The impact of comorbid posttraumatic stress disorder on eating disorder treatment outcomes: Investigating the unified treatment model.

Purpose: Many women with eating disorders (EDs) have comorbid posttraumatic stress disorder (PTSD). However, there have been few studies on how comorbid PTSD may impact ED treatment outcomes.

Method: Participants were 2,809 patients from residential ED treatment facilities who were treated using the Unified Treatment Model (UTM). We investigated whether PTSD diagnosis at admission was associated with changes in Eating Disorder Examination-Questionnaire (EDE-Q) scores, binge eating, self-induced vomiting, and restriction, across three time points, as well as clinically significant improvement and treatment drop-out.

Results: Using latent growth models, with time modeled as a second-order polynomial, we found that EDE-Q scores and behavioral symptoms decreased from admission to discharge, but increased from discharge to 6-month follow-up. PTSD diagnosis was associated with higher baseline EDE-Q scores and restriction, and lower binge-eating frequency. PTSD diagnosis was not associated with symptom change over time, treatment dropout, or clinically significant change.

Discussion: Although PTSD diagnoses were associated with higher ED symptom levels at admission, PTSD was not associated with worse treatment outcomes, suggesting the UTM is a promising treatment for patients with and without PTSD. Future studies should investigate the impact of ED treatment on PTSD symptoms in order to determine the need for integrated treatments for these comorbid conditions.