New Study Shows Link Between PTSD and Dementia

In a University of California study, a link has been shown from post-traumatic stress disorder (PTSD) in veterans to an increased risk for developing age-related dementia such as Alzheimer’s disease.

The study, led by Deborah Barnes, PhD, followed over 180,000 older veterans, mostly men, for seven years. Just over 53,000 of the subjects had been diagnosed with PTSD. When the study began in 2000, none of the participants had been diagnosed with any type of dementia but by the end of the study in 2007, 17% had been diagnosed with some kind of degenerative cognitive disorder.

Researchers excluded any subjects with histories of depression, substance abuse or head injury before finding that veterans with PTSD had a 77% increased likelihood of developing dementia. Results were also adjusted to eliminate other risk factors.

Barnes says, “We can’t say from a study like this one that PTSD causes dementia. But if it does, one theory is that stress is to blame.”

Previous research has shown evidence that chronic stress, such as that caused by PTSD, can actually damage the part of the brain that is needed for learning and memory.

This study is particularly alarming given the commonality of PTSD in combat vets and the fact that symptoms can remain for a lifetime in some veterans. Studies have shown that up to 15% of Vietnam vets still had symptoms of PTSD more than 15 years after returning home and up to 12% of World War II vets were still experiencing symptoms more than 40 years later.

17% of vets returning from Afghanistan and Iraq are suffering from PTSD. This group may be at even higher risk due to the large amount of soldiers who also have brain injuries related to explosive exposure.

The study was co-funded by the Department of Defense and the National Institute on Aging and was published in the June issue of Archives of General Psychiatry.