New research suggests that veterans who have experienced a traumatic brain injury are at an increased risk for developing dementia. Researchers found they were 60 percent more likely to be diagnosed with dementia before someone without a brain injury. However, the study was able to prove an association but not a cause-and-effect relationship.
Study author Deborah Barnes, an associate professor in the department of psychiatry at the University of California, San Francisco, School of Medicine, said, “Our results suggest that [brain injury] may increase the risk of developing dementia in older veterans, with an age of onset about two years earlier. So clinicians may want to keep an eye out for signs of cognitive impairment in older veterans with a history of [brain injury].”
For the study, almost 190,000 veterans who were 68 years old, on average, were evaluated by researchers. All were dementia-free. Of these vets, 1,229 had been diagnosed with a brain injury. After a nine year follow-up period, researchers found that 16 percent of those with a brain injury developed dementia, compared to 10 percent of those without a brain injury. In addition, those who did develop dementia, began seeing signs at 78.5 years old, on average, while those without a brain injury, didn’t see signs until an average age of almost 81.
The risk for developing dementia was also increased in those who experienced depression, post-traumatic stress disorder (PTSD) or cerebrovascular disease. Researchers were not able to identify a specific reason for the increased risk, but Barns suggests it’s because “each ‘hit’ to the brain reduces the brain’s ability to bounce back after being damaged.”