Hot flashes and the brain

It would be insulting and inaccurate to suggest that the menopausal meltdown known as a hot
flash is all in a woman’s head. But the brain plays a big, rather mysterious, role.

The latest evidence comes from a study of the anti-depressant Lexapro led by University of
Pennsylvania researcher Ellen W. Freeman. Over eight weeks, Lexapro was much better than a
placebo at reducing hot flash severity and frequency among 205 women of a certain age.

Lexapro improves mood by boosting the brain’s supply of serotonin, a chemical messenger.
Similar drugs — including Paxil, Effexor, Prozac, and Zoloft — also provide varying degrees
of hot flash relief.

This makes sense, since serotonin helps carry messages from the hypothalamus — the part of
the brain that controls body temperature — to the heart, blood vessels, and sweat glands.

Scientists don’t understand why menopausal hormone declines make the hypothalamus go
haywire, perceiving the body as too hot and ordering a cool-down. (Hormone supplements, the
gold standard flash therapy, have rare, serious side effects — thus the search for other

Even less understood than the physiology, however, is the psychology.

Consider that hot flash frequency was cut by at least half for 36 percent of the women
taking placebo. (Lexapro helped 55 percent who took it.)

And when all the women stopped taking pills, flashes promptly increased for the Lexapro
group — but not the placebo group. Three weeks later, women were still benefiting from their
fake therapy.

That provides “further evidence” of Lexapro’s effects, Freeman and her coauthors wrote in
the study published Tuesday in the Journal of the American Medical Association.

But it also suggests that for some women, resetting the thermostat is partly a matter of
mind over matter.

“Whatever changed with the placebo, it didn’t change back,” said Freeman, a professor of
obstetrics and gynecology at Penn. “I thought that was extremely interesting.”

Lexapro maker Forest Pharmaceuticals may prefer to point out another interesting result:
Side effects such as insomnia, dry mouth, and dizziness were more commonly reported by women taking placebo than the drug.

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