
When people face dangerous or traumatic situations, often the term “fight-or-flight response” is used—either standing up to the threat or running away from it. But what happens when someone experiences psychological trauma and doesn’t react in the usual way?
Historically, some people suffering from trauma did not receive a post-traumatic stress disorder (PTSD) diagnosis because they did not show the typical signs of heightened heart rate, increased blood pressure, or the urge to fight or run. Dr. Ruth Lanius, Scientist at London Health Sciences Centre Research Institute (LHSCRI) and Psychiatrist at London Health Sciences Centre (LHSC), has changed the field by uncovering other, less recognized responses to trauma.
A breakthrough in trauma research
In the early stages of her research, Dr. Lanius discovered that not everyone who experiences trauma reacts with a heightened sense of action. In fact, some individuals exhibit an underreaction.
“Our research has shown through brain scans that people may respond differently to a traumatic event and it’s not always a fight-or-flight response – sometimes they react by freezing or completely shutting down, which also needs to be treated,” says Lanius.
This was a crucial finding in understanding PTSD, as it went beyond the traditional fight-or-flight view.
A personal encounter: Same trauma, two different responses
A turning point in Dr. Lanius’ research came when she met a couple who had experienced the same traumatic event—witnessing a devastating car accident in which another car caught fire, tragically killing a young passenger. Both the wife and husband were affected by PTSD, but their reactions were very different. The wife responded by freezing; her brain scans revealed an underactive response to the event, causing her to shut down and disconnect from the tragedy. On the other hand, the husband’s response was much more reactive, with his heart rate spiking and stress levels rising whenever he relived the event.
This case helped Dr. Lanius realize that two people could experience the same trauma but respond in vastly different ways. Her continued research revealed that there are several ways the brain and body can react to trauma, including:
- Flight: A desire to escape the situation, running away from danger.
- Fight: An increased heart rate and blood pressure, causing a person to fight back against the perceived danger.
- Freeze: The person becomes physically immobilized, unable to move or respond. Their eyes may even lock in place as their body “freezes” in response to the trauma.
- Shut down: This response leads to a decrease in heart rate and blood pressure, causing some individuals to faint or mentally disengage from the traumatic event.
“It’s only with a proper understanding of the mechanisms underlying PTSD that we can advance new therapies and create better outcomes for patients,” explains Lanius.
The promise of deep brain reorienting (DBR)
As part of her groundbreaking work, Dr. Lanius and her team have been studying a new treatment called deep brain reorienting (DBR) developed by Dr. Frank Corrigan, a psychiatrist from Scotland. DBR is a form of therapy that helps individuals who are dealing with trauma, shock, and stress by teaching their brains to react differently to negative feelings. It aims to help the brain process trauma and shock in a healthier way, so that individuals can regain control over their emotions and mental state.
DBR combines mindfulness techniques, body awareness, breathing exercises, and sometimes even special equipment to retrain the brain’s response to trauma. The results are remarkable, with patients showing both mental and physical improvements.
“We’ve seen some wonderful clinical outcomes using DBR, but also amazing neurobiological changes,” says Dr. Lanius. “The brain seems capable of rewiring itself completely after treatment, allowing people to get healthier.”

Understanding PTSD as both a physical and mental disorder
One of Dr. Lanius’ major contributions is her recognition that PTSD is not just a mental issue—it’s also physical. Her research has shown physical changes in the brains of those who have experienced trauma, leading to avenues to pursue better treatment options and outcomes for patients.
“It’s critical that we treat both the psychological and physiological aspects of trauma to achieve healing,” she notes.
Passion for research
Dr. Lanius’ work is not done. A passion for psychiatry and research was ignited during her internship, where she worked with traumatized individuals, and it continues to this day.
She notes the importance of continuing to advance medicine through health research.
“Hospital-based research like the work we do at LHSCRI is critical,” Dr. Lanius explains. “In order to be a top hospital, research must guide the clinical care we provide.”
Dr. Lanius is a renowned figure in the field of PTSD research. She is the Director of the PTSD Research Unit at LHSCRI and Western University and has contributed to establishing specialized services for the treatment of PTSD. Dr. Lanius also holds the Harris-Woodman Chair in Mind-Body Medicine at the Schulich School of Medicine & Dentistry at Western.
With over 150 published papers on traumatic stress, Dr. Lanius is a leading voice in the field, regularly lecturing on PTSD internationally. She recently co-authored The Impact of Early Life Trauma on Health and Disease with Eric Vermetten and Clare Pain.
Life outside of work
When she’s not focused on her research or treating patients, Dr. Lanius enjoys spending time with her husband and friends, listening to music, exploring museums, and walking in nature. She also enjoys traveling, and recently visited Venice, capturing beautiful moments from a local carnival which she now has framed in her office at University Hospital.
“It’s important to have a healthy balance between both work and life. I find fulfillment in both which helps me bring my best self to patients and colleagues at work, and to family and friends at home,” explains Lanius.