Epidemiological Characteristics of Disaster-related Suicides in the 34 Years since the Great East Japan Earthquake

Ken Inoue^1*, Haruo Takeshita², Yoshikazu Takinami³, Masaharu Hoshi⁴, Yoshihiro Noso⁵, Nobuo Takeichi⁶, Junko Fujihara², Kaori Kimura-Kataoka², Yasuyuki Fujita⁶, Rei Wake⁷, Tsuyoshi Miyaoka⁷, Satoko Ezoe⁸, Jun Horiguchi⁷, Yuji Okazaki^9,10

¹Department of Public Health, Gunma University Graduate School of Medicine, Gunma, Japan

²Department of Legal Medicine, Faculty of Medicine, Shimane University, Shimane, Japan

³Department of Emergency and Critical Care Medicine, Faculty of Medicine, Shimane University, Shimane, Japan

⁴Hiroshima University, Hiroshima, Japan

⁵Department of General Medicine, Faculty of Medicine, Shimane University, Shimane, Japan

⁶Faculty of Medicine, Shimane University, Shimane, Japan

⁷Department of Psychiatry, Faculty of Medicine, Shimane University, Shimane, Japan

⁸Shimane University Health Service Center Izumo, Shimane, Japan

⁹Michinoo Hospital, Nagasaki, Japan

¹⁰Tokyo Metropolitan Matsuzawa Hospital, Tokyo, Japan

*Corresponding Author:

Ken Inoue
Department of Public Health
Gunma University Graduate School of Medicine
Gunma, Japan
E-mail: ke-inoue@med.shimane-u.ac.jp

Visit for more related articles at International Journal of Emergency Mental Health and Human Resilience

Abstract

The Great East Japan Earthquake struck Japan with a magnitude of 9.0 at 2:46 PM on March 11, 2011. Five years have passed since the earthquake and subsequent tsunami struck, but the mental and physical care of the victims, the livelihoods of those affected, and the economic impact of the disaster continue to cause social concern (Orui, Harada, & Hayashi, 2014; Tokuzu, Ouchi, Kikuchi & Konno, et al., 2015; Yabuki, Ouchi, Kikuchi & Konno, 2015; Hara, 2015). Over the past few years, research has examined the effects of the disaster on the cognitive function of the elderly (Ishiki et al., 2016), and one study suggested that oxidative stress may be associated with disaster-related hypertension (DRH) in individuals exhibiting effects of the Great East Japan Earthquake (Shiraishi et al., 2016).

The Great East Japan Earthquake struck Japan with a magnitude of 9.0 at 2:46 PM on March 11, 2011. Five years have passed since the earthquake and subsequent tsunami struck, but the mental and physical care of the victims, the livelihoods of those affected, and the economic impact of the disaster continue to cause social concern (Orui, Harada, & Hayashi, 2014; Tokuzu, Ouchi, Kikuchi & Konno, et al., 2015; Yabuki, Ouchi, Kikuchi & Konno, 2015; Hara, 2015). Over the past few years, research has examined the effects of the disaster on the cognitive function of the elderly (Ishiki et al., 2016), and one study suggested that oxidative stress may be associated with disaster-related hypertension (DRH) in individuals exhibiting effects of the Great East Japan Earthquake (Shiraishi et al., 2016). In the past, we reported several characteristics of disaster-related suicides in the two years after the Great East Japan Earthquake (Inoue et al., 2015): “in the year of the disaster, the majority of disaster-related suicides were by men, but 2 years later the proportion of disasterrelated suicides by women increased”, and “in the year of the disaster, motives for disaster-related suicides were primarily ‘health problems’ and ‘economic and life problems’, but after the disaster ‘health problems’ were more often cited as the motive for disaster-related suicide”. A research of Liaw et al showed that the number of suicide increased after the large earthquake in Nantou County (Liaw et al., 2008). However, a study of Shoaf et al described that the suicide rates did not increase after the Northridge earthquake (Shoaf et al., 2004). There was a report that suicide rates among females increased immediately after the large earthquake in Nantou County in 1999; the report showed that the rates among males increased slightly in the year, and those rates increased further in 2000 and 2001 (Yip., 2009). Since another earthquake will probably strike Japan in the future, ascertaining the characteristics of subsequent disaster-related suicides and identifying trends in those suicides may help in the development of medium to long-term measures to prevent other disaster-related suicides. With this in mind, the current study examined trends in disaster-related suicides in the three to four years since the Great East Japan Earthquake, and we discussed as descriptive epidemiology.

This study (1) examined the number of suicides by men and women in Japan in 2014 and 2015 based on a report by the National Police Agency (National Police Agency., 2016) and also calculated the ratio of female/male suicides.

This study also (2) examined the number of suicides by men and women related to the Great East Japan Earthquake in 2014 and 2015 based on a report by the Cabinet Office (Cabinet Office., 2016) and calculated the ratio of female/male suicides in relation to that disaster.

Finally, this study (3) examined the motives for suicide related to the Great East Japan Earthquake in 2014 and 2015 based on a report by the Cabinet Office (Cabinet Office., 2016) and calculated the proportion of suicides due to a specific motive. The motives for suicide were classified as “family problems”, “health problems”, “economic and life problems”, “work problems”, “problems of relations between the sexes”, “problems in school”, “other,” and “unknown”. Suicide could be due to multiple motives, so multiple motives could be cited.

The findings suggested trends in disaster-related suicides in the three to four years since the Great East Japan Earthquake, and these trends were examined in order to devise measures to prevent those suicides. This study used only numerical data without individual information.

Suicide Trends in Japan

There were 17,386 suicides by men in Japan in 2014 and 8,041 suicides by women. There were 16,681 suicides by men in Japan in 2015 and 7,344 suicides by women. The ratio of female/male suicides in Japan was 0.46 in 2014 and 0.44 in 2015.

Suicides Related to the Great East Japan Earthquake

There were 11 suicides by men and 11 by women related to the Great East Japan Earthquake in 2014. There were 13 suicides by men and 10 by women related to the Great East Japan Earthquake in 2015. The ratio of female/male suicides related to the Great East Japan Earthquake was 1 in 2014 and 0.77 in 2015.

Motives for Suicide Related to the Great East Japan Earthquake

The detailed motives for suicides related to the Great East Japan Earthquake in 2014 and 2015 are shown in Table 1. In 2014, the most frequently cited motive for suicide was “health problems” (37.9%), followed by “unknown” (20.7%) and “family problems” (17.2%). In 2015, the most frequently cited motive for suicide was “health problems” (40.6%), followed by “unknown” (25.0%) and “family problems” (18.8%) (Table 1).

Table 1: Motives for suicide related to the Great East Japan Earthquake in 2014 and 2015

The ratio of female/male suicides in Japan was 0.46 in 2011. The female/male ratio of suicides related to the Great East Japan Earthquake was 0.31 in 2011 (the male/female ratio was 3.23), and the female/male ratio of such suicides was 0.65 in 2013 (the male/female ratio was 1.53). The biggest causes of suicide were “health problems”, “economic and life problems”, and “unknown” (20.8%) in 2011 (Inoue et al., 2015). Although the female/male ratio of suicides in Japan remained roughly constant in 2011, 2014, and 2015, the proportion of suicides by women in related to the Great East Japan Earthquake increased in 2014 and 2015 in comparison to 2011. The same trend was noted in 2014 and 2015 in comparison to 2013. In other words, the proportion of suicides by women in the three to four years after the Great East Japan Earthquake has increased from the proportion observed two years after the disaster. The proportion of suicides due to “health problems” in relation to the Great East Japan Earthquake increased about two-fold in 2014 and 2015 in comparison to 2011, but the proportion of suicides due to “economic and life problems” decreased by about one-half to one-third.

A study by Kukihara et al. found that depression and post-traumatic stress disorder (PTSD) were prevalent among the survivors of massive earthquakes, tsunamis, and accidents at nuclear power plants (Kukihara et al., 2014). Another study examined patients with cardiovascular disease (CVD) after the Great East Japan Earthquake (Onose et al., 2015). That study found that being female, having experienced the tsunami, having suffered property loss, being poor, and the medication use of insomnia were related to PTSD, and the study also found that PTSD was prevalent after the earthquake in patients with CVD (Onose et al., 2015). There were some reports that PTSD prevention measure after disaster was important item (Jiang et al., 2014; Hu et al., 2016). Therefore, measures specifically addressing “women” and individuals with “health problems” (both physical and mental disorders) must be implemented over a prolonged period after a disaster. In terms of prevention and treatment, experts in clinical medicine and social medicine, administrative bodies, private organizations, and the public together need to understand the key aspects of a long-term follow-up after a disaster, and medical experts, administrators, and organizations need to implement that follow-up.

References

1. Cabinet Office, Government of Japan. (2016). http://www8.cao.go.jp/jisatsutaisaku/toukei/pdf/h2801/s3.pdf# search='%E6%9D%B1%E6%97%A5%E6%9C%AC%E5%A4%A7%E9%9C%87%E7%81%BD%E3%81% AB%E9%96%A2%E9%80%A3%E3%81%99%E3%82%8B%E8%87% AA%E6%AE%BA%E8%80%85%E6%95%B0+%E5%B9%B3%E6%88%9028%E5%B9%B41%E6%9C%88%E5%88%86''. Last access date: 17 March 2016
2. Hara, K. (2015). The presentstatus of, and issues related to, mental health activities in the Ishinomaki Region, with a focus on outreach activities. SeishinShinkeigakuZasshi, 117,472-477.
3. Hu, X., Cao, X., Wang, H., Chen, Q., Liu, M. &Yamamoto, A. (2016).Probable post-traumaticstress disorder and itspredictors in disaster-bereaved survivors: A longitudinal study after the Sichuan earthquake.Archives of Psychiatric Nursing, 30, 192-197
4. Inoue, K., Fujita, Y., Miyaoka, T., Ezoe, S.& Horiguchi, J. (2015).Importance of measures to prevent suicides related to the Great East Japan earthquake among women.Psychiatry and Clinical Neurosciences, 69, 596
5. Ishiki, A., Okinaga, S., Tomita, N., Kawahara, R., Tsuji, I., Nagatomi, R., et al. (2016).Changes in cognitive functions in the elderly living in temporary housing after the Great East Japan earthquake.PLoS One, 11,e0147025
6. Jiang, R.F., Tong, H.Q., Delucchi, K.L., Neylan, T.C., Shi, Q. &Meffert, S.M. (2014).Interpersonal psychotherapy versus treatment as usual for PTSD and depression among Sichuan earthquake survivors: a randomized clinical trial.Conflict and Health, 8, 14
7. Kukihara, H., Yamawaki, N., Uchiyama, K., Arai, S.& Horikawa, E. (2014). Trauma, depression, and resilience of earthquake/tsunami/nuclear disaster survivors of Hirono, Fukushima, Japan.Psychiatry and Clinical Neurosciences, 68, 524-533
8. Liaw, Y.P., Wang, P.W., Huang, C.C., Chang, C.M. &Lee, W.C. (2008). The suicide mortality rates between 1997-1998 and 2000-2001 in Nantou County of Taiwan following the earthquake of September 21 in 1999. Journal of Forensic Sciences, 53, 199-202
9. National Police Agency.(2016). https://www.npa.go.jp/safetylife/seianki/jisatsu/H27/H27_jisatunojoukyou_01.pdf
10. Last access date: 22 March 2016
11. Onose, T., Nochioka, K., Sakata, Y., Miura, M., Tadaki, S., Ushigome, R., et al. (2015).Predictors and prognostic impact of post-traumatic stress disorder after the great East Japan earthquake in patients with cardiovascular disease.Circulation Journal, 79, 664-667
12. Orui, M., Harada, S.&Hayashi, M. (2014).Changes in suicide rates in disaster-stricken areas following the Great East Japan earthquake and their effect on economic factors: An ecological study.Environmental Health and Preventive Medicine, 19, 459-466
13. Shiraishi, Y., Kujiraoka, T., Hakuno, D., Masaki, N., Tokuno, S. &Adachi, T. (2016). Elevation of derivatives of reactive oxygen metabolites elevated in young "disaster responders" in hypertension due to Great East Japan earthquake. International Heart Journal, 57, 61-66
14. Shoaf, K., Sauter, C., Bourque, L.B., Giangreco, C. &Weiss, B. (2004). Suicides in Los Angeles County in relation to the Northridge earthquake.Prehospital and Disaster Medicine, 19, 307-310
15. Tokuzu, K., Toyama, A., Uchida, S. &Suwa, K. (2015).SeifuoyobiFukushimakenniyorusinsaifukkounotorikumiFukushimakennojyuuminnokenkounikanrensurukuninotorikumi.Progress in Medicine, 35, 823-826
16. Yabuki, S., Ouchi, K., Kikuchi, S.&Konno, S. (2015). Pain, quality of life and activity in aged evacuees living in temporary housing after the Great East Japan earthquake of 11 March 2011: a cross-sectional study in Minamisoma City, Fukushima prefecture. BMC Musculoskeletal Disorders, 16, 246
17. Yip, P. (2009).Effects of an earthquake on suicide rates in Nantou, Taiwan.British Journal of Psychiatry, 194, 190