Menopause has long been synonymous with hot flashes, poor sleep patterns and memory trouble. But these sometimes-laughable memory lapses aren’t quite so funny, researchers now say.
Recent studies have found low estrogen levels often cause notable memory problems in the months following a woman’s last period. Understanding why is the mission of Vanderbilt University’s Paul Newhouse, MD, professor of Psychiatry, Pharmacology, and Medicine and director of the Center for Cognitive Medicine. Newhouse arrived in Nashville four years ago to establish the center where much of his work examines cognitive performance in women and the elderly.
Estrogen & the Aging Brain
“I’ve been studying the effects of menopause on memory and cognitive and intellectual function for many years and from many perspectives,” Newhouse said.
Studies examine how estrogen alters the brain, potential benefits of estrogen on brain functioning, and how to test theories in a way that reveals the mechanisms behind it. And since estrogen doesn’t seem to be a fit for every postmenopausal woman, he hopes to learn whom it benefits most.
Current studies focus on women who have noticed changes in memory function after menopause as opposed to those who don’t, with the former group at a seemingly higher risk of late life memory impairment. While no good epidemiological studies exist on the topic, smaller studies have found approximately one-third of women report cognitive changes during this stage of life.
Nicotine as a Memory Aid?
Newhouse’s memory studies aren’t limited to menopausal women. Last year, VUMC received a $9.4 million grant from the National Institute on Aging (NIA) to test the effectiveness of a transdermal nicotine patch in improving memory loss in older adults with mild cognitive impairment (MCI), a precursor to Alzheimer’s disease.
About 300 older individuals with MCI will be enrolled at about 20 different sites around the country, including Vanderbilt, in the two-year MIND (Memory Improvement through Nicotine Dosing) study — the largest study of a nicotine patch in nonsmokers. The research is a continuation of Newhouse’s work into nicotine as a treatment for MCI. A 2012 study published in Neurology looked at 74 nonsmokers for six months at three sites.
Women, the Brain & Stress Response
Newhouse also is examining the link between menopause, depression and stress. “We’re looking at how women who are vulnerable to depression may differ in terms of how the brain responds to stress,” Newhouse said. “We have evidence that menstrual cycles and estrogen levels regulate the body’s stress response. We want to extend that to older women after menopause because there’s preliminary evidence that estrogen can help stress before menopause but can exaggerate it after. The brain changes during and after menopause, and we want to understand why.”
MRIs and brain scans measure brain activity that occurs during psychosocial stress. The technique shows participants’ neurological signatures and demonstrates how the brain modulates the body’s stress response in real time activity.
“Women with prior depression may still get benefits from estrogen after menopause on the modulation of emotion,” Newhouse said. “We don’t fully understand the neurological mechanisms behind it but are beginning to explore it.”
He said the idea of stress response post-menopause is very interesting and that Vanderbilt researchers were among the first to discover and report it. “Estrogen can modulate stress response, and we didn’t know that till now,” Newhouse said of the fairly recent discovery. That’s because sex steroids like estrogen and testosterone aren’t traditionally thought of as stress modulators. Newhouse believes those sex steroids are derived from the same cholesterol backbone as hormones like glucocorticoids.
“The brain seems to respond to sex hormones in a very specific way, and we’re trying to map that out in younger and older women,” he said. Newhouse hopes his work will lead to new treatment for memory loss and Alzheimer’s disease and is developing new molecules for memory loss to address different aspects of the aging brain.
RELATED LINKS:
Estrogen, Stress & Depression: A Neurocognitive Model (JAMA Psychiatry 2015)
