A growing number of veterans are returning from combat with post-traumatic stress disorder, or PTSD, and it may be increasing their risk of Alzheimer’s and other forms of dementia in old age, a new study shows.
PTSD is a growing problem in the military, where veterans exposed to the stress of combat put them at risk of depression, anxiety, sleeplessness and other psychiatric problems. In some studies, as many as one in six returning veterans from Iraq and Afghanistan had signs of PTSD. The figures are even higher for Vietnam vets. The condition can also be persistent, leading to lifelong disability and an increased risk of medical problems throughout life, as well as problems with thinking, learning and memory.
The current study, from the Archives of General Psychiatry, a journal of the American Medical Association, found that veterans with PTSD were nearly twice as likely to develop dementia in old age than those who did not suffer from the disorder. Even when controlling for factors like head injuries and depression, which are risk factors for Alzheimer’s disease, the risk of developing dementia was notably increased.
The study looked at records from 181,093 veterans ages 55 and older. Of these, 53,155 had PTSD. Over seven years of follow-up testing, the researchers found that more than 30,000 or more than 17 percent, of the veterans had developed Alzheimer’s or other forms of dementia. Veterans who had PTSD had a 10.6 percent risk of developing dementia, whereas the risk among those without PTSD was 6.6 percent.
The authors, from the University of California, San Francisco, noted that dementia risk may be increased for various reasons. Persistent stress may damage the hippocampus, a part of the brain critical for memory and learning. Chronic stress may also later levels of hormones and brain chemicals critical for memory.
“The finding that PTSD is associated with a near doubling of the risk of dementia has important public health, policy and biological implications,” the authors concluded. “It is important that those with PTSD are treated, and further investigation is needed to see whether successful treatment of PTSD may reduce the risk of adverse health outcomes, including dementia.”
The doctors also noted that it will be important for older veterans to get regular mental check-ups and assessments to looks for signs of cognitive problems, including signs of Alzheimer’s, as they get older.
Kristine Yaffe, MD; Eric Vittinghoff, PhD; Karla Lindquist, MS; et al: “Posttraumatic Stress Disorder and Risk of Dementia Among US Veterans.” Archives of General Psychiatry, Vol 67 (No. 6), June 2010, pages 608-613.