Alzheimer's disease, menopause and the impact of the estrogenic environment.

Decades ago, postmenopausal hormone replacement was considered the panacea for midlife women. Prevention of the age-related cognitive decline was among the top alleged benefits of this therapy. However, the data from the Women's Health Initiative Memory Study (WHI-WHIMS) study showed the opposite, indicating worsening of several cognitive domains in hormone users. Since WHIMS recruited women who were 65 years or older, it became crucial to investigate the effects of hormone therapy in the early menopause as well. Recent studies, such as WHIMS-Young, the Kronos Early Estrogen Prevention Study and the Early versus Late Intervention Trial with Estradiol targeted the younger women, and indeed showed that hormone therapy may have positive cognitive outcomes in this age group. Whether or not hormone therapy has an effect on already demented women remains to be further explored, as data are scarce.