For some people, a single traumatic event like a shooting, a natural disaster or a violent assault, can leave an imprint that lingers long after the immediate danger has passed. Memories of that event may return with unusual intensity, shaping mood, behavior, and mental health in ways that are difficult to predict. Others exposed to similar trauma recover without developing lasting memory problems or trauma-related symptoms.
Why those outcomes diverge is a central question in stress and trauma research. Clinicians have long observed that severe acute stress can permanently alter memory for some people but not others, and that women face roughly twice the lifetime risk of posttraumatic stress disorder (PTSD). Recent research from the University of Pennsylvania in collaboration with the University of California-Irvine suggests that part of the answer may lie in the brain's biological state at the precise moment trauma occurs.
Elizabeth Heller, PhD, an associate professor of Pharmacology in the Perelman School of Medicine at the University of Pennsylvania, and her team in the Heller Lab, have now shed light on how the brain's biological state at the time of stress-particularly its estrogen levels-can shape vulnerability long after the acute stress has lifted. Working together with Tallie Z. Baram, MD, PhD, a professor of Anatomy and Neurobiology, Pediatrics, Neurology, and Physiology/Biophysics at UC Irvine, Heller helped uncover that estrogen levels in the brain may play a surprising role in this vulnerability, and for both sexes.
The study, published in Neuron, also provides new insight into why women are more likely than men to develop post-traumatic stress disorder (PTSD) and to face higher dementia risk later in life.
