We also tested the nominally significant SNPs for dominant and recessive allelic effects. Minor alleles at SNP rs1229984 showed evidence for dominant effects on both phenotypes, although the dominant model did not increase the significance of the associations over additive allelic coding. One SNP that was nominally associated with max drinks in the additive model, rs284787 in ADH7 (P = 0.04), showed evidence for recessive allelic effects on max drinks (P = 0.01) and DSM-IV symptom count (P = 0.0009).
