Next, to test whether marital status was a relevant moderator of genetic influences on alcohol use across time, we examined the interaction between marital status, polygenic risk score, and age to predict heavy episodic drinking. Among married individuals at age 21, we found that heavy episodic drinking was higher among those with higher polygenic scores compared to those with lower polygenic scores. This finding is indicative of a pathogenic gene-by-environment interaction effect among those who marry early (i.e., by age 21), suggesting that early marriage does not have the same protective benefit in terms of attenuating genetic predispositions as seen in older samples (Dinescu et al., 2016; Heath et al., 1989; Horn et al., 2013; Kendler et al., 2016).
