How Childhood Trauma Shapes the PMDD Brain

If you live with Premenstrual Dysphoric Disorder (PMDD), you might sometimes ask yourself: why me?

The answer could lie further back than you’d expect - all the way in your early childhood.

The hidden link between trauma and PMDD

Your feelings of extreme emotional sensitivity, overwhelm and irritability before your period are also familiar to around 31 million women worldwide who suffer with PMDD. So, you might be wondering if you all have something in common?

Research from psychiatrist Jayashri Kulkarni (2022) suggests you do, finding that 83% of women with PMDD had experienced trauma in their early childhood. This included childhood physical abuse, sexual abuse, emotional abuse or neglect.

This discovery invites us to take a more complete look at PMDD - one that doesn't just focus on your present symptoms, but also considers your past experiences.

How trauma primes your brain

Early trauma can lay the foundations to make your brain react strongly to your hormones in later life.

Let’s think about how your brain develops in childhood to understand how this works. Early on, your brain is extremely plastic, meaning it's easily adapted by your environment. If you endured repeated stress as a child, such as abuse or neglect, your nervous system is shaped to respond in a way that’s not necessarily useful for day to day life.

This change still exists even when you’re an adult, altering how your brain and body responds to any stress. Now, when we talk about stress, we’re not necessarily talking about that deadline you have coming up. Stress to the body is any internal change which alters your body’s natural balance, such as hormonal shifts during the menstrual cycle.

One major player in this is something called a Hypothalamic-Pituitary-Adrenal (HPA) axis.

The HPA Axis: Your brain’s stress system

The HPA axis is your central stress-response system.

Here’s how it works:

1. Your brain detects stress and activates your hypothalamus

2. The hypothalamus sends signals to your pituitary gland in your brain and alerts your adrenal glands on top of your kidney

3. Your adrenal glands release cortisol - your primary stress hormone.

Cortisol readies your body for action, triggering your fight or flight response. Once the threat has passed, cortisol feeds back to the brain and shuts the system in a self-regulating loop.

The HPA axis is also modulated by an important chemical called ALLO (short for allopregnanolone). ALLO interacts with receptors in your brain that normally bind to a neurotransmitter called GABA. This interaction is really important as it has a calming effect on your body.

This all sounds great right? A well-balanced system designed to navigate stress. But trauma can throw everything out of whack.

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Trauma and the HPA axis

If you were exposed to frequent or chronic stress in childhood, your HPA axis would have been triggered constantly.

Over time, the repeated activation can cause your HPA axis to become dysregulated, leading to:

· Chronic low cortisol

· Poor recovery from stress 

· Heightened anxiety or emotional volatility

Animal studies also show that ongoing stress can reduce ALLO levels (Hantsoo & Epperson, 2016), adding insult to injury as ALLO’s calming effects are lost, an issue commonly seen if you have PMDD.

Cortisol and your cycle: the impact of trauma

So what’s the impact of your HPA axis going haywire? Cortisol isn’t released as it should be.

Normally, cortisol shifts during the menstrual cycle, rising in the follicular phase where you have less reactivity to stress, and falling in the luteal phase where stress sparks more of a reaction (Hantsoo, 2023).

However, having PMDD means you have a blunted HPA axis. You therefore have:

· Lower basal cortisol.

· Lower cortisol release to stress.

This blunted stress response is even more pronounced if you have a history of early trauma, as cortisol levels are much lower in the late luteal phase, right before your period (Nayman, 2023).

Now you might be wondering what’s wrong with having lower cortisol levels? Isn't cortisol a bad stress hormone? Not entirely. Cortisol has many different roles aside from stress regulation, such as blood pressure regulation and blood sugar control. Essentially, we need cortisol to not be too high-or too low, for our body to function normally.

To make matters more complicated, your HPA axis is also sensitive to both estrogen and progesterone. So during the late luteal phase, when estrogen drops and progesterone rises, your trauma-shaped dysregulation gets a whole lot worse.

To summarizse, trauma triggers your HPA axis too much, causing it to malfunction and mess up your body’s response to stress, namely - your cortisol release. But how does this lead to PMDD?

Because cortisol helps to regulate mood. When levels drop too low, particularly in a brain already sensitive to stress, it can lead to those symptoms you know all too well: depression, irritability, and emotional dysregulation.

What this means for you

Living with PMDD can feel debilitating, but understanding the trauma-PMDD connection may offer you reassurance. You are not ‘broken’ and it’s not ‘just hormones’. Your brain has adapted to past stress, and that sensitivity now shapes how you experience your cycle.

Like most conditions, PMDD is the result of both biology and lived experience. When you understand how and why your brain works the way it does, you can begin to work with it.

Samphire helps you do exactly that, by logging your daily experiences across your cycle to create personalized insights. This helps you spot patterns, plan with more clarity, and respond to your cycle on your own terms.

Tracking your cycle is a powerful tool, and you can use Nettle™ alongside to address your symptoms at the source. Nettle™ users report their symptoms of PMDD being ‘greatly reduced’ and ‘almost unnoticeable’, and that they ‘no longer had severe mood swings’ as the gentle brain stimulation mimics your brain in the follicular phase, helping you manage those particularly tough days.

Together, Samphire and Nettle™ offer a powerful brain-centered approach to managing PMDD, helping you take control.

This article is part of a series exploring the comorbidities of Premenstrual Dysphoric Disorder (PMDD), find more on ADHD, Autism, EDS, BPD and eating disorders.