Psychiatric syndromes in Parkinson's disease

Purpose of review: To examine progress about relevant behavioural and psychiatric disorders in Parkinson's disease, such as depression, apathy, psychosis, and impulse control disorder.Recent findings: Several recent studies have characterized the phenomenology of depression in Parkinson's disease, and randomized controlled trials have demonstrated the efficacy of tricyclics, selective serotonin reuptake inhibitors and psychotherapy for depression in Parkinson's disease. Apathy is a valid behavioural syndrome in Parkinson's disease and is associated with depression and cognitive deficits. Psychosis is highly prevalent in the late stages of the disease, but there are few effective therapeutic modalities for this psychiatric condition. Impulse control disorders are also relatively frequent in Parkinson's disease, and are associated with comorbid psychiatric disorders.Summary: Standardized criteria should be used to diagnose depression and apathy in Parkinson's disease. Psychotherapy and pharmacotherapy are useful treatment modalities for affective disorders in Parkinson's disease. Clozapine is still the most effective, albeit rarely used, treatment for psychosis in Parkinson's disease. Impulse control disorders are relatively frequent in Parkinson's disease and all patients should be screened for this complex disorder.