A 12-Week Double-Blind, Placebo-Controlled, Flexible-Dose Trial of Vilazodone in Generalized Social Anxiety Disorder

Abstract

Objective: To examine the efficacy, safety, and tolerability of vilazodone for subjects (aged 18-75 years) with generalized social anxiety disorder.

Method: Forty-four subjects with generalized social anxiety disorder (DSM-IV-TR criteria) were randomized to vilazodone or placebo in a 12-week double-blind, flexible-dose trial. Change from baseline to endpoint on the Liebowitz Social Anxiety Scale (LSAS) was the primary outcome measure. Secondary outcome measures included response and remission rates and changes in depression and anxiety. Data were collected between November 2012 and April 2014. The study was conducted at a private clinical trials facility in New York, New York.

Results: The mean baseline LSAS score was 91.9 (SD = 17.5) and the mean Clinical Global Impressions-Severity scale score was 5.3 (SD = 0.56), indicating marked to severe illness. There were no significant baseline differences in severity of social anxiety between the treatment groups. At the end of treatment, in the intent-to-treat sample (n = 39), the vilazodone group had improved significantly more than the placebo group by 14.3 points on the LSAS (t = 1.80, P = .04, one-tail test) (Cohen d = 0.58).

Conclusions: The findings suggest that vilazodone may be a promising treatment for social anxiety disorder. Further study is needed given the limited sample size.

Trial registration: ClinicalTrials.gov identifier: NCT01712321.

Figures

Figure 1.

Consort Diagram for Vilazodone Clinical Study aExcludes 2 ITT subjects with fewer than 6 weeks at minimum dose level; includes 16 completers and 1 early termination subject who achieved minimally adequate treatment. bExcludes 3 ITT subjects with fewer than 6 weeks at minimum dose level; includes 17 completers. Abbreviation: ITT = intent-to-treat.

Figure 2.

Liebowitz Social Anxiety Scale and Effect Size at Each Visit (intent-to-treat)a aBars are 1 standard error from the mean.

Figure 3.

Liebowitz Social Anxiety Scale and Effect Size at Each Visit (minimally adequately treated)a aBars are 1 standard error from the mean.