ORIGINAL RESEARCH Trends in Probable PTSD in Firefighters Exposed to the World Trade Center Disaster, 2001–2010 Jackie Soo, MPH; Mayris P. Webber, DrPH, MPH; Jackson Gustave, MPH; Roy Lee, BS; Charles B. Hall, PhD; Hillel W. Cohen, DrPH, MPH; Kerry J. Kelly, MD; David J. Prezant, MD ABSTRACT Objective: We present the longest follow-up, to date, of probable posttraumatic stress disorder (PTSD) after the 2001 terrorist attacks on the World Trade Center (WTC) in New York City firefighters who participated in the rescue/recovery effort. Methods: We examined data from 11 006 WTC-exposed firefighters who completed 40 672 questionnaires and reported estimates of probable PTSD by year from serial cross-sectional analyses. In longitudinal analyses, we used separate Cox models with data beginning from October 2, 2001, to identify variables associated with recovery from or delayed onset of probable PTSD. Results: The prevalence of probable PTSD was 7.4% by September 11, 2010, and continued to be associated with early arrival at the WTC towers during every year of analysis. An increasing number of aerodigestive symp- toms (hazard ratio [HR] 0.89 per symptom, 95% confidence interval [CI] 0.86-.93) and reporting a decrease in exercise, whether the result of health (HR 0.56 vs no change in exercise, 95% CI 0.41-.78) or other reasons (HR 0.76 vs no change in exercise, 95% CI 0.63-.92), were associated with a lower likelihood of recovery from probable PTSD. Arriving early at the WTC (HR 1.38 vs later WTC arrival, 95% CI 1.12-1.70), an increas- ing number of aerodigestive symptoms (HR 1.45 per symptom, 95% CI 1.40–1.51), and reporting an in- crease in alcohol intake since September 11, 2001 (HR 3.43 vs no increase in alcohol intake, 95% CI 2.67- 4.43) were associated with delayed onset of probable PTSD. Conclusions: Probable PTSD continues to be associated with early WTC arrival even 9 years after the terrorist attacks. Concurrent conditions and behaviors, such as respiratory symptoms, exercise, and alcohol use also play important roles in contributing to PTSD symptoms. (Disaster Med Public Health Preparedness. 2011;5:S197-S203) Key Words: World Trade Center, mental health, posttraumatic stress disorder, psychological symptoms, firefighters T he terrorist attacks on the World Trade Cen- ter (WTC) towers on September 11, 2001 (9/11) killed 2974 residents and workers in lower Manhattan, including 343 rescue workers (341 firefighters and 2 paramedics) from the Fire Depart- ment of the City of New York (FDNY). After the towers collapsed, rescue/recovery workers endured hazardous and chaotic working conditions for up to 10 months. Since 9/11, posttraumatic stress disorder (PTSD) has been of major interest because it is arguably one of the most prevalent and debilitating consequences of terrorism-related incidents. 1 Among WTC rescue/ recovery workers, the prevalence of probable PTSD has been reported to be anywhere from 11% to 19.5%, depending on the screening instrument that was used and the time interval between 9/11 and data collection. 2-4 We use the term “probable PTSD” here and in subsequent analyses to indicate that the out- come is determined through a screening instrument rather than a diagnostic interview. In WTC-exposed populations, PTSD symptoms have been associated with heavy alcohol use. 5 In another study of survivors after a mass shooting in Killeen, Texas, PTSD symptoms were associated with seeking mental health treatment immediately after the event, 6 and a study of US military veterans found co-occurring PTSD symp- toms and respiratory disease. 7 The first major longitu- dinal study of PTSD trends after the WTC attacks found that 8.7% of all rescue workers and volunteers demon- strated chronic PTSD symptoms, 10.8% demonstrated delayed onset symptoms (present at follow-up in 2006- 2007 but not enrollment in 2003-2004), and 3.5% dem- onstrated resolved symptoms (present at enrollment but not at follow-up). 4 We present the longest follow-up, to date, of PTSD re- lated to the WTC attacks among FDNY firefighters. We update our previous work of PTSD trends among the FDNY population 8 by extending our cross-sectional analyses of probable PTSD by year, through Septem- ber 11, 2010. Furthermore, we perform multivariable analyses in 2 longitudinal cohorts to identify factors as- CME online Disaster Medicine and Public Health Preparedness S197 (Reprinted) ©2011 American Medical Association. All rights reserved.