We tested the hypothesis that allelic variants of the human dopamine D2 receptor E8 genotype are associated with (i) dopamine D2 antagonist tiapride dose in treatment of alcohol withdrawal (n = 50) and (ii) with anxiety and depression in patients during alcoholism detoxification therapy (admission n = 87; discharge n = 50). DRD2 E8 A/A genotype was associated with increased dose of tiapride during a 9-day detoxification therapy and with increased anxiety and depression scores on admission and 2 weeks later. The findings suggest a pharmacogenetic influence of DRD2 E8 genotype on tiapride efficacy in alcohol withdrawal. In an earlier report, DRD2 E8 A/A genotype was associated with reduced responsiveness to the dopamine D2 agonist apomorphine; however, it is not clear whether both findings share the same biological basis. Earlier findings concerning association of DRD2 E8 A/A with increased anxiety and depression are replicated for the first time.