Early weight gain predicts treatment response in adolescents with anorexia nervosa enrolled in a family-based partial hospitalization program

Objective: Improved treatment outcome in family-based treatment (FBT) for anorexia nervosa (AN) is predicted by weight gain occurring early in the course of treatment (i.e., about 4 lbs by week 4). Although prior work suggests that early weight gain in higher levels of care (e.g., partial hospitalization programs [PHP]) predicts weight restoration at discharge, no study has examined the specific rate of gain within FBT-informed PHP programs that best predicts treatment response. Method: This study examined rate of weight gain in pounds and percent expected body weight (EBW) that predicts positive outcome in 70 patients (M age = 15.49 years, SD = 2.56) with AN who were enrolled in a family-based PHP. Results: Receiver operator characteristic analyses demonstrated that changes in %EBW during weeks 2–5 were more useful than changes in weight in predicting positive outcome. Gaining at least 8.9 pounds or over 8% of EBW in the first 4 weeks of treatment significantly predicted positive outcome. Discussion: Findings suggest that positive outcome in an FBT-informed PHP is predicted by rapid weight gain in the initial weeks of treatment. Research is needed to identify specific family and patient characteristics that facilitate weight gain and to develop corresponding interventions to improve outcome.