Managing psychosis in Parkinson's disease

Psychotic symptoms are common in drug-treated Parkinson's disease patients. These consist primarily of visual hallucinations, but also include other symptoms, in particular auditory symptoms. Delusions are considerably less common but are more problematic because they are most commonly paranoid in nature. Psychotic symptoms carry a poor p-rognosis in terms of an increased risk of imminent dementia, nursing home placement and death. Only clozapine has level I evidence to support its use, but quetiapine is usually used first as it is sometimes helpful and is the only other antipsychotic drug proven not to worsen motor function in Parkinson's disease. There is less support for the use of cholinesterase inhibitors. Electroconvulsive therapy may be used in extremis, when all else fails.