We report on the effectiveness and safety of gamma-hydroxybutyric acid in the therapy of overt alcohol withdrawal syndromes, their prevention, and the prevention of relapses in formerly detoxified alcoholics. We studied 321 patients (236 men, 85 women), divided into two open-study groups for the treatment and prevention of alcohol withdrawal syndromes and one double-blind study group to evaluate the effects of gamma-hydroxybutyric acid versus placebo on alcoholic craving and relapses in detoxified patients. Gamma-hydroxybutyric acid treatment promptly reduced withdrawal symptoms in all patients and prevented alcohol withdrawal syndromes in 55% of cases. The attenuation of craving in detoxified patients was significantly greater in the gamma-hydroxybutyric acid-treated group in comparison with the placebo-treated group. The therapeutic use of gamma-hydroxybutyric acid was not accompanied by serious side effects. Gammahydroxybutyric acid diversion was poorly represented: gamma-hydroxybutyric acid-induced abuse was reported in 4 (1.1%) of 345 treated patients, and only 9 cases of gamma-hydroxybutyric acid acute poisoning were reported in the years 1992-1995. Our results suggest that gamma-hydroxybutyric acid, with a favorable risk/benefit ratio, is a clinically useful drug in the treatment of alcohol dependence.