Stress Today, Dementia Tomorrow? Study Finds Middle-Aged Women Most at Risk

May 9, 2020

by Terra Marquette

Research shows today’s stressors can impact future brain functioning, especially for women. It is this gender difference that was the subject of a recent study conducted by researchers at Johns Hopkins University.

The longitudinal study confirms Alzheimer’s Association statistics: One in six women over the age of 60 — compared to just one in 11 men — will eventually be diagnosed with dementia. Could one trigger be midlife stress that unfairly targets women?

“We can’t get rid of stressors, but we might adjust the way we respond to stress, and have a real effect on brain function as we age,” 

says Cynthia Munro, Ph.D., associate professor of psychiatry and behavioral sciences at the university’s School of Medicine, in a Hopkins release. “And although our study did not show the same association for men, it sheds further light on the effects of stress response on the brain with potential application to both men and women,” she adds.

The current study expands on previous research about stress and aging. From other studies, we know that in terms of age-related stress response changes, women experience triple what men experience. Other research confirmed that extremely stressful times in life can cause temporary memory and cognitive problems. So how do these two pieces of information relate to memory loss in later life?

The study results found that the more stressful life experiences a woman had in midlife, the more likely she was to experience a decline in recalling and recognizing words in later years. Word recognition declined by an average of 1.2 words for women without stressors at midlife but fell by 1.7 words for women who had experienced at least one stressor in midlife.

Women who reported one-time traumatic events at midlife, however, did not experience these declines. Researchers say that this finding suggests that it is ongoing stress — the type experienced when there is, say, a long-term illness — that does the most damage to brain functioning.

“Chronic stress can impair the body’s ability to respond to stress in a healthy manner,” Munro says.

“A normal stress response causes a temporary increase in stress hormones like cortisol, and when it’s over, levels return to baseline and you recover. But with repeated stress, or with enhanced sensitivity to stress, your body mounts an increased and sustained hormone response that takes longer to recover,” adds Munro. “We know if stress hormone levels increase and remain high, this isn’t good for the brain’s hippocampus — the seat of memory.”

For the men studied, researchers say no link was found between either type of stress in midlife and a loss in word recall or recognition later. Study authors also report that stress in early life is not a good predictor of later cognitive decline in either women or men.

Although it appears that ongoing stress at midlife is most harmful to women, researchers caution that the results of this study do not prove cause and effect. But if future studies establish that stress response is the cause of dementia, then stress management and other interventions–such as medications currently in development–could help relieve the body’s chemical response to stress and help avoid or delay cognitive decline.

Findings are published in the July 2019 issue of the International Journal of Geriatric Psychiatry.