Increased risk of depression in patients with Parkinson disease: A nationwide cohort study

Objective: The association between Parkinson disease (PD) and depression remains unclear, particularly in the Asian population. The purpose of this study is to investigate the risk of depression in patients with PD using population-based data. Methods: Based on the National Health Insurance Research Database of Taiwan, we identified 1,698 patients with PD aged 40 years or older diagnosed in 2000-2003. With frequency matching procedure, we randomly selected 6,792 subjects without PD stratified by sex and age. Both cohorts were followed until the end of 2008 or diagnosis of depression. Risk of depression associated with PD was estimated in the multivariate Cox hazards regressions. Diabetes, hypertension, and hyperlipidemia were more prevalent at baseline in patients with PD. Results: Compared with the cohort without PD, the hazard ratio (HR) for depression in PD patients was 4.06 (95% CI: 3.15-5.23), which increased to 4.26 (95% CI: 3.29-5.51) after adjustment for age, sex, urbanization, income, and coexisting medical conditions. In the sex stratification, the HR of depression for men with PD was 4.42 (95% CI: 2.93-6.67) compared with men without PD. The HR for the association between PD and depression in women was 4.22 (95% CI: 3.02-5.88). Conclusion: This study suggests that patients with PD are at an elevated risk of depression, particularly for men. Integrated care for early identification and treatment of depression are crucial for patients with PD.