Catechol-O-methyltransferase gene val158met polymorphism and depressive symptoms during early childhood

Catechol-O-Methyltransferase (COMT) is a critical regulator of catecholamine levels in the brain. A functional polymorphism of the COMT gene, val158met, has been linked to internalizing symptoms (i.e., depression and anxiety) in adolescents and adults. We extended this research by investigating whether the val158met polymorphism was associated with childhood symptoms of depression and anxiety in two independent samples of young children (Ns=476 and 409). In both samples, preschool-aged children were genotyped for the COMT val158met polymorphism. Symptoms of psychopathology were assessed via parent interviews and primary caregiver reports. In both samples, children homozygous for the val allele had higher levels of depressive symptoms compared to children with at least one copy of the met allele. Our findings extend previous research in older participants by showing links between the COMT val158met polymorphism and internalizing symptoms in early childhood. © 2013 Wiley Periodicals, Inc

A Longitudinal Investigation of Predictors of the Association Between Age 3 and Age 6 Behavioural Inhibition.

Children who exhibit elevated levels of the temperament trait behavioural inhibition (BI) across time may be at greatest risk for anxiety. However, little research has investigated the influence of other temperamental traits, particularly positive emotionality (PE), on the continuity of BI in childhood, nor whether parental overprotection influences associations between early and later child BI. To explore whether PE and overprotection shape associations between early and later BI, this longitudinal study of three-year-olds

The serotonin transporter linked polymorphic region and brain-derived neurotrophic factor valine to methionine at position 66 polymorphisms and maternal history of depression: Associations with cognitive vulnerability to depression in childhood

Preliminary work indicates that cognitive vulnerability to depression may be associated with variants of the serotonin transporter promoter polymorphism (5-HTTLPR) and the valine to methionine at position 66 (val66met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene; however, existing reports come from small samples. The present study sought to replicate and extend this research in a sample of 375 community-dwelling children and their parents. Following a negative mood induction, children completed a self-referent encoding task tapping memory for positive and negative self-descriptive traits. Consistent with previous work, we found that children with at least one short variant of the 5-HTTLPR had enhanced memory for negative self-descriptive traits. The BDNF val66met polymorphism had no main effect but was moderated by maternal depression, such that children with a BDNF methionine allele had a heightened memory for negative self-descriptive traits when mothers had experienced depression during children\u27s lifetimes; in contrast, children with a methionine allele had low recall of negative traits when mothers had no depression history. The findings provide further support for the notion that the 5-HTTLPR is associated with cognitive markers of depression vulnerability and that the BDNF methionine allele moderates children\u27s sensitivity to contextual factors. Copyright © Cambridge University Press 2013

The dopamine D2 receptor gene and depressive and anxious symptoms in childhood: Associations and evidence for gene-environment correlation and gene-environment interaction

ObjectiveS: Research implicates the A1 allele of the dopamine D2 receptor gene (DRD2) Taq1A polymorphism in the development of depression and anxiety. Furthermore, recent papers suggest that children with A1 allele of this gene may receive less positive parenting, and that the effects of this gene on child symptoms may be moderated by parenting. We sought to replicate and extend these findings using behavioral measures in a nonclinical sample of young children. Methods: In a sample of 473 preschool-aged children and their mothers, structured clinical interview measures and maternal reports of child symptoms were collected, and standardized observations of parent-child interactions were conducted. Results: An association was detected between the DRD2 A1 allele and symptoms of depression and anxiety indexed using interview and parent report methods. As found in previous reports, children with the DRD2 A1 allele received less supportive parenting and displayed higher levels of negative emotionality during parent-child interactions. Tests of mediation and moderation were conducted. Conclusion: We found associations between the DRD2 A1 allele and early-emerging anxious and depressive symptoms in a community sample of preschool-aged children, and evidence of a gene-environment correlation and moderation of the main effect of child genotype on child symptoms by parenting. © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins

Preschool Irritability:Longitudinal Associations With Psychiatric Disorders at Age 6 and Parental Psychopathology

OBJECTIVE: There is increasing scientific and clinical attention to chronic irritability in youth. However, little is known about the predictive validity and clinical significance of chronic irritability during early childhood. This prospective, longitudinal study examined associations of chronic irritability with psychiatric disorders and parental psychopathology in a large community sample of preschoolers. METHOD: Four hundred sixty two preschool-age children were assessed at ages 3 and 6. Child psychopathology was assessed at baseline (age 3) and follow-up (age 6) using a diagnostic interview, the Preschool Age Psychiatric Assessment (PAPA), with parents. Items from the PAPA were used to create a dimensional measure of chronic irritability. Parental psychopathology was assessed with a diagnostic interview at baseline. RESULTS: Chronic irritability was concurrently associated with a wide range of psychiatric disorders and functional impairment at ages 3 and 6. Age 3 irritability predicted age 6 depression, oppositional defiant disorder, and functional impairment after controlling for baseline disorders. Irritability was also associated with parental depression and anxiety. CONCLUSIONS: Findings underscore the central role of irritability in early-emerging mental health problems. They are consistent with longitudinal studies in older youth indicating that chronic irritability predicts later depression and anxiety and support the importance of early detection and interventions targeting preschool irritability