His Stress, Her Stress

The New Neuroscience of Stress and Gender
by Dr. Heidi Hanna, AIS Executive Director

Our relationship with stress is dynamic and unique. The brain’s plasticity means that even with genetic predispositions, we can shape both the structure and function of our neural networks through experiences and lifestyle choices.

The lens through which we see challenges in life may be adjusted over time based on circumstances, but is primarily custom fit in our early years. Up until the age of about 9 or 10, the brain is radically adaptable, pruning away neural connections that we perceive to be less valuable so that our cortical real estate can focus on what we deem most important.

During these formative years, much of what we sense to be “neuron worthy” happens in our non-conscious processing related to safety and survival. We have five times more fear-based circuits in the brain, and pay bout 80% more attention to potential threats than rewards.

Although many people shy away from the topic, and some outright ignore the scientific foundation of what I’m about to suggest, recent research has clearly identified differences in what has been called male and female brain patterns related to stress. The hesitation to confidently share these variances is no doubt related to past overstatements and misinterpretations that claimed certain gender orientations to be weaker than others.

In fact, not that long-ago brain differences like size and connectivity lead some scientists to suggest that research validated female inferiority. We now know that both male and female brain patterns are beneficial and that both also have vulnerabilities if not managed effectively.

If we want to optimize our brain health and fitness, we must first understand to the best of our ability what makes us tick. Ignoring gender differences doesn’t make us more equal, unless you consider ignorance something to strive for. With so much data providing access into our own neural landscape, we now have the ability to radically elevate our collective knowledge and modify how we work with each other to optimize performance while also improving collective health and happiness.

What We Know Now

Over the past decade, credible research has demonstrated that there are clear differences between male and female brain patterns. Most scientists agree that we need to refrain from overstating or stereotyping men and women into one of two distinct categories, but rather consider a spectrum of male and female brain types with variation depending on several key factors. These include elements of both biology and behavior.

1) Biology.

Bruce McEwen has suggested that we consider hormones to be one determining factor in how brain patterns function. Rather than merely looking at male and female structures, we can see more of the full picture when we evaluate levels of estrogen and testosterone that are present at the time. McEwen’s research at Rockefeller University showed that in male animals, stress caused the dendrites in the hippocampus and prefrontal cortex to shrink, and spine synapses (connections between neurons) to be lost.

However, in female animals going through the same stress experience, cortical shrinkage did not occur, and the dendrites that connected with the amygdala (responsible for fear and anxiety) actually expanded, but only in the presence of estrogens. Without estrogen intact, the impact of stress on the brain mirrored that of the male animals.

Ute Habel, Professor of Neuropsychological Gender Research for the University Clinic for Psychiatry, Psychotherapy, and Psychosomatics at RWTH Aachen University in Germany, provides us with a different picture of cerebral dynamics based on fMRI scans. Although the behavioral output of men and women in Habel’s research was the same, the manner by which study participants came to their conclusions was markedly different.

Overall, brain activation was much higher in women compared with men in all tasks, particularly during the follicular phase, suggesting a role for estrogen in the empathy response. Although there was some overlap in brain regions that were activated, “women tended to activate more emotion and self-related regions whereas men activated more cortical, or cognitive areas,” she said.

2) Behavior.

One challenge of gender research of the past is that we were only comparing behavior and outcome of brain processing to evaluate differences. While it’s true that both men and women find success across multiple domains in life — leadership, business, education, parenting, innovation — the way we get there may be quite unique. And although we might not think the journey matters as much as the destination, when it comes to the impact of stress on the brain our unique processing patterns could mean the difference of life and death.

I say this because the male and female brains are motivated by different elements, both biologically and behaviorally, and the side effects or costs of doing business vary just as much. Research by Shelley Taylor at UCLA revealed that the “fight or flight” response we’ve been taught to accept as universal is only part of the story.

It turns out that studies of both humans and animals demonstrate a role for oxytocin in the stress response. In men, testosterone seems to mitigate the more calming, affiliative effect of oxytocin in the brain. While in women, the female hormone estrogen seems to enhance oxytocin, causing more women to turn to others to “tend or befriend” in the midst of stress than men.

Because women can be more challenging for researchers to study due to hormonal fluctuations that modify results, most testing has been focused on only male subjects. As we see more gender differences surface, many advocates strongly recommend we include more women in scientific studies. Especially those involving medication, which has already proven to have dramatic differences in levels of both effectiveness and the number and intensity of side effects.

Where Do We Go From Here?

We have only scratched the surface when it comes to the neuroscience of stress and gender, however these early findings clearly tell us that the more we learn the less we may really know for sure. But this is a temporary gap that can quickly be bridged once we accept these unique patterns are real and create collaborations that are truly integrative in design.

Part of the joy and genius of scientific discovery is staying open and curious to what lies ahead. Anytime I discuss gender differences I prepare myself for the myriad of questions and challenges that will be triggered by fear-based reactions to identifying differences as potential weaknesses that could be held against us. I want to emphasize that being different is not a bad thing, but ignoring differences is.

I believe that our greatest stress in life is trying to be someone we’re not. Most of the time we don’t even realize we’re doing this until we’re so exhausted by life that we finally open ourselves up to learning who we really are, and commit to living in a way that is more aligned with our core strengths.

As women, our stress sensitivity can be one of our greatest gifts. Female brain patterns tend to show great empathy, intuition, and emotional intelligence; traits we know are incredibly valuable across many domains. However, if we don’t manage it effectively, this same sensitivity can turn against us. Women have higher rates of anxiety and depression, and tend to internalize stress leading to more wear and tear on both the brain and body. In contrast, men tend to have higher rates of “fight or flight” types of stress reactions, triggering increases in aggressive behavior, substance abuse, and suicide.

When we know better, we can do better. There is no one-size-fits-all solution for stress. With advancements in science and technology, we are beginning to see the importance of personalization in medicine, and in our self-care strategies. By looking into our unique differences, capitalizing on the vast research in neuroscience and epigenetics, we can clarify the best strategies for optimizing our own energy, and using stress as a stimulus for positive change rather than a trigger for burnout and breakdown.

To be continued.