Objective: The present study investigated the efficacy and tolerability of escitalopram in the prevention of relapse of major depressive disorder (MDD) in older patients who had responded to acute treatment with escitalopram.
Method: A total of 405 patients who were aged 65 years or older with a primary diagnosis of MDD (according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria) and a Montgomery-Asberg Depression Rating Scale (MADRS) total score of 22 or more received 12-week, open-label escitalopram 10 or 20 mg per day treatment. Remitters (MADRS </=12) were randomized to 24-week double-blind treatment with escitalopram or placebo. The primary efficacy parameter was the time to relapse, defined as either an increase in MADRS total score to 22 or more or lack of efficacy as judged by the investigator.
Results: Three hundred five patients achieved remission and were randomly assigned to treatment with escitalopram (N = 152) or placebo (N = 153). The primary analysis showed a clear beneficial effect of escitalopram relative to placebo on the time to relapse (log-rank test, chi(2) = 27.6, df = 1, p <0.001). The risk of relapse was 4.4 times higher for placebo- than for escitalopram-treated patients (chi(2) test, chi(2) = 22.9, df = 1, p <0.001). Significantly fewer escitalopram-treated patients relapsed (9%) compared with placebo (33%) (chi(2) test, chi(2) = 27.1, df = 1, p <0.001). Escitalopram was well tolerated with 53 patients (13%) withdrawn as a result of adverse events during the open-label period and three (2%) escitalopram-treated patients and six (4%) placebo-treated patients during double-blind treatment (not significant). The overall withdrawal rate, excluding relapses, was 7.2% for escitalopram and 8.5% for placebo during the double-blind period (not significant).
Conclusion: Escitalopram was effective in preventing relapse of MDD in older patients and was well tolerated as continuation treatment.