In summary, the findings of this study provide the first evidence that environmental factors, namely parental monitoring and deviant peer affiliation, moderate the influence of an opioid-related gene in the development of AUDs in adolescents. Specifically, these findings highlight the importance of examining interactions between genotype and parental monitoring and deviant peer affiliation, as our data suggest that genetic influences the development of AUDs in adolescents vary dramatically as a function of these factors. Importantly, these environmental factors are tractable and amenable to behavioral intervention, providing an important buffer against the development AUDs in youth.