A randomized controlled trial of atomoxetine in generalized social anxiety disorder

The current mainstays of social anxiety disorder pharmacotherapy are serotonergic agents, with less known about the efficacy of more noradrenergic drugs. Atomoxetine (ATM), a highly selective norepinephrine reuptake inhibitor, is currently approved for the treatment of attention-deficit/hyperactivity disorder (ADHD). We describe the first controlled trial of ATM with respect to efficacy and tolerability in adults with the generalized subtype of social anxiety disorder (GSAD) without comorbid ADHD. Twenty-seven outpatients with clinically prevailing diagnoses of GSAD by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition were randomized in a 1:1 ratio to 10 weeks of double-blind flexible-dose treatment with either ATM 40-100 mg per day (n = 14) or placebo (n = 13). Primary efficacy outcome was score at end point on the Liebowitz Social Anxiety Scale in the intention-to-treat sample. There were no significant group differences in patients completing the study (ATM, 79%; placebo, 77%). Whereas ATM was well tolerated, there were no significant differences in clinical efficacy between ATM and placebo for GSAD. There were few responders overall (ATM, 21%; placebo, 33%), but proportions were similar in each group (chi [1, 26] = 0.47; P = 0.67). Analysis of variance with repeated measures on the Liebowitz Social Anxiety Scale was performed to detect any differential change in social anxiety symptoms between groups. A significant time effect was found (F = 8.71; P = 0.007), but the time-by-treatment interaction was nonsignificant (F = 0.013; P = 0.91). Although the small sample size limits confidence in the reported results, the comparable, and low, response rates for ATM and placebo suggest that in the absence of comorbid ADHD, ATM is unlikely to be an effective agent for the treatment of GSAD.