Analyses of the alcohol-induced Stimulation revealed a main effect of OPRM1 genotype (β = 1.84, SE = 0.93, t = 1.97, p = .05), an OPRM1 × Alcohol interaction (β = −1.06, SE = 0.52, t = −2.04, p< .05), and an OPRM1 × Alcohol × Time interaction (β = 0.53, SE = 0.28, t = 1.92, p = .056). As shown in Figure 2, these results suggest that G-allele carriers report greater stimulation overall, greater stimulation in response to alcohol versus placebo, and greater increases in stimulation in the alcohol condition across time, as compared to A-allele homozygotes. A similar pattern of results was found for OPRM1 effects on alcohol-induced Vigor and Positive Mood. Analyses of alcohol-induced Vigor revealed a main effect of OPRM1 genotype effect (β = 0.85, SE = 0.37, t = 2.29, p< .05), an OPRM1 × Alcohol interaction (β = −0.48, SE = 0.19, t = −2.49, p< .05), and an OPRM1 × Alcohol × Time interaction (β = 0.21, SE = 0.10, t = 2.00, p< .05). See Figure 3. Likewise, for Positive Mood
