Dopamine receptor responsivity in alcoholic patients before and after detoxification

OBJECTIVE: To assess central dopamine receptor responsivity in alcoholic patients during their usual alcohol consumption and after detoxification. METHOD: Plasma prolactin levels were measured at 0, 30, 60, and 90 min after administration of 5 mg haloperidol i.m. in 21 hospitalized male alcoholic patients during usual alcohol consumption, and 13 days later (mean, range 7-17 days), after detoxification. The test was also performed in seven healthy male volunteers. The patterns of prolactin responses were compared using repeated measures analysis of variance. RESULTS: The prolactin responses to haloperidol increased significantly after detoxification compared to those during usual alcohol consumption (state x time interaction P < 0.01; planned comparisons for times 0 and 90 min between states P = 0.03). Compared to controls, the responses of the patients before detoxification were lower (group-time interaction P = 0.001), and the difference was not significant after detoxification (P = 0.19). The magnitude of plasma prolactin (PRL) responses were not related to duration of alcohol abuse, score in the Brief Michigan Alcoholism Screening Test (BMAST) scale, or family history of alcoholism. CONCLUSIONS: Alcohol detoxification is accompanied by a normalization of the low responsivity of central dopaminergic receptors during alcohol abuse. The data support the hypothesis of a participation of the central dopaminergic system in alcohol dependence.