Estrogenic effects on memory in women.

Sufficient evidence now exists to support the contention that estrogen influences cognitive functioning in women. Moreover, the data strongly suggest that estrogen exerts a specific and not a global effect on cognitive functions. Whereas estrogen enhances and/or maintains aspects of verbal memory, it is without effect, or possibly even has a negative influence on spatial memory. Indeed, there is some preliminary evidence that progesterone may enhance visual-spatial skills in women but this needs to be confirmed. Estrogen also exerts a positive effect on sexually dimorphic cognitive skills in which females typically excel such as verbal articulation and fine motor skills. While the weight of the evidence supports the above conclusion, findings across studies are not entirely consistent. Some of the methodological problems that weaken these studies include generalizing from one or two cognitive tasks to the entire realm of cognitive functions, neglecting to assay plasma levels of estradiol to confirm cycle phase or compliance with hormone administration and neglecting to consider the differential availability to the brain of the various estrogen preparations and the effects of different routes of administration. Although, for the most part, the menstrual cycle studies and the postmenopausal studies in healthy women show that estrogen maintains verbal memory, the effect size is modest. There is no reason to believe, for example, that verbal memory is truly impaired in women during phases of the menstrual cycle marked by low levels of estrogen. Nor are 45-year-old untreated, surgically menopausal women clinically impaired to any degree that affects their daily functioning in the real world. In both cases, however, decrements in performance occur reliably in the laboratory. This raises the issue, therefore, of the clinical meaningfulness of these findings. One way to address the clinical relevance of the relationship between estrogen and memory and thus, on cognitive functioning of the brain, is to examine what is known of estrogenic effects on other physiological systems where we already have substantial information. For example, the vast majority of women experience bone loss following the menopause and many develop osteopenia (bone density more than two standard deviations below mean peak bone mass levels) which is asymptomatic. Then, with advancing age, some women with osteopenia develop osteoporosis, predisposing them to fractures following minimal trauma. It has been estimated that 40 per cent of women who live to age 80 will develop spinal fractures and 33 per cent of women who live to age 90 will experience a hip fracture.(ABSTRACT TRUNCATED AT 400 WORDS)