Olanzapine for Psychosis in Patients With Parkinson's Disease With and Without Dementia

Twenty-one patients with Parkinson's disease and psychosis were included in an open-label 8-week trial of olanzapine. Eight subjects had dementia. Six subjects (29%) discontinued treatment prematurely because of drowsiness. Delusions and hallucinations improved significantly, and 80% were rated as much or very much improved. There was no worsening of parkinsonism or cognition.