The A1 Allele at the D2 Dopamine Receptor Gene and Alcoholism

In general, heterogeneity among studies (for alcoholics or controls) is considerably greater than differences between alcoholics and controls overall. The findings to date can best be explained by more conservative interpretations than a confirmed physiologically important allelic association between DRD2 alleles and alcoholism. These other possibilities include sampling error and ethnic variation in those studies that individually showed a large effect.