Is weight gain really a catalyst for broader recovery?: The impact of weight gain on psychological symptoms in the treatment of adolescent anorexia nervosa.

The main aims of this study were to describe change in psychological outcomes for adolescents with anorexia nervosa across two treatments, and to explore predictors of change, including baseline demographic and clinical characteristics, as well as weight gain over time. Participants were 121 adolescents with anorexia nervosa from a two-site (Chicago and Stanford) randomized controlled trial who received either family-based treatment or individual adolescent supportive psychotherapy. Psychological symptoms (i.e., eating disorder psychopathology, depressive symptoms, and self-esteem) were assessed at baseline, end of treatment, 6-month, and 12-month follow-up. Conditional multilevel growth models were used to test for predictors of slope for each outcome. Most psychological symptoms improved significantly from baseline to 12 month follow-up, regardless of treatment type. Depressive symptoms and dietary restraint were most improved, weight and shape concerns were least improved, and self-esteem was not at all improved. Weight gain emerged as a significant predictor of improved eating disorder pathology, with earlier weight gain having a greater impact on symptom improvement than later weight gain. Adolescents who presented with more severe, complex, and enduring clinical presentations (i.e., longer duration of illness, greater eating disorder pathology, binge-eating/purging subtype) also appeared to benefit more psychologically from treatment.