Few studies have evaluated whether an association exists between response to alcohol and polymorphisms in the OPRM1 gene. In one study, the ability of naltrexone to blunt an alcohol-induced high was found to be greater in those participants with the 118G allele [94]. The finding of a more intense response to a mu opioid receptor antagonist found by Ray and Hutchinson [94] is consistent with previous studies that have demonstrated that subjects with the 118G allele that were given naloxone had higher cortisol concentrations [36]. It is also consistent with the finding that naltrexone may be more efficacious for the treatment of alcoholism in those with at least one 118G allele [32]. However, Ray and Hutchinson [94,95] have also reported that young participants in an IV alcohol challenge, with one 118G allele, reported feeling more subjective feelings of "high" across rising breath alcohol concentrations, as compared to those participants homozygous for the 118A allele. These findings are not consistent with the findings in the present study for the 118G allele, nor are they particularly consistent with studies that have found
