Fluoxetine, comprehensive cognitive behavioral therapy, and placebo in generalized social phobia

BACKGROUND: Generalized social phobia is common, persistent, and disabling and is often treated with selective serotonin reuptake inhibitor drugs or cognitive behavioral therapy. OBJECTIVE: We compared fluoxetine (FLU), comprehensive cognitive behavioral group therapy (CCBT), placebo (PBO), and the combinations of CCBT/FLU and CCBT/PBO. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Two academic outpatient psychiatric centers. PATIENTS: Subjects meeting a primary diagnosis of generalized social phobia were recruited via advertisement. Seven hundred twenty-two were screened, and 295 were randomized and available for inclusion in an intention-to-treat efficacy analysis; 156 (52.9%) were male, 226 (76.3%) were white, and mean age was 37.1 years. INTERVENTIONS: Treatment lasted for 14 weeks. Fluoxetine and PBO were administered at doses from 10 mg/d to 60 mg/d (or equivalent). Group comprehensive cognitive behavioral therapy was administered weekly for 14 sessions. MAIN OUTCOME MEASURES: An independent blinded evaluator assessed response with the Brief Social Phobia Scale and Clinical Global Impressions scales as primary outcomes. A videotaped behavioral assessment served as a secondary outcome, using the Subjective Units of Distress Scale. Adverse effects were measured by self-rating. Each treatment was compared by means of chi2 tests and piecewise linear mixed-effects models. RESULTS: Clinical Global Impressions scales response rates in the intention-to-treat sample were 29 (50.9%) (FLU), 31 (51.7%) (CCBT), 32 (54.2%) (CCBT/FLU), 30 (50.8%) (CCBT/PBO), and 19 (31.7%) (PBO), with all treatments being significantly better than PBO. On the Brief Social Phobia Scale, all active treatments were superior to PBO. In the linear mixed-effects models analysis, FLU was more effective than CCBT/FLU, CCBT/PBO, and PBO at week 4; CCBT was also more effective than CCBT/FLU and CCBT/PBO. By the final visit, all active treatments were superior to PBO but did not differ from each other. Site effects were found for the Subjective Units of Distress Scale assessment, with FLU and CCBT/FLU superior to PBO at Duke University Medical Center, Durham, NC. Treatments were well tolerated. CONCLUSIONS: All active treatments were superior to PBO on primary outcomes. Combined treatment did not yield any further advantage. Notwithstanding the benefits of treatment, many patients remained symptomatic after 14 weeks.