Menopause
The menopause transition typically begins between 40 and 50 years of age (average 47.5). The duration of perimenopause may be for up to eight years. Women will often, but not always, start these transitions (perimenopause and menopause) about the same time as their mother did.
Postmenopausal confusion
Research on menopause as a whole declined with the end of the Women's Health Initiative (WHI) studies, but research on the treatment of symptoms associated with menopause—especially the treatment of cognitive decline—continues. New research refutes the WHI findings that estrogen therapy (ET) is not a useful treatment for menopausal symptoms. This is especially shown in Alzheimer's research as the Women's Health Initiative Memory Study refuted the argument that a decline in oestrogens and progestogens seen during menopause increases vulnerability to neurodegenerative diseases. Mice are the main subject for research involving the effects of estrogen on brain health, cognition, and neurodegenerative disorders, and research in this area continues.