Efficacy and tolerability of serotonin transport inhibitors in obsessive-compulsive disorder. A meta-analysis.

BACKGROUND: Questions have been raised regarding the relative efficacy and tolerability of the different serotonin transport inhibitors in the treatment of obsessive-compulsive disorder. We compared the results from four large multicenter placebo-controlled trials of the serotonin transport inhibitors clomipramine hydrochloride (N = 520), fluoxetine hydrochloride (N = 355), fluvoxamine maleate (N = 320), and sertraline hydrochloride (N = 325) for the treatment of obsessive-compulsive disorder.

METHODS: Effect size was calculated by subtracting the end-point drug treatment mean change from the end-point placebo mean change and dividing by the end-point pooled change standard deviation. A test for overall differences between effect sizes was conducted, followed by all possible pairwise comparisons. The Yale-Brown Obsessive Compulsive Scale was the primary outcome measure for all four studies.

RESULTS: All four agents were significantly more effective than placebo, with clomipramine significantly more effective than the other three treatments, which did not differ in effect size. A significantly greater percentage of patients treated with clomipramine were rated much or very much improved than were patients treated with fluoxetine, fluvoxamine, or sertraline.

CONCLUSION: While the results of this meta-analysis support the superiority of clomipramine, head-to-head, double-blind comparisons of these compounds would be the best test of comparative efficacy and tolerability.