The Natural History of Depression in Parkinson's Disease within 30-Month Follow-Up.

Depression is one of the most common and persistent nonmotor syndromes occurring in 35% of patients diagnosed with PD. However, little information is known about the longitudinal study of its natural history of depression in PD. In this study, we identified 110 patients who are diagnosed with idiopathic PD and recruited them for assessing information about their PD related motor and nonmotor symptoms and rating scales.