Rapid Response to Day Hospital Treatment in Bulimia Nervosa and Purging Disorder

Treatments for bulimia nervosa (BN) have relatively high rates of nonremission and relapse, meaning that improving treatments is a high priority in this area. Rapid response to treatment -cessation of binge eating and vomiting symptoms within the first weeks of treatment - is a robust predictor of improved post-treatment outcomes and lower relapse rates, but no study has tried to facilitate rapid response as a means of improving treatment outcomes. The present study responds to this gap in the literature by testing a 4-session CBT-based individual intervention for rapid response (i.e., \"CBT-RR\"), designed to augment standard day hospital (DH) treatment for BN and Purging Disorder (PD) by focusing on strategies and skills for rapid symptom interruption. CBT-RR will be compared to a matched-intensity augmentative motivational interviewing (MI) intervention. Participants will be recruited from a hospital-based day program for eating disorders, and will be randomly assigned to one of the two conditions in addition to the DH as usual. participants will be assessed at pre-intervention, post-intervention, week 4 of DH, post-DH, and 6 months follow-up. It is hypothesized that compared to those who receive MI, patients who receive CBT-RR will be more likely to exhibit a rapid response to day hospital treatment (i.e., \