Post-traumatic stress disorder (PTSD) is common among veterans returning from combat and there is some evidence that it may be associated with reduced cognitive function. However, no study has yet investigated if PTSD increases the risk of developing dementia.
To address this emerging issue, Kristine Yaffe, MD, Professor of Psychiatry, Neurology and Epidemiology and Associate Chair of Research for the Department of Psychiatry at the University of California, San Francisco, and Chief of Geriatric Psychiatry and Director of the Memory Disorders Clinic at the San Francisco VA Medical Center, and colleagues sought to determine if PTSD is associated with risk of developing dementia among older veterans in the U.S. receiving treatment in veterans’ medical centers.
They studied 181,093 veterans aged 55 years and older without dementia (53,155 veterans diagnosed with PTSD and 127,938 veterans without PTSD) using data from the Department of Veterans Affairs National Patient Care Database. Mean baseline age of the veterans was 68.8 years and 97% were male. They followed the veterans from 2001 through 2007, including tracking whether they were diagnosed with Alzheimer’s/dementia.
The researchers found that veterans with PTSD in the study developed new cases of dementia at a rate of 10.6% over the seven years of follow-up; those without PTSD had a rate of 6.6%. (Note: This is updated data from the researcher, which is why it differs from the attached abstract.) Even after adjusting for demographics, and medical and psychiatric comorbidities, PTSD patients in this study were still nearly twice as likely to develop incident dementia compared to veterans without PTSD (HR = 1.8, 95% CI 1.7-1.9). Results were similar when they excluded those with a history of traumatic brain injury, substance abuse or depression.
“It is critical to follow patients with PTSD, and evaluate them early for dementia,” Yaffe said. “Further research is needed to fully understand what links these two important disorders. With that knowledge we may be able to find ways to reduce the increased risk of dementia associated with PTSD.”