Objective: Several small-scale studies have suggested a biological link between obsessive-compulsive disorder (OCD) and Parkinson disease (PD). However, the temporal association of OCD and subsequent PD remained unclear.
Methods: Here, we used Taiwan National Health Insurance Research Database and included the data of 28,722 patients with OCD ( International Classification of Diseases, Ninth Revision, Clinical Modification code: 300.3) and 287,220 matched controls between 2001 and 2009. They were followed until the end of 2011 to identify diagnosis of new-onset PD ( International Classification of Diseases, Ninth Revision, Clinical Modification code: 332.0). The frequency of psychiatric outpatient visits for OCD per year (<5, 5-10, and >10) was identified as a proxy of OCD severity.
Results: Using the stratified Cox regression model, the hazard ratio of developing PD among patients with OCD was 2.70 (95% confidence interval = 1.74-4.18) compared with matched controls. Among patients with OCD, those with >10 psychiatric outpatient visits per year for OCD (hazard ratio = 3.18, 95% confidence interval = 2.06-4.93) were more likely to develop PD during the follow-up period compared with those with <5 psychiatric outpatient visits per years for OCD.
Conclusions: OCD was found to be an independent risk factor for PD. The mechanisms underlying the temporal association between OCD and subsequent PD require further investigation.
Copyright © 2022 by the American Psychosomatic Society.