Further investigation of citalopram on alcohol consumption in heavy drinkers: responsiveness possibly linked to the DRD2 A2/A2 genotype

Citalopram, a selective serotonin reuptake inhibitor. has been suggested to reduce alcohol intake, at least in some studies. The present study aimed t o replicate our earlier finding that citalopram reduces alcohol intake only in subjects with a weekly consumption ranging between 300 and 800 g of pur e alcohol. Subjects (n = 37) in this study were therefore randomized into a double-blind treatment with either 40 mg of citalopram daily or placebo fo r a 4-week period. Another purpose was to investigate whether different mea sures of central neurotransmission might predict an effect of citalopram or placebo on alcohol consumption. Therefore, prolactin response to d-fenflur amine, platelet monoamine oxidase-B activity, as well as the genotype of th e dopamine D2 receptor (DRD2), A1 and A2 alleles, were determined and relat ed to individual changes in alcohol consumption. Citalopram was not found t o be superior to placebo in reducing alcohol intake. Prolactin responses to d-fenfluramine and levels of platelet monoamine oxidase-B activities were not related to changes in alcohol consumption, regardless of treatment with citalopram or placebo. When subjects were grouped according to the presenc e or absence of the DRD2 Al allele, those with the genotype DRD2 A2/A2 were found to transiently reduce their alcohol consumption during citalopram tr eatment. This finding seems to indicate that, in subjects with heavy alcoho l consumption, possession of the genotype DRD2 A2/A2 may be prerequisite fo r a treatment effect of citalopram. (C) 2001 Elsevier Science Inc. All righ ts reserved.