Pharmacologic enhancement of central nervous system serotonin and dopamine functions has been postulated to improve maintenance of abstinence in patients with alcoholism. To test this hypothesis, patients with alcoholism who completed a 42-day inpatient treatment program were randomized to be administered, in a double-blind fashion, either 5-hydroxytryptophan and carbidopa, levodopa and carbidopa, or placebo for 1 year. Eight of 31 patients who entered the analysis remained abstinent from alcohol for 1 year; however, there was no significant effect of the treatment condition on maintenance of abstinence. Baseline psychologic measures showed that patients who abstained from alcohol had more education and higher scores on memory function tests. Measures of cerebrospinal fluid obtained before the start of the study indicated that all patients who had higher concentrations of the dopamine metabolite homovanillic acid relapsed, suggesting that further research is needed to elucidate the role of dopamine in alcoholism.