Square-root transformations of AlcQF, SRE-Total, SRE-3month, SRE-Heavy, and ASQ-Light were employed to achieve normality. In order to assess the relations of rs1799971 and rs3778150 with these and the other measures of subjective response to alcohol and alcohol use, hierarchical multiple regression analyses composed of three steps were conducted. Age, age-squared (to account for linear and quadratic effects of age), sex, and the first three eigenvectors generated from the principal components analysis designed to control for population stratification were entered into the model first to control for their effects before including rs1799971 and rs3778150 in the second and third steps, respectively. In this way, results could be evaluated to assess whether rs3778150 was significantly associated with any of the alcohol sensitivity and alcohol use phenotypes after accounting for the effects of rs1799971 genotype. Standardized regression coefficients are provided in the text below, and unstandardized regression coefficients and standard errors are reported in Tables 2–4.
