Trauma is in and of itself a well-researched precursor to multiple other mental and physical health disorders, so it’s not surprising to experts in the field that it’s linked to PMDD. “It’s really astounding how many disorders are predicted by trauma,” says Tory Eisenlohr-Moul, a clinical psychologist and incoming associate director of translational research in the women’s mental health research program at the University of Illinois, Chicago.
Trauma causes changes in the hypothalamic-pituitary-adrenal (HPA) axis, a stress-responsive system that enables us to adapt to environmental challenges and stressors, explains Eisenlohr-Moul. “The ultimate byproduct of the HPA axis is cortisol, a hormone that mobilizes energy resources in order to respond to stressful events and to meet the energy demands of life.”
In her research on women with trauma and PMDD, Eisenlohr-Moul has most commonly found a blunting of the stress response—that is, a flat line or small increase in cortisol after a stressful situation—whereas people without trauma have a significant increase. These women also appear to have increased sensitivity to their ovarian steroid hormones during the luteal phase, which seems to dysregulate that HPA axis, altering thyroid function, increasing pain sensitivity, and impairing sympathetic nervous system function.
This may explain why PMDD/PMS share traits in common with post-traumatic stress disorder (PTSD), something war veterans and first responders often experience.
Where it gets sticky is attempting to understand why this association exists. There is research suggesting that those with the estrogen alpha receptor (ESR1) gene have a higher risk of PMDD, but this field of research is relatively new. “We don’t know a lot about whether trauma is causing hormone sensitivity, or whether it’s just that trauma is so common in women that…they tend to have more symptoms because they have more underlying mental health symptoms anyway, and it amplifies the expression of their hormone sensitivity,” says Eisenlohr-Moul.
A 2016 study in Psychoneuroendocrinology looks at this association between past abuse and PMDD. Though not a direct cause, the researchers found that “history of physical abuse unmasked a positive association between cyclical increases in P4 [progesterone] and mood symptoms.”
However, this research opens more questions than it answers. Eisenlohr-Moul admits that they simply haven’t studied the subject comprehensively enough to know why. “I wonder if maybe things like duration of abuse or timing of abuse [are responsible]. Did it happen during a critical brain development period? Maybe the physical abuse is more likely to be chronic.”
There are also studies linking dysregulation of the serotonin and allopregnanolone systems, for which doctors often prescribe SSRI drugs, but these don’t work for every woman. Barnes had “a horrible reaction” to Serafem, a form of Prozac.
Eisenlohr-Moul and others in her field are careful to clarify that underlying mental health issues and their effects on PMDD symptoms do not suggest that PMDD symptoms are only in the sufferer’s head. She feels that medicine generally “focuses on fixing the biology, and they don’t zoom out and look at the context in which it happened. [Trauma] is a situation where prevention would truly be worth a lot more. We know that trauma influences mental health.”