Objectives: The primary aim of the study was to evaluate the effectiveness and tolerability of open-label olanzapine on motor and vocal tics in children and adolescents with Tourette syndrome (TS). Secondary aims included assessing the response of TS-associated disruptive behaviors to olanzapine exposure.
Method: Twelve children and adolescents (mean age 11.3 +/- 2.4 years, range 7-14 years) with Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) TS were enrolled in a single-site, 6-week, open-label, prospective, flexible-dose design in outpatients receiving monotherapy with olanzapine. Standardized ratings of tic symptoms, disruptive behaviors, and aggression were obtained, along with adverse events and safety data.
Results: Over the 6-week trial, olanzapine administration was associated with a significant decrease in total tic severity as measured by the Yale Global Tic Severity Scale (30% reduction by week 6; effect size 0.49). A significant majority of subjects were rated as "much improved" or "very much improved" on the Clinical Global Impressions-Improvement Scale (GCI-I) by both clinicians (67%; 8/12) and parents (64%; 7/11). Attention-deficit/hyperactivity disorder (ADHD) symptoms showed significant improvements from baseline for both inattention (33% decrease) and hyperactive/impulsivity (50% decrease) scores (effect sizes 0.44 and 0.43, respectively). Aggression was also decreased as assessed by fewer numbers of aggressive episodes on the Overt Aggression Scale (OAS). Little change in anxiety symptoms was noted. The most widely reported side effects were drowsiness/sedation and weight gain; adverse events were generally well tolerated. Mean weight gain of 4.1 +/- 2.0 kg was observed over the 6-week trial, a mean percent change of 8.4 +/- 4.4 (p < 0.001).
Conclusions: Additional studies of the benefits of olanzapine treatment for tic control as well as the commonly associated co-morbid features of TS are indicated, especially if approaches to predict or minimize weight gain can be determined.