Higher polygenic predispositions for alcohol problems (based on GWAS estimates from a population-based sample of young adults) predicted a higher number of adolescent alcohol problems in an independent, population-based sample. In addition, environmental factors in adolescence moderated these polygenic predispositions. Genetic predispositions were more important under conditions of low parental knowledge and high peer deviance. These gene-by-environment interactions, although small in magnitude, are consistent with previous findings from studies that show that environments low in social control or high in social opportunity permit the expression of genetic predispositions [10]. In contrast, environments high in social control or low in social opportunity may inhibit the expression of that same predisposition. Accordingly, prevention and intervention efforts that increase parental knowledge and decrease affiliations with deviant peers may be one strategy for reducing risk for adolescents with genetic predispositions toward alcohol problems; however additional study is needed before making strong claims about the potential effectiveness of such interventions.
