Models with two-way interaction terms indicated that GABRA2 had a significant effect on alcohol dependence among men, but no influence among women. Also, no significant moderation of genotype by daily hassles or uplifts was identified when effects were held constant across gender, leading to the erroneous conclusion that there were no GxE effects. In contrast, when gender-specific GxE effects were examined (a GxExE effect), a strong and significant negative association between positive daily experiences on risk for alcohol dependence emerged, but only among men with the high-risk genotype at GABRA2. These findings were present in the full COGA sample, and in a subsample that excluded probands with alcohol dependence.
