Perimenopause and cognition.

The impact of perimenopause on cognition seems to be characterized by an absence of improved scores rather than a decline. In the SWAN, the perimenopausal decrement in cognitive performance was not accounted for; however, increases in anxiety and depressive symptoms had independent, unfavorable effects on performance. Estradiol has been found to protect against changes resulting from serotonin withdrawal and defend against changes from cholinergic depletion. There is support for the critical timing hypothesis--that estrogen benefits cognitive function when instituted early, but not later. The menopausal transition may affect cognitive function in older age owing to worsened cardiovascular risk factors.