The Psychological Impact of the Great East Japan Earthquake on Japan Ground Self-Defense Force Personnel: A Three-Wave, One-Year Longitudinal Study

Abstract

Objective: Approximately 70,000 Japan Ground Self-Defense Force (JGSDF) personnel were dispatched in the wake of the 2011 Great East Japan Earthquake and the tsunami and nuclear disaster that followed. This study was conducted to evaluate the mental health of the JGSDF personnel and the correlates. Methods: Data collected from 56,753 participants at three time points (one, six, and 12 months after mission completion) were analyzed. Those who scored 25 or more points on the Impact of Events Scale–Revised (IES-R) and the Kessler Psychological Distress Scale (K10) were allocated into the high posttraumatic stress response (high-PTSR) group, and the high general psychological distress (high-GPD) group, respectively. Results: The multiple logistic regression analysis identified the following factors as the significant risk factor related to high-PTSR or high-GPD status, with odds ratios of 2.0 or higher: deployment length of three or more months, being personally affected by the disaster, and being overworked continuously for three or more months after mission completion. No significant association was observed for duties with radiation exposure risk. Conclusions: Our findings suggest that disaster workers may be able to conduct disaster relief activities more safely with mission-related considerations of shorter deployment length and recognizing the effects on personnel personally affected by the disaster, in addition to avoiding overworking personnel after mission completion.

Funding and Acknowledgments

We thank all the participants and medical staff of the Japan Ground Self-Defense Force who supported our research. The views expressed in this article are those of the authors and do not reflect the position or policy of the Japan’s National Defense Medical College or Ministry of Defense. This work was partly supported by the Japanese Society for the Promotion of Science KAKENHI (grant 26461779).

Additional information

Notes on contributors

Masanori Nagamine

Masanori Nagamine, MD, PhD, is affiliated with the Division of Behavioral Science, National Defense Medical College Research Institute, Tokorosawa, Japan. Taisuke Yamamoto, MD, PhD, is affiliated with the Military Medicine Research Unit, Test and Evaluation Command, Japan Ground Self-Defense Force, Tokyo, Japan. Jun Shigemura, MD, PhD, Masaaki Tanichi, MD, and Aihide Yoshino, MD, PhD, are affiliated with the Department of Psychiatry, School of Medicine, National Defense Medical College, Tokorozawa, Japan. Go Suzuki, MD, PhD, is affiliated with the Japan Aerospace Exploration Agency, Tokyo, Japan. Yoshitomo Takahashi, MD, PhD, is affiliated with the Department of Disaster Psychiatry, Division of Clinical Medicine, Faculty of Medicine, University of Tsukuba, Japan. Masaki Miyazaki, MD, PhD, is affiliated with the Central Readiness Force, Japan Ground Self-Defense Force, Tokyo, Japan. Yasuhide Uwabe, MD, PhD, is affiliated with the Japan Self-Defense Force Sapporo Hospital, Tokyo, Japan. Nahoko Harada, RN, PhD, is affiliated with the Department of Mental Health Psychiatric Nursing, School of Nursing, Faculty of Medicine, University of Miyazaki, Japan. Kunio Shimizu, MD, PhD, is affiliated with the Division of Behavioral Science, National Defense Medical College Research Institute, Tokorozawa, Japan.