Post-traumatic Stress Disorder and Risk of Parkinson Disease: A Nationwide Longitudinal Study

Objective: Increasing evidence has suggested a relationship between post-traumatic stress disorder (PTSD) and neurodegenerative disorder, such as Alzheimer disease. The association between PTSD and Parkinson disease (PD), however, remains unclear. Method: Using the Taiwan National Health Insurance Research Database, 7,280 subjects (1,456 patients aged >= 45 years with PTSD and 5,824 age-/sex-matched individuals without PTSD) were enrolled between 2002 and 2009 and followed to the end of 2011. Subjects who developed PD during the follow-up period were identified. Results: An increased risk of developing PD was found in patients with PTSD (Wald chi(2) = 12.061, hazard ratio [HR]: 3.46, 95% confidence interval [CI]: 1.72-6.96) compared with individuals without PTSD, after adjusting for demographic data and medical and psychiatric comorbidities. The sensitivity tests after excluding the first year observation (Wald chi(2) = 7.948, HR: 3.01, 95% CI: 1.40-6.46) and the first 3-year observation (Wald chi(2) = 5.099, HR: 3.07, 95% CI: 1.16-8.15) were consistent. Conclusions: Patients with PTSD had an elevated risk of developing PD in later life. Further studies would be required to clarify the exact pathophysiology between PTSD and PD and to investigate whether the prompt intervention for PTSD may reduce this risk.