Veterans aged 55 years or older with PTSD (post-traumatic stress disorder) appear to have a higher risk of developing dementia over a 7-year period, compared to individuals without PTSD, says a new report published in Archives of Psychiatry today, a JAMA/Archives journal.
PTSD occurs in a significant number of veterans returning from conflict areas or war zones, the article informs. Up to 17% of veterans coming home from Iraq and Afghanistan are thought to have PTSD, while 10% to 15% of Vietnam veterans had PTSD symptoms for at least 15 years after their return. Previous studies have linked PTSD to a wide variety of medical conditions in younger and middle-aged veterans, along with declines in thinking, learning and memory (cognitive performance).
Kristine Yaffe, M.D., of the University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, and team studied 181,093 veterans, aged 55 years and older (average age 68.8, 96.5% men) between 1997 and 2000. 53,155 of them had PTSD and 127,938 did not.
During a 7-year follow up (2000-2007), 17.2% (31,107) of the veterans developed dementia. Meaning:
- A 10.6% risk of developing dementia for veterans with PTSD
- A 6.6% risk of developing dementia for veterans without PTSD
Veterans with PTSD were still more likely to develop dementia when the analyses were adjusted for important differences, including demographic variables and other medical and psychiatric illnesses.
The authors wrote:
There are several reasons why patients with PTSD may have an increased risk of developing dementia.
PTSD may be a risk factor for dementia, or chronic stress may link the two conditions. Stress may harm the hippocampus, a brain area critical for memory and learning, or cause alterations in neurotransmitter and hormone levels that could hasten dementia.
The authors concluded:
The finding that PTSD is associated with a near doubling of the risk of dementia has important public health, policy and biological implications. 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. In addition, it is critical to follow up patients with PTSD, especially if they are of an advanced age, to screen for cognitive impairment. Finally, mechanisms linking PTSD and dementia must be identified in hope of finding ways to improve the care and outcomes of patients with PTSD.