Surprise — Period Hormones Don’t Scramble Your Brain

Jul 5, 2017 at 8:00 a.m. ET
Image: Chaloner Woods/Stringer/Getty Images

It’s hard to get away from stereotypes connected to our periods. The trope of women being angry, emotional and even less able to perform on the job during “that time of the month” is old and tired, but it persists. Even the president of the United States can’t seem to stop bringing up “blood” in connection with prominent women he wants to disparage. Now, a first-of-its-kind study published July 4 in Frontiers in Behavioral Neuroscience provides some scientific proof for what most people with periods already know: Our hormones don’t keep our brains from properly functioning.

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Researchers at University Hospital Zürich, led by Dr. Brigitte Leeners, monitored the estrogen levels of 68 women of varying ages throughout two menstrual cycles. During their periods, the subjects participated in neuropsychological tests to measure their visual memory, attention and cognitive bias. The researchers didn't take into account things like food cravings, emotions, or sexual stimuli for this study, because those measures "do not assess prefrontal cognitive abilities." They found no meaningful connection between estrogen levels and cognitive function. The biggest takeaway came from comparing the two cycles: Even when a person experienced some cognitive discomfort during one cycle, that same person often did not experience the same thing during the next period.

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Previous studies looked at only one menstrual cycle, introducing bias and ultimately fueling stereotypes, according to Leeners.

“They resulted in false positive associations and the false conclusion that women’s cognitive performance is hormone regulated,” she said. “Such an assumption is the background of the myth that women’s cognitive performance is strongly influenced by the menstrual cycle and any resulting prejudice toward women’s abilities in private and professional life.”

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These findings are great for science because they answer a big question that many researchers have blamed for a lack of research into women’s health issues — the difficulty of controlling for menstruation when studying pretty much anything else about the body or mind. Much medical research, for example, is done on men in part because researchers are reluctant to have to control for periods and because — especially in the U.S. — digging into potential gender differences in the body and brain is often controversial.

Dr. Louann Brizendine, a neuropsychiatrist and author of the books The Female Brain and The Male Brain, said the results seem to confirm decades of experience. She has found that about 80 percent of women report feeling more uncomfortable physical and mood symptoms during some cycles than during others, but only about 8 percent report debilitating noticeable discomfort during every period. That 8 percent is typically the group that makes its way to Brizendine’s clinic, the Women’s Mood and Hormone Clinic at the University of California San Francisco. Brizendine opened the clinic in 1988 and says she hoped that by now there would be copycats around the country. That’s not yet the case, but she is hopeful that increased interest and funding for women’s health will change that.

Dr. Mary Jane Minkin, an OB-GYN and professor at Yale University School of Medicine, cautions that this new research shouldn’t keep doctors from taking menstruation-related health complaints seriously. Premenstrual dysphoric disorder, which causes significant and life-affecting mood shifts before one’s period, affects about 5 percent of women and is often misdiagnosed. But the good news is that those symptoms and others such as cramping can usually be addressed with birth control, an SSRI or in some cases over-the-counter medication.

“I’ve been in practice since 1979, and I can honestly say I don’t think I’ve ever taken care of a patient in my life who was significantly impaired by one part of her cycle that she couldn’t put her finger on the atomic button,” Minkin told SheKnows. “There are hormones at play with memory and cognition, but I don’t think it’s anything that can’t be overcome. Do some women feel depressed? Yes. Debilitated? No.”

Next, Leeners’ team in Zürich plans to look into the science behind hormonal cravings. But for now, let's stop discounting the mental capacity of people who menstruate, OK?