Depression increases in patients with Parkinson's disease according to the increasing severity of the cognitive impairment

Objective: To test the hypothesis that severity of cognitive impairment modifies the association between depression and Parkinson's disease (PD). Method: One-phase population-based door-to-door surveys. This is a secondary analysis of 1,451 people aged 65 years and older with cognitive impairment living in defined catchment areas. Depression was estimated according to ICD-10, self-reported PD, disability according to WHODAS-II and cognitive status according to the CSI-D. Results: The mean age of the sample was 79.3 years old and most (69%) were women. Of the total sample, 16.1% had depression and it was significantly higher among participants with PD. There was an increase on the ORs of the association between depression and PD with decreased scores in the cognitive test (Adjusted OR from 0.98 to 8.04). Conclusion: The association between depression and PD increases with the severity of the cognitive impairment.