Depression in Parkinson disease--epidemiology, mechanisms and management.

Depression is a common symptom in patients with Parkinson disease (PD), and is found at higher rates in these individuals than in healthy populations or patients with other neurodegenerative disorders. Aarsland et al. discuss both the course of depression and the mechanisms that may contribute to the enhanced susceptibility to depression in patients with PD. Management strategies to control depression in these individuals are also highlighted.