Long-term treatment of obsessive-compulsive disorder after an acute response: A comparison of fluoxetine versus placebo

Few controlled studies have evaluated the longterm continuation of pharmaco therapy for relapse prevention in patients with obsessive-compulsive disord er (OCD), This study assessed efficacy and safety of fluoxetine versus plac ebo in preventing relapse of OCD during a 52-week period in responders to s hort-term administration of fluoxetine. Patients who met DSM-IV criteria fo r OCD and had a Yale-Brown Obsessive Compulsive Scale score greater than or equal to 19 were treated with single-blind fluoxetine 20, 40, or 60 mg/day (based on physician assessment of response and tolerability). After 20 wee ks, responders were randomly assigned to receive continued treatment with f luoxetine or placebo and were monitored for relapse for up to 52 weeks. Of 130 patients who entered the study, 71 (55%) were randomly assigned to rece ive fluoxetine (N = 36) or placebo (N = 35), Patients who received fluoxeti ne had numerically lower relapse rates compared with those who received pla cebo, although the difference was not significant (Kaplan-Meier 1-year rela pse rates: fluoxetine, 20.6%; placebo, 31.9%; one-tailed p value = 0.137). In additional analyses evaluating patients on the basis of fluoxetine dose at randomization, patients who continued treatment with fluoxetine 60 mg/da y (N = 52) had significantly lower rates of relapse than those who were swi tched to placebo (Kaplan-Meier 1-year relapse rates: fluoxetine, 17.5%; pla cebo, 38.0%; one-tailed p value = 0.041). Those who responded to the acute treatment phase with 40 (N = 18) or 20 (N = 1) mg/day had low overall rates of relapse, and the difference between continued fluoxetine and placebo tr eatment for these patients was not significant, For responders to the 60 mg /day dosage, those patients who continued treatment with fluoxetine were pr ovided greater protection against relapse than those patients switched to p lacebo.