The team from the University of Rochester Medical Center found that the issue is not really impaired memory. Instead, the team found a link between complaints of forgetfulness and the way middle-aged, stressed women learn or "encode" new information.
"This is not what most people think of traditionally when they think of memory loss," said co-author Mark Mapstone, Ph.D., assistant professor of Neurology. "It feels like a memory problem, but the cause is different. It feels like you can't remember, but that's because you never really learned the information in the first place."
The findings come from Mapstone and Miriam Weber, Ph.D., memory experts at the University's Memory Disorders Clinic who are seeing more and more middle-aged women who say they are having problems with forgetfulness.
"We see a lot of women who are afraid they are losing their minds," said Weber, a senior instructor of Neurology, who presented the results. "A lot of women complain that their thinking or their memory isn't what it used to be. Their big fear is that it's early Alzheimer's disease."
The team found nothing to support the idea that such women are on their way to developing Alzheimer's disease, and they didn't find any problem with what most people consider "memory." But they did make a finding that helps explain why women in their 40s and 50s frequently say they're having memory problems: It's possible that their changing moods and hectic lives make it harder to keep track of everything.
The work is the latest salvo in a years-long back and forth about memory, menopause, and estrogen. Doctors long thought that hormone-replacement therapy helped protect women against cognitive decline. But three years ago, scientists announced that HRT slightly raises the risk of developing dementia. Those results came soon after other results where scientists said that HRT brings with it increased risk of breast cancer, heart disease, and stroke.
When it comes to memory, a study in 2003 of more than 800 women found no evidence that memory problems occur as part of menopause. But neuropsychologists like Weber and Mapstone continue to see a steady stream of patients reporting memory problems as they approach menopause, mixing in with more typical older patients with problems like Alzheimer's disease.
So Weber and Mapstone put 24 women who complained of memory problems through a battery of tests that tested several cognitive skills, not just traditional memory, where a piece of information is stored away and then retrieved later.
Like the 2003 study, Weber and Mapstone found no evidence that women approaching menopause suffer from strictly memory problems any more than anyone else - of the 24 women tested, they found only one who had any type of impaired memory, where a person flat out forgets things she once knew or remembered.
Looking more closely, however, they did find that the women who complained more about problems with forgetfulness had a harder time learning or "encoding" new information, which can masquerade as a problem with memory. While the team found a clear correlation between the level of the women's complaints and their ability to learn new information, Weber and Mapstone point out that none of the women actually had an impaired ability to learn new information. They say a larger, more thorough study, involving hundreds of women and a broad array of cognitive tests before and during menopause, is needed to understand the link more fully.
Mapstone and Weber liken the problem of encoding new information to a situation where a doctor tells a patient that something serious may be wrong and gives a lot of detail. Afterwards, the person gets home and can hardly remember what the doctor said. It's not that the person necessarily forgot what was said; it's more likely that they never really heard the doctor the first time, because they were so anxious and worried.
The same may be true of women approaching menopause, many of whom live a life filled with stress and worry. Indeed, Weber and Mapstone found that most of the women in their study had some sort of mood distress, including symptoms of depression or anxiety.
"When people spread their attention thin, it's difficult to encode new information. When they're worried or anxious about being late for work, or the problems of an aging parent - that sort of stress can rob your attentional resources and impact your ability to encode information properly," said Mapstone, who said similar difficulty taking in new information is typical of nearly any man or woman who is anxious or depressed.
Weber said the study points out the importance for women who are feeling anxious or depressed to seek treatment, a step that should ease any cognitive difficulties.
"What characterizes these women is that they're being pulled in a lot of different directions. Many work - they have careers, aging parents, children. Then they're going through this dramatic hormonal change," Weber said.
"This will resonate for most women," said Weber. "There really is something going on. And perhaps knowing that their perceived problems with memory do not suggest early dementia might alleviate their concerns and actually improve their functioning - it's one less thing to worry about."