Alcohol use behaviors established during adolescence are important contributing factors for the later progression to alcohol dependence (Grant et al., 2006; Pitkanen et al., 2005). These data provide an example of the important interplay of genetic and environmental risks in the development of drinking milestones during this critical period of adolescence. Using a longitudinal sample of European and African American adolescent drinkers, we demonstrate that the ADH1B rs1229984 minor A allele is associated with a protective effect for early drinking behaviors, and in the environmental high-risk context of most or all best friends drinking, this genetic protection is negated.
