This clinical experiment attempted to evaluate the importance of the putative OPRM1 asn40asp genetic polymorphism in predicting naltrexone effects on alcohol in a group of individuals meeting criteria for alcohol dependence, but who were not seeking treatment. A number of studies had suggested that the asparagine to aspartate substitution at the 40 position on the mu opiate receptor protein resulted in a different response to alcohol, a greater mitigation of alcohol effects by naltrexone, or a greater treatment response to naltrexone (Ray et al., 2011). This study utilized a previously validated sub-acute naltrexone dosing and bar-lab strategy to further evaluate the role of this single SNP OPRM1 difference under controlled conditions. In addition, since the brain opioid and dopamine systems interact, and likely play a role in reward and reinforcement, we also explored interaction of the OPRM1 asp40 SNP with the putative dopamine transporter VNTR.
