Finding a link between PTSD and dementia raises the question of why

Male military veterans with PTSD were found to have a nearly 2-fold-higher risk of developing dementia, compared to those without post-traumatic stress disorder, an anxiety disorder that is highly prevalent because of combat. Results of a study into this link are published in this month's Archives of General Psychiatry.

The study involved 181,093 veterans 55 years or older without dementia from 1997 through 2000. Between 2000 and 2007, researchers discovered 17 percent of the men developed dementia, according to the abstract by Dr. Kristine Yaffe and colleagues at the University of California, San Francisco, and San Francisco Veterans Affairs Medical Center. They presented their work last year in Vienna at the International Conference on Alzheimer's Disease.

"Mechanisms linking these important disorders need to be identified with the hope of finding ways to reduce the increased risk of dementia associated with PTSD," they write. Some theories: that PTSD contributes to the cause of dementia, that chronic stress plays a role, or that stress damages the hippocampus or cause alterations in neurotransmitter and hormone levels that could precipitate dementia.

Finding a link between PTSD and dementia was not entirely surprising. "We already know that traumatic brain injury and certainly chronic stress increase the risk of cognitive decline and what this paper refers to as 'accelerated aging,' which may in turn lead to early dementia. So it makes sense that PTSD would increase the risk for dementia in the long run," Maria C. Carrillo, a senior director for the Alzheimer's Association, told Medscape.

Read the Medscape article.

Read the abstract from the Archives of General Psychiatry.