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 χ2 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.