Gene-Environment Interplay for Childhood and Adolescent Antisocial Behavior

Individual differences in parenting behavior are associated with youth conduct problems (CP), but few studies examine the independent associations of positive and negative parenting with CP, despite their factorial independence. Monoamine oxidase-A (MAOA) genotype and callous-unemotional (CU) traits are also associated with CP and may moderate the association between parenting behavior and CP. This dissertation is based on two independent samples: Sample 1 is a two-year prospective longitudinal study of approximately 221 well-characterized 6-9 year-old youth with and without attention-deficit/hyperactivity disorder (ADHD) whereas Sample 2 consisted of nearly 2,500 adolescents followed prospectively for six years from the National Longitudinal Study of Adolescent Health (Add Health). In each sample, we tested the association of multi-method and multi-dimensional measures of positive and negative parenting factors, MAOA, and their interaction as predictors of growth in CP (oppositional defiant disorder, conduct disorder, rule-breaking behavior, and aggressive behavior), including evaluation of potential differential susceptibility. We also tested the moderating role of CU traits with respect to the prospective prediction of CP from parenting behavior in Sample 1. Several key results emerged from these inter-related studies: first, overall, MAOA-L youth displayed more significant growth in CP, but a significant parenting x MAOA interaction suggested that children with MAOA-H displayed more growth in CP at higher levels of corporal punishment and at lower levels of parental involvement than MAOA-L youth. We also observed significant interactions where positive reinforcement predicted growth in aggressive behavior, but only in children with high CU traits: no association was observed among children with mean or low CU traits. Overall, these studies suggest that genetic and trait-level factors significantly moderated the association between parenting and CP. Implications for intervention development and delivery are discussed with respect to the development of significant CP