Clomipramine in the treatment of patients with obsessive-compulsive disorder. The Clomipramine Collaborative Study Group.

Two double-blind studies at 21 centers evaluated the therapeutic efficacy, safety, and tolerability of up to 300 mg/d of clomipramine hydrochloride or an equivalent number of placebo capsules in the treatment of 520 patients with obsessive-compulsive disorder, of whom 239 had had the disorder for at least 2 years (study 1) and 281 had been ill for at least 1 year (study 2). On the two principal measures of the severity of the disorder, ie, the Yale-Brown Obsessive Compulsive Scale and the National Institute of Mental Health Global Obsessive Compulsive Scale, clomipramine was significantly more effective than placebo in both studies. The mean reduction in the Yale-Brown Obsessive Compulsive Scale score at the end of 10 weeks of treatment was 38% and 44% in studies 1 and 2, respectively, for the clomipramine-treated patients and 3% and 5% for the placebo-treated patients. The drug was also found to be superior on the basis of the physicians' and patients' evaluations of global therapeutic change. The most frequently observed adverse effects during clomipramine therapy were those typically associated with tricyclic antidepressant drugs. Although uncommon, the occurrence of seizures and elevated aminotransferase values are potentially serious side effects of clomipramine. Clomipramine was generally well tolerated and was effective in reducing obsessive and compulsive symptoms.