The scars of trauma do not always fade with time. Instead, they not only manifest into emotional turmoil, but also have the power to mutate the body’s everyday functions. Recently, a report finding that Oklahoma leads the nation in childhood trauma made local headlines, and as mental health experts like TU President Gerard Clancy explain the repercussions of trauma, TU psychology students are studying those effects and researching how trauma alters the body’s response to pain.
Psychology doctoral student Natalie Hellman is helping to shed light on why some victims of trauma develop chronic pain. She published her 10th article, “Conditioned Pain Modulation in Sexual Assault Survivors,” in the American Pain Society’s The Journal of Pain. Her team’s findings could uncover why victims of trauma develop chronic pain. “What I would really like to do is develop preventative interventions that we could administer in the emergency room after a sexual assault,” she said. “If we understand these risk factors, then maybe we can develop interventions to prevent them from developing chronic pain.”
The paper is an analysis of data from a bigger study, “The Oklahoma Study of Native American Pain Risk (OK-SNAP),” led by Jamie Rhudy, psychology professor and director of TU’s Psychophysiology Laboratory for Affective Neuroscience (PLAN), and Joanna Shadlow, applied associate professor of psychology. The larger OK-SNAP study identified risk factors that contribute to the prevalence of chronic pain in Native Americans. Because the study recruited a large number of participants, it provided an opportunity to identify individual differences associated with pain risk, regardless of whether the risk was specific to Native Americans.
Utilizing participants from OK-SNAP, Hellman organized three groups of people:
- Sexual assault survivors
- People who experienced trauma but no sexual assault
- People who have never experienced any trauma
Testing reactions to pain
All three groups were exposed to pain in a laboratory setting through an electrode on their ankle. The subjects also placed their hands in cold water while receiving electric stimulations to evaluate how their bodies regulate pain when simultaneously experiencing the cold water and electric stimulations.
In healthy, pain-free people, the pain from the cold water lessened the pain from the electric stimulations, and it decreased the number of neural signals. All groups reported the pain was mitigated by the introduction of cold water. “Their pain inhibited their pain, but when we looked at the neural signals encoding pain, we saw a different story,” Hellman said.
Pain on the brain
Typically, when the body reacts to two pain stimuli, there are fewer neural signals encoding the pain, and this was the reaction of the group with no trauma or sexual assault. However, Hellman was surprised to discover that the participants who experienced trauma without sexual assault did not have a change in their number of neural signals, but the tremendous findings were with the sexual assault survivors.
“When we looked at sexual assault survivors,” Hellman said, “they had the same amount of pain, but the body was sending more pain signals to the brain. This implies that maybe sexual assault survivors have heightened excitability within the circuitry that connects their brain to their spinal cord.”
Hellman’s findings could be significant in the treatment of sexual assault and chronic pain. Through psychotherapies, people could retrain the body and brain to process pain at a more appropriate level, which could mean fewer prescriptions for pain relief. “It’s exciting for both providers and patients given the high addiction rates of opiates, and it’s expensive to be on an opiate regimen,” she said. “But these findings suggest sexual assault survivors would be great candidates for cognitive behavioral therapy, which helps improve their quality of life by not experiencing pain at a higher level.”
Last year, Hellman was invited to the International Society for Traumatic Stress Studies conference in Washington, D.C., and the European Society for Traumatic Stress Studies conference in Rotterdam, Netherlands. “That was a humbling experience because I was invited to be on the panel in Rotterdam, and it is very rare for students to be able to present,” she said.