Parkinson's disease (PD) is frequently associated with psychiatric problems. Depression generally responds to antidepressant medications or to electroconvulsive therapy (ECT). The nondepressive psychoses generally require a reduction in parkinsonian medications, or possibly a "drug holiday." In patients whose psychosis fails to respond to a reduction in medication or who cannot tolerate the worsening parkinsonism, an antipsychotic drug should be added. Clozapine is probably the drug of choice, with low potency neuroleptics being second-line options.