Rapid response to behavioral/pharmacological obesity treatments for binge-eating disorder predicts better clinical outcomes

Abstract

Objective: The objective of this study was to examine rapid response and its prognostic significance in participants with binge-eating disorder (BED) and obesity in a randomized clinical trial testing behavioral and pharmacological obesity treatments for BED. Methods: A total of 136 participants were randomly assigned (balanced 2 × 2 factorial) to 16-week behavioral and/or pharmacological (naltrexone/bupropion) obesity interventions. Masked assessments occurred monthly throughout treatment and at posttreatment. Results: Rapid response (≥65% reduction in frequency of binge-eating episodes after 1 month of treatment), observed in 55% (n = 75/136) of participants, was unrelated to baseline sociodemographic and clinical characteristics. Rapid response was more common in behavioral therapy than not and in naltrexone/bupropion than placebo. Rapid response was associated with binge-eating remission. Mixed models revealed that rapid response was associated with greater reductions in binge-eating frequency, eating-disorder psychopathology, percent weight loss, and metabolic variables (total cholesterol, glycated hemoglobin A1c) at posttreatment. Rapid response effects on outcomes did not vary by treatment. Conclusions: In a randomized clinical trial testing behavioral and pharmacological obesity treatments for BED with co-occurring obesity, rapid response was a robust prognostic indicator of binge-eating remission and significantly better behavioral, psychological, and metabolic outcomes. Non-rapid response to behavioral and pharmacological obesity treatments could signal a need to switch to alternative treatments.