Combined clozapine and electroconvulsive therapy for the treatment of drug-induced psychosis in Parkinson's disease.

Drug-induced psychosis is a serious late complication of Parkinson's disease (PD) that requires aggressive treatment. Recent studies have found clozapine a highly effective and ECT a possibly useful intervention. Two cases are presented that illustrate a possible treatment role for ECT. The cases demonstrate that ECT has significant but short-lived antipsychotic effects when used alone. However, patients who do not respond to clozapine monotherapy can be given adjunctive treatment with ECT. The combination therapy resulted in abrupt alleviation of psychotic symptoms in one of the cases, and maintenance with low-dose clozapine allowed for long-term efficacy. On the basis of these findings, a therapeutic approach to patients with drug-induced psychosis in PD is suggested.