Two-Way ANCOVAs with group (controls vs. alcoholics) and PDYN genotype (CC and CT genotypes vs. TT genotype; subjects with the C, high risk genotype were pooled) as between factors revealed no additional significant effects in the caudate nucleus, while uncovered a significant main effects of alcoholism for PDYN [F(1, 35) = 7.3, p = 0.011], Dyn A [F(1, 39) = 5.3, p = 0.027] and LER [F(1, 35) = 10.3, p = 0.003], and a trend for Dyn B [F(1, 36) = 3.84, p = 0.058] in the putamen (Figure 2). This evidence concerns the gene PDYN and alcohol drinking.