My husband found me sobbing on the kitchen floor. My job was in upheaval, my travel schedule was gruelling and, with two hours left before my next departure, I’d discovered that my laptop was dead. This was the moment my husband walked in to console me, and in an impressive feat of bad timing, he also asked whether I was premenstrual.
I went from sobbing to supernova in about two seconds, enraged by his presumption that surging female hormones were responsible for my emotional distress. The only thing that saved him was that, a few days later, I discovered that he’d been right.
I am a scientist who studies the nature of emotions. For most of my scientific career, I didn’t believe that women systematically had emotional eruptions right before their period, even though I experienced them occasionally. Studies suggested that women who believe in premenstrual syndrome (PMS), when asked about it in retrospect, tend to misremember the symptoms as more severe than they were. The evidence for PMS overall was inconsistent. Certainly, I knew of no neurological reason that women should feel, just before their period, that the world was crashing down on them.
Some women may have a short window before their period when, if something bad happens, they will feel more negative or stressed and will remember that unpleasant event more easily.
My doubt was also political in nature. During my clinical internship more than 20 years ago, my boss, a psychiatrist, asked me to research how PMS prevents women from thinking clearly. I told him he was a relic of the Stone Age. Women were as consistently clearheaded as men, if not more so.
But recently, a researcher in my lab, Joe Andreano, an expert on female hormones, showed me some surprising data. As a woman’s levels of progesterone and oestrogen vary, so does the connectivity between two brain networks: the default mode network and the salience network. These networks play key roles in creating your emotional life.
If I hadn’t seen the data with my own eyes, I wouldn’t have believed it.
When scientists say that brain networks are “strongly connected” or have “increased connectivity”, it means that the neurons have an easier time passing information back and forth. In the case of the default mode and salience networks, increased connectivity means (among other things) that you may experience more powerful negative emotions. In earlier research, for example, my colleagues and I found that people reported more intense sadness when watching the sentimental movie Stepmom and more intense fear when watching the horror movie The Ring Two in the moments when these brain networks were more connected.
There has also been a flurry of recent studies indicating that certain cocktails of ovarian hormones can make women feel lousy, particularly a week or so before menstruation. Female test subjects who receive ovarian hormones designed to mimic the menstrual cycle, for example, report an increase in negative mood. They also remember negative material better, and they show enhanced stress responses. Women who use contraceptives containing progesterone even have an increased risk of depression and suicide attempts.
In previous years, I might have been inclined to discount or dismiss those findings, citing the behavioural research that shows that women tend to misremember the severity of their PMS symptoms. But combined with Dr. Andreano’s research, the findings suggested a brain-based reason that some women may experience greater emotional distress just before their period.
Biology is real
Andreano and I, along with several other colleagues, published a recent paper in the journal Trends in Neurosciences, knitting together data from various sources. We explained how negative emotion, memory for negative events and the connectivity of these two brain networks all vary with the concentration of ovarian hormones. We ventured that these changes happen in sync with the menstrual cycle — a hypothesis that we’re currently testing.
Now, I’m not saying that women turn into helpless snowflakes for a few days each month. I’m just saying that the biology is real: Some women may have a short window before their period when, if something bad happens, they will feel more negative or stressed and will remember that unpleasant event more easily.
A few bad feelings or memories aren’t inherently harmful, of course. But this window of vulnerability, combined with other risk factors, could increase the odds of developing mood disorders like depression.
As a scientist, I find these discoveries a fascinating opportunity to investigate and improve women’s health. As a feminist, I have to admit that they violate my cherished belief that behaviour in men versus women is dominated by social factors rather than biology. Social factors are still potent, but they don’t tell the whole story.
That said, it would be wrong to conclude that women are emotional and men are rational, or any such nonsense. On average, men and women don’t differ in their emotions, even if stereotypes suggest otherwise. (And hormones also fluctuate in men, though the emotional consequences are not well studied.)
Furthermore, negative emotions do not conflict with clear, rational thinking, despite what my old boss thought. Sure, intense feelings sometimes lead you to do regrettable things, but so do intense thoughts, and men and women have plenty of both. Just ask my husband.
Lisa Feldman Barrett is a professor of psychology at Northeastern University, where she focuses on the study of emotion