A double-blind placebo-controlled pilot study of olanzapine in childhood/adolescent pervasive developmental disorder

Atypical antipsychotics have been shown to improve disruptive and repetitive behaviors in pervasive developmental disorders (PDDs), but they require assessment of potential side effects. This is the first placebo-controlled trial of olanzapine in the treatment of children and adolescents with PDD. Eleven patients with a diagnosis of either autism, Asperger's syndrome, or PDD not otherwise specified (PDD-NOS) and aged 6-14 years were randomised into an 8-week double-blind, placebo-controlled, parallel treatment study with olanzapine. There was a significant linear trend x group interaction on the Clinical Global Impressions-Improvement (CGI-I) and 50% on olanzapine versus 20% on placebo were responders. Olanzapine was associated with significant weight gain (7.5 ± 4.8 lbs vs. 1.5 ± 1.5 lbs on placebo). Olanzapine may be a promising treatment for improving global functioning of PDDs, but the risk of significant weight gain remains a concern. Additional studies are needed to determine the efficacy and safety of olanzapine in the treatment of children with PDD.