To determine whether psychiatrically stable patients with a history of drug-induced psychosis could be successfully weaned off their antipsychotic drug, we offered consecutive Parkinson disease (PD) patients on quetiapine or clozapine, who were free of any on-going psychosis, to be slowly weaned off their antipsychotic drug. Before the study was aborted 6 PD patients (mean age, 78 years) with an average antipsychotic exposure of 20 months (5 on quetiapine, 1 on clozapine) were enrolled. After the antipsychotic agent was discontinued, psychosis recurred in 5 of 6 patients. In 3 patients the "rebound psychosis" was worse than the original psychotic episode and required subsequent higher antipsychotic medication doses.
(c) 2004 Movement Disorder Society.