Association of <Emphasis Type="Italic">ADAM10</Emphasis> and <Emphasis Type="Italic">CAMK2A</Emphasis> Polymorphisms with Conduct Disorder: Evidence from Family-Based Studies

Twin and family studies have shown that genetic factors play a role in the development of conduct disorder (CD). The purpose of this study was to identify genetic variants associated with CD using a family-based association study. We used 4,720 single nucleotide polymorphisms (SNPs) from the Illumina Panel and 11,120 SNPs from the Affymetrix 10K GeneChips genotyped in 155 Caucasian nuclear families from Genetic Analysis Workshop (GAW) 14, a subset from the Collaborative Study on the Genetics of Alcoholism (COGA). 20 SNPs had suggestive associations with CD (p < 10⁻³), nine of which were located in known genes, including ADAM10 (rs383902, p = 0.00036) and CAMK2A (rs2053053, p = 0.00098). Our results were verified using the International Multi-Center ADHD Genetics Project (IMAGE) dataset. In conclusion, we identified several loci associated with CD. Especially, the two genes (ADAM10 and CAMK2A) have been reported to be associated with Alzheimer’s disease, bipolar disorder and depression. These findings may serve as a resource for replication in other populations.     

The Dopamine Receptor D4 Gene (<Emphasis Type="Italic">DRD4</Emphasis>) Moderates Family Environmental Effects on ADHD

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prime candidate for exploration of gene-by-environment interaction (i.e., G x E), particularly in relation to dopamine system genes, due to strong evidence that dopamine systems are dysregulated in the disorder. Using a G x E design, we examined whether the DRD4 promoter 120-bp tandem repeat polymorphism, previously associated with ADHD, moderated the effects of inconsistent parenting and marital conflict on ADHD or Oppositional-Defiant Disorder (ODD). Participants were 548 children with ADHD and non-ADHD comparison children and their parents. Homozygosity for the DRD4 promoter 120-bp tandem repeat insertion allele increased vulnerability for ADHD and ODD only in the presence of inconsistent parenting and appeared to increase susceptibility to the influence of increased child self-blame for marital conflict on ADHD inattention. DRD4 genotypes may interact with these proximal family environmental risk factors by increasing the individual’s responsivity to environmental contingencies.     

Transactional Associations Between Youths’ Responses to Peer Stress and Depression: The Moderating Roles of Sex and Stress Exposure

This study examined transactional associations between responses to peer stress and depression in youth. Specifically, it tested the hypotheses that (a) depression would predict fewer effortful responses and more involuntary, dysregulated responses to peer stress over time; and (b) fewer adaptive and more maladaptive responses would predict subsequent depression. Youth (M age = 12.41; SD = 1.19; 86 girls, 81 boys) and their maternal caregivers completed semi-structured interviews and questionnaires at three annual waves. Multi-group comparison path analyses were conducted to examine sex and stress-level differences in the proposed reciprocal-influence model. In girls and in youth exposed to high levels of peer stress, maladaptive stress responses predicted more depressive symptoms and adaptive stress responses predicted fewer depressive symptoms at each wave. These findings suggest the utility of preventive interventions for depression designed to enhance the quality of girls’ stress responses. In boys, depression predicted less adaptive and more maladaptive stress responses, but only at the second wave. These findings suggest that interventions designed to reduce boys’ depressive symptoms may help them develop more adaptive stress responses.     

Childhood Social Withdrawal,Interpersonal Impairment,and Young Adult Depression: A Mediational Model

Building on interpersonal theories of depression, the current study sought to explore whether early childhood social withdrawal serves as a risk factor for depressive symptoms and diagnoses in young adulthood. The researchers hypothesized that social impairment at age 15 would mediate the association between social withdrawal at age 5 and depression by age 20. This mediational model was tested in a community sample of 702 Australian youth followed from mother’s pregnancy to youth age 20. Structural equation modeling analyses found support for a model in which childhood social withdrawal predicted adolescent social impairment, which, in turn, predicted depression in young adulthood. Additionally, gender was found to moderate the relationship between adolescent social impairment and depression in early adulthood, with females exhibiting a stronger association between social functioning and depression at the symptom and diagnostic level. This study illuminates one potential pathway from early developing social difficulties to later depressive symptoms and disorders.     

Severity of Children’s ADHD Symptoms and Parenting Stress: A Multiple Mediation Model of Self-Regulation

The goal of the current study was to determine the extent to which the perceived self-regulation deficits across behavioral, cognitive, and emotional domains seen in children with ADHD explain the association between the severity of ADHD symptoms and parenting stress. Participants for this study included 80 children (mean age = 10 years, 9 months) with a DSM-IV diagnosis of ADHD confirmed by a comprehensive clinical diagnostic assessment. Parents reported their own stress levels as well as the severity of their children’s ADHD symptoms, aggression, emotional lability, and executive functioning difficulties. Results indicated that the severity of children’s hyperactivity/impulsivity symptoms but not their inattention related to parenting stress. Multiple mediational analyses indicated that the association between hyperactivity/impulsivity and parenting stress was explained by children’s perceived comorbid aggression levels, emotional lability, and executive functioning difficulties. No significant differences in the strength of the mediators were found. The current study provides initial data showing that the perceived impairments in children’s self-regulation across emotional, cognitive, and behavioral domains are what parents report as stressful, not simply the severity of ADHD symptoms. Due to the cross-sectional nature of this study and shared variance from relying solely on parent report, it will be critical for future research to replicate our findings using longitudinal and multi-informant data such as teacher reports and standardized assessments.     

Biased Self-Perceptions,Peer Rejection,and Aggression in Children

This study examined whether children’s biased self-perceptions of peer acceptance are associated in a linear or curvilinear fashion with aggression, whether associations are moderated by peer rejection status, and whether associations apply uniquely to reactive aggression. Children in the 4th through 7th grades completed a self-report measure on their social functioning (SPPC; Harter 1982), and teachers reported on children’s social functioning and aggression. Self-perceptual bias was operationalized as the standardized residual difference between children’s self-perceptions and their teachers’ perceptions of their peer acceptance. Rejected status moderated associations between biased self-perceptions and reactive aggression. Among non-rejected children, biased perceptions were not significantly associated with reactive aggression. In contrast, among peer-rejected children, reactive aggression was elevated in those who greatly underestimated as well as in those who even modestly overestimated their peer acceptance. This pattern was observed whether or not proactive aggression was statistically controlled. In contrast, biased self-perceptions were not associated with proactive aggression for rejected or nonrejected children. Implications are discussed with regard to future research and potential interventions for aggressive children.     

Parental Marital Discord and Treatment Response in Depressed Adolescents

Evidence suggests that parental marital discord contributes to the development of internalizing and externalizing symptoms in children and adolescents. Few studies, however, have examined the association between parental marital discord and youth’s response to treatment. The present study examined the impact of interparental discord on treatment response in a randomized control trial of adolescents with major depression enrolled in the Treatment for Adolescents with Depression Study (TADS). Participants were 260 adolescents from two-parent households randomly assigned to one of four treatment groups: fluoxetine (FLX), cognitive behavior therapy (CBT), their combination (COMB), or placebo (PBO). Logistic regressions revealed that parental marital discord interacted with youth gender and co-morbid oppositionality symptoms to predict group differences in treatment response.     

Maternal Depressive Symptoms and Child Social Preference During the Early School Years: Mediation by Maternal Warmth and Child Emotion Regulation

This longitudinal study examined processes that mediate the association between maternal depressive symptoms and peer social preference during the early school years. Three hundred and fifty six kindergarten children (182 boys) and their mothers participated in the study. During kindergarten, mothers reported their level of depressive symptomatology. In first grade, teachers rated children’s emotion regulation at school and observers rated the affective quality of mother-child interactions. During second grade, children’s social preference was assessed by peer nomination. Results indicated that mothers’ level of depressive symptomatology negatively predicted their child’s social preference 2 years later, controlling for the family SES and teacher-rated social preference during kindergarten. Among European American families, the association between maternal depressive symptoms and social preference was partially mediated by maternal warmth and the child’s emotion regulation. Although the relation between maternal depressive symptoms and children peer preference was stronger among African American families than Europrean American families, its mediation by the maternal warmth and child’s emotion regulation was not found in African American families.     

Developmental Risk and Young Children’s Regulatory Strategies: Predicting Behavior Problems at Age Five

Children with early developmental delays are at heightened risk for behavior problems and comorbid psychopathology. This study examined the trajectories of regulatory capabilities and their potentially mediating role in the development of behavior problems for children with and without early developmental delays. A sample of 231 children comprised of 137 typically developing children and 94 children with developmental delays were examined during mildly frustrating laboratory tasks across the preschool period (ages 3–5). Results indicated that children with delays had greater use of maladaptive strategies (distraction, distress venting) and lower use of adaptive strategies (constructive coping) than typically developing children. For both groups, strategies had similar rates of growth across time; maladaptive strategies decreased and adaptive strategies increased. The intercept of strategy use, but not the slope, was found to mediate the relation between developmental risk and externalizing behaviors. Findings support that dysregulation, rather than the developmental risk, may be responsible for the high levels of comorbid psychopathology.     

Effects of Child Psychopathology on Maternal Depression: The Mediating Role of Child-Related Acute and Chronic Stressors

In light of recent research highlighting the potential effects of children’s behavior on mothers’ mental health, the current study examined 679 mothers and their adolescent children from a community-based sample to determine the effects of youth psychopathology on maternal depression and levels of child-related stress in mothers’ lives. It was hypothesized that the number of past clinical diagnoses in 15-year-old adolescents would predict the presence of maternal depression at youth age 15 and 5 years later, as well as more episodes of maternal depression during the follow-up period. Furthermore, it was hypothesized that increased levels of child-related stress in mothers’ lives would mediate these relationships. Regression analyses indicated that past youth diagnoses do confer risk for the presence of current and future maternal depression, as well as more episodes of maternal depression, and mediation analyses revealed that child-related acute and chronic stress were mediators of the relationship between youth diagnoses and the presence of maternal depression at follow-up. Findings suggest that increased levels of child-related objective stress in mothers’ lives are one mechanism by which children’s psychopathology affects mothers’ future risk for depression.