(PS8-A21) Examining How Medical, Behavioral, and Emotional Changes During Residential Treatment Moderate Improvements in Eating Disorder Pathology

Patients with severe eating disorders (EDs) often require residential treatment. In particular, patients with anorexia nervosa (AN) are more likely to drop out of treatment prematurely and less likely to experience sustained symptom remission following treatment compared to other EDs. Although the ED field has identified numerous pre- and post-treatment predictors of outcome among individuals with EDs, there is a scarcity of research on the processes that occur during treatment. Indeed, there is some debate regarding the most important treatment foci of treatment -- nutritional intervention vs. emotion regulation -- particularly for low-weight patients. The inability to obtain adequate weight restoration for clinically low-weight patients has significant biological, psychological, and medical consequences. Thus, change in weight is an important component of treatment. However, difficulties in emotion regulation, such as emotional avoidance, have also been found to influence the risk for and maintenance of ED and may impede treatment progress. Finally, research indicates a reduction in behavioral and cognitive symptoms is crucial for ED recovery. Identifying which of these processes facilitate the most change during ED treatment can inform treatment targets and improve care. Therefore, the aim of this study is to investigate whether weight, cognitive/behavioral, or emotional changes may best explain improvement in ED pathology from admission to discharge. Participants are 228 girls and women (M_age = 22.3) who received residential treatment for their AN diagnosis from The Renfrew Center. Patients attended treatment for at least four weeks (average length of stay = 36.5 days) and completed weekly assessments that included a measure of ED cognitions and behavioral urges (e.g., I had strong urges to exercise in order to burn calories or influence my shape/weight) and emotional avoidance (e.g., I tried to suppress feelings I don’t like by trying not to think about them). Patients’ weekly weight changes were also used from their medical records. Multilevel modeling will be utilized to investigate whether the slope of the cognitive/behavioral urges, emotional avoidance, or weight gain moderates the most change in ED pathology from admission to discharge. By identifying which mechanisms of change are most influential on treatment progress, patient care can be improved.