Collectively, molecular genetic studies (Tables 3 and 4) provide some evidence for the two forms of alcohol-related GxE implicated in studies using aggregate measures of genotypic variation. First, consistent with a diathesis-stressor model, both distal and proximal stressors were more strongly associated with drinking among individuals with certain gene variants. Second, results indicated that more permissive socio-cultural factors may dampen the protection afforded by variation in alcohol metabolism genes that buffer against heavy drinking. For example, the decreasing protective effect of the ALDH2*2 allele over time in Japan co-occurred with socio-cultural changes associated with post-industrial urbanization, including more liberal attitudes toward drinking and decreasing alcohol prices (Higuchi, Matsushita, Maesato, & Osaki, 2007; Takano, Nakamura, & Watanabe, 1996). Such results highlight the possibility that macro changes in alcohol-related economic and public policies (e.g., availability, advertising, and social norms) may protect against AUDs among individuals with genetic liability and among those with genotypes that provide protection from heavy drinking.
