PMDD isn't “being dramatic”, it’s visible on brain scans…
By Alice van der Schoot
For too long, those of us experiencing Premenstrual Dysphoric Disorder (PMDD) have been dismissed as "overreacting" or told our debilitating symptoms are simply part of being a woman. But neuroimaging research provides the evidence that PMDD is a legitimate neurobiological condition.
Understanding PMDD
PMDD is a cyclical, hormone-based mood disorder with severe emotional and psychological symptoms (e.g. depressed mood, anger, anxiety) in response to normal menstrual cycle hormone fluctuations. Symptoms typically occur 1-2 weeks before menstruation. It's classified as a depressive disorder in the DSM-5 (1).
Unlike PMS, PMDD symptoms are so intense that they significantly disrupt work, relationships, and daily functioning. Many sufferers describe feeling like a completely different person in their luteal phase.
PMDD “officially” affects 3-8% of us with a menstrual cycle (2), though the actual prevalence is likely higher because medical gaslighting is common. Many have their clinical concerns dismissed without evaluation due to ignorance or bias. Silencing from medical professionals is common, along with misdiagnoses.
Despite widespread misinformation about PMDD being a 'hormonal imbalance', studies show no differences in estrogen and progesterone levels between those with and without PMDD. Instead, it's agreed that PMDD involves an altered sensitivity or "abnormal negative brain reaction" to normal hormone fluctuations of the menstrual cycle (3). In the research, there are a few biological mechanisms found that could contribute to this sensitivity (4). That’s for another article!
Neuroimaging Showed Differences in PMDD
In a 2022 study, researchers in Sweden used advanced MRI scanning on 89 women with PMDD and 42 healthy controls during the luteal phase (5). They discovered striking structural differences between those with PMDD and those who did not have PMDD.
(Note: The following brain regions I list might not make much sense, but I’ll explain more about what this means later in the article):
- Women with PMDD had smaller gray matter volume in ventral posterior cortices and the cerebellum compared to controls.
- Women with PMDD had smaller volumes in the right amygdala and putamen compared to controls.
- A thinner cortex was observed in women with PMDD compared to controls across widespread brain regions, particularly in the left hemisphere. This wasn’t a small difference - effect sizes ranged from moderate to large.
Artificial Intelligence Was Able to Distinguish Who Had PMDD!
Once these structural differences were identified, a machine learning analysis (artificial intelligence) achieved something unprecedented: it managed to distinguish PMDD from controls based on these structural measures with an accuracy of 74%.
What Do These Brain Differences Mean?
While studies have not linked specific symptoms of PMDD directly to these brain differences yet, what we know about these brain regions does align with PMDD symptoms in ways that make scientific sense. Here's some examples:
The amygdala is a major processing centre for emotions, particularly fear and anxiety. Differences in this area could be associated with increased vulnerability to anxiety, and could also play a role in why normal daily stresses can feel overwhelming.
The putamen helps regulate motivation, reward, and goal-directed behaviour. Differences in this area could contribute to difficulties with motivation, decision-making, and attention. It could feel like having a “dimmer switch” on life’s pleasures.
Widespread thinning in the left brain is particularly telling. The left side typically handles logical thinking, language, and talking yourself through problems. When this area is thinner, it could be harder to inhibit emotional responses, to think your way out of emotional spirals or even find the right words to explain how you're feeling.
The widespread nature of the cortical changes suggests PMDD affects multiple brain networks simultaneously - explaining why symptoms are so varied and severe, spanning mood, cognition, and even physical sensations for some.
Our Suffering is Real
For all of those suffering from PMDD who've been told to "just deal with it", this brain scan evidence provides something invaluable: validation that our suffering is real, measurable, and worthy of medical attention and proper support.
References
1. DSM-5 diagnostic classification Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Association. 2013
2. Reilly TJ, Patel S, Unachukwu IC, et al. The prevalence of premenstrual dysphoric disorder: Systematic review and meta-analysis. J Affect Disord. 2024;349:534-540.
3. Hantsoo L, Epperson CN. Premenstrual Dysphoric Disorder: Epidemiology and Treatment. Curr Psychiatry Rep. 2015;17(11):87.
4. Hantsoo L, Payne JL. Towards understanding the biology of premenstrual dysphoric disorder: From genes to GABA. Neurosci Biobehav Rev. 2023;149:105168.
5. Dubol M, Stiernman L, Wikström J, et al. Differential grey matter structure in women with premenstrual dysphoric disorder: evidence from brain morphometry and data-driven classification. Transl Psychiatry. 2022;12(1):250.