A Randomized Controlled Two-Stage Trial in the Treatment of Bulimia Nervosa, Comparing CBT Versus Motivational Enhancement in Phase 1 Followed by Group Versus Individual CBT in Phase 2

Objective: To conduct a randomized, controlled, two-stage trial in the treatment of bulimia nervosa, comparing cognitive-behavioral therapy (CBT) versus motivational enhancement in Phase 1 followed by group versus individual CBT in Phase 2. Methods: A total of 225 patients with bulimia nervosa or eating disorder not otherwise specified (EDNOS) were recruited into a randomized controlled trial lasting 12 weeks with follow-ups at 1 year and 2.5 years. Results: Patients improved significantly across all of the interventions with no differences in outcome or treatment adherence. Including motivational enhancement therapy rather than a CBT first phase of treatment did not affect outcome. Conclusions: Outcome differences between individual and group CBT were minor, suggesting that group treatment prefaced by a short individual intervention may be a cost-effective alternative to purely individual treatment. EDNOS = eating disorder not otherwise specified; BN = bulimia nervosa; CBT = cognitive-behavioral therapy; MET = motivational enhancement therapy; MET-I = individual course of motivational enhancement therapy offered before individual cognitive therapy; MET-G = individual motivational enhancement therapy offered before cognitive behavior therapy group; CBT-G = individual cognitive behavior therapy offered before cognitive behavior therapy group; RCT = randomized controlled trial; NHS = National Health Service.