During adolescence, presence of the ADH1B variant (GA/AA genotypes) was associated with a protective main effect among ever-drinkers for first intoxication and first DSM-5 symptom in univariate and multivariate models (Table 2). In the final interaction model set with GxE product terms, the effect of the ADH1B variant was strong for both first intoxication (HR=0.56, 95% CI 0.41–0.76) and first DSM-5 symptom (HR=0.45, 95% CI 0.26–0.77). In secondary analyses of the entire sample that included never-drinkers, presence of the variant exhibited no effect on drinking initiation (HR in univariate model=1.12, 95% CI 0.92–1.36), consistent with the mechanism of the variant of only exhibiting an effect in response to alcohol consumption.
