PMDD: Understanding the Hidden Causes Behind Severe Premenstrual Mood Symptoms

Gemma Knaap
Sep 22
3 min read

If your mood changes dramatically in the week or two before your period — to the point of feeling like a different person — you’re not alone. You might be dealing with PMDD.

Premenstrual Dysphoric Disorder (PMDD) is a severe, hormone-related mood disorder that affects around 5–8% of menstruating women. But it’s often under-recognised and misdiagnosed, especially because it’s not just a "worse version of PMS."

PMDD is cyclical, debilitating, and can deeply affect your relationships, work, and emotional wellbeing.

And while most conventional explanations focus on serotonin and hormones, there’s more going on under the surface — including inflammation, histamine, GABA signalling, and the gut-brain axis.

What Is PMDD?

PMDD is characterised by severe mood changes that occur only in the luteal phase of your cycle — usually 1–2 weeks before your period — and resolve shortly after bleeding begins.

Symptoms may include:

Irritability or rage
Depression or emotional sensitivity
Anxiety or panic
Brain fog or fatigue
Sleep disturbance
Appetite changes or cravings
Feeling “out of control”

It’s not caused by abnormal hormone levels — it’s about an abnormal sensitivity to normal hormone fluctuations.

Lesser-Known Causes and Triggers of PMDD

While hormone shifts are part of the story, emerging research reveals deeper mechanisms that help explain why some people react so strongly in the luteal phase.

1. Heightened Sensitivity to Allopregnanolone

Allopregnanolone is a metabolite of progesterone that influences the calming GABA receptors in the brain.
In PMDD, some women may have altered GABA receptor function — leading to anxiety, insomnia, or emotional dysregulation in response to normal luteal-phase progesterone.

2. Histamine Intolerance

Oestrogen increases histamine release — and histamine can aggravate anxiety, irritability, insomnia, and digestive issues.
If your body struggles to break down histamine (due to DAO enzyme issues, gut dysbiosis, or nutrient deficiencies), it may build up and intensify PMDD symptoms.

3. Inflammation and Immune Reactivity

Inflammatory cytokines can affect neurotransmitter production and HPA axis function.
Women with PMDD may show higher markers of inflammation, particularly in the luteal phase.
Chronic low-grade inflammation from poor diet, stress, gut issues or environmental toxins may play a role.

4. Gut-Brain Axis Disruption

The gut microbiome influences serotonin, GABA, dopamine, and inflammation.
Dysbiosis, leaky gut, or reduced postbiotic production may increase PMDD risk or severity.
Gut health also impacts oestrogen metabolism — further compounding hormonal sensitivity.

5. Nutrient Deficiencies

Key nutrients for neurotransmitter balance and hormone metabolism include:

Magnesium: regulates GABA, oestrogen detoxification, and stress response
Vitamin B6: cofactor in serotonin and GABA production
Zinc: anti-inflammatory and hormone-modulating
Omega-3s: reduce inflammation and support brain function

Deficiencies in these can worsen PMDD symptoms.

How Is PMDD Diagnosed?

Diagnosis typically involves tracking symptoms over at least two full menstrual cycles to confirm timing and severity.

PMDD symptoms must:

Occur in the luteal phase
Resolve within a few days of menstruation
Significantly impact daily functioning
Be absent during the follicular phase

PMDD Is Not “All in Your Head”

Understanding that PMDD is not simply a serotonin imbalance, or a sign of weakness, can be hugely validating. It’s a biological sensitivity — often made worse by modern lifestyle factors, gut imbalances, and nervous system overload.

And while conventional treatment often focuses on SSRIs or hormonal suppression, many women benefit from addressing the root causes through natural, evidence-based strategies.

Looking for Support?

If you suspect PMDD and want to explore holistic strategies that include hormone support, gut health, and nervous system care, I'd love to help. Click here for 1:1 support for cycle-related mood symptoms, or download Healthy Hormone Foundations to get started with food and lifestyle changes that can make a real difference.