Other studies have focused on aggregate measures of genetic risk, testing for moderation of risk associated with genome-wide, polygenic scores. In line with previous twin studies, polygenic risk scores were more strongly associated with alcohol problems (Salvatore et al., 2014) and externalizing behaviors (Salvatore et al., 2015) under conditions of low parental monitoring and high peer deviance. In another study, the effect of polygenic risk scores on smoking was mitigated in neighborhoods with greater social cohesion (Meyers et al., 2013). These aggregate measures of genetic risk still explain relatively small amounts of variance in AUD, or other substance use outcomes. However, as GWAS sample sizes continue to grow and phenotyping in the discovery samples is further refined, our ability to detect the interplay of genetic risk and environmental influences will increase (Dudbridge, 2013).
