Efficacy of paroxetine for relapse prevention in social anxiety disorder: a 24-week study

Abstract

Background: The efficacy of selective serotonin reuptake inhibitors in the acute treatment of social anxiety disorder (social phobia) is well established.

Objective: To evaluate whether the efficacy of paroxetine hydrochloride in this disorder is maintained in the long term.

Methods: This was a placebo-controlled multicenter study comprising a single-blind acute treatment phase (12 weeks) and a randomized, double-blind maintenance treatment phase (24 weeks) for patients who had responded to paroxetine during the acute phase. Four hundred thirty-seven adult patients with social anxiety disorder (according to Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, code 300.23) entered the acute phase, and 323 continued into the maintenance phase (162 paroxetine and 161 placebo). The principal outcome measure was the proportion of patients relapsing during the maintenance phase.

Results: Two hundred fifty-seven patients completed the study (136 paroxetine-treated and 121 placebo-treated patients). Significantly fewer patients relapsed in the paroxetine group than in the placebo group (14% vs 39%; odds ratio, 0.24; 95% confidence interval, 0.14-0.43; P<.001). At the end of the study, a significantly greater proportion of patients in the paroxetine group showed improvement as shown on the Clinical Global Impression global improvement rating compared with the placebo group (78% vs 51%; odds ratio, 3.66; 95% confidence interval, 2.22-6.04; P<.001). Compared with placebo, paroxetine treatment significantly (P<.001) improved the symptoms of social anxiety as shown on the Liebowitz Social Anxiety Scale, Social Phobia Inventory, Sheehan Disability Scale, Symptom Checklist-90 score, and EuroQol visual analogue scale, indicating decreased disability and increased well-being. Paroxetine was well tolerated.

Conclusion: Paroxetine is an effective long-term treatment for social anxiety disorder.