Differential weight restoration on olanzapine versus fluoxetine in identical twins with anorexia nervosa

Objective: No studies have compared the response to selective serotonin reuptake inhibitors and atypical antipsychotics in anorexia nervosa. This case study examines such a comparison. Method: This report describes a case of 12-year-old identical twins with anorexia nervosa, one of whom was treated with olanzapine and the other with fluoxetine, while undergoing family therapy. Results: Twin A treated with fluoxetine went from 75 to 84.4% ideal body weight, while Twin B treated with olanzapine went from 72 to 99.9% ideal body weight over the course of 9 months. Discussion: This case supports the need for adequately powered, controlled clinical trials to test the efficacy of olanzapine in adolescents presenting with anorexia nervosa. © 2011 by Wiley Periodicals, Inc.