Cognitive behavioural therapy compared to control conditions in treating bulimia nervosa and binge‐eating disorder: A systematic review and meta‐analysis

OBJECTIVE: Our systematic review and meta-analysis aimed to investigate how Cognitive-Behavioural Therapy (CBT) performs against control conditions, such as waiting-list, self-help interventions, psychological and pill placebos and treatment as usual (TAU) in Bulimia Nervosa (BN) and Binge Eating Disorder (BED). METHODS: We systematically searched MEDLINE, Embase, PsycINFO, Cochrane CENTRAL, WHO ICTRP, ClinicalTrials.gov for randomized controlled trials (RCTs) comparing CBT to any control condition, in patients with BED and BN. Analyses employed random-effects models, calculating risk ratios (RR) for dichotomous outcomes, weighted mean differences (MD) for continuous outcomes and standardized mean differences (SMD) when scales varied. The primary outcomes were remission and binge eating frequency. Subgroup and sensitivity analyses assessed robustness. RESULTS: 42 RCTs (2807 participants randomized) were included. CBT demonstrated superiority over waitlists in achieving remission (RR = 3.21, 95% CI: 2.15; 4.81) and in reducing binge-eating frequency (SMD = -.88, 95% CI: -1.08; -.69). However, compared to self-help, effects were attenuated for remission (RR = 1.53, 95% CI 1.19; 1.95) and were not significant for binge frequency (SMD = -.14, 95% CI: -.32; .04). Data were scarce for other inactive comparators. DISCUSSION: The superiority of CBT is contingent on the comparator used, highlighting the necessity for rigorous controls such as a psychological placebo or other therapy modalities.