In the current study, we adopted a polygenic approach to examine alcohol problems in adolescence. Adolescence represents an important developmental period for the initiation of alcohol use [20], and, for some, the development of alcohol problems [21]. Longitudinal developmental studies indicate that the heritability of alcohol use increases across adolescence [4,22], making this an important period of the lifespan for beginning to identify the genetic predispositions toward alcohol problems, and how these predispositions interface with key environmental factors (e.g., low parental knowledge and affiliations with deviant peers) known to be associated with higher levels of alcohol problems. We tested the hypotheses that: (1) polygenic risk for alcohol problems—derived from GWAS estimates in one population-based sample—would predict alcohol problems in adolescence in a second, independent, population-based sample; and (2) parenting and peer factors in adolescence would moderate polygenic risk to predict alcohol problems in the independent sample.
