Depression is associated with impairment of ADL, not motor function in Parkinson disease.

Depression was diagnosed in 15% of 100 consecutive patients with Parkinson disease (PD). Depression was associated with lower cognition, history of depression, and a higher Unified Parkinson's Disease Rating Scale score. The latter was due to differences in the activities of daily living (ADL) subscale (17 +/- 7 vs 12 +/- 6; p = 0.004) rather than the motor subscale (30 +/- 13 vs 26 +/- 13; p = 0.27). These results suggest that ADL impairment may in part be due to depression. Patients with PD with poor function should be closely evaluated for depression.