Comparing the effectiveness and predictors of cognitive behavioural therapy-enhanced between patients with various eating disorder diagnoses: a naturalistic study

Cognitive behaviour therapy-enhanced (CBT-E) is an effective treatment for non-underweight patients with eating disorders. Its efficacy and effectiveness is investigated mostly among transdiagnostic samples and remains unknown for binge eating disorder. The aim of the present study was to assess several treatment outcome predictors and to compare effectiveness of CBT-E among adult out-patients with bulimia nervosa (n=370), binge eating disorder (n=113), and those with a restrictive food pattern diagnosed with other specified feeding and eating disorders (n=139). Effectiveness of CBT-E was assessed in routine clinical practice in a specialised eating disorders centre. Eating disorder pathology was measured with the EDEQ pre- and post-treatment, and at 20 weeks follow-up. Linear mixed model analyses with fixed effect were performed to compare treatment outcome among the eating disorder groups. Several predictors of treatment completion and outcome were examined with a regression analysis. No predictors for drop-out were found, except the diagnosis of bulimia nervosa. Eating disorder pathology decreased among all groups with effect sizes between 1.43 and 1.70 on the EDE-Q total score. There were no differences in remission rates between the three groups at end of treatment or at follow-up. Eating disorder severity at baseline affected treatment response. The results can be generalised to other specialised treatment centres. No subgroup of patients differentially benefited from CBT-E supporting the transdiagnostic perspective for the treatment of eating disorders. Longer-term follow-up data are necessary to measure persistence of treatment benefits.