Trajectories of psychological distress among individuals exposed to the 9/11 World Trade Center disaster.

Background: Individuals present in lower Manhattan during the 9/11 World Trade Center (WTC) disaster suffered from significant physical and psychological trauma. Studies of longitudinal psychological distress among those exposed to trauma have been limited to relatively short durations of follow-up among smaller samples.
Methods: The current study longitudinally assessed heterogeneity in trajectories of psychological distress among WTC Health Registry enrollees - a prospective cohort health study of responders, students, employees, passersby, and residents in the affected area ( N = 30 839) - throughout a 15-year period following the WTC disaster. Rescue/recovery status and exposure to traumatic events of 9/11, as well as sociodemographic factors and health status, were assessed as risk factors for trajectories of psychological distress.
Results: Five psychological distress trajectory groups were found: none-stable, low-stable, moderate-increasing, moderate-decreasing, and high-stable. Of the study sample, 78.2% were classified as belonging to the none-stable or low-stable groups. Female sex, being younger at the time of 9/11, lower education and income were associated with a higher probability of being in a greater distress trajectory group relative to the none-stable group. Greater exposure to traumatic events of 9/11 was associated with a higher probability of a greater distress trajectory, and community members (passerby, residents, and employees) were more likely to be in greater distress trajectory groups - especially in the moderate-increasing [odds ratios (OR) 2.31 (1.97-2.72)] and high-stable groups [OR 2.37 (1.81-3.09)] - compared to the none-stable group.
Conclusions: The current study illustrated the heterogeneity in psychological distress trajectories following the 9/11 WTC disaster, and identified potential avenues for intervention in future disasters.