Psychosis in Parkinson's disease: diagnosis and treatment.

1. This article reviews the prevalence, diagnosis, pathophysiology and management of psychosis in Parkinson's disease. 2. Psychosis in Parkinson's disease has been associated with all antiparkinsonian medications. The most common symptoms are vivid disturbing dreams, visual hallucinations and paranoid delusions. 3. The emergence of psychosis reduces the patient's functional capacity and increases caregiver burden. It also poses a therapeutic dilemma because effective treatment of psychotic symptoms may result in worsening of motor symptoms and vice versa. 4. Increased physician awareness is essential for proper diagnosis and management. Withdrawal of anticholinergic medications and amantadine followed by levodopa dose adjustment is effective in many patients. 5. Atypical neuroleptics, in low doses, may be successful when other measures have failed. However, these agents are not approved for treating Parkinsonian psychosis and must be considered as investigational therapies.