This year, the U.S. Department of Veterans’ Affairs (VA) and other federal health agencies have reported of evidenced-based research demonstrating a common link between post-traumatic stress disorder (PTSD) among veterans and later-life dementia. With 6–11% of Afghanistan veterans and 12–20% of Iraq veterans returning to the U.S. with PTSD, the VA has been investigating these individuals’ additional risks of mental problems based on the mental health of their predecessors.
A new study, published in the Journal of the American Geriatrics Society by researchers at Michael E. DeBakey VA Medical Center in Houston, has found that veterans with PTSD are more likely to develop dementia than their counterparts without PTSD. Dr. Salah Qureshi and colleagues conducted a study on a total of 10,481 veterans aged 65 and older who had been admitted to their VA medical center at least twice from 1997 to 1999. The researchers continued to collect data on the study participants’ outpatient history until 2008. Participants were grouped into several categories for comparison: those who were diagnosed with PTSD and had experienced combat-related injuries (153 individuals), those with PTSD but no combat injuries (3,660 individuals), those without PTSD but with combat injuries (1,503 individuals), and those without PTSD or combat injuries (5,165).
Overall, 36.4% of the participants had PTSD. Veterans who had PTSD but did not have combat injuries had the highest incident rate and prevalence of dementia out of the study’s participants (11.1%). Those who had PTSD and had experienced combat-related injuries had a dementia rate of 7.2%, the second highest incident rate among the study. On the other hand, those without PTSD had the lowest incident rates of dementia. Veterans without PTSD but had experienced combat-related injuries had a 5.9% incident rate of dementia, and those who were not diagnosed with PTSD or had experienced combat injuries had an dementia incident rate of 4.5%. Even after the researchers controlled for other risk factors for dementia—including high blood pressure, diabetes, heart disease, and stroke—the incidence and prevalence of dementia among veterans with PTSD but no combat injuries remained twice as high as the rates among veterans without PTSD.
Although the researchers cannot clearly establish the immediate cause of this increased risk, their study significantly demonstrates that veterans with PTSD experience higher incidence and prevalence of dementia in later life than their counterparts. The researchers suggest that the occurrence of PTSD may increase one’s susceptibility for dementia, or that recurring episodes of PTSD may be early symptoms of dementia that has not yet been identified. Also, PTSD and dementia may share common characteristics. The common symptom of memory loss among PTSD and dementia patients might indicate that damage to the region of the brain that controls memory, the hippocampus, could be caused by acute stress. Yet further research will be needed in order to determine the actual causal effects of dementia among this population. However, the researchers note that it is most important to find out whether treating PTSD will help reduce the risk of dementia. Because veterans experience a higher rate of PTSD than the general population, those returning from Iraq or Afghanistan who are subsequently diagnosed with PTSD should properly be screened for dementia as they age.
In June, the U.S. Department of Defense and the National Institute on Aging also found that veterans with PTSD were nearly twice as likely to develop dementia or Alzheimer’s disease as they age than veterans without PTSD. In a seven-year investigation of 181,093 older veterans, the results showed that the veterans with PTSD had a 10.6% incident rate of dementia, while those without PTSD only had a 6.6% dementia incident rate. The veterans with PTSD were 77% more likely to develop dementia than those without it when risk factors related to Alzheimer’s disease were included. The same results were concluded even after excluding those veterans who had a history of clinical depression, substance abuse, or head injury.
PTSD is a multifaceted, chronic illness that may last for a certain number of years or can span an entire lifetime. In the U.S., 5.2 million Americans are believed to experience PTSD in a given year. An estimated 14% of Americans over the age of 71 have a type of dementia.
Source: HealthDay, Robert Preidt, Vets With Stress Disorder More Likely to Develop Dementia, September 2, 2010