This won't help one bit.
PTSD Linked to 2-fold Increased Risk for Dementia in Veterans
In the first study to show this association, Kristine Yaffe, MD, from the University of California, San Francisco, and colleagues found that older veterans with PTSD had nearly a 2-fold increased risk for dementia compared with their counterparts without PTSD.
The findings, which were presented here at the Alzheimer's Association 2009 International Conference on Alzheimer's Disease (ICAD 2009), showed that veterans with PTSD developed new cases of dementia at a rate of 10.6% over the 7 years of follow-up, vs 6.6% of those without PTSD.
“What we found was that over the 7-year period those with PTSD had about a doubling of the risk of developing dementia,” Dr. Yaffe told reporters attending a press conference.
In addition, PTSD did not appear to be associated with a particular dementia type but rather had an “across-the-board effect” for all dementias, including vascular dementia and Alzheimer's disease (AD).
Previous research has shown that PTSD, a common sequela of trauma exposure, is associated with increased mortality and morbidity related to cardiovascular disease and depression, among others. Further, it is estimated that 15% to 20% of individuals experiencing a serious traumatic event will develop PTSD.
In addition, said Dr. Yaffe, it is important to understand that PTSD is often a chronic condition. "Just because the exposure that causes PTSD may have occurred 20 or 30 years ago doesn't mean it necessarily goes away or that it is without long-term sequelae,” said Dr. Yaffe.
Further, while some evidence suggests that PTSD can affect cognition and is linked with lower hippocampal volume, until now no one has investigated a potential link between PTSD and dementia, said Dr. Yaffe.
To examine the question of whether PTSD might carry an increased risk for dementia, the researchers used data from the Department of Veterans Affairs National Patient Care Database.
The retrospective cohort study included 181,093 veterans aged 55 years and older without dementia at baseline and compared rates of newly diagnosed dementia or cognitive impairment in 53,155 subjects with a diagnosis of PTSD and 127,938 subjects without PTSD.
Subjects' mean age at baseline was 68.8 years, and 97% were male. Over the 7-year follow-up period, those without PTSD had a rate of dementia rate of 6.6%, vs 10.6% for those with PTSD.
After adjustment for demographics and medical and psychiatric comorbidities, PTSD patients were still nearly twice as likely to develop incident dementia (HR, 1.77; 95% CI, 1.7 – 1.9). The results were similar when investigators excluded subjects with a history of traumatic brain injury, substance abuse, or depression.
Need for Replication
Because the study is the first to show this association, Dr. Jaffe said these findings should be considered “somewhat preliminary” and need to be replicated. Nevertheless, she added, if the results can be reproduced and the mechanisms identified, the implications could be significant.
“In light of current wars and other traumatic exposures, if you could effectively treat people with PTSD, it may provide us with a way to prevent dementia. The other thing we need to do is increase awareness that PTSD is not just a one-time diagnosis. It could potentially be a lifetime diagnosis, with the possibility of maybe major sequelae down the line associated with aging,” said Dr. Jaffe.
Commenting on the study, Alzheimer's Association spokesperson Maria Carillo, PhD, said the findings are particularly critical in light of the current conflicts in Iraq and Afghanistan, which will likely add to the growing burden of Alzheimer's disease, which is expected to increase exponentially over the next 20 to 30 years as the population ages.
The study is funded by the US Department of Defense.
Alzheimer's Association 2009 International Conference on Alzheimer's Disease: Abstract 09-A-459-ALZ. Presented July 13, 2009.
Caroline Cassels is the news editor for Medscape Psychiatry. A medical and health journalist for 20 years, Caroline has written extensively for both physician and consumer audiences. She helped launch and was the editor of Health Digest, an award-winning Canadian consumer health publication. She was also national editor of the Heart & Stroke Foundation of Canada's Web site before joining Medscape Neurology & Neurosurgery in 2005. She is the recipient of the 2008 American Academy of Neurology Journalism Fellowship Award.