Early Menopause Associated with Cognitive Decline, Study Shows

Women who experience menopause under the age of 40 are more likely to have worse depressive symptoms and cognitive decline when compared with women who undergo menopause at age 50 or older, according to a recent study published in the journal Alzheimer’s and Dementia. To test a potential relationship between sex and menopause age, 4,286 men were also included in the study.

Dementia disproportionately affects women worldwide, leading some experts to believe that it is a sex-based disease, the study says.

"When looking for associations, we want to rule out as many other modifiable risk factors for dementia as possible," Miharu Nakanishi, lead author and associate professor at the Tohoku University Graduate School of Medicine in Japan, said in a news release. “Since early menopause increases the risk of depression, which then increases the risk of dementia, we had to control for this factor to determine if early menopause in and of itself was a direct risk factor,” “Understanding this relationship in-depth could potentially help us design treatments that delay the onset of dementia in at-risk patients.”

Menopause is defined as the time in a woman’s life when she stops menstruating. In the United States, the average age is 52 years old. Early menopause, also referred to as premature ovarian failure, occurs in an estimated 5–10% of women. Modifiable risk factors that may contribute to early menopause include smoking, alcohol drinking and physical inactivity.

Nakanishi and her team used data from the English Longitudinal Study of Ageing (ELSA) to classify menopause age into three categories: < 40, 40 to 49 and ≥ 50 years old. A total of 4,726 women were included in the study. with approximately 10% reporting early menopause.

Examples of cognitive function measured included orientation, immediate recall, delayed recall and verbal fluency, with higher scores indicating better cognitive function.

Assessments were conducted during participant interviews and self-completed questionnaires starting in 2002 and then every two years for 10 years.

For example, at baseline, the verbal fluency of women with early menopause had a coefficient of -1.39. By the end of the study, that coefficient had changed to −0.56. For women who experienced menopause from 40 to 49, those numbers were -0.41 and −0.14, respectively. Male verbal fluency changed from 0.16 to -0.31.

An association with depression

Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Higher scores indicated greater severity.

In women with early menopause, depressive symptoms were associated with a coefficient of 0.61, and women with later menopause were associated with a coefficient of 0.24. Male depressive symptoms had a coefficient of -0.39. At the end of the study, those numbers changed to 0.19, 0.08 and -0.15, respectively.

Nakanishi and her team recommend depression screening in women who experience early menopause because depression is a risk factor for dementia.

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