Finally, while the correlation between sumAD3r and factAD3r_1 is strong (0.911), the correlation falls to 0.370 with the second factor score (factAD3r_2) which primarily loads onto the two DSM-IIIR criteria that address alcohol withdrawal. We did not observe an association with factAD3r_1 and only detected nominal association (p = 0.03) between one SNP in intron 3 (rs4695152) and the second factor score. Previous association studies have found evidence that GABRA2 genetic variation modulates aspects of alcohol withdrawal (Fehr et al., 2006; Soyka et al., 2008) and this relationship may explain, to an extent, our finding with the factAD3r_2 score. For both “within” and “total” tests, no significant association (smallest p-value ∼0.01 before correction for multiple testing) was detected between the alcohol use measures, including quantity and frequency of consumption, and SNPs in GABRA2.
