PSYCHOTHERAPY AND BULIMIA-NERVOSA - LONGER-TERM EFFECTS OF INTERPERSONAL PSYCHOTHERAPY, BEHAVIOR-THERAPY, AND COGNITIVE-BEHAVIOR THERAPY

Objective: To determine whether cognitive behavior therapy (CBT) for b ulimia nervosa has a specific therapeutic effect and determine whether a simplified behavioral treatment (BT) of CBT is as effective as the full treatment. Design: Randomized controlled trial involving three ps ychological treatments. Two planned comparisons, CBT with interpersona l psychotherapy (IPT), and CBT with BT. Closed 12-month follow-up peri od. Independent assessors. Setting: Secondary referral center. Patient s: Seventy-five consecutively referred patients with bulimia nervosa. Patients with concurrent anorexia nervosa were excluded. Interventions : Cognitive behavior therapy, IPT, BT conducted on an individual outpa tient basis. There were nineteen sessions over 18 weeks. Six experienc ed therapists administered all three treatments. There was no concurre nt treatment. Main Outcome Measure: Frequency of binge eating and purg ing. Results: High rate (48%) of attrition and withdrawl among the pat ients who received BT. Over follow-up, few patients undergoing BT met criteria for a good outcome (cessation of all forms of binge eating an d purging). Patients in the CBT and IPT treatments made equivalent, su bstantial, and lasting changes across all areas of symptoms, although there were clear temporal differences in the pattem of response, with IPT taking longer to achieve its effects. Conclusions: Bulimia nervosa may be treated successfully without focusing directly on the patient' s eating habits and attitudes to shape and weight. Cognitive behavior therapy and IPT achieved equivalent effects through the operation of a pparently different mediating mechanisms. A further comparison of CBT and IPT is warranted. The behavioral version of CBT was markedly less effective than the full treatment.