Risk of dementia increased among female veterans with TBI, PTSD, depression

Dec 13, 2018

Female military veterans who have traumatic brain injury, posttraumatic stress disorder or depression long after their service may be more likely to later develop dementia than female veterans without those conditions, according to a study published in the December 12, 2018, online issue of Neurology®, the medical journal of the American Academy of Neurology.

"Previous studies have shown that male veterans with these conditions may be at higher risk of dementia, but few studies have included female veterans," said study author Kristine Yaffe MD, of the University of California, San Francisco and a member of the American Academy of Neurology. "Understanding how these conditions affect women is critical as more women join the military, more women take on combat roles and since women may be at greater risk for some of these conditions. It's estimated that almost one in three veterans deployed for Operations Enduring Freedom and Iraqi Freedom have one of these conditions."

The study involved 109,140 female veterans with an average age of 69 who received care at a Veterans Health Administration medical center and had at least one follow-up visit. Participants' medical records were reviewed to determine who had a diagnosis of traumatic brain injury, posttraumatic stress disorder, or depression at the start of the study.

A total of 81,135 women had none of the conditions; 20,410 had depression only; 1,363 had posttraumatic stress disorder  only; 488 had traumatic brain injury only; and 5,044 had more than one condition.

None of the participants had dementia at the start of the study. During the average of four years of follow-up, 4,125 of the women, or 4%, developed dementia.

The study found that women with posttraumatic stress disorder were about 80% more likely to develop dementia than women who did not have posttraumatic stress disorder. Women with depression were about 70% more likely to develop dementia than women who did not have depression.

Women with traumatic brain injury were about 50% more likely to develop dementia than women who did not have traumatic brain injury. The risk of dementia was doubled for women with more than one of these conditions, compared to women who did not have any of the conditions.

These results were calculated after researchers adjusted for other factors that could affect the risk of dementia, such as high blood pressure, diabetes, and alcohol abuse. The results were similar to what previous studies have found in male veterans.

Of the women with none of the conditions, 3.4% developed dementia, compared to 5.2% of the women with depression, 3.9% of the women with posttraumatic stress disorder, 5.7% of the women with traumatic brain injury and 3.9% of the women with more than one condition.

"These results highlight the need for increased screening for traumatic brain injury, PTSD and depression, particularly among female veterans, as well as the potential role for treatment of these conditions to reduce dementia risk," Yaffe said.

Yaffe noted that the study does not determine that these conditions cause an increase in dementia; it shows an association.

A limitation of the study is that researchers used medical diagnoses codes to determine who had depression, posttraumatic stress disorder, traumatic brain disorder and dementia, and it is possible that women with less severe symptoms of these disorders did not receive diagnoses and were not counted.

Source: News Release
American Academy of Neurology
December 12, 2018