A clomipramine dosage reduction study in the course of long-term treatment of obsessive-compulsive disorder patients.

Ten patients with DSM-III-R obsessive-compulsive disorder (OCD) who were being treated chronically with clomipramine (270 +/- 20 mg/day) were studied to determine the minimum dose of clomipramine needed to maintain therapeutic benefit. These 10 patients were among the 17 of 18 patients recently reported to develop a return of OC symptoms following discontinuation of clomipramine under double-blind, placebo-controlled conditions. Each patient was rated twice--open and double-blind--at both initial and minimum doses of clomipramine, using the following three OC measures: the Yale-Brown Obsessive Compulsive Scale (YBOCS), the National Institute of Mental Health-Obsessive Compulsive Scale (NIMH-OC), and the National Institute of Mental Health Global Obsessive-Compulsive Scale (NIMH Global OC Scale). Gradual, open dosage reduction resulted in a mean dosage of 165 +/- 19 mg/day, a reduction of 105 mg/day (approximately 40%, t = 5.55, p less than .001). This decrease in dose was accompanied by no significant change in the three OC measures, as determined by paired t-test. These results suggest that even though OCD patients were not able to discontinue medication completely, they were able to do well at lower doses than those used initially in treatment of the disorder.