36). These findings are somewhat discordant with the results of the study by Filbey and colleagues (10), where the G-allele carriers exhibited greater mesocorticolimbic activation than A-allele homozygotes both pre- and post-priming, although the absence of a pre- versus post-priming contrast in the Filbey paper limits the comparability of the study results. Further, the difference in sample characteristics between the two studies may add to the complexity of the findings. For example, the endogenous opioid-mediated dopaminergic functioning caused by the ingestion of alcohol may differ in alcohol dependent individuals (as in the current study) as compared to non-dependent light or heavy drinkers (as in the Filbey study) (37), which could potentially explain the discrepancy of reward-related regional activation between the two study samples. The present study findings should be considered preliminary, however, given the small sample sizes available for the genetic analysis.
