Traumatic brain injury in veterans may increase risk of dementia, according to a recent study Reuters reported.

Researchers found that older veterans who have experienced a traumatic brain injury (TBI) are 60 percent more likely to later develop dementia than veterans without traumatic brain injury.

"These findings suggest that a history of [traumatic brain injury] contributes risk for dementia in later life in veterans. If we assume that this relationship is causal, it seems likely that the same increased risk probably occurs with [traumatic brain injury] in the civilian population as well," study author Deborah E. Barnes said in a statement.

For the study, researchers recruited more than 188,700 veterans with an average age of 68 at the start of the study. All were free of dementia at the start of the study and had at least one visit to a Veteran Affairs health care facility at the start of the study and again an average of seven years later.

Of the cohort, a total of 1,229 of the veterans had a traumatic brain injury diagnosis. During the follow-up period, 196 veterans with the condition, or 16 percent, developed dementia, compared to 18,255, or 10 percent of those without it.

After adjusting for other factors that could affect the risk of dementia, such as diabetes, high blood pressure, depression and alcohol abuse, researchers determined that veterans with traumatic brain injury were 60 percent more likely to develop dementia than those without the condition.

Based on their findings, veterans with traumatic brain injury developed dementia two years earlier than those without it. Also, those who did not develop dementia died 2.3 years earlier if they had a traumatic brain injury.

The researchers also found that the risk of dementia was higher in veterans with traumatic brain injury who also had depression, post-traumatic stress disorder or cerebrovascular disease than in those with either traumatic brain injury or these other conditions alone.

The findings were recently published in the online issue of Neurology.

"This study convincingly shows that mild trauma has a role in increasing the risk of dementia and sheds light on the more complex relationship between medical and psychiatric diseases with TBI in the development of the future risk of dementias. Neuroscientists must take a careful and comprehensive approach and avoid oversimplified claims of causality," said Rodolfo Savica, MD, MSc, of the University of Utah School of Medicine in Salt Lake City, and a member of the American Academy of Neurology, who wrote an editorial accompanying the study.