Trauma + Me: How Trauma Rewires the Brain (#2)

Welcome back, friends. In the first post of this series, we explored the basics of trauma—what it is, how it manifests, and how awareness is the first step toward healing. Today, we’re going deeper into the science of trauma.

Specifically, we’ll unpack how trauma rewires the brain and what that means for how we think, feel, and live. Buckle up—this post is packed with research, stats, and insights that might just change the way you see yourself and the world.

What Trauma Does to Your Brain

Trauma changes your brain in ways that are as fascinating as they are unsettling. When you experience a traumatic event, your brain shifts into survival mode—a state designed to protect you from immediate danger. But when that state becomes chronic, it rewires your brain in ways that can have lasting effects. Let’s break this down by looking at the key players in your brain’s trauma response:

1. The Amygdala: The Alarm Bell

The amygdala is the brain’s fear center. It’s responsible for detecting threats and triggering your fight, flight, or freeze response. Research shows that in individuals with trauma, the amygdala becomes hyperactive. This means your brain is constantly scanning for danger, even when you’re safe.

• Research Insight: A 2017 study published in Biological Psychiatry found that individuals with PTSD had significantly higher activity in the amygdala when exposed to threatening stimuli compared to those without PTSD. This hyperactivity explains why trauma survivors often feel on edge or easily startled.

• Personal Perspective: I’ve lived this. After years in solitary confinement, my amygdala was so overworked that even the sound of a door closing made my heart race. My brain didn’t trust that I was safe.

  
  

2. The Prefrontal Cortex: The Voice of Reason

The prefrontal cortex (PFC) helps you make rational decisions and regulate emotions. Trauma suppresses the activity of the PFC, which is why it can feel impossible to think clearly or stay calm in stressful situations.

• Research Insight: A 2014 review in The Lancet Psychiatry noted that individuals with trauma often show reduced activity in the PFC, particularly in areas associated with decision-making and emotional regulation.

• Real-Life Impact: This suppression can lead to impulsive behavior, difficulty focusing, and trouble managing stress. For me, this looked like overreacting to minor conflicts because my PFC was too overwhelmed to hit the brakes.

  
  

3. The Hippocampus: The Memory Keeper

The hippocampus processes and stores memories, helping you distinguish between past and present. Trauma can shrink the hippocampus, making it harder to process memories or recognize that a threat is no longer present.

• Research Insight: A landmark study in Nature Neuroscience found that trauma survivors had up to 20% smaller hippocampal volumes compared to those without trauma. This shrinkage contributes to flashbacks and the feeling of being “stuck” in the traumatic event.

• Personal Reflection: I’ve experienced this firsthand. For years, certain sounds or smells would transport me back to moments of fear, even though I was miles away from that reality.

  
  

Trauma doesn’t just impact your brain—it affects your entire body. Here’s what we know from decades of research:

1. Chronic Stress and the HPA Axis

The hypothalamic-pituitary-adrenal (HPA) axis is your body’s stress response system. In trauma survivors, this system becomes dysregulated, leading to chronic stress.

• Data Point: A study in Psycho neuroendocrinology found that individuals with PTSD had higher baseline levels of cortisol (the stress hormone), which can lead to inflammation, fatigue, and even heart disease.

• Impact on Health: Trauma survivors are at increased risk for conditions like diabetes, hypertension, and autoimmune disorders. Trauma isn’t just in your head—it’s in your body too.

  
  

2. Emotional Dysregulation

Trauma can make it difficult to manage emotions, leading to mood swings, anger outbursts, or emotional numbness.

• Study Highlight: A 2020 meta-analysis in Frontiers in Psychology found that trauma survivors were significantly more likely to struggle with emotional regulation, particularly in high-stress situations.

• What This Looks Like: For me, this meant avoiding or closing down in relationships because I didn’t trust my ability to handle the emotional ups and downs.

  
  

The effects of trauma ripple out, impacting not just the individual but also families, communities, and even entire systems. Let’s look at the bigger picture:

• Economic Cost: A 2021 report from the CDC estimated that childhood trauma (adverse childhood experiences or ACEs) costs the U.S. over $581 billion annually in health care, lost productivity, and criminal justice expenses.

• Intergenerational Impact: Trauma doesn’t stay contained—it’s passed down. A study in JAMA Psychiatry found that children of trauma survivors are more likely to experience mental health challenges themselves.

• Social Cost: Unresolved trauma contributes to cycles of violence, addiction, and poverty, perpetuating systemic inequities.

If all of this feels heavy, that’s because it is. Trauma is a complex, far-reaching issue, and it’s easy to feel overwhelmed by its scope. But here’s the silver lining: trauma is also treatable. The brain’s ability to rewire itself—known as neuroplasticity—means that healing is always possible.

For me, the first step was education. Once I understood what trauma had done to my brain, I could start to undo its effects. I began to notice the patterns in my thoughts and behaviors, asking myself:

• “Is this reaction about what’s happening now, or is it about something that happened then?”

• “What can I do to calm my brain in this moment?”

This awareness didn’t fix everything overnight, but it gave me a starting point. It was the first domino in a chain reaction of healing.

What’s Next?

In the next post, we’ll dive into Trauma in our relationships. We’ll explore how trauma can create obstacles in our love life. If this post was about the “what” of trauma, the next will be about “how” and specifically—how it lingers in our closest relationships. Additionally, what we can do to notice if we are bringing our unhealed trauma into our relationships.

For now, I leave you with this:

Trauma changes you, but it doesn’t define you. The brain is resilient, and with the right tools, you can rewrite the story trauma tried to tell.

Until next time,

Troy Rienstra