Psychological Medicine

Original Articles

Trajectories of PTSD risk and resilience in World Trade Center responders: an 8-year prospective cohort study

R. H. Pietrzaka1a2a3 c1, A. Federa3, R. Singha3, C. B. Schechtera4, E. J. Brometa5, C. L. Katza3, D. B. Reissmana6, F. Ozbaya3, V. Sharmaa3, M. Cranea7, D. Harrisona8, R. Herberta7, S. M. Levina7, B. J. Lufta9, J. M. Molinea10, J. M. Stellmana11, I. G. Udasina12, P. J. Landrigana7 and S. M. Southwicka1a2a3

a1 National Center for Posttraumatic Stress Disorder, VA Connecticut Healthcare System, West Haven, CT, USA

a2 Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA

a3 Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA

a4 Department of Family and Social Medicine, Albert Einstein College of Medicine of Yeshiva University, Bronx, NY, USA

a5 Department of Psychiatry, Stony Brook University, Stony Brook, NY, USA

a6 Office of the Director, National Institute for Occupational Safety and Health, Washington, DC, USA

a7 Department of Preventive Medicine, Mount Sinai School of Medicine, New York, NY, USA

a8 Department of Environmental Medicine, Bellevue Hospital Center/New York University School of Medicine, New York, NY, USA

a9 Department of Medicine, Division of Infectious Diseases, Stony Brook University, Stony Brook, NY, USA

a10 Department of Population Health, Hofstra North Shore-Long Island Jewish School of Medicine, Great Neck, New York, USA

a11 Department of Health Policy and Management, Mailman School of Public Health, Columbia University, NY, USA

a12 Department of Environmental and Occupational Medicine, UMDNJ – Robert Wood Johnson Medical School, Piscataway, NJ, USA


Background Longitudinal symptoms of post-traumatic stress disorder (PTSD) are often characterized by heterogeneous trajectories, which may have unique pre-, peri- and post-trauma risk and protective factors. To date, however, no study has evaluated the nature and determinants of predominant trajectories of PTSD symptoms in World Trade Center (WTC) responders.

Method A total of 10835 WTC responders, including 4035 professional police responders and 6800 non-traditional responders (e.g. construction workers) who participated in the WTC Health Program (WTC-HP), were evaluated an average of 3, 6 and 8 years after the WTC attacks.

Results Among police responders, longitudinal PTSD symptoms were best characterized by four classes, with the majority (77.8%) in a resistant/resilient trajectory and the remainder exhibiting chronic (5.3%), recovering (8.4%) or delayed-onset (8.5%) symptom trajectories. Among non-traditional responders, a six-class solution was optimal, with fewer responders in a resistant/resilient trajectory (58.0%) and the remainder exhibiting recovering (12.3%), severe chronic (9.5%), subsyndromal increasing (7.3%), delayed-onset (6.7%) and moderate chronic (6.2%) trajectories. Prior psychiatric history, Hispanic ethnicity, severity of WTC exposure and WTC-related medical conditions were most strongly associated with symptomatic trajectories of PTSD symptoms in both groups of responders, whereas greater education and family and work support while working at the WTC site were protective against several of these trajectories.

Conclusions Trajectories of PTSD symptoms in WTC responders are heterogeneous and associated uniquely with pre-, peri- and post-trauma risk and protective factors. Police responders were more likely than non-traditional responders to exhibit a resistant/resilient trajectory. These results underscore the importance of prevention, screening and treatment efforts that target high-risk disaster responders, particularly those with prior psychiatric history, high levels of trauma exposure and work-related medical morbidities.

(Received November 23 2012)

(Revised February 16 2013)

(Accepted February 25 2013)

(Online publication April 03 2013)

Key words

  • Disaster;
  • latent modeling;
  • longitudinal data;
  • post-traumatic stress disorder;
  • responders;
  • risk factors