New research published in the journal Neurology shows that veterans who have experienced brain injury while in active service are 60 percent more likely to develop dementia later in life than those without head injuries, bolstering the association long believed to exist between brain injuries and cognitive difficulties in later life.
The study evaluated more than 188,000 veterans over the course of seven years and found that those who suffered brain trauma also developed dementia two years earlier on average. The researchers also noted that the risk was even higher for those who also suffered depression or post-traumatic stress disorder.
“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 traumatic brain injury in the development of the future risk of dementias,” said lead researcher Dr Rodolfo Savica of the University of Utah School of Medicine in Salt Lake City.
All veterans involved in the study were free of dementia at the onset of the study and were followed up with seven years later.
Of the participants, 1,229 veterans had previously been diagnosed with brain trauma. At the time of the follow-up, 16 percent of those who suffered brain trauma had developed dementia, compared to 10 percent of those without a diagnosed brain injury.
Notably, the researchers observed that those who had suffered brain injury but did not develop dementia also died an average of 2.3 years earlier, at age 77 compared to 79.3 years.
“These findings suggest that a history of traumatic brain injury contributes risk for dementia in later life in veterans,” said study author Dr Deborah Barnes, of the University of California.
“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.”