Drugs For Mild Cognitive Impairment - Medications For Memory Impairment: Improving Memory Understanding Age Related Memory Loss

Estrogen therapy and memory

For decades, women and their doctors have considered the role of estrogen in memory and other mental abilities. After menopause, when levels of the sex hormone fall, some women report that their memory function is not as good as it used to be. It is not clear if this decline is due to hormonal effects on brain function, stress or other psychological issues, sleep disturbance due to hot flashes, or a combination of factors. Nevertheless, the association between menopause and memory difficulty raises the question: Does postmenopausal hormone replacement improve a woman's memory or other aspects of cognitive function?

The Women's Health Initiative, a large national study of the role of hormone therapy on women's health, addressed this question. The results from the memory component of the project, WHIMS, published in 2003, showed that combination estrogen/progestin therapy (Prempro) not only didn't improve memory in postmenopausal women, it actually doubled women's risk for dementia. (Earlier findings from the same large research group had already linked the use of Prempro with an increased risk of heart attack, stroke, and breast cancer.)

WHIMS included 4,532 women ages 65 and older who didn't have dementia when the trial began. About half of the women took a daily dose of Prempro, and the other half took a placebo. The women didn't know which they were taking. For five years, researchers gave the women memory tests and evaluated them for dementia. Forty women in the hormone therapy group developed probable dementia, compared with 21 women in the placebo group.

In 2004, the researchers reported that estrogen therapy without progestogen was linked to an increased risk of dementia and also of stroke. A related study suggested that estrogen alone might also increase the risk of mild cognitive impairment.

Researchers suggest that one reason hormone therapy increases the risk of dementia and stroke is that it also increases the risk of blood clots. Clots can obstruct blood vessels and reduce blood flow to the brain, causing small "silent" strokes.

Hormone therapy may yet have a role in preserving memory or even treating memory impairment in some women. Clinical trials have found that 45-year-old women who had surgical menopause and took estrogen therapy had better verbal memory than similar women who did not take estrogen. But studies have found no benefit to older women who started taking estrogen therapy many years after they had surgical menopause. This finding suggests that estrogen therapy may have to be started soon after menopause in order to reap a memory-protective effect. Some researchers wonder if the same may be true of combination estrogen/progestin therapy started early in menopause. WHIMS looked only at women ages 65 and older.

There is evidence that estrogen therapy might reduce the symptoms of Alzheimer's disease in women. Clinical trials are under way to investigate whether estrogen therapy, alone or with progestin, as well as raloxifene (Evista), an estrogen-like drug that is prescribed for osteoporosis, can help women with mild to moderate Alzheimer's disease. In 2005, researchers reported in the American Journal of Psychiatry that women who took 120 mg of Evista for three years were one third less likely to have mild cognitive impairment; however, they found that it did not seem to protect against Alzheimer's disease.

So the estrogen story has not yet fully unfolded. In the meantime, doctors recommend that women take postmenopausal hormones only for short-term relief of severe menopausal symptoms such as hot flashes.