Abstract
The current study examined the interpersonal model of binge eating, which posits that interpersonal problems lead to negative affect, which results in binge eating, over the course of two psychotherapy treatments (interpersonal psychotherapy and cognitive behavioural therapy) in 162 adults with binge‐eating disorder. A series of longitudinal simple mediation analyses preliminarily showed that treatment addresses the mechanisms of the interpersonal model of binge eating as theoretically proposed in predicting reductions in binge eating, the primary dependent variable, and the secondary dependent variables including global eating disorder psychopathology, shape concern, and weight concern, but not reductions in restraint or eating concern. Moderated mediation analyses did not fully support treatment differences, as changes in the mechanisms of the interpersonal model occurred in both treatments and suggest both treatments addressed negative affect and interpersonal precipitants of eating disorder symptomatology. Future research should replicate this study using variables that do not overlap in time to investigate causation of the model, and more generally, further examine theoretical treatment models and treatment mediators as this research could help improve efficacy of treatment for binge‐eating disorder.