In the first study, published earlier this year in the British Journal of Pharmacology, researchers gave male and female rats doses of fluoxetine (a.k.a. Prozac). Then, they analyzed the rats' brains for levels of a particular enzyme, which deactivates the sedative allopregnanolone and its related compounds. PMS symptoms could be triggered by the body producing a decreased amount of the sedative, causing us to react a little more sensitively to stress. But, the researchers found that in the female rats (who also go through a reproductive cycle), fluoxetine elevated the levels of allopregnanolone.
And, in a study published last week in European Neuropsychopharmacology, researchers also found that fluoxetine increased the level of allopregnanolone in rats. The team concluded that this, rather than the antidepressant's well-known effect on serotonin, was responsible for preventing an increased sensitivity to stress.
These studies build on a mountain of previous research indicating that fluoxetine and other antidepressants can curb PMS symptoms, but they're some of the first to suggest they can prevent those symptoms, too. So, although doctors have been prescribing antidepressants to help with PMS symptoms for a while, now it seems that we should be thanking their effect on this allopregnanolone-controlling enzyme.
And, the more recent study found that you need a much lower dose of fluoxetine in this scenario than what's used to treat depression. It also worked much faster. So, although rat doses aren't always scalable to human ones, the researchers suggest that low doses of antidepressants could be effective with PMS.
But, we're also learning more and more about how PMS may be a "culture-bound syndrome," meaning that even if hormones are to blame for any changes during that time of the month, how we interpret and react to them could be influenced by societal expectations. Finally, let us not forget that oldest of truths: Wherever they come from, cramps and mood swings suck.