The goal of this study was to examine the role of sensation seeking and social support in linking genetic risk to alcohol use. We examined two alternative models, one in which both sensation seeking and social support serve as indirect pathways linking genetic risk to alcohol use (Figure 1, Panel A), and another in which sensation seeking serves as an indirect pathway linking genetic risk to alcohol use, and social support moderates the association between genetic risk and sensation seeking and alcohol use (Figure 1, Panel B). Complex behavioral outcomes, such as alcohol use, are polygenic such that many common genetic variants contribute to risk. In this study, we index individuals’ genetic predispositions by using a genome-wide polygenic score (GPS) approach that aggregates effects of common genetic variants across the genome. The calculation of reliable GPS requires a discovery genome-wide association study (GWAS) with a large sample size to estimate the effects of common genetic variants across the genome (Dudbridge, 2013). We focused on alcohol consumption genome-wide polygenic scores (alc-GPS) because the largest GWAS on alcohol-related phenotype to date was
