Why do we still not know what causes PMS?

August 12, 2016

In 1931, a condition called “premenstrual tension” was described for the first time in a scientific study by gynecologist Robert Frank. His advice for women with severe cases of premenstrual tension? Radiate the ovaries, or completely remove them. Fast forward 80 years and the treatment of premenstrual syndrome (PMS) hasn’t progressed far from this drastic approach. Yes, as a last resort, women with extreme PMS still opt to have their ovaries taken out. If removing an entire organ sounds archaic, it is, but there’s a reason why this still happens in the 21st century.

For decades, PMS, its causes, and the question whether it is actually a medical condition have been shrouded in mystery. PMS is a complicated health problem as symptoms and severity differ in every woman and, even in individuals, often vary from month to month. This makes it difficult to study and has led to a vicious cycle developing in PMS research – scientists don’t understand what causes PMS, meaning there is little scientific research into it, and, in turn, less funding for new studies.

What’s known is that PMS has to do with hormone changes during the luteal phase of the menstrual cycle. Chemical changes in the brain – a reduction of serotonin triggered by these hormone change – may also play a role in PMS. So may lifestyle factors like stress and diet. Others may have a genetic predisposition to PMS, psychologist Carolyn Janda says.

To put how little research has been done into PMS into context, a search of titles and abstracts on ResearchGate found there are over five times more studies into erectile dysfunction than into premenstrual syndrome. That’s despite the fact that approximately 19 percent of men experience erectile dysfunction over the course of their lifetime, while over 90 percent of women report some symptoms of PMS.

Over 40% of women who have PMS do not respond to treatments currently available

Defining the symptoms is where the problem of researching PMS starts. Researchers still don’t agree on what the symptoms of PMS are – over 150 are commonly listed, from the predictable bloating and mood swings, to headaches, sleep disorders, and even clumsiness.

This lack of consensus means women are often unsure which symptoms they can actually attribute to their period, and which are unrelated. This also makes treatment – let alone finding a cure apart from hysterectomy – difficult. Treatment currently includes taking a class of antidepressants, selective serotonin reuptake inhibitors, to easy emotional imbalances. Hormonal contraception is commonly used too. There’s also evidence that certain alternative treatments help alleviate symptoms, including chasteberry. However, over 40% of women who have PMS do not respond to treatments currently available, and five percent have premenstrual dysphoric disorder (PMDD), a condition so severe that 15 percent of sufferers attempt suicide at some point in their lives.

Figure: Schmelzer et al. in Health Care For Women International 36

“When I experience intense bouts of PMS that include a combination of lethargy, irritability, difficulty concentrating, mood swings, anxiety or crying spells, seemingly simple things like getting out of bed or talking to more than one person at a time can feel like a feat,” said one woman. Symptoms like hers have tragically been confused with, and diagnosed as bipolar disorder.

“I suspect that this is a fancy way of saying it’s really just in a woman’s head”

According to PMS researchers, patient stories like these are unlikely to change until the science gets taken more seriously and receives more funding from institutions. Kathleen Lustyk, a psychologist from the University of Washington, has had grant reviews rejected on the grounds that PMS does not actually exist. Her reviewers suggested it was “merely a product of our society or culture that has painted a natural process in a negative light and that, given its monthly predictability, leads to suffering through anticipation.” “I suspect that this is a fancy way of saying it’s really just in a woman’s head,” Lustyk said. That’s despite the fact that PMS can affect women’s lives far longer than a couple of days per month – for example, symptoms of anger or anxiety can wreak havoc on relationships for years to come.

However, investment in research isn’t the only key to improving what we know about PMS.  Researchers struggle to compare results across studies. The International Society for Premenstrual Disorders, a group of researchers and medical professionals working on women’s health, recently released a consensus to standardize the diagnosis and management of PMS. They recommend women keep a diary recording symptoms for at least two months. Period tracking apps like Clue could help to do this. Women use the app to record how their bodies change over the course of their menstrual cycle, including physical and mental symptoms. This information, the company says, is already attracting a lot of interest from medical professionals.

Together, eight decades after Robert Frank first described PMS, researchers, doctors and patients are getting behind this monthly medical mystery of the female body. They’re finding ways to study the syndrome, hoping to break through the vicious circle of ignorance and lacking funds. And who knows, maybe, written in the pages of a journal, or pulled from the data of an app, there’s a gentler cure to be found, too.

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