Low-dose olanzapine monotherapy in girls with anorexia nervosa, restricting subtype: focus on hyperactivity.

Objective: The aim of this study was to evaluate the efficacy of olanzapine in girls with anorexia nervosa, restricting subtype (ANr). Methods: Thirteen patients (mean age 13.7 +/- 2.3 years, age range 9.6-16.3 years) enrolled in a multimodal treatment for ANr were evaluated with standardized measures at baseline and after 1 and 6 months after starting low-dose olanzapine monotherapy (mean dose 4.13 mg/day). Results: A significant improvement was evident on weight (body mass index, BMI), global functioning (Children's Global Assessment Scale, CGAS), eating attitudes (Eating Attitudes Test-26, EAT-26), anxious-depressive symptoms (Child Behavior Checklist, CBCL) and hyperactivity (Structured Inventory for Anorexic and Bulimic Syndromes, SIAB). At the end of the 6-month follow up, 7 patients were responders according to an improvement of at least 50% in the EAT-26 results. The only measure that improved significantly in responders, but not in nonresponders, was hyperactivity (SIAB). Clinical improvement, in terms of both body mass index (BMI) recovery and global functioning, paralleled the improvement of hyperactivity, was evident at the end of the first month of treatment, and further increased in the following 5 months, with minimal side effects. Conclusions: Low-dose olanzapine monotherapy may be useful as adjunctive treatment of youths with ANr. It is suggested that efficacy may be mediated by a decrease of hyperactivity.