Males reported significantly more drinks per drinking day (5.6±0.3) compared to females (4.3±0.2; p=0.001); therefore gender was included as a covariate in the primary analyses of PC1 for acute adaptation. There were no significant differences between any other pairs of demographic variables (all p≥0.10). There was no significant effect of session order on PC1 (p>0.49); hence session order was excluded from further analyses. The final model included family history of alcoholism, recent drinking history, SNP genotype, and the recent drinking history*genotype interaction; gender was retained as a covariate.
