This study provides initial evidence that parenting practices and affiliation with deviant peers moderate the effect ofOPRM1 on risk for developing an AUD during adolescence, such that genotypic risk for an AUD was significantly lower when parental monitoring was higher and significantly heightened when youth affiliated with more deviant peers. While preliminary, our findings suggest there is heterogeneity in AUD risk in adolescents carrying the G allele and that parental monitoring may play a protective role against vulnerability for AUDs in youth at elevated risk based on OPRM1genotype. Similarly, there was a significant genotype by deviant peer affiliation interaction, such that adolescent carriers of the G allele who reported high levels of deviant peer affiliation were more likely to develop an AUD. This effect was less pronounced in youth who were homozygous for the A allele and low levels of deviant peer affiliation were associated with a low prevalence of AUDs regardless of genotype. These data build on recent findings from longitudinal twin studies that indicate that genetic influences on adolescent substance use are strongest when parental monitoring is relatively
