Led by scientists from Temple University and involving a national collaboration of researchers, a new study shows how decreased hippocampal involvement is associated with the development of post-traumatic stress disorder. Sam McLean, MD, MPH, leads the NIH-funded AURORA study.
CHAPEL HILL, NC – Results of the largest prospective study of its kind indicate that in the first days and weeks after experiencing trauma, individuals faced potentially threatening situations that had less activity in their hippocampus – a brain structure that is crucial to form memories of situations that are dangerous and that are safe – developed more severe symptoms of post-traumatic stress disorder (PTSD).
This association between decreased hippocampal activity and risk of PTSD was especially strong in individuals who had more involuntary defensive responses to startle responses.
This research, published in the Journal of Neuroscience, suggests that individuals with a greater defensive response to potentially threatening events may have a harder time learning whether an event is dangerous or safe. They are also more likely to have severe forms of PTSD, including symptoms such as being always on the lookout for danger, self-destructive behaviors such as drinking too much or driving too fast, difficulty sleeping and concentrating, irritability, angry outbursts, and nightmares.
“These findings are important both to identify specific brain responses associated with vulnerability to develop PTSD, and to identify potential treatments that target memory processes for these individuals to prevent or treat PTSD,” said senior author Vishnu Murty. , PhD, assistant professor of psychology and neuroscience at Temple University.
This research is part of the national Advancing Understanding of RecOvery after TraumA (AURORA) Study, a multi-institutional project funded by the National Institutes of Health, nonprofit funding organizations such as One Mind, and partnerships with leading technology companies. The organizing principal investigator is Samuel McLean, MD, MPH, professor of psychiatry and emergency medicine at the University of North Carolina School of Medicine and director of the UNC Institute for Trauma Recovery.
AURORA enables researchers to use data from patient participants who enter emergency rooms at hospitals across the country following trauma, such as car accidents or other serious incidents. The ultimate goal of AURORA is to encourage the development and testing of preventive and treatment interventions for individuals who have experienced traumatic events.
AURORA scientists know that only a subset of trauma survivors develop PTSD, and that PTSD is associated with increased sensitivity to threats and a decreased ability to engage neural structures that retrieve emotional memories. But how these two processes interact to increase the risk of developing PTSD is not clear. To better understand these processes, Murty and colleagues characterized brain and behavioral responses of individuals two weeks after the trauma.
Using brain imaging techniques combined with lab- and survey-based testing for trauma, researchers found that the individuals with less activity in their hippocampus and the greatest defensive responses to surprising events after trauma had the most severe symptoms.
“In these individuals, greater defensive responses to threats may lead them to learn information about what is happening so that they can distinguish between what is safe and what is dangerous,” said Büşra Tanriverdi, the study’s lead researcher and graduate student at Temple. “These findings highlight an important PTSD biomarker targeting how people form and retrieve memories after trauma.”
“These latest findings add to our list of AURORA discoveries that help us understand the differences between individuals who develop post-traumatic stress disorder and those who don’t,” said McLean, an author of the paper. “Studies focusing on the early aftermath of trauma are critical because we need a better understanding of how PTSD develops so that we can prevent PTSD and best treat PTSD.”
“Since initiating our financial support for the AURORA study in 2016, we remain steadfast in our commitment to helping AURORA researchers make important discoveries and bridge the gaps in funding for mental health research and patient support,” said Brandon Staglin, president of One. mind.
Check the AURORA website for prediction tools, presentations and publications arising from AURORA studies.
Research and clinical personnel from the following institutions were critical to patient care and to this research study: Albert Einstein Healthcare, Baystate Medical Center, Beth Israel Deaconess Medical Center, Boston Medical Center, Brigham and Women’s Hospital, Cooper Health Institute, Emory University, Henry Ford Health System, Indiana University, Massachusetts General Hospital, Rhode Island Hospital, The Miriam Hospital, St. Joseph Hospital, Temple University, Thomas Jefferson University, University of Massachusetts Chan Medical School, University of Alabama at Birmingham, University of Cincinnati, University of Florida College of Medicine–Jacksonville, University of Pennsylvania, Vanderbilt University, Washington University in St. Louis, Wayne State University, Ascension St. John Hospital, Wayne State University, Detroit Receiving Hospital, William Beaumont Hospital, Wayne State University , McLean Hospital, University of Missouri-St. Louis, UNC Medical Center, UNC School of Medicine, University of California San Francisco, Northern California Institute for Research and Education, Harvard University Medical School, and Harvard University School of Public Health.