We keep talking about how PMS and PMDD are real, physical, genetic, biochemical, hormonal conditions, and not, as some would have you believe, simply “in your imagination” or a “neurosis.” We’re happy to report that the evidence—scientific evidence—keeps rolling in that the supports our position.
We have to keep revisiting this, and hammering the topic home, because sometimes it seems as if the only people who understand PMS (and this goes for PMDD too) are the women who suffer from it, and occasionally an understanding husband or partner who is truly supportive. All too often doctors, health care practitioners, family and friends seem to think PMS is an imaginary affliction that women dream up because…well, apparently, just because. But let's get real for a second: no woman would actually wish for a bloated, achey feeling several days out of the month; for difficulty concentrating and brain fog; for fatigue and mood swings; and all the other PMS symptoms that are no walk in the park, despite what the PMS doubters think.
Now, the good news: the “PMS is imaginary” school of thought took a major hit last year when research was published showing that among identical twins, there is a strong genetic component to premenstrual syndrome. When a strong genetic component is proven it suggests a biochemical or physical basis for a condition, rather than a purely psychological or emotional one. As always in the world of science, more studies are needed to confirm the findings, but this study of 176 sets of girl twins clearly showed that the tendency to PMS is an inherited trait.
The results of this study made us curious: has any other researcher looked into this question? Twin studies are among the most reliable studies for a wide variety of medical conditions and personality characteristics because they make it clear what is being affected by genetics, and what is a result of environment and psychology.
As it turns out, a 1993 study looked at this same question of PMS in twins and found that, lo and behold, there is a strong genetic influence on PMS. This study came from Australia; the one mentioned above came from Canada. We weren’t surprised by this: it seems the United States has a prejudice against PMS—many people don’t take it seriously, and assume that only PMDD, the most severe type of PMS, is “real.” There are studies showing this genetic component for PMDD as well: a 2007 study showed that a variation in an estrogen receptor gene is associated with PMDD.
Of course, these studies don’t mean that genetics is the one and only cause of PMS and PMDD: the genes involved could cause a woman to have higher than usual requirements for vitamin B6, calcium, or magnesium, or some other nutrient, or to be more susceptible to the effects of caffeine or stress.
If you’re a scientific type, here’s how to look up the two PMS studies themselves (you can go directly to pubmed or try google scholar):
October 2011, The heritability of premenstrual syndrome. Lead author: Jahanfar S, in the Journal Twin Research and Human Genetics
April 1993, The premenstrual syndrome: a twin study. Lead Author: Condon JT, in the British Journal of Psychiatry.
