Estrogen Modulation of Mood and Cognition Following Monoaminergic Depletion in Post-Menopausal Women

This study will examine whether estrogen administration in postmenopausal women can alter
the response to changes in brain chemistry brought about by dietary manipulation. Women who
are recently menopausal (50-60 yrs. of age) and over 20 years postmenopausal (>70 yrs. of
age) will take estrogen or placebo for three months. At the end of that time they will
participate in three challenges using dietary techniques to briefly change the relative
amounts of neurotransmitters in the brain that are believed to be related to mood regulation
(serotonin, dopamine, and norepinephrine). Previous research has shown that these dietary
manipulations can briefly produce negative changes in mood. The investigator hypothesizes
that estrogen administration will blunt or buffer these negative effects in a quantifiable
way. The investigator believes that this will provide a direct test of the ability of
estrogen to meaningfully change the brain chemistry of mood in a clinically measurable and
positive way. The proposed procedure will also allow assessment of the effects of estrogen
on brain neurotransmitter systems after many years of very low estrogen levels.