Arts & Sciences

Understanding a traumatized brain

Illustration by Elliott Golden

PTSD treatment isn’t one-size-fits-all, and the reason why may lie in our neurobiology.

Stress can affect the body in several different ways, from muscle tension to throbbing headaches. Even more, when the stress stems from trauma and is particularly intense and unrelenting, people can develop symptoms that last long after the stressful event is over, including flashbacks, nightmares, anxiety and depression. 

Such symptoms may lead to a diagnosis of post-traumatic stress disorder, or PTSD, which affects an estimated 12 million Americans — from war veterans to sexual assault survivors to COVID-19 frontline workers. Yet, despite extensive documentation of PTSD symptoms, the brain chemistry driving them is still poorly understood, says Dr. Jacklynn Fitzgerald, assistant professor of psychology.

Fitzgerald is a behavioral neuroscientist by training and first became interested in the study of PTSD as a graduate student when she worked closely with an adviser who was a psychiatrist treating patients at a Veterans Affairs hospital. 

Dr. Jacklynn Fitzgerald

“One question was: What is the neurobiology of these individuals that manifests the symptoms of PTSD?” Fitzgerald says. “We’ve been tackling that question for over a decade now.” 

Psychotherapy and cognitive behavioral therapy along with medication are widely used tools to treat PTSD today, but Fitzgerald says that only about 50 to 70 percent of patients see improvement from these treatments. Part of the research that Fitzgerald and colleagues at Marquette’s Translational Affective Neuroscience Lab do is to better understand how someone’s unique neurobiology affects which treatments will be effective.

One way Fitzgerald and her research team study the neurobiology of PTSD is by studying stress hormones and stress systems in the body, including the endocannabinoid system, which plays an essential role in the central nervous system. 

“One thing we often find in our research is that individuals who have experienced trauma and go on to develop depression look neurobiologically very different from people who have been exposed to trauma and go on to develop PTSD,” Fitzgerald says. “One of the clearest neurobiological markers that differentiate the two is cortisol stress hormones that we can collect from the blood.” 

The lab has also worked with Dr. Rachel Bollaert, clinical assistant professor of exercise science at Marquette, to learn how exercise, like yoga, can alleviate symptoms of PTSD by affecting the endocannabinoid system. Going forward, Fitzgerald hopes that collaborative work like this will give her lab the best opportunity to study both the mechanisms and treatment of PTSD. “I really do see our future branching in a lot of collaborative ways to try to use what we know about the brain in this disorder to help answer these different nuanced questions that people want to ask about PTSD,” she says.