To address these gaps in the literature, we report findings from a longitudinal study of a sample of young adults enriched for risk who were followed between ages 21 and 25 where we examined (1) whether marriage was associated with frequency of heavy episodic drinking, and (2) whether marital status moderated measured genetic influences (as measured with a genome-wide polygenic risk score) to predict frequency of heavy episodic drinking across time. Genome-wide polygenic risk scores reflect a state-of-the-science approach to index one’s level of genetic predisposition for a given trait or behavior (Wray et al., 2014). This approach uses the results from a genome-wide association study (GWAS) in a large-scale discovery sample to calculate personalized indices of genetic risk in a target sample. Common genetic variants, or single nucleotide polymorphisms (SNPs), are tested for their association with a given trait/behavior in the discovery sample (Bogdan, Baranger, & Agrawal, 2018; Maier, Visscher, Robinson, & Wray, 2018; Salvatore et al., 2014; Wray et al., 2014). Then, the effect sizes from the discovery GWAS are used to calculate the weighted linear composite corresponding to the number of risk-increasing alleles carried by each individual in the target sample.
