Cognitive Behavioral Therapy to Treat Bulimia Nervosa in Adolescents

Overview

The claire project is a research study testing the use of Cognitive Behavioral Therapy (CBT) to help teenage girls develop healthier eating habits and better ways to manage weight and shape concerns. The study is enrolling girls who are members of the Kaiser Permanente Health plan in the Northwest region. They must be between the ages of 12 and 18 and report binge eating and/or purging (vomiting, laxative or diuretic use) at a research established threshold to be eligible for the study. Girls enrolled in the study will either receive the 6-20 session CBT intervention at the time of enrollment or 6 months after they enroll. Assessments including questions about eating behaviors, mood, and general functioning are given on enrollment in the study, and 3- and 6-months following enrollment (also at 9- and 12-months for those in the delayed treatment condition).

The overall aim of this study is to develop a manual-based cognitive behavioral therapy (CBT) intervention to treat bulimia nervosa spectrum conditions (BN and EDNOS) in adolescents identified with these conditions in a large HMO in the Pacific Northwest. Eating disorders are among the most common, impairing, and serious mental health problems-particularly among women. BN and its subclinical variants usually arise in adolescence and affects as many as 10% of young women. Yet despite the significance of these conditions, there are no systematic studies of empirically-based interventions for adolescents with BN and EDNOS. We propose to design an intervention based on the adult CBT model, addressing developmental considerations of adolescents, as well as the risk and maintaining factors of adolescent BN/EDNOS. In addition to developing the adolescent-specific CBT protocol, we will evaluate adolescent, family, and medical provider satisfaction with this intervention. We will estimate effect-size and effect-size variability of this intervention's impact on primary (binge and purge cessation and frequency) and secondary outcomes measured post-treatment and at a 6-month follow-up. These results will inform a subsequent, full-scale, randomized clinical trial. We will develop the intervention in two distinct phases. The first phase (months 1 to 18) will consist of at least two development cycles of the adolescent BN-CBT program. In each cycle, we will draft a version of the intervention, test it with several clinical cases, obtain feedback from adolescents and their parents, and then generate a new version of the intervention. We will start with a 6-20 session adaptation of the Fairburn, Marcus, and Wilson (1993) CBT intervention, and modify it to fit an adolescent population. The development and revision process will be led by our core Expert Group of clinicians and researchers meeting weekly. We will be guided by the Expert Group's prior experiences developing and evaluating CBT for adult BN, and CBT for adolescent depression; and qualitative feedback from youth, parent, and provider stakeholders. In the second phase (months 19 to 32), we will conduct a larger pilot for the purpose of estimating effect size, using the stable, final version of the intervention. The pilot will enroll 50 adolescents and their families who are identified through their pediatric providers in the HMO or in response to a mass mailing of recruitment materials and a screening questionnaire. Half of the participants will be randomized to receive the intervention immediately upon enrollment and half (Wait List) to a treatment as usual followed by a delayed intervention 6 months after enrollment. Data will be collected through interviews with the teen and a parent at baseline, 3 months, 6 months and for the Wait List teens, at 9 months and 12 months post enrollment.