Posttraumatic stress disorder among 3,271 civilian World Trade Center survivors of the September 11, 2001 terrorist attacks

Introduction: Much research has documented population-level PTSD after the 9/11 WTC attacks. However, long-term effects on primary victims remain largely unexplored. This study documents PTSD and associated risk factors 2-3 years after the attacks among a large cohort of civilians who evacuated the towers on the morning of 9/11.

Method: A CATI questionnaire was administered between 9/2003 and 11/2004 as enrollment in the WTC Health Registry. Tower survivors were recruited through key informants, employee and security badge lists and self-identification. Questions included demographics, exposures characterizing varying degrees of life threat on 9/11, and the PTSD-Checklist. An assessment of the individual and cumulative effects of risk factors was conducted using logistic regression.

Results: Estimates of PTSD 2-3 years after 9/11 ranged from 15% using a validated cutoff to 22% based on DSM-IV criteria. Women and minorities were at greater risk for PTSD. A strong inverse relation existed between income and PTSD. Five characteristics of exposure predicted PTSD: high floor location, late evacuation, dust cloud exposure, witnessing horror, and injury. Working for a company that sustained casualties also predicted PTSD. In an adjusted multivariable model, each additional exposure was associated with a two-fold increase in PTSD risk.

Conclusions: Substantial psychological morbidity exists among primary victims years after the WTC disaster, particularly among lower SES groups and those with multiple 9/11 exposures. Identifying PTSD risk factors may suggest potential avenues of targeted interventions for treatment and preparedness training, which can reduce the mental health burden related to 9/11 and future man-made disasters.