Randomized Clinical Trial of Family-Based Treatment and Cognitive-Behavioral Therapy for Adolescent Bulimia Nervosa

Abstract

Objective: There is a paucity of randomized clinical trials (RCTs) for adolescents with bulimia nervosa (BN). Prior studies suggest cognitive-behavioral therapy adapted for adolescents (CBT-A) and family-based treatment for adolescent bulimia nervosa (FBT-BN) could be effective for this patient population. The objective of this study was to compare the relative efficacy of these 2 specific therapies, FBT-BN and CBT-A. In addition, a smaller participant group was randomized to a nonspecific treatment (supportive psychotherapy [SPT]), whose data were to be used if there were no differences between FBT-BN and CBT-A at end of treatment.

Method: This 2-site (Chicago and Stanford) randomized controlled trial included 130 participants (aged 12-18 years) meeting DSM-IV criteria for BN or partial BN (binge eating and purging once or more per week for 6 months). Outcomes were assessed at baseline, end of treatment, and 6 and 12 months posttreatment. Treatments involved 18 outpatient sessions over 6 months. The primary outcome was defined as abstinence from binge eating and purging for 4 weeks before assessment, using the Eating Disorder Examination.

Results: Participants in FBT-BN achieved higher abstinence rates than in CBT-A at end of treatment (39% versus 20%; p = .040, number needed to treat [NNT] = 5) and at 6-month follow-up (44% versus 25%; p = .030, NNT = 5). Abstinence rates between these 2 groups did not differ statistically at 12-month follow-up (49% versus 32%; p = .130, NNT = 6).

Conclusion: In this study, FBT-BN was more effective in promoting abstinence from binge eating and purging than CBT-A in adolescent BN at end of treatment and 6-month follow-up. By 12-month follow-up, there were no statistically significant differences between the 2 treatments.

Clinical trial registration information: Study of Treatment for Adolescents With Bulimia Nervosa; http://clinicaltrials.gov/; NCT00879151.

Keywords: adolescent medicine; bulimia nervosa; cognitive-behavioral therapy; eating disorders; family-based treatment.

Figure 1

Consolidated Standards of Reporting (CONSORT) diagram. Note: CBT = cognitive-behavioral therapy; FBT = Family-based therapy; SPT = supportive psychotherapy.

Figure 2

Estimated trajectories of abstinence rate using longitudinal mixed effects modeling. Note: Curves presented here are overall curves and therefore may not exactly agree with the main effect estimates presented in Table 2 that are averaged across two sites; observed n: 51 family-based therapy for bulimia nervosa (FBT-BN) and 58 cognitive-behavioral therapy adapted for adolescents (CBT-A) at baseline; both 43 at end of treatment (EOT); both 34 at 6-month follow-up (FU); 29 FBT-BN and 41 CBT-A at 12-month follow-up.

Figure 3

Moderator effect depicted using dichotomized Family Environment Scale (FES) conflict (N = 109). Note: CBT-A = cognitive-behavioral therapy adapted for adolescents; EOT = end of treatment; FBT-BN = Family-based therapy for bulimia nervosa.