PTSD May Double Chances of Dementia
A new study, published in the British Journal of Psychiatry, is the first-ever global meta-analysis on the possible link between post-traumatic stress disorder (PTSD) and developing dementia up to seventeen years later. The researchers looked at 13 studies, spanning four continents and 1,693,678 people total.
From pooling data from eight studies, the researchers found that those with PTSD faced a 61% higher risk for dementia. Two studies, using different methods, both yielded data suggesting that PTSD was associated with double the chances of developing dementia.
Interestingly, this dementia risk was higher among the general population with PTSD than it was among veterans with PTSD, perhaps because veterans are more likely to receive treatment for PTSD, at least in the countries examined by the studies. This at least suggests that treating someone's PTSD will lower their chances of developing dementia later.
“A lot of people with PTSD don’t access treatment, sometimes due to a lack of mental health care capacity but also because of stigma which often keeps people away from seeking help," says senior author Dr Vasiliki Orgeta of UCL Psychiatry. "We now have more evidence of how traumatic experiences and accessing treatment could have a long-lasting impact for individuals and influence future risk of developing dementia.”
The researchers note that the studies tended to control for at least some other dementia risk factors, including higher alcohol intake, depression, and social isolation. However, people experiencing PTSD already have an above average chance of developing these factors, meaning that the real impact of PTSD on one's dementia risk could be significantly higher.
While we don't know exactly how PTSD alone increases the likelihood of developing dementia, the researchers theorize it could have to do with the brain remaining in hyper-vigilance mode and repeatedly re-experiencing trauma, adding to stress-related activity in the brain and prompting social isolation.
“PTSD, which appears to be common among people who have been hospitalised with Covid-19, remains an underdiagnosed, under-treated, and under researched mental health condition, yet it can have serious long-term consequences," explains Dr. Orgeta. "As our study has shown, PTSD impacts our brain health by increasing vulnerability to dementia. An important question is how, and whether we could learn from these findings to develop preventative treatments for those with elevated risk.”