Youth Appraisals of Inter-parental Conflict and Genetic and Environmental Contributions to Attention-Deficit Hyperactivity Disorder: Examination of GxE Effects in a Twin Sample

Identification of gene x environment interactions (GxE) for attention-deficit hyperactivity disorder (ADHD) is a crucial component
to understanding the mechanisms underpinning the disorder, as prior work indicates large genetic influences and numerous environmental
risk factors. Building on prior research, children’s appraisals of self-blame were examined as a psychosocial moderator of
latent etiological influences on ADHD via biometric twin models, which provide an omnibus test of GxE while managing the potential
confound of gene-environment correlation. Participants were 246 twin pairs (total n = 492) ages 6–16 years. ADHD behaviors were assessed via mother report on the Child Behavior Checklist. To assess level of
self-blame, each twin completed the Children’s Perception of Inter-parental Conflict scale. Two biometric GxE models were
fit to the data. The first model revealed a significant decrease in genetic effects and a significant increase in unique environmental
influences on ADHD with increasing levels of self-blame. These results generally persisted even after controlling for confounding
effects due to gene-environment correlation in the second model. Results suggest that appraisals of self-blame in relation
to inter-parental conflict may act as a key moderator of etiological contributions to ADHD.