849 children drawn from the Oregon ADHD-1000 Cohort, which used a case control sample and an accelerated longitudinal design to track development from childhood (at year 1 ages 7-13) through adolescence (at year 6 ages 13-19). Results showed the mediational pathway from prenatal smoking through surgency to hyperactivity-impulsivity at Year 1 was significant (indirect effect estimate = .053, p < .01). The mediational pathway from polygenic risk through effortful control to inattention at Year 6 was also significant (indirect effect estimate = .084, p < .01). Both results were independent of the association between inattention and hyperactivity-impulsivity and control for the alternative etiological input and held across parent- and teacher-report of ADHD symptoms. In line with dual pathway models of ADHD, early prenatal risk for hyperactivity-impulsivity appears to operate through surgency, while polygenic genetic risk for inattention appears mediated by effortful control.

Reinforcement Sensitivity Theory of Personality Questionnaire: Factor Structure Based on CFA and ESEM, and Associations with ADHD

Revised reinforcement sensitivity theory (r-RST) of personality is a major neuropsychological theory of motivation, emotion and personality. This paper presents the results of a study examining: (1) the factor structure of the Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ) using confirmatory factor analysis (CFA) and exploratory structural equation modeling (ESEM); and (2) the relationships of the r-RST constructs in the RST-PQ with attention deficit hyperactivity disorder (ADHD) symptom groups of inattention (IA) and hyperactivity/impulsivity (HI). A total of 572 (Sample 1) and 309 (Sample 2) adults completed the RST-PQ. Participants in Sample 2 also completed a questionnaire measuring ADHD symptoms. Results revealed more support for the ESEM model with six factors than the CFA model. For both the ESEM and CFA models, both IA and HI symptom groups were associated positively with the RST-PQ constructs of behavioral inhibition system (BIS) and behavioral approach system (BAS) Impulsivity, with IA also associated negatively with the BAS-Goal-Drive Persistence. The theoretical implications of these findings for understanding the factor structure of the RST-PQ, and for ADHD (IA and HI) in terms of r-RST, are discussed.

Hyperactive Child Syndrome and Estimated Life Expectancy at Young Adult Follow-Up: The Role of ADHD Persistence and Other Potential Predictors

OBJECTIVE

We examined if ADHD Combined Type or Presentation (ADHD-C) reduced estimated life expectancy (ELE) at young adulthood and if the persistence of ADHD to adulthood further adversely affected ELE.

METHOD

A young adult follow-up of 131 hyperactive and 71 control cases was used to derive 14 variables that were entered into a life expectancy calculator to generate ELE scores. Both ratings of executive function (EF) in everyday life and tests of EF and IQ were measured along with comorbid psychopathologies.

RESULTS

Childhood ADHD-C was associated with a 9.5-year reduction in healthy ELE, and a 8.4-year reduction in total ELE relative to control children by adulthood. The persistence of ADHD to adulthood was linked to a 12.7-year reduction in ELE. Several background traits accounted for more than 39% of variation in ELE.

CONCLUSION

Childhood ADHD-C predicts a significantly reduced ELE by adulthood, which is further reduced by the persistence of ADHD to adult follow-up.

ADHD risk genes involved in dopamine signaling and metabolism are associated with reduced estimated life expectancy at young adult follow-up in hyperactive and control children

ADHD is associated with an elevated risk of mortality and reduced estimated life expectancy (ELE) by adulthood. Reduced life expectancy is substantially related to the trait of behavioral disinhibition; a correlate of both ADHD and of several dopamine genes related to dopamine signaling and metabolism. We therefore hypothesized that several ADHD risk genes related to dopamine might also be predictive of reduced ELE. Using a longitudinal study of 131 hyperactive children and 71 control cases followed to young adulthood, we examined whether several polymorphisms involving DRD4, DAT1, and DBH were related to ELE. The homozygous 9/9 allele of DAT1 and the heterozygous allele of DBH TaqI were associated with 5- and 2-year reductions, respectively, in total ELE. They did not operate on ELE through any relationships to ADHD specifically or behavioral disinhibition more generally. Instead, they showed links to alcohol use (DBH), reduced education, smoking, and reduced exercise (DAT1) employed in the computation of ELE. We conclude that polymorphisms of two dopamine genes are linked to reductions in ELE independently of their association with ADHD.

Testing for the mediating role of endophenotypes using molecular genetic data in a twin study of ADHD traits

Family and twin studies have identified endophenotypes that capture familial and genetic risk in attention-deficit/hyperactivity disorder (ADHD), but it remains unclear if they lie on the causal pathway. Here, we illustrate a stepwise approach to identifying intermediate phenotypes. First, we use previous quantitative genetic findings to delineate the expected pattern of genetically correlated phenotypes. Second, we identify overlapping genetic associations with ADHD-related quantitative traits. Finally, we test for the mediating role of associated endophenotypes. We applied this approach to a sample of 1,312 twins aged 7-10. Based on previous twin model-fitting analyses, we selected hyperactivity-impulsivity, inattention, reading difficulties (RD), reaction time variability (RTV) and commission errors (CE), and tested for association with selected ADHD risk alleles. For nominally significant associations with both a symptom and a cognitive variable, matching the expected pattern based on previous genetic correlations, we performed mediation analysis to distinguish pleiotropic from mediating effects. The strongest association was observed for the rs7984966 SNP in the serotonin receptor gene (HTR2A), and RTV (P = 0.007; unadjusted for multiple testing). Mediation analysis suggested that CE (38%) and RTV (44%) substantially mediated the association between inattention and the T-allele of SNP rs3785157 in the norepinephrine transporter gene (SLC6A2) and the T-allele of SNP rs7984966 in HTR2A, respectively. The SNPs tag risk-haplotypes but are not thought to be functionally significant. While these exploratory findings are preliminary, requiring replication, this study demonstrates the value of this approach that can be adapted to the investigation of multiple genetic markers and polygenic risk scores. © 2016 The Authors. American Journal of Medical Genetics Part B: Neuropsychiatric Genetics Published by Wiley Periodicals, Inc.

Personality profiles in adults with attention deficit hyperactivity disorder (ADHD)

BACKGROUND

Previous studies suggested that the presence of ADHD in children and young adolescents may affect the development of personality. Whether or not the persistence of ADHD in adult life is associated with distinct personality patterns is still matter for debate. To address this issue, we compared the profiles of the Temperament and Character Inventory (TCI) that assesses personality dimensions in 119 adults ADHD and 403 controls.

METHODS

ANCOVA were used to examine group differences (controls vs. ADHD and ADHD inattentive type vs. ADHD combined + hyperactive/impulsive types) in Temperaments and Characters. Partial correlation coefficients were used to assess correlation between TCI and expression and severity of symptoms of ADHD.

RESULTS

High novelty seeking (NS), harm avoidance (HA) and self-transcendence (ST) scores as well as low self-directedness (SD) and cooperativeness (C) scores were associated with ADHD diagnosis. Low SD was the strongest personality trait associated with adult ADHD. Cases with the ADHD inattentive type showed higher HA and lower SD scores compared to the combined and hyperactive/impulsive types. High HA scores correlated with inattention symptoms whereas high NS and ST scores were related to hyperactive symptoms. Finally low SD and high NS were associated with increased ADHD severity.

CONCLUSIONS

Distinct temperaments were associated with inattentive versus hyperactive/impulsive symptoms supporting the heterogeneous nature of the disorder.

Attention deficit hyperactivity disorder and personality characteristics in older adults in the general Dutch population

OBJECTIVE

The authors wanted to examine the association between attention deficit hyperactivity disorder (ADHD) and personality characteristics and the potential mediating role of these characteristics in the relationship between ADHD and depression in older adults in the general Dutch population.

METHODS

Data from the Longitudinal Aging Study Amsterdam in 2008/2009 were used in a cross-sectional design on 231 participants with and without ADHD aged 60-94 years. Questionnaires assessing self-esteem, self-efficacy, mastery, neuroticism, and social inadequacy were administered. ADHD was measured by means of ADHD diagnosis and level of ADHD symptoms. Linear regression analyses were performed to assess the association between ADHD (symptoms) and personality characteristics. Single and multivariate mediation analyses were performed to examine the mediating role of personality characteristics in the relationship between ADHD (symptoms) and depressive symptoms.

RESULTS

ADHD was significantly negatively associated with sense of mastery (B = -2.44, t = -3.14, df = 228, p = 0.002), self-esteem (B = -1.16, t = -2.27, df = 228, p = 0.02), and self-efficacy (B = -2.33, t = -2.02, df = 228, p = 0.045) and positively associated with neuroticism (B = 0.99, t = 4.90, df = 228, p <0.001) and social inadequacy (B = 0.65, t = 3.32, df = 229, p = 0.001). In the single mediation analyses, all personality characteristics were mediators in the relationship between ADHD symptoms and depressive symptoms. In the multivariate analysis only mastery and self-esteem were mediators.

CONCLUSION

Older adults with ADHD reported lower self-esteem and sense of mastery and higher levels of neuroticism and social inadequacy than older adults without ADHD. Mastery and self-esteem partly explained the association between ADHD and depressive symptoms in old age. The results implicate that in treatment clinicians should pay attention to the personality characteristics of older adults with ADHD.

Personality dimensions as common and broadband-specific features for internalizing and externalizing disorders

Several researchers have suggested that the nature of the covariation between internalizing and externalizing disorders may be understood better by examining the associations between temperament or personality and these disorders. The present study examined neuroticism as a potential common feature underlying both internalizing and externalizing disorders and novelty seeking as a potential broad-band specific feature influencing externalizing disorders alone. Participants were 12- to 18-year-old twin pairs (635 monozygotic twin pairs and 691 dizygotic twin pairs; 48 % male and 52 % female) recruited from the Colorado Center for Antisocial Drug Dependence. Genetic and nonshared environmental influences shared in common with neuroticism influenced the covariation among distinct internalizing disorders, the covariation among distinct externalizing disorders, and the covariation between internalizing and externalizing disorders. Genetic influences shared in common with novelty seeking influenced the covariation among externalizing disorders and the covariation between major depressive disorder and externalizing disorders, but not the covariation among internalizing disorders or between anxiety disorders and externalizing disorders. Also, after accounting for genetic and environmental influences shared in common with neuroticism and novelty seeking, there were no significant common genetic or environmental influences among the disorders examined, suggesting that the covariance among the disorders is sufficiently explained by neuroticism and novelty seeking. We conclude that neuroticism is a heritable common feature of both internalizing disorders and externalizing disorders, and that novelty seeking is a heritable broad-band specific factor that distinguishes anxiety disorders from externalizing disorders.

Adult attention deficit hyperactivity disorder symptoms and five-factor model traits in a clinical sample: a structural equation modeling approach

Relationships among attention deficit hyperactivity disorder (ADHD) symptoms and adult personality traits have not been examined in larger clinically diagnosed samples. We collected multisource ADHD symptom and self-report NEO Five-Factor Inventory (Costa and McCrae [Odessa, FL: Psychological Assessment Resources, Inc, 1992) data from 117 adults with ADHD and tested symptom-trait associations using structural equation modeling. The final model fit the data. Inattention was positively associated with neuroticism and negatively associated with conscientiousness. On the basis of ADHD expression in adulthood, hyperactivity and impulsivity were estimated as separate constructs and showed differential relationships to extraversion and agreeableness. A significant positive relationship between hyperactivity and conscientiousness arose in the context of other pathways. ADHD symptoms are reliably associated with personality traits, suggesting a complex interplay across development that warrants prospective study into adulthood.

Personality Traits Elucidate Sex Differences in Attention-Deficit/Hyperactivity Disorder Comorbidity During Early Childhood

Attention-Deficit/Hyperactivity Disorder (ADHD) is highly comorbid with other childhood disorders, and there are striking sex differences in this comorbidity, particularly during early childhood. For example, boys with ADHD are more likely to exhibit comorbid disruptive behavior and neurodevelopmental disorders, compared to girls, during early childhood. Yet, explanations for these well-established sex differences remain in short supply. The current study evaluated the novel hypothesis that personality traits may serve as intermediate phenotypes that help explain sex differences in common ADHD comorbidity profiles during early childhood. Study participants were 109 children between the ages of 3 and 6 and their primary caregivers and teachers/daycare providers, recruited from the community and over-recruited for ADHD-related problems. Primary caregivers completed the Child Behavior Checklist, and teachers/daycare providers completed the Teacher Report Form as a measure of child behavior problems. Examiners completed the California Q-Sort as a measure of child personality traits. Moderated mediation analyses suggested that personality traits explain associations between ADHD and oppositional-defiance, aggression, and language problems in a sex-specific manner. While high neuroticism mediated associations between ADHD and oppositional-defiance in girls, disagreeableness mediated associations between ADHD and aggression and low conscientiousness mediated associations between ADHD and neurodevelopmental language problems in boys. Sex differences in trait-psychopathology associations may help explain sex differences in comorbidity profiles with possible implications for child assessment and personalized early intervention.

Child dopamine active transporter 1 genotype and parenting: evidence for evocative gene-environment correlations

The dopamine active transporter 1 (DAT1) gene is implicated in psychopathology risk. Although the processes by which this gene exerts its effects on risk are poorly understood, a small body of research suggests that the DAT1 gene influences early emerging negative emotionality, a marker of children's psychopathology risk. As child negative emotionality evokes negative parenting practices, the DAT1 gene may also play a role in gene-environment correlations. To test this model, children (N = 365) were genotyped for the DAT1 gene and participated in standardized parent-child interaction tasks with their primary caregiver. The DAT1 gene 9-repeat variant was associated with child negative affect expressed toward the parent during parent-child interactions, and parents of children with a 9-repeat allele exhibited more hostility and lower guidance/engagement than parents of children without a 9-repeat allele. These gene-environment associations were partially mediated by child negative affect toward the parent. The findings implicate a specific polymorphism in eliciting negative parenting, suggesting that evocative associations play a role in elevating children's risk for emotional trajectories toward psychopathology risk.

An examination of the specificity of motivation and executive functioning in ADHD symptom-clusters in adolescence

OBJECTIVE

Motivation and executive functioning are central to the etiology of attention-deficit/hyperactivity disorder (ADHD). Furthermore, it has been hypothesized that motivation should show specificity of association with ADHD-impulsivity/hyperactivity symptoms, whereas executive functioning should show specificity of association with ADHD-inattention symptoms. This study tests this specificity-hypothesis and extends previous research by conceptualizing motivation to include both reactivity to reward and punishment.

METHODS

Executive functioning was assessed using two different laboratory measures (the Wisconsin-Card-Sort and Stop-Signal Tasks) and motivation was measured using a laboratory measure of sensitivity to reward and punishment (the Point-Scoring-Reaction-Time Task).

RESULTS

Findings suggested specificity of association between executive functioning and symptoms of inattention, and between motivation and symptoms of impulsivity/hyperactivity. However, support varied across indices of executive functioning.

CONCLUSIONS

Results provide support for multiple component models of ADHD symptoms and extend the literature by providing a theoretically based conceptualization of motivation grounded on developmental neuroscience models of motivated behavior.

A Five-Factor Model framework for understanding childhood personality disorder antecedents

The present contribution reviews evidence that supports the relevance of childhood antecedents of personality disorders, and advocates that the validity of a Five-Factor Model framework for describing general trait differences in childhood can be extended towards the field of developmental personality difficulties. In addition, we suggest that several traditional childhood Axis I conditions include a substantial trait component that may be responsible for the recurring finding that childhood Axis I disorders are predictive for adult Axis II disorders. Given the valuable information provided by a trait assessment, we further propose to integrate dimensional personality and personality pathology measures as standard tools in mental health assessments at a young age.

A controlled study of personality and affect in Tourette syndrome

OBJECTIVE

Tourette syndrome (TS) can increase the likelihood of social and emotional difficulties which may shape an individual's personality and self-perception. We investigated personality and affect in patients with TS.

METHODS

Twenty-five adults with TS (2 with co-morbid obsessive compulsive disorder, 4 with co-morbid attention-deficit hyperactivity disorder and 4 with both co-morbidities), who were not clinically depressed, and 25 matched controls participated in the study. They completed the Ten-Item Personality Index, the Positive and Negative Affect Scale and the Beck Depression Inventory.

RESULTS

Adults with TS exhibited no differences from controls in reported emotional experience or depressive symptoms but did differ for four of the five assessed personality dimensions; extraversion, conscientiousness, openness and emotional stability. Individuals with pure TS (who had no co-morbid conditions) exhibited reduced extraversion and emotional stability compared to controls. Personality scores were not related to tic severity, yet lower emotional stability scores were associated with higher ratings of negative affect.

CONCLUSIONS

This study is limited by a restricted sample in terms of size and source. However, our findings indicate that in the absence of depression and common co-morbidities, people with TS differ from controls in indices of personality, which are linked to negative affectivity.

Diversity in pathways to common childhood disruptive behavior disorders

Oppositional-Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD) are highly comorbid, a phenomenon thought to be due to shared etiological factors and mechanisms. Little work has attempted to chart multiple-level-of-analysis pathways (i.e., simultaneously including biological, environmental, and trait influences) to ODD and ADHD, the goal of the present investigation. 559 children/adolescents (325 boys) between the ages of 6 and 18 participated in a multi-stage, comprehensive diagnostic procedure. 148 were classified as ODD; 309 were classified as ADHD, based on parent, teacher, and clinician ratings. Children provided buccal or salivary samples of DNA, assayed for select markers in DRD4 and 5HTT. Parents completed the Alabama Parenting Questionnaire and the California Q-Sort. Children completed the Child Perception of Interparental Conflict Scale. Correlational associations consistent with multiple-level-of-analysis pathways to ODD and ADHD emerged. For ODD, children with the short allele of the 5HTT promoter polymorphism had higher neuroticism and ODD symptoms regardless of level of self-blame in relation to inter-parental conflict, whereas children without this allele had more ODD symptoms only in the context of more self-blame for inter-parental conflict. For ADHD (and ODD), children homozygous for the long allele of DRD4 120 bp insertion polymorphism had lower conscientiousness when exposed to inconsistent parenting, whereas children without this genotype were more resilient to effects of inconsistent discipline on conscientiousness. Thus, ODD and ADHD appear to demonstrate somewhat distinct correlational associations between etiological factors and mechanisms consistent with pathway models using a multiple-level-of-analysis approach.

[A study of temperament and personality in children diagnosed with attention-deficit hyperactivity disorder (ADHD)]

BACKGROUND

The study of children's personality and its development has generated several theoretical models in psychology. In a developmental approach, Buss and Plomin elaborated a genetic model of temperament that involves four dimensions: emotionality (refers to the negative quality of the emotion and the intensity of the emotional reactions), activity (intensity and frequency of a person's energy output in motor movements and speech), sociability (search for social relationships and preference for activities with others) and shyness (behavioural inhibition and feelings of distress when in interaction with strangers). The psychobiological approach postulates a biological model of personality. Thus, in Gray's first model, there are two brain systems that explain behaviours: the Bbehavioural Activation System (BAS) related to impulsivity and the Behavioural Inhibition System (BIS) linked to anxiety. Finally, dispositional theories seek to identify functional units of the normal personality from the factorial approach. Accordingly, Barbaranelli et al. build a questionnaire, the big five questionnaire for children (BFQ-C), which is intended to estimate the emergence of five fundamental dimensions (energy/extraversion, agreeableness, conscientiousness, emotional instability and intellect/openness) in children from 8 to 18 years. The clinical study we will present concerns the personality of children suffering from attention-deficit hyperactivity disorder (ADHD). STUDY 1:

METHODS AND RESULTS

In a first study, we compared the ratings of 33 children with ADHD regarding their personality, as well as the ratings of their parents, over a one-year interval. The EAS questionnaire tapping into the genetic model put forth by Buss and Plomin evaluates four dimensions: emotionality, activity, sociability and shyness. The BIS/BAS scales for children correspond to Gray's first psychobiological model of personality. The BIS scale is unidimensional and the BAS scale is divided into three subscales (drive, fun-seeking and reward responsiveness). The answers collected from parents at the two moments of completion of the EAS were comparable and the correlations were all higher than 0.70. Concerning the children, there were no significant differences between the two time periods but the correlations were rather low. On the BIS/BAS scales, they varied from 0.22 (fun-seeking BAS scale) to 0.51 (BIS scale), whereas the obtained correlations on the EAS ranged from 0.32 (emotionality) to 0.58 (activity and shyness). Finally, to compare the answers of the children with their parents on the EAS questionnaire, we used a correlation coefficient test. For time 1, the correlations varied from 0.54 (emotionality) to 0.69 (sociability), and for time 2, they varied from 0.18 (sociability) to 0.50 (shyness). The concordance between the parents' and children' answers was thus higher than in a group from the general population. STUDY 2:

METHODS AND RESULTS

In the second study, we compared the personality of children with ADHD (n=35) with a sample from the general population (n=35). The two groups of subjects were matched on age (mean: 12.7 years) and made comparable for gender. Participants with ADHD were comparable with control participants on the BIS, as well as on the reward responsiveness subscale of the BAS. Furthermore, participants with ADHD and controls were comparable concerning the tendency to avoid and the anxiety. However, as expected, those with ADHD obtained higher scores on two subscales of the BAS. Concerning the traits of temperament, participants with ADHD reported being more active and having greater emotionality than did control subjects. On the other hand, there were no group differences for the two other aspects of temperament (sociability and shyness). Finally, participants with ADHD obtained higher scores on the BFQ-C than did control participants. It is interesting to note that children with ADHD obtained higher scores on the extraversion scale of the BFQ-C and the activity scale of the EAS. Our findings parallel the existing literature concerning the neuroticism scale of the BFQ-C and the BAS, but not the agreeableness and conscientiousness scales of the BFQ-C.

DISCUSSION

It is interesting to note that children have a less stable representation of their own temperament as compared to the evaluation of their parents. This study replicates the findings of previous research on adults with ADHD regarding neuroticism (emotional instability), but contrary to findings in adults with ADHD, children obtained elevated scores on the conscientiousness and agreeableness subscales. In accordance with our hypotheses, children with ADHD could be distinguished from control participants on the BAS, particularly for the drive and reward responsiveness subscales. Furthermore, they also obtained higher scores on the extraversion subscale of the BFQ-C and the on the EAS activity subscale.

Role of dopamine receptors in ADHD: a systematic meta-analysis

The dopaminergic system plays a pivotal role in the central nervous system via its five diverse receptors (D1-D5). Dysfunction of dopaminergic system is implicated in many neuropsychological diseases, including attention deficit hyperactivity disorder (ADHD), a common mental disorder that prevalent in childhood. Understanding the relationship of five different dopamine (DA) receptors with ADHD will help us to elucidate different roles of these receptors and to develop therapeutic approaches of ADHD. This review summarized the ongoing research of DA receptor genes in ADHD pathogenesis and gathered the past published data with meta-analysis and revealed the high risk of DRD5, DRD2, and DRD4 polymorphisms in ADHD.