limitation is the fact that participants accurately guessed the alcohol and saline conditions, thereby raising the potential for expectancy effects. At least one study has found that G-allele carriers report greater expectancy for the rewarding effects of alcohol (i.e., drinking to enhance positive affect) (Miranda et al., 2010). Further, the absence of taste, visual, and olfactory alcohol cues in the alcohol infusion may have dampened the overall experience of alcohol craving, consistent with previous comparisons of oral versus intravenous alcohol administration (Ray et al., 2007). Lastly, the OPRM1 × Alcohol × Time interaction predicting stimulation was marginal (p = 0.56) and should be interpreted with caution and in the context of the totality of the findings.
