About

Dr. Benjamin Luft is a Professor of Medicine with a focus on Infectious Diseases. His research includes studying the health impacts of the World Trade Center disaster, particularly among rescue and recovery workers, with investigations into post-traumatic stress disorder, respiratory problems, and related mental and physical health outcomes. He has contributed to understanding the long-term effects of disaster exposure, including the psychological and physical sequelae experienced by responders, and has been involved in genomic studies of Lyme disease pathogens such as Borrelia burgdorferi. His work emphasizes the integration of mental and physical health monitoring in disaster response populations and advances knowledge in infectious disease genomics and trauma-related health issues.

Research topics

• Medicine
• Internal medicine
• Environmental health
• Psychology
• Audiology
• Cardiology
• Demography
• Pathology
• Neuroscience
• Computational biology
• Radiology
• Psychiatry
• Genetics
• Biology

Selected publications

• Increased phosphorylated tau (pTau-181) is associated with neurological post-acute sequelae of coronavirus disease in essential workers: a prospective cohort study before and after COVID-19 onset

  EBioMedicine · 2026-01-01 · 4 citations

  articleOpen accessSenior author

  BACKGROUND: The COVID-19 pandemic led to a spectrum of post-acute sequelae including several neurological complications including cognitive dysfunction labelled Neurological PASC (N-PASC). We hypothesised that N-PASC was associated with changes in neurological biomarkers after COVID-19. METHODS: N-PASC was established when individuals reported accepted neurological symptoms persisting for ≥3 months arising alongside validated COVID-19. Plasma samples were retrieved from before and after COVID-19 onset among all (n = 227) essential workers who developed COVID-19 with N-PASC and demographically matched with data from 227 controls who either developed COVID-19 without N-PASC (n = 124) or did not develop COVID-19 before follow-up (n = 103). We used single molecular analysis measured pTau-181, GFAP, NfL, Aβ40/42, and total Aβ burden (IAB). Risk factors for N-PASC were examined prior to COVID-19 infection. Multivariable adjusted generalised linear longitudinal modelling with random intercepts was used to examine changes in biomarkers after COVID-19 onset. FINDINGS: N-PASC was only associated with higher IAB before COVID-19 onset (area under the receiver-operating curve = 0.77). Longitudinal analyses revealed plasma pTau-181 levels increased by 59.3% (95% C.I. = [45.2, 73.4] P = 0.006) following COVID-19 onset in participants who developed N-PASC that were worst among participants reporting central nervous symptoms persisting ≥1.5 years. Post-COVID-19 decreased GFAP and NfL were associated with peripheral symptoms of N-PASC, but not with increased pTau-181. Having ≥20% increases in pTau-181 were associated with increased Aβ40/42 levels at follow-up, and with central neurological symptoms including lingering brain fog and loss of taste/smell. INTERPRETATION: N-PASC with symptoms consistent with central damage were associated with increased pTau-181 levels. Increases in pTau-181 were associated with increased risk of changes to amyloid biomarkers consistent with Alzheimer's disease in participants with N-PASC and could therefore inform N-PASC prognostication. FUNDING: This study was supported in part by funding from the Centers for Disease Control and Prevention (CDC/NIOSH CDC-75D30122c15522) and the National Institutes of Health (NIH/NIA AG049953).

  PublisherDOI

• From Word Sequences to Behavioral Sequences: Adapting Modeling and Evaluation Paradigms for Longitudinal NLP

  ArXiv.org · 2026-01-12

  articleOpen access

  While NLP typically treats documents as independent and unordered samples, in longitudinal studies, this assumption rarely holds: documents are nested within authors and ordered in time, forming person-indexed, time-ordered $\textit{behavioral sequences}$. Here, we demonstrate the need for and propose a longitudinal modeling and evaluation paradigm that consequently updates four parts of the NLP pipeline: (1) evaluation splits aligned to generalization over people ($\textit{cross-sectional}$) and/or time ($\textit{prospective}$); (2) accuracy metrics separating between-person differences from within-person dynamics; (3) sequence inputs to incorporate history by default; and (4) model internals that support different $\textit{coarseness}$ of latent state over histories (pooled summaries, explicit dynamics, or interaction-based models). We demonstrate the issues ensued by traditional pipeline and our proposed improvements on a dataset of 17k daily diary transcripts paired with PTSD symptom severity from 238 participants, finding that traditional document-level evaluation can yield substantially different and sometimes reversed conclusions compared to our ecologically valid modeling and evaluation. We tie our results to a broader discussion motivating a shift from word-sequence evaluation toward $\textit{behavior-sequence}$ paradigms for NLP.

  PublisherOA PDF

• Posttraumatic Stress Disorder and Handgrip Strength Among World Trade Center Firefighters and Emergency Medical Responders

  International Journal of Environmental Research and Public Health · 2026-03-25

  articleOpen access

  Posttraumatic stress disorder (PTSD) has been linked to impaired physical function, which in turn predicts falls, morbidity, and mortality. However, few studies have used objective measures such as handgrip strength to assess physical function. In this cross-sectional study, we investigated associations of average PTSD symptom severity and symptom domain severity with measures of maximum handgrip strength and handgrip asymmetry from 11/2021–12/2023, among 381 male firefighters and emergency medical responders who responded to the World Trade Center disaster, using covariate-adjusted linear regression models. PTSD was diagnosed using the Structured Clinical Interview for the DSM-5 in 17% of responders. Greater overall PTSD average symptom severity was associated with weaker maximum handgrip strength (β = −4.43 lbs; 95%; CI: −8.77, −0.09; p = 0.045). Higher re-experiencing symptom severity was associated with weaker maximum handgrip strength (β = −4.17 lbs; 95% CI: −8.13, −0.22; p = 0.039). Avoidance symptoms were associated with weaker handgrip strength in adjusted models (β = −4.14 lbs; 95% CI: −7.56, −0.73; p = 0.018), and associated with a larger negative difference assessing for hand asymmetry (β = −2.20 lbs; 95% CI: −4.18, −0.22; p = 0.029). Findings suggest that PTSD may contribute to long-term physical decline, even in populations with high baseline fitness.

  PublisherOA PDFDOI

• From Word Sequences to Behavioral Sequences: Adapting Modeling and Evaluation Paradigms for Longitudinal NLP

  arXiv (Cornell University) · 2026-01-12

  preprintOpen access

  While NLP typically treats documents as independent and unordered samples, in longitudinal studies, this assumption rarely holds: documents are nested within authors and ordered in time, forming person-indexed, time-ordered $\textit{behavioral sequences}$. Here, we demonstrate the need for and propose a longitudinal modeling and evaluation paradigm that consequently updates four parts of the NLP pipeline: (1) evaluation splits aligned to generalization over people ($\textit{cross-sectional}$) and/or time ($\textit{prospective}$); (2) accuracy metrics separating between-person differences from within-person dynamics; (3) sequence inputs to incorporate history by default; and (4) model internals that support different $\textit{coarseness}$ of latent state over histories (pooled summaries, explicit dynamics, or interaction-based models). We demonstrate the issues ensued by traditional pipeline and our proposed improvements on a dataset of 17k daily diary transcripts paired with PTSD symptom severity from 238 participants, finding that traditional document-level evaluation can yield substantially different and sometimes reversed conclusions compared to our ecologically valid modeling and evaluation. We tie our results to a broader discussion motivating a shift from word-sequence evaluation toward $\textit{behavior-sequence}$ paradigms for NLP.

  PublisherDOI

• White matter microstructural abnormalities in neurological poste-acute sequelae of coronavirus disease: Imaging signatures consistent with persistent neuroinflammation

  Brain Behavior & Immunity - Health · 2026-05-02

  articleOpen accessSenior author

  Background: Essential workers, many of whom were infected with coronavirus disease (COVID-19) at work before vaccination, developed Neurological Post-Acute Sequelae of COVID-19 (N-PASC) at high rates. Method: To characterize white matter abnormalities associated with N-PASC and to examine correlates of symptomatology, we recruited 54 participants with N-PASC and compared them to 26 participants with no COVID-19 history or who recovered from acute COVID-19 without PASC into a neuroimaging study to profile the cerebral connectome starting from 1/1/2021-12/31/2024. Diffusion parameters from whole-brain white matter and cortical gray matter analyses were examined with multi-shell diffusion MRI data. Correlational tractography was used to examine the nature and extent of white matter changes. Results: Participants with N-PASC lasting, on average, 2.7 years had global and tract-specific white matter alterations after adjusting for demographics across measures of white matter health. Correlational tractography located pronounced bilateral changes to the fornix and minor forceps, possibly providing indirect evidence of axonal injury or demyelination in these regions. But diffusion measures alone cannot determine the specific underlying biological process. Diffusion measures were associated with the presence of fatigue, executive impairment, anosmia and mood disorders, but not brain fog. Conclusions: Results identify changes in N-PASC consistent with neuroinflammation that help explain cognitive dysfunction, providing insights into the long-term cerebral implications of COVID-19 and suggesting that symptoms may reflect evidence of a cerebral changes persisting years after symptom onset.

  PublisherDOI

• Gastroesophageal Reflux Disease in the World Trade Center Health Program General Responder Cohort

  American Journal of Industrial Medicine · 2025-04-02

  articleOpen access

  BACKGROUND: People participating in the rescue, recovery, and clean-up effort after the September 11, 2001 attack on the World Trade Center (WTC) were exposed to a complex mix of noxious substances and subsequently experienced elevated gastroesophageal reflux disease (GERD) incidence, the second-most-common WTC-related condition. METHODS: Longitudinal WTC Health Program data, collected between July 2002 and December 2022, were used to describe the sample characteristics, diagnostic procedures, and treatment of consenting cohort members with self-reported GERD who reported incident GERD for a year or longer (n = 19,067). Cross-tabulations and binomial logistic regression, adjusted for confounders including comorbidities, assessed the associations with intermittent and resolved, compared with unresolved, GERD. RESULTS: 12.6% of the study cohort reported intermittent GERD; 5.5% reported GERD resolution. Analyses indicated that most GERD resolution was reported by people of color and those with body mass index <25, and by cohort members who had longer postdiagnosis follow-up and implemented dietary modifications together with proton pump inhibitors or Program-approved antacids. GERD-certified members who underwent endoscopy, used medications without dietary modifications, or used bed head-elevation, and those with Barrett's disease (5.8%) or esophageal cancer (0.1%) may have had more severe GERD and reported little resolution. CONCLUSIONS: The use of GERD services was consistent with clinical guidelines. Members' implementing dietary modifications in conjunction with proton pump inhibitors or Program-approved antacids reported more resolution and may have had less severe GERD. Earlier diagnosis and intervention might increase earlier therapeutic resolution.

  PublisherOA PDFDOI

• Polygenic Risk and Exposure Severity Predict Trajectories of PTSD: A Prospective Cohort Study

  Molecular Psychiatry · 2025-09-19

  articleOpen access
  PublisherOA PDFDOI

• A Systematic Evaluation of Large Language Models for PTSD Severity Estimation: The Role of Contextual Knowledge and Modeling Strategies

  Research Square · 2025-12-25

  preprintOpen access
  PublisherOA PDFDOI

• Posttraumatic stress disorder, major depression, and mild cognitive impairment: A cohort study of world trade center responders

  Psychiatry Research · 2025-11-12 · 1 citations

  articleOpen accessSenior author
  PublisherOA PDFDOI

• Body mass index is associated with functional brain network efficiency in midlife world trade center responders with cognitive impairment

  Discover Neuroscience · 2025-11-17

  articleOpen accessSenior author

  Higher body mass index (BMI) is associated with lowered risk of dementia in aging populations, possibly because it improves cognitive reserve in old age. Little is known about mechanisms implicated in reductions in vulnerability and less is known about implications of BMI in cognitively impaired (CI) individuals at midlife. Here, we examined whether BMI relates to functional brain network efficiency and cognition in a physically active cohort of midlife World Trade Center (WTC) responders with documented 9/11-related exposures, testing how systemic inflammatory burden and body composition jointly shape brain networks. Resting-state fMRI data from 99 WTC responders and 10 matched controls were analyzed. Functional cerebral network efficiency metrics included characteristic path length (CPL), clustering coefficients (CC), global efficiency (GE), and small-worldness (SWN), and were derived across proportional sparsity thresholds to enhance robustness. Multivariate models tested the effects of BMI, CI, and their interaction on network efficiency. Higher BMI and CI were independently associated with cerebral network efficiency. A significant BMI × CI interaction was identified (CPL: p=0.024; SWN: p=0.010; GE: p=0.034), indicating that the positive association between BMI and network efficiency was strongest among cognitively impaired responders. Specifically, elevated BMI correlated with more integrated and efficient networks (e.g., shorter CPL and greater CC, GE, and SWN). Functional network efficiency metrics were modestly associated with attention and processing speed, but not with memory or visuospatial performance, suggesting selective relevance to cognitive domains vulnerable to early disruption. Consistent with hypotheses of cognitive reserve, this study provides novel evidence that functional brain network topology is influenced by BMI among cognitively impaired WTC responders. Findings highlight a complex interplay among systemic health, brain organization, and cognitive function at midlife.

  PublisherOA PDFDOI

Recent grants

• NIH Grant U10OH008216

  NIH · $37.7M · 2011

• Mind Body Treatment for WTC Responders with Comorbid PTSD and Respiratory Illness

  NIH · $1.5M · 2013–2017

• Structural and Functional Neuroimaging of Post Traumatic Stress Disorder and Cognitive Impairment in World Trade Center Responders

  NIH · $2.4M · 2016–2020

• Epigenetic Linkage Between PTSD and Respiratory Disease in WTC Responders

  NIH · $1000k · 2012–2015

• NIH Grant R01AI037256

  NIH · $3.7M · 2004

Frequent coauthors

• Richard Hafner

  National Institute of Allergy and Infectious Diseases

  293 shared

• Sophie Pueyo

  Centre Hospitalier de la Côte Basque

  289 shared

• J Aubertin

  286 shared

• Sean Clouston

  General Department of Preventive Medicine

  249 shared

• Steven E. Schutzer

  Rutgers, The State University of New Jersey

  233 shared

• Roger Salamon

  227 shared

• Jean‐Louis Vildé

  224 shared

• Philippe Morlat

  Bordeaux Population Health

  211 shared

Education

• M.D.

  not specified