Brief early adolescent multi-family therapy (BEAM) trial for anorexia nervosa: a feasibility randomized controlled trial protocol.

Introduction: Multi-family therapy (MFT) is a recommended treatment for adolescent anorexia nervosa internationally. Despite recent significant advances in single-family therapy, the evidence base for MFT remains relatively small. Several individual and family factors have been associated with poorer outcomes in single-family therapy, many of which may be addressed or ameliorated by MFT if delivered early in treatment. This trial aims to determine the feasibility and acceptability of adding a five-day multi-family therapy group to the early stages of family therapy for anorexia nervosa. Secondary objectives are to explore effect size changes in key individual and family factors across treatment.

Methods: This feasibility trial will use a randomised controlled design. Sixty adolescents (age 10-17 inclusive) with anorexia nervosa or atypical anorexia nervosa and their parents will be recruited from a community-based specialist eating disorder service in London, UK. Participants will be randomly allocated to receive six months of eating disorder focussed family therapy with a five-day MFT group (experimental group) or without (control group). Block randomisation will be conducted by the King's Clinical Trials Unit and researchers will be blind to participants' intervention allocation. Feasibility, acceptability and secondary outcomes measures will be collected at baseline, post-MFT, end of treatment, six-month and 12-month follow-up. Feasibility and acceptability will be assessed according to trial sign-up rates, retention, measure completion rates and satisfaction. Secondary outcomes include physical health improvements, changes in psychiatric symptoms, emotion regulation and reflective function capacity, expressed emotion, parental difficulties and therapeutic alliance. Descriptive data and exploration analysis of trends and effect sizes will be reported upon at trial completion.

Discussion: The five-day MFT program developed for this study is novel, brief and more accessible than previous MFT models. The inclusion of a data collection point during treatment and follow-up will allow for an investigation of trends during and after treatment. This will allow exploration and comparison of future potential mediators and moderators of MFT and FT-AN outcomes and how these may differ between treatments.

Trial Registration: ISRCTN registry; ISRCTN93437752 , on 27 January 2021.