Imaging Study Reveals Brain Changes in WTC Responders With Chronic PTSD

Stony Brook-led published research could provide new clue to PTSD diagnosis

STONY BROOK, NY, December 18, 2025 - Chronic post-traumatic stress disorder (PTSD) is one of the main health problems suffered by World Trade Center (WTC) responders. It a condition that can be difficult to diagnose based just on how a responder feels at a given time. Now a new brain imaging study led by researchers at Stony Brook University has uncovered measurable physical changes in the brain structures of WTC responders who have chronic PTSD. The findings are explained in a paper published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.

According to data from WTC health programs, including the Stony Brook WTC Health and Wellness Program at Stony Brook Medicine, many WTC responders experienced severe trauma at Ground Zero and about 23 percent of the responders developed PTSD. Nearly 25 years after the attacks, a large portion of responders still grapple with various levels of PTSD.

Essentially, this imaging study of 99 responders (about half with PTSD and half without PTSD) reveals that gray matter (used for processing) in the brain looks more like white matter (used for neuronal signaling) in the responders with PTSD. The images are consistent with changes in the balance of myelinated to unmyelinated neurons (fast- and slow-conducting nerve cells) across both brain hemispheres.

The changes were most strongly associated with re-experiencing symptoms in individuals with PTSD. These cortical differences found in the study could serve as surrogate biomarkers, as well as for early screening strategies, for compromised brain health in people suffering from chronic PTSD.

"Currently, health professionals diagnose PTSD using symptom inventories based on how people feel, yet there is no way to verify responders' statements in relation to their mental health status," explains Sean Couston, lead author, Professor in the Department of Family, Population, and Preventive Medicine at the Renaissance School of Medicine (RSOM) at Stony Brook University, and in the Program in Public Health. "Our study shows that a structural brain imaging parameter could be helpful in differentiating people with PTSD from trauma-exposed responders without PTSD. One theory is that the results imply PTSD symptoms are associated with a change in the cellular balance of the cortex."

This image is a depiction of the standard brain in gray and white, with the yellow and red colors showing where gray-white contrast (GWC) is different between responders with or without PTSD. Based on the study, the yellow color indicates which areas of the brain appear to have much less GWC, and the red color indicates where GWC differences were milder.
Credit: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging / Zhou et al.

The imaging method

The study used gray-white contrast (GWC) neuroimaging, an MRI-based technique that may enhance studies of neuronal health for traumatized individuals. GWC acts as a proxy for intracortical myelination density, examining the apparent blurriness of the white and gray matter interface based on differences in signal intensity.

By using this technique, an increase in contrast represents a sharper boundary, indicative of a healthy transition from gray matter to cerebral white matter. A less distinct border (low GWC) suggests an abnormal concentration of myelin, the fatting insulating layer, pointing to a disruption in the brain's processing speed and consistency.

According to Clouston, the reductions of GWC in brains could imply there is more myelin content in these regions than is normal in trauma-exposed responders without PTSD.

The research team also found that GWC could be combined with other markers of intracortical health do improve the team's ability to objectively identity WTC responders with PTSD.

Given these results, Clouston says that measuring GWC, combined with other diagnostic methods, could help improve diagnosis of PTSD since there are currently no objective methods to validate whether a person reporting PTSD symptoms may have the disorder or not.

"Biological tests for PTSD have eluded researchers for many years, but our study illustrates that modern analytic methods may be starting to reveal brain signatures of the disorder," adds co-author Roman Kotov, PhD, Professor in the Department of Psychiatry and Behavioral Health in the RSOM.

The investigators were surprised to find widespread dysfunction across much of the brain of responders with chronic PTSD.

Co-author Benjamin Luft, MD, Director of the Stony Brook WTC Health and Wellness Program, who has cared for WTC responders since shortly after 9/11 and has led many studies related to their health over the years, summarized what the study results mean to the body of research on PTSD after trauma exposures:

"Our study, expanding on clues from other studies, shows that PTSD is linked to measurable physical changes in brain structure, offering biological evidence that trauma reshapes neural integrity. These findings point toward new approaches for PTSD diagnosis and treatment."