A 20-year longitudinal cohort study of post-traumatic stress disorder in World Trade Center responders

Post-traumatic stress disorder (PTSD) is a debilitating condition with serious implications for mental and physical health. Although previous studies have documented PTSD prevalence and short-term trajectories, detailed examination of long-term symptom patterns remains limited, especially in large cohorts. This study investigates 20-year PTSD symptom trajectories in World Trade Center responders, constituting one of the largest and longest studies of PTSD to date.

We aimed to answer the following questions. How stable are symptoms? What is the average trajectory? What are atypical trajectories? How quickly do symptoms improve and worsen? Does symptom course differ across demographics or predict functional impairments or mental health care utilization? Data include 81,298 observations from 12,822 responders. Symptoms were stable in the short term but changed significantly over two decades, peaking over a decade after exposure and declining modestly thereafter. Demographic differences in average trajectories were small. The median time before symptoms improved was 8–10 years for PTSD cases (median = 8.88; 95% confidence interval, 8.01–9.79). Most experienced improvement after a decade but approximately 10% reported elevated symptoms two decades after trauma. Changes in symptoms predicted higher functional impairments and mental health care utilization.

Our findings highlight the enduring impact of PTSD among World Trade Center responders, with substantial variability in individual trajectories. Despite overall modest declines, a subset remained highly symptomatic, underscoring the need for continued treatment. These results emphasize the importance of long-term monitoring and highlight the need for tailored treatment strategies for trauma-exposed populations.