A 24-Week Randomized, Double-Blind, Placebo-Controlled Study of Escitalopram for the Prevention of Generalized Social Anxiety Disorder

Stuart A. Montgomery, MD; Rico Nil, PhD; Natalie Dürr-Pal, MD; Henrik Loft, PhD; Jean-Philippe Boulenger, MD

J Clin Psychiatry 2005;66(10):1270-1278

Article Abstract

Objective: Escitalopram has proven efficacy in the short-term treatment of generalized social anxiety disorder (SAD). The present relapse prevention study investigated relapse rates during a 24-week, randomized, double-blind, placebo-controlled period in patients with generalized SAD who had responded to 12-week open-label treatment with escitalopram.

Method: A total of 517 patients with a primary diagnosis of generalized SAD (per DSM-IV criteria) and a Liebowitz Social Anxiety Scale (LSAS) total score of >= 70 received 12 weeks of open-label treatment with flexible doses (10-20 mg/day) of escitalopram. Of these patients, 371 responded (Clinical Global Impressions-Improvement scale [CGI-I] score of 1 or 2) and were randomly assigned to 24 weeks of double-blind treatment with escitalopram (10 or 20 mg/day) (N = 190) or placebo (N = 181), continuing with the dose level administered at the end of the open-label period. Relapse was defined as either an increase in LSAS total score of >= 10 or withdrawal due to lack of efficacy, as judged by the investigator. The study was conducted from January 2001 to June 2002.

Results: Survival analysis of relapse and time to relapse showed a significant advantage for escitalopram compared to placebo (log-rank test: p < .001). The risk of relapse was 2.8 times higher for placebo-treated patients than for escitalopram-treated patients (p < .001), resulting in significantly fewer escitalopram-treated patients relapsing (22% vs. 50%), at both doses. Escitalopram was well tolerated during double-blind treatment of generalized SAD, and only 2.6% of the escitalopram-treated patients withdrew because of adverse events. The overall discontinuation rate, excluding relapses, was 13.2% for patients treated with escitalopram and 8.3% for patients treated with placebo.

Conclusion: Escitalopram was effective and well tolerated in the long-term treatment of generalized SAD.