Low-Dose Olanzapine in the Treatment of Adolescents with Anorexia Nervosa: An Observational Naturalistic Case–Control Study

Abstract

Background:

Although recent articles have investigated the use of low-dose olanzapine in different psychiatric conditions, only one study so far has assessed this treatment in 13 girls with anorexia nervosa (AN).

Methods:

Observational naturalistic case–control study aimed at reporting the use and tolerability of low-dose olanzapine in the context of a multidisciplinary hospital intervention for adolescents with AN. Three groups with AN were compared: group 1 was treated with low-dose olanzapine (≤5 mg/day), group 2 with full-dose olanzapine (>5 mg/day), and group 3 (control group) was treated without antipsychotics. Psychopathology was assessed at admission (T0) and discharge (T1) with Eating Disorders Inventory-3 Eating Disorders Risk, Body Uneasiness Test Global Severity Index (BUT-GSI), Beck's Depression Inventory-II (BDI-II), and Self-administered Psychiatric Scales for Children and Adolescents, Depression subtest (SAFA-D). Possible differences among the three groups, concerning clinical and treatment variables, were screened. Then, potential differences of T0–T1 modifications in psychopathological variables among the three treatment groups were assessed with analyses of covariance, corrected for baseline psychopathology and potential confounders, including possible concurrent antidepressants.

Results:

A total of 118 patients were enrolled (F = 94.1%; mean age = 15.4 ± 1.7 years), including 52 controls, 37 treated with low-dose olanzapine, and 29 with full-dose olanzapine. Low-dose olanzapine was well tolerated and used for a mean of 132.1 (±98.6) days, starting with a dosage of 3.4 (±1.2) mg/day and increasing to a maximum dose of 4.4 (±1.1) mg/day. The multidisciplinary intervention resulted in an improvement of BUT-GSI (p < 0.001), BDI-II (p < 0.001), and SAFA-D (p < 0.001) for the entire sample. Individuals treated with full-dose olanzapine experienced a significantly lower improvement in depressive measures: BDI-II (F[2,61] = 12.653, p < 0.001, η² = 0.269) and SAFA-D (F[2,57] = 7.413, p = 0.001, η² = 0.170), than the other groups.

Discussion:

This naturalistic controlled study expands the existing evidence on the use and tolerability of low-dose olanzapine in adolescents with AN. These results should be assessed in wider and prospective samples.