Review of the putative association of dopamine D2 receptor and alcoholism: a meta-analysis.

Eight recent studies have focused on the putative association of the dopamine D2 receptor (DRD2) gene and alcoholism. In this report, these studies are reviewed and the data and findings are examined in a meta-analysis. Four reports find a statistically significant increased risk for alcoholism in subjects carrying the A1 allele and 4 failed to observe a significant increase in risk. Overall, our meta-analysis of the results from all 8 studies supported a statistically significant association between the A1 allele of DRD2 and alcoholism, with an apparent increase in relative risk associated with increased severity of alcoholism. These results must be interpreted cautiously because the A1 allele of DRD2 varies significantly in frequency from one population to another. This variability in the population frequency of the A1 allele could result in an apparent association resulting from unrelated population differences. These findings support the need for carefully designed studies that minimize the ethnic heterogeneity of the subject and control populations.