Cortisol and Oxytocin Hardwire Fear-Based Memories
The "stress hormone" and "love hormone" can both hardwire anxiety and PTSD.
Posted Jul 10, 2015
Do you have any deeply rooted fear-based memories associated with a traumatic life experience? In 2003, I was jumped and beaten up by three guys while walking home from dinner at Pete’s Tavern through Stuyvesant Park to my apartment in the East Village.
To this day, when I pass the fountain where they kicked my body and bashed my head in, I have a neurobiological response that causes my levels of the "stress hormone" cortisol to skyrocket. I describe the incident in my first book saying,
I was like a punching bag at their disposal, facedown at first and then curled up in a fetal position, getting kicked primarily in the torso and head. The feeling was unlike anything I had ever experienced. It felt like being in an industrial washing machine with about eight cinder blocks. Your whole life really does flash before your eyes when you think you're going to die.
Why does every detail of a fear-based experience become deeply embedded into long-term memory? Researchers have identified that the "stress hormone" cortisol and the “love hormone” oxytocin actually work together to create a double whammy of deep rooted fear-based memories during, and after, times of distress.
Most likely, these neurobiological responses are part of an evolutionary survival mechanism to protect someone from revisiting life-threatening situations by deeply embedding a traumatic experience and flagging the memory for importance.
Cortisol Drives the Reconsolidation of Stress-Related Memories
A July 2015 study, “Effects of Cortisol on Reconsolidation of Reactivated Fear Memories," was published in the journal Neuropsychopharmacology.
In human experiments, the researchers discovered that cortisol strengthens memories of traumatic stress or experiences that evoke fear. Not only does cortisol kick in while a fear-based memory is being formed for the first time, cortisol levels also spike when someone has a flashback of the experience as the memory reconsolidates and is encoded into specific neurons.
These findings help to explain why humans have intense neurobiological responses to trauma that become deeply embedded in specific neural networks associated with Post-Traumatic Stress Disorder (PTSD), anxiety, and panic attacks.
The researchers from the Ruhr-Universität Bochum found that for most people a vivid memory of a stressful experiences can fade away over time. However, someone suffering from PTSD or paralyzing anxiety can be haunted by the harrowing memories of a previous traumatic experience indefinitely.
The secretion of cortisol reinforces the consolidation and intensity of these memories during the hours following the event in which a memory is formed immediately after the experience. Cortisol spikes again when someone is forced to re-live or recollect triggers of the experience cortisol levels spike again and consolidate the fear-based memory more deeply.
In a press release, co-author Dr. Oliver T. Wolf of the International Graduate School of Neuroscience in Bochum said, "The results may explain why certain undesirable memories don't fade, for example in anxiety and PTSD sufferers. If a person remembering a terrifying event has a high stress hormone level, the memory of that specific event will be strongly reconsolidated after each retrieval.”
Oxytocin Hardwires Fear-Based Memories Linked to Social Defeat
Oxytocin, popularly known as the "love hormone," is largely responsible for feeling socially connected and bonding with people, as well as our overall well-being. Typically, oxytocin is considered beneficial to mental health due to its prosocial benefits and ability to reduce stress and anxiety.
Ironically, evidence of the ability of oxytocin to trigger anxiety in humans has recently emerged. Under times of social defeat or trauma, oxytocin appears to target a specific area of the brain that reinforces fear-based memories.
In July 2013, researchers at Northwestern Medicine published a study, “Fear-Enhancing Effects of Septal Oxytocin Receptors,” in Nature Neuroscience.
The study shows that oxytocin—which is typically associated with our most positive, intimite bonds and falling in love—is also responsible for some of our most long lasting psychological pain, including the memories associated with a break up.
It appears that oxytocin can bring us extreme highs, but also extreme lows in the spectrum of human emotions. While oxytocin fortifies the most powerful bonds of a relationship, it's also likely to be the culprit behind the gut-wrenching feelings of social isolation, loneliness, and being brokenhearted.
For this study on the link between oxytocin and fear-based memories, the researchers used region-specific manipulations of the mouse oxytocin receptor (Oxtr) gene (Oxtr). The scientists were able to identify the lateral septum as the brain region mediating fear-enhancing effects of Oxtr.
The research shows that one function of oxytocin is to strengthen social memory in this specific region of the brain. If an experience is painful or distressing, oxytocin will activate the lateral septum and intensify the negative memory.
In a press release, Jelena Radulovic, professor in psychiatry and behavioral sciences and pharmacology at Northwestern, and senior author of the study said, "By understanding the oxytocin system's dual role in triggering or reducing anxiety, depending on the social context, we can optimize oxytocin treatments that improve well-being instead of triggering negative reactions."
Conclusion: Facing Your Fear-Based Memories Head-On
Like cortisol, under certain circumstances, oxytocin has the ability to hardwire fear-based memories. What can someone do to rewire these fear-based memories?
In The Athlete's Way, I describe how I approached getting over my PTSD after being beaten up. Instinctively, I used the power of social connectivity and knowledge of classical fear conditioning to rewire my brain. Below is a description of my personal process of overcoming my deepest fear-based memories. On p. 280 I write,
I knew the most important thing for me to do to get over the deeply rooted fear conditioning was to go back to the scene of the crime. Right after the attack, if I got within a two-block radius of the scene, which I had to do in order to get home, my adrenaline and cortisol would go crazy. I would start shaking and having heart palpitations.
I approached the gates of the park with my friend Nikki Haran. My body went into spasms. She and I stood on the big slab of stone around the fountain where I had been beaten up. We stood there for a few minutes holding hands and my heart calmed down. I had conquered the fear—and it made me feel OK. Not great, but at least I could cope. It bonded Nikki and me, and our friendship took on a deeper meaning and significance.
Every day for weeks, I went out of my way to go back to that slab of stone and stand on it, alone, look around, and proceed home. It was like a pilgrimage, a very therapeutic one. To this day, every time I walk through the park I walk directly over that very same stone, and it makes me feel really strong. Going back to the place that scares me the most and facing it head-on makes me feel as if I am the ruler of my destiny. And creates a self-fulfilling prophecy.
I believe that using social connectivity and the power of oxytocin in areas of my brain not linked to the trauma allowed me to rewire a fear-based memory and was fundamental for helping me get over my personal battle with PTSD.
If you suffer from anxiety, panic attacks, or post-traumatic stress disorder, I hope these scientific findings and my personal experience will help you overcome the debilitating power of fear-based memories. Also, seeking professional help is always a good idea when you're coping with trauma or overcoming fear-based memories.
If you'd like to read more on this topic, check out my Psychology Today blog posts:
- "The Neurobiology of the "Love Hormone" Revealed"
- "Holding a Grudge Produces Cortisol and Reduces Oxytocin"
- "The "Love Hormone" Drives Human Urge for Social Connection"
- "Cortisol: Why "The Stress Hormone" Is Public Enemy No. 1"
- "Optimism Stabilizes Cortisol and Lowers Stress"
- "The Neurobiology of Grace Under Pressure"
- "Mindfulness: The Power of "Thinking About Your Thinking"
- "The Neuroscientists Discover the Roots of "Fear-Evoked Freezing""
- "Optogenetics Allows Neuroscientists to Turn Fear Off and On"
- "Decoding the Neuroscience of Fear and Fearlessness"
- "The Neuroscience of Forming New Memories"
- "The Neuroscience of Recalling Old Memories"
- "Returning to an Unchanged Place Reveals How You Have Changed"
© Christopher Bergland 2015. All rights reserved.
Follow me on Twitter @ckbergland for updates on The Athlete’s Way blog posts.
The Athlete’s Way ® is a registered trademark of Christopher Bergland.