By Daniel Dunaief
Volunteers at the World Trade Center site on 9/11 have had more significant post traumatic stress disorder than police officers, firefighters, and other trained professionals, according to a recent Stony Brook University study.
This was among a host of findings in research published in the journal Nature Mental Health about the mental health consequences for those on site after the attacks in downtown Manhattan.
“Being a volunteer responder was a significant risk factor, compared to being a trained professional responder,” explained Frank Mann, lead author and Senior Research Scientist in the Department of Medicine and Program in Public Health at the Renaissance School of Medicine at Stony Brook University.
Mann and his colleagues studied PTSD symptoms over 20 years, from 2002 to 2022, to understand the impact of this national tragedy on the mental health of those who arrived at the site to offer their help.
The higher risk for volunteers likely reflects some combination of self-selection based on resilience, professional screening, past experience coping with trauma and, maybe most importantly, the training professional first responders receive, Mann said.
“The relative contributions of these factors, however, remains unknown because these factors ‘jumble together’ when testing occupational differences” he explained.
The researchers found that symptoms can change over time, showing signs of improvement and then worsening before another recovery.
The median time before symptoms improved consistently was between eight to ten years for confirmed PTSD cases, with most patients experiencing improvement a decade after enrolling in care through the Stony Brook WTC Health and Wellness Program.
The top 10 percent of those who had the poorest prognosis incurred about half of the total mental health care costs, which includes talk therapy with a psychiatrist, clinical psychologist or social worker.
Heterogeneity
Responders varied greatly in the severity and course of their symptoms over time.
“There is a substantial heterogeneity both between individuals and within individuals,” Mann explained. “Individual differences are the norm, not the exception.”
This suggests that mental health professionals need to remain vigilant with patients whose overall health may appear to improve, only to see it decline. Although specific triggers were not identified, the Stony Brook team recently published another study in Psychological Medicine that sheds light on stress-related dynamics and how they contribute to PTSD symptom severity over time.
While the study is not well-suited to speak to the efficacy of treatment to create an enduring remission from PTSD, the experience of the participants who received screenings and free treatment over the course of years suggests that time-limited interventions are unlikely to produce lasting changes.
“Continuous monitoring is so important,” Mann added. “If individuals exposed to trauma are only monitored once, shortly after their exposure, this will inevitably miss many late-onset and relapsing cases. So repeated monitoring is needed to ensure nobody ‘falls between the crack,’ and everyone gets the attention and treatment they need.”
For politicians and health care leaders, this study suggests that the mental health consequences for first responders who assisted after a significant event with extensive trauma can require ongoing attention for years.
“Politicians, clinicians and public health officials should anticipate the effects of trauma to reverberate for many years, even decades, after the traumatic experience,” Mann said.
Previous studies have also demonstrated that the battle with PTSD tends to be more severe with events where the trauma is man made, compared with devastation from natural disasters such as tornadoes, hurricanes, or earthquakes.
Additionally, female first responders, who represented about 10 percent of the total population, showed slightly elevated, but statistically significant, differences from their male counterparts in developing PTSD. That could partially be a by-product of the higher level of comfort among women in sharing the effect of their trauma with the health care community.
“This supposition remains speculative because it was not measured or tested in our study,” Mann explained.
To be sure, the observational study is not sufficiently broad to apply across the board to first responders.
“WTC responders do not represent the full diversity of people with PTSD,” Mann said. “Consequently, the generalizability of findings to other populations, especially those with more women, greater racial diversity and exposure to nonintentional trauma, such as natural disasters, should be examined further in future studies.”
Future studies
In the search to find an underlying biological mechanism for PTSD, the Stony Brook researchers are measuring nearly 10,000 differentially expressed proteins and then are using statistical methods to reduce this large pool of target proteins to a smaller, more plausible set of candidates. Of these differentially expressed proteins, they anticipate that anywhere from a couple of dozen to nearly 1,500 could emerge as candidates.
In a 2023 review of the search for biomarkers for mental health problems such as PTSD published in the journal World Psychiatry, Anissa Abi-Dargham, Professor and Chair in the Department of Psychiatry and Behavioral Health at Stony Brook, described neuroimaging, genetic, molecular and peripheral assay efforts to determine susceptibility of or presence of illness and predict treatment response or safety.
The review highlighted a critical gap in the biomarker validation process, suggesting that the overwhelming majority of candidate biomarkers has not proven sufficiently reliable, valid and useful for clinical benefit.
Mann is hoping to develop a reliable, replicable signal for poor long term course that can translate into a formal blood test and the development of pharmacological intervention.
From Maine to Rochester

Born in Maine, where he spent his childhood, Mann moved to the suburbs of Rochester, New York, close to where he currently lives.
A gardening hobbyist, Mann enjoys spending time with his wife Aubrey, who is a registered nurse, and their sons Leland, 3 years old, and Cambden, 3 months old. He also appreciates the opportunity to grab lunch with high school friends.
Mann believes parenting has enriched his perspective and practice as a scientist.
“Witnessing my toddler’s resilience after every stumble reminds me that the same adaptive processes we study in PTSD recovery are not abstract — they are embodied in real human development,” he explained. “The empathy I gain through daily caregiving brings an even greater sense of urgency and responsibility to my work.”
Each protein or pathway he maps is not just a point on a graph, but, more importantly, is a potential lever to improve lives, Mann suggested.