Risk and resilience in trajectories of post-traumaticstress symptoms among first responders after the2011 Great East Japan Earthquake : 7-yearprospective cohort study


First responders to disasters are at risk of developing post-traumatic stress disorder (PTSD). The trajectories of post-traumatic stress symptom severity differ among individuals, even ifthey are exposed to similar events. These trajectories have notyet been reported in non-Western first responders.



We aimed to explore post-traumatic stress symptom severitytrajectories and their risk factors in first responders to the 2011Great East Japan Earthquake (GEJE)–a historically large earth-quake that resulted in a tsunami and a nuclear disaster.



A total of 55 632 Japan Ground Self-Defense Force (JGSDF) per-sonnel dispatched to the GEJE were enrolled in this 7-year lon-gitudinal cohort study. PTSD symptom severity was measuredusing the Impact of Event Scale-Revised. Trajectories wereidentified using latent growth mixture models (LGMM). Ninepotential risk factors for the symptom severity trajectories wereanalysed using multinomial logistic regression.



Five symptom severity trajectories were identified:‘resilient’(54.8%),‘recovery’(24.6%),‘incomplete recovery’(10.7%),‘late-onset’(5.7%), and‘chronic’(4.3%). The main risk factors forthe four non-resilient trajectories were older age, personal dis-aster experiences and working conditions. These working con-ditions included duties involving body recovery or radiationexposure risk, longer deployment length, later or no post-deployment leave and longer post-deployment overtime.



The majority of first responders to GEJE were resilient anddeveloped few or no PTSD symptoms. A substantial minorityexperienced late-onset and chronic symptom severity trajec-tories. The identified risk factors can inform policies for preven-tion, early detection and intervention in individuals at risk ofdeveloping symptomatic trajectories.


Taku Saito, Florentine H. S. van der Does, Masanori Nagamine, Nic J. van der Wee, Jun Shigemura, Taisuke Yamamoto, Yoshitomo Takahashi, Minori Koga, Hiroyuki Toda, Aihide Yoshino, Eric Vermetten and Erik J. Giltay | 2022
In: British Journal of Psychiatry ; ISSN: 0007-1250
Online ahead of print DOI: 10.1192/bjp.2022.21
Aged, Earthquakes, Environmental Disasters, Japanese, Nuclear Accidents, Posttraumatic Stress Disorder, Psychotrauma, PTSD (en), Regression, Self Defense, Tsunamis
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