Model 2 (Table 2) presents the estimates for G × E. There was a significant interaction between relationship status and polygenic scores for each alcohol behavior. We refitted each of these models with interactions between relationship status and each covariate and interactions between GPS and each covariate (plotted in Fig. 2; see Supporting information, Tables S3–S5 for full results) to account for possible confounding [41]. P-values were attenuated, especially in the models for drinking frequency and AD symptoms, but the nature of the interactions remained unchanged for the other phenotypes. The shape of the interaction was similar among all phenotypes, but most pronounced for intoxication. In the case of intoxication frequency, there was a stronger association between genetic risk score and intoxication frequency among individuals who are not in romantic relationships, and a relatively weaker association between genetic risk score and intoxication frequency among those who were in romantic relationships.
