This trial is part of a larger project designed to elucidate the neurobiological bases of repetitive behavior disorders and to develop rational, safe, and effective pharmacological treatments. Thus far, the project has established a pathophysiological basis for stereotyped behavior disorder, demonstrated the role of central dopamine deficiency in stereotyped behavior disorder, and provided evidence of the efficacy of both 5-HT uptake inhibitors and atypical antipsychotics in treating stereotyped behaviors.