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.
