Psychosis in Parkinson's disease

Psychosis is a disabling nonmotor complication of Parkinson's disease (PD). Visual hallucinations are the most common clinical manifestation and have been observed in up to 40% of patients with advanced disease in hospital-based series. Age, cognitive dysfunction, depression, as well as severity and duration of disease have all been identified as risk factors in multiple studies. All major anti parkinsonian drugs can induce psychosis in at-risk patients. Early drug-induced psychosis has been observed in up to 16% of patients treated with dopamine agonists and has been associated with increased risk for the development of dementia later on. Management of psychosis in PD is complex and includes control of potential triggers and reductions of polypharmacy as well as the addition of atypical antipsychotics. Cholinesterase inhibitors may prove an additional option in psychotic PD patients with dementia. (C) 2003 Movement Disorder Society.