A reality test: How well do we understand psychosis in Parkinson's disease?

Psychosis in Parkinson's disease (PD) is a major source of distress to patients and caregivers. Although the advent of atypical antipsychotic agents has, to some extent, resolved a clinical dilemma by preserving motor function while treating psychosis, our understanding of psychosis in PD remains in a nascent state. In this article the authors address several issues relating to psychosis in PD including the following: 1) prevalence, 2) possible etiologies and risk factors and 3) treatment. They also identify limitations in our understanding of this complex phenomenon and conclude that, despite availability of reasonable treatments for psychosis in PD, the search for a better understanding of the phenomenon must continue.