Background: Parkinson's disease (PD) is frequently accompanied by dementia or depression which can aggravate the clinical picture of the disease and increase the risk of care dependency (CD). Little is known about the associations between PD, these neuropsychiatric comorbidities and CD in outpatients.
Patients and methods: A nationwide sample of outpatients (n=1,449) was examined by office-based neurologists (n=315) comprising the documentation of the general, neurological status and the degree of CD. The dementia status was clinically rated according to the established DSM-IV criteria. Depression was screened with the Montgomery-Asberg Depression Rating Scale (MADRS).
Results: Overall, 18.3% of all patients were care dependent. Even after adjustment for PD severity, patients with depression (OR=2.8; 95% CI 1.8-4.3), dementia (OR=2.7; 95% CI 1.8-4.1) or both (OR=3.9; 95% CI 2.5-60,0) were at higher risk for CD than patients without dementia or depression. Patients aged ≥76 years were fourfold more likely to be care dependent than patients aged ≤65 years (OR=3.5; 95% CI 2.3-5.5). Across all age groups, patients with depression featured the highest increments (from 11.9 to 42.0%).
Conclusion: The risk for CD is substantially elevated in outpatients with PD when further neuropsychiatric symptoms are present. The data suggest that depression contributes equally to disability as does dementia.