Building on this prior research the current study focused on whether DAT1 A9 and A10 genotypes independently or in epistatic interaction with the OPRM1 G-allele influence alcohol consumption, and subjective responses to orally administered alcohol in young, healthy, social drinkers. Our choice of candidate genotypes was based on 1) the well-established interactions between opioidergic and DAergic systems, 2) the demonstrated functional significance of the A118G SNP and the DAT VNTRs, and 3) prior exploratory studies showing epistatic interactions between OPRM1*G and DAT A9 vs A10 alleles. The two prior studies (Anton et al., 2012, Ray et al., 2014) selected subjects based on prospectively determined A118G genotype, and then completed retrospective DAT1 genotyping on the selected subjects. To better understand of the role of DAT1 A9 vs A10 alleles in alcohol response, and examine epistatic interactions with OPRM1*G alleles, subjects in the current study were genotyped for both DAT1 (A9 vs A10) and OPRM1 (AA vs *G) genotypes after completion of the alcohol sensitivity sessions. We opted to study social drinkers rather than persons with AUD to minimize the effects of
