Maternal Parenting Behaviors Amplify Environmental Influences on Developmental Trajectories of Alcohol Use During Adolescence.

Compared to peer alcohol use, less is known on how parenting practices may modify genetic and environmental contributions to alcohol use longitudinally across adolescence. This study examined whether two maternal parenting behaviors, supervision and harsh parenting, may suppress or amplify genetic and environmental influences on three distinct developmental trajectories of adolescent alcohol use: normative increasing, early-onset, and low trajectories. Participants were drawn from a longitudinal study of a population-based twin sample (N = 842, 84% European descent, 52.7% female). Adolescents self-reported their past year alcohol use at ages 13, 14, 15, and 17 years, and their mothers reported their supervision and harsh parenting when twins were 13, 15, and 17 years old. Maternal supervision amplified non-shared environmental influence on the normative increasing and early-onset trajectories, whereas maternal harsh parenting amplified shared environmental influence on the early-onset trajectory and non-shared environmental influence on the low trajectory, respectively. The findings suggest maternal parenting practices as a potent developmental context that modulates the environmental influences of other proximal processes on adolescent alcohol use, and suggest that family-based parenting-focused intervention could be especially beneficial for adolescents following the early-onset trajectory.