NATIONAL HARBOR, MD. – Women who had a longer exposure to estradiol before menopause had a significantly lower risk of developing depression during the menopausal transition, based on data from 1,282 women.
"It is unclear why some women are at increased risk of depression while undergoing the menopausal transition," said Dr. Wendy Marsh of the University of Massachusetts, Worcester.
Data from previous studies have suggested that endocrine factors in general, and estrogen levels in particular, may contribute to a woman’s susceptibility to depression during menopause, she noted.
Dr. Marsh and her colleagues reviewed data from 1,282 women participating in the Study of Women's Health Across the Nation (SWAN), a multisite, long-term epidemiologic study of women during midlife and through the menopausal transition. The women were premenopausal when they entered the study.
"It is unclear why some women are at increased risk of depression while undergoing the menopausal transition."
Each additional year of premenopausal estradiol exposure conveyed a 15% reduction in risk of experiencing depression during menopause (hazard ratio, 0.85) after confounding factors including premenopausal depression, baseline age, smoking status, education, antidepressant use, ethnicity, and length of time in the study were controlled for.
The average duration of estradiol exposure was 36 years. Longer exposure was significantly associated with a lower risk of having a score of 16 or higher on the Center for Epidemiologic Studies Depression (CES-D) scale.
Estradiol has been shown to affect mood regulation, Dr. Marsh noted, but "it is unknown how such a modulatory effect during premenopausal years would lead to a protective effect against depression during the menopausal transition," she said.
Although the data are preliminary, they may provide a foundation for further research that may help clinicians identify and manage women at increased risk for depression during menopause.
"Additional analyses will further qualify and quantify other variables related to estrogen exposure, including use of oral contraceptives, pregnancies, and lactation," Dr. Marsh said at the annual meeting of the North American Menopause Society.
The Study of Women’s Health Across the Nation is supported by grants from the National Institutes of Health, the U.S. Department of Health and Human Services, the National Institute of Nursing Research, and the NIH Office of Research on Women’s Health. Dr. Marsh reported having no relevant financial disclosures.