Suicide and Suicide Prevention Activities Following the Great East Japan Earthquake 2011: A Literature Review

Background: Since the Great East Japan Earthquake (GEJE), numerous studies have been conducted, but no comprehensive review study has been carried out. Thus, this literature review aimed to examine how the GEJE might affect suicide and suicidal behaviors from a long-term perspective. Methods: For the literature review, a search of electronic databases was carried out to find articles written in English and in Japanese that were related to suicide and its risk factors, as well as suicide prevention activities following the GEJE. Thirty-two articles were then selected for the review. Results: There were several findings, as follows: (1) gender differences in suicide rates in the affected area: nationwide, the suicide rates in men showed a delayed increase, whereas suicide rates in women increased temporarily immediately after the GEJE; (2) the suicide rates increased again in the recovery phase; (3) the background of the suicides was linked to both disaster-related experiences, and indirect reasons pertaining to the GEJE; and (4) intensive intervention combined with a high-risk and community-focused approach could prevent suicides following the disaster. Conclusions: Although further accumulation of knowledge about suicide and suicide prevention is essential, these findings can contribute to response, recovery, and preparedness in relation to future disasters.


Introduction
The Great East Japan Earthquake (GEJE), which occurred on 11 March 2011, was the largest in Japanese history. The earthquake generated a massive tsunami that reached a maximum height of 9.3 m, travelling up to 10 km inland across flat areas and causing severe damage to the affected areas in the Iwate, Miyagi, and Fukushima prefectures. This was followed by a separate tsunami, which hit the Fukushima Daiichi Nuclear Power Plant operated by the Tokyo Electric Power Company, causing radiation disasters in the Fukushima Prefecture. Thus, the disaster caused many to lose family members, experience severely damaged homes, and face harsh conditions after evacuation. The experience has affected the psychological and mental health of residents and, as a consequence, could lead to suicidal behavior.
However, according to a previous systematic review study, natural disasters have been shown to have differing effects on suicide rates (e.g., a slight increase or decrease immediately after the disaster, a delayed increase, and no association with the disaster) [1]. Therefore, a consistent understanding has not yet been reached regarding changes in suicide rates after a devastating disaster. Furthermore, the backgrounds of those who died by suicide or who attempted suicide after devastating disasters are still uncertain, although mental disorders such as depression and post-traumatic stress disorder (PTSD), low social support, and disaster-related experiences such as injury to the person and their relatives were identified as the most important risk factors for suicide ideation based

Literature Selection Process
The initial search, using the proper combination of keywords ("the Great East Japan Earthquake" and "suicide"/"Fukushima" and "suicide" in PubMed and "Higashi Nihon Daishinsai" and "Jisatsu"/"Fukushima houshasen" and "Jisatsu" in Ichushi-Web), led to the identification of 180 articles (41 in English and 139 in Japanese). Subsequently, after screening the identified articles, 17 English articles were excluded because they were commentary, special feature or duplicated articles for the two keywords "GEJE" and "Fukushima". Similarly, 128 Japanese articles were excluded because they were almost all commentary and special feature articles or duplicated by those listed in PubMed. Next, 35 articles (24 in English and 11 in Japanese) were examined in terms of their content; 3 articles were excluded because they included no direct outcomes related to the GEJE and the Fukushima Daiichi Nuclear Power Plant accident (i.e., the main outcome did not relate to the GEJE but to the Kumamoto Earthquake of 2016; the monitoring of long-term suicide rates ran from 2001 to 2014 and did not include the effect of the GEJE; and the research methods were unclear). Finally, 32 articles (21 articles in English and 11 articles in Japanese) were selected for this literature review ( Figure 1).

Categorizing Selected Articles
The selected articles that met the inclusion/exclusion criteria were categorized as follows: (1) descriptive epidemiological study about regional suicide rates in the affected area or other areas; (2) ecological study examining the factors related to the suicide rates; (3) cross-sectional or longitudinal study examining the factors related to suicidal ideation or behavior; (4) descriptive study concerning those who attempted suicide and visited emergency hospitals; (5) case reports; (6) practical reports regarding suicide prevention activities and disaster-related mental health activities; and (7) review study of counselors' daily records and training interventions for the counselors.

Categorizing Selected Articles
The selected articles that met the inclusion/exclusion criteria were categorized as follows: (1) descriptive epidemiological study about regional suicide rates in the affected area or other areas; (2) ecological study examining the factors related to the suicide rates; (3) cross-sectional or longitudinal study examining the factors related to suicidal ideation or behavior; (4) descriptive study concerning those who attempted suicide and visited emergency hospitals; (5) case reports; (6) practical reports regarding suicide prevention activities and disaster-related mental health activities; and (7) review study of counselors' daily records and training interventions for the counselors.

Ethical Considerations
Not applicable as this was a literature review study.

Results
After the selection and categorization of the articles, seven categories were identified concerning the GEJE and suicide and suicide prevention activities (Table 1). In this results section, selected articles from each category are summarized and integrated.

Descriptive Epidemiological Study about Regional Suicide Rates in the Affected Area or Other Areas
In total, 13 articles were categorized as descriptive epidemiological studies, of which 4 targeted the changes in suicide rates in non-affected areas, nationwide and in Tochigi Prefecture, which is located in the south of Fukushima.
According to the nationwide studies, suicide rates in women increased for several months immediately after the GEJE [5,6] whereas, conversely, the rates in men showed a large decline for several months following the GEJE [5,6], and suicide by men aged 40-64 years and 65 years and over exhibited a large decline in the years following the GEJE, a decline which attenuated over time [7]. In Tochigi Prefecture, located in the south of Fukushima Prefecture, suicide rates in 2011 increased and peaked in May, which contrasted with the years 2008, 2009, and 2010, which saw rates peak in March [8].
In three severely affected areas in the Iwate, Miyagi, and Fukushima prefectures, articles that analyzed suicide rate trends for a period of 2-5 years after the GEJE reported that the suicide rate of men in the disaster-affected areas initially decreased significantly following the GEJE [9][10][11][12], but then showed a delayed increase [10][11][12]. Although one study reported that the female suicide rate declined slightly initially, and then increased significantly over the subsequent 3-year period [12], it was not clear whether there was an association between the GEJE and suicide rates in the affected area comparable to that for males. The overall suicide rate decreased initially, then increased from 2-3 years after the GEJE [11,13].
For a period of over 5 years following the GEJE, known as "the recovery phase", a couple of articles reported that the suicide rate in men increased again, which was probably because of the termination of financial aid for evacuees in need and the cutting of social ties amongst evacuees [13][14][15].
With regard to disaster-related suicide, which was defined as individuals who died by suicide who were either evacuees or directly affected by the GEJE (as reported by the Cabinet Office), men accounted for a large proportion of suicides in the year in which the disaster occurred, but the proportion of suicides among women increased two years after the disaster [16]. The main motives for suicides were health problems, which increased significantly after the GEJE [16]. The 99 disaster-related suicide cases defined by the Cabinet Office in Fukushima were notably higher in men than in women, whereas disaster-related suicides among women in their 50s and 80s were much higher compared with overall suicide rates in either Fukushima or Japan [17].

Ecological Study Examining the Factors Related to the Suicide Rates
According to two studies which examined the association between the suicide rates in the affected area and related factors, the suicide rates in the affected prefectures, namely Iwate, Miyagi, and Fukushima, did not exhibit a significant association with bankruptcy cases, or the ratio of effective job offers two years after the GEJE [18]. However, the high suicide rate in Iwate Prefecture was found to be related to the small number of temporary houses and small disaster recovery budgets [19].

Cross-Sectional or Longitudinal Study Examining Factors Related to Suicidal Ideation or Behaviors
In three cross-sectional studies regarding suicidal ideation among young girls and adults, both groups showed a significant association with disaster-related experiences such as loss of their home, completely or partially damaged homes, and loss of family or relatives. These studies were conducted in the three-year period following the GEJE [20][21][22]. However, one study that targeted junior high school students showed no significant association with disasterrelated experiences, and this was conducted five years after the disaster, indicating that the psychological effects of the disaster may have subsided over time [23]. Other factors related to suicidal ideation were identified as risks related to the following: not being married, poor subjective physical health, suffering from a mental illness, and onset of chronic or delayed mental illness among adult evacuees [21,22].

Descriptive Study Concerning Those Who Attempted Suicide and Visited Emergency Hospitals
According to the two descriptive studies concerning attempted suicides, the number of suicide attempts during the serious conditions of the post-disaster period were significantly higher than in the pre-disaster period, in both the affected and non-affected areas, and this continued for several months [24,25]. In another article, the clinical features of the suicide attempt cases during a four-week period were characterized as acute stress, depressive state, and secondary stress reaction, for example, caused by drastic environmental and lifestyle changes [26]. However, another article reported that the background psychosocial factors related to suicide attempts were variable (e.g., family problems, intersexual problems, and alcohol), and had little direct connection to the GEJE, even though the individuals were all evacuees [27].

Case Reports
One case report article reported that "Since a few months after the disaster, many people have perceived that they are going to lose their neighborhood support networks and have diminished hope for the future without any concrete financial support provided by the government". This was based on a study which involved searching newspaper articles [28].

Practical Reports Regarding Suicide Prevention Activities and Disaster-Related Mental Health Activities
We identified four practical reports regarding disaster-related mental health and suicide prevention activities, which were implemented in coastal municipalities in Miyagi Prefecture and a municipality in the evacuation area as a consequence of the nuclear disaster in Fukushima.
In Higashi-Matsushima City, Ishinomaki City, and Kesennuma City in Miyagi Prefecture, a year after the GEJE, those among the almost 1500 evacuees who were in a depressive state, e.g., PTSD, anxiety disorders, insomnia, alcoholism, or suicidal ideation, were referred to psychiatrists or public health nurses in the public health centers [29].
In Iitate Village, which was within the evacuation area as a result of the Fukushima Daiichi Nuclear Power Plant accident, some suicide prevention measures were implemented as follows: (1) screening of evacuees for mental health issues and outreach to those who were at high risk; (2) gatekeeper training for public office workers; and (3) supervision and support for public health nurses. Although the direct cause was unknown, the number of suicides in Iitate did not exhibit a sharp increase after the GEJE, with the number staying flat at 0-2 per year pre-and post-disaster [30].
In Sendai City, Miyagi Prefecture, a disaster mental health team was established following the GEJE, and it provided psychosocial and social support to address the psychosocial issues of evacuees on an ongoing basis. Although the direct effect of the disaster on mental health was unknown, at the time of the report the suicide rate in Sendai had not increased since the GEJE [31]. Furthermore, during the COVID-19 pandemic, the suicide rate in the affected area in Sendai, which was provided with disaster-related mental health interventions, showed a continuous declining trend. Conversely, there were increasing trends in suicide rates nationally and in the non-affected area of Sendai [32].

Review Study of Counselors' Daily Records and Training Interventions for Counselors
According to two articles, the percentage of counselors who were involved in helping residents who had suicidal ideation increased considerably, from 21.1% one year after the GEJE to more than 50% after two years [33,34]. As a result, seminars and gatekeeper training were conducted to help counselors cope with residents' mental health issues and suicidal problems and as a result, their confidence to cope with the residents' suicidal ideation showed a significant increase [35,36].

Nationwide All residents of the prefectures
The 95% confidence intervals for the ratio were calculated to determine any statistically significant increases or decreases in the suicide rate nationwide and in the three affected prefectures.
After the earthquake, the male suicide rate in March 2011 was 18% lower than the average mortality rate for the previous 3 years. However, it increased by 18% in May and 8% in June, and increased mortality was observed in women.   In the evacuation areas, the male suicide rate increased immediately after the disaster and then decreased steeply around 1.5 years after the disaster. However, with the lifting of the evacuation order, it again exceeded that of non-evacuation areas and continued to do so for the next 3 years.
On the other hand, the suicide rate in women in the evacuation areas started to increase later than that in men. Among the cases of disaster-related suicide, men accounted for a large proportion of suicides in the year that the disaster occurred, but the proportion of suicides among women increased 2 years after the disaster. The main motives for the related suicides were health problems, which increased significantly after the GEJE.
(2020) [17] Disaster-related suicide numbers and rates 7 years after the GEJE Fukushima Prefecture 99 suicide cases which were determined to be disaster-related suicides Descriptive analysis of suicide rates by age, gender, means, and occupation among disaster-related suicide cases as defined by the Cabinet Office.
Age-standardized disaster-related suicide rates were notably higher in men than in women. In addition, disaster-related suicide rates in Fukushima were higher in women in their 50s and 80s compared with overall suicide rates in Fukushima or Japan.
(2). Ecological study (2 articles) All residents of disaster-stricken and neighboring prefectures Using the multiple regression model, the association between suicide rates and economic variables was evaluated based on the number of bankruptcy cases and ratio of effective job offers and comparing the disaster-stricken and neighboring prefectures.
In disaster-stricken areas, male suicide rates decreased during the 24 months following the earthquake. Multiple regression analysis showed that bankruptcy cases and ratio of effective job offers were only significantly associated with male post-disaster suicide rates in the neighboring prefectures rather than in the disaster-stricken prefectures.  (1) The cumulative incidence of suicidal ideation using the Cox proportional hazard model.
(2) A multiple logistic regression analysis was conducted to examine risk factors for the onset of suicidal ideation.
(1) Amongst 1019 respondents, the cumulative incidence of suicidal ideation 1, 2, and 3 years after the earthquake was 1.4%, 2.4%, and 2.8%, respectively-significantly higher than that in the control. (2) Not being married, being injured in the disaster, and poor subjective physical health were associated with suicide ideation. Disaster experience was not associated with psychological symptoms (PTSD, depression, anxiety) or suicide risk in junior high school students 5 years after the GEJE. The suicide risk appeared to be the same as that in the general population in Japan.
(4). Descriptive study concerning those who attempted suicide and visited emergency hospitals (4 articles) The clinical records of all patients who visited the medical center near the nuclear plant from 1 year before to 1 year after the disaster were reviewed (n = 981).
The risk of nonfatal suicide attempts (those who survived) using high mortality methods (methods other than self-poisoning and wrist-slitting) was significantly higher, by three to four times, for 4 months after the series of disasters, and then decreased. There was no significant increase in nonfatal suicide attempts using low-mortality methods (self-poisoning and wrist slitting) after the disaster. The clinical features of cases within 4 weeks were classed as acute stress, and after 4 weeks they were classed as secondary stress reactions, such as drastic environmental changes in lifestyle. Depressive states were also noted. In a note that she left behind, a woman wrote that she did not want to bother her son's family and had chosen to take refuge in the grave. In the months following the disaster, many people perceived that they were going to lose their neighborhood support networks and had diminished hope for the future, in the absence of any concrete financial support provided by the government. Almost 1500 evacuees who relocated to temporary housing

Unknown
Evacuees who had experienced a depressive state, PTSD, anxiety disorders, insomnia, alcoholism, and suicidal ideation were referred to a psychiatrist or public health nurse in the public health centers.

All residents in Sendai City
To address the psychosocial issues of evacuees, the disaster mental health team provided psychosocial and social support. The suicide rate in the disaster-affected area was used as one of the outcome indicators of this activity.
Although the direct effect of this disaster-related mental health activity was unknown, at the time of the report the suicide rate in Sendai City had not increased since the GEJE. The suicide rate trends were assessed using exponential smoothing time series modelling. The area in question is the disaster-affected area which has seen the implementation of disaster-related mental health activities on an ongoing basis, including during the COVID-19 pandemic.
During the COVID-19 pandemic, the suicide rate in the affected areas showed a declining trend, whereas the national rates and the rates in the non-affected areas showed an increasing trend, although the affected areas were higher than the national average at the beginning of the COVID-19 pandemic.  To evaluate the outcomes of the training program, including a pre-and post-survey, and a follow-up survey 2 months after the intervention was conducted.
The program content regarding suicide was as follows: specific ways to communicate with residents who have suicidal thoughts: (a) questioning about the suicidal thoughts, and (b) encouraging a person to seek appropriate professional help. As a result, counselors' confidence to cope with the resident's suicidal thoughts showed a significant increase.

Gender Differences in Suicide Rates in the Affected Area and Nationwide in the Period of Two to Three Years
According to descriptive epidemiological studies regarding changes in suicide rates nationwide and in the non-affected prefecture, suicide rates in women increased temporarily immediately after the GEJE [5,6,8], but suicide rates in the affected prefectures and areas, especially in men, showed a decline for almost two years, and then exhibited a delayed increase [9][10][11][12]. This phenomenon of a delayed increase in male suicide rates was a consistent trend in the affected area following the GEJE, and similar trends were observed in previous studies [37][38][39].
The direct reason for the differences between genders in both non-affected and affected areas is unknown, but some studies have suggested that women are more sensitive and susceptible to adverse events [5], and that increases in female suicide rates during social crises is greater and more prolonged [6]. Therefore, the female suicide rates might increase temporarily immediately after the GEJE in the non-affected area. Intensive and long-term mental healthcare services and psychosocial support [6,10], together with the boosting of economic conditions via reconstruction and recovery [9] could help to reduce suicides in the affected area.
That said, previous studies have mainly focused on monitoring suicide rates in the disaster-affected areas, and few studies have examined this while including national data. Our literature review confirmed that the national trend was different from that of the disaster-affected areas. If large-scale disasters occur in the future, it will be important to keep in mind that suicide rates can also increase in non-affected areas as well as in in the disaster-affected areas, in particular among women.

Suicide Rates Increasing Again in the Recovery Phase
Historically, studies monitoring suicide rates have spanned a period of five years at most, but the literature following the GEJE included long-term monitoring studies of seven to eight years [13][14][15]. These studies found that suicide rates, both in the coastal areas severely damaged by the tsunami and in the evacuation area due to the Fukushima Daiichi Nuclear Power Plant accident, increased again during the recovery phase seven to eight years after the GEJE [13][14][15], although the prevalence of post-disaster suicidal ideation showed a decreasing trend according to a previous study [23,40]. In the recovery phase, the provision of temporary housing was terminated, which increased economic hardship for needy evacuees. Additionally, disruption of the social connectedness established in the temporary housing may have had an influence. These findings were similar to those of a previous review study that found building social ties worked positively to prevent suicide and that those from lower socio-economic strata were at risk of suicide [3,4]. These findings represent an important lesson for future disasters and need to be borne in mind even in the recovery phase.

Background to the Case of Suicide and Suicidal Behaviors Following the GEJE
Firstly, according to the case report identified in our literature review, the background of the suicide case was "diminished hope for the future" and "lack of concrete financial support" [28]. Health problems (including mental health issues) as a motive for suicide based on the suicide statistics of the national police agency increased significantly after the GEJE [16]. In the same way as significant changes involving life and work [41,42], the effects of instability, physical problems [42][43][44], living difficulties [31,45], and hopelessness for the future [46] can be major factors in suicides in the immediate to medium-term period following the GEJE. Additionally, suicidal ideation showed a significant association with not only having disaster-related experiences but also the onset of mental illness [20][21][22], which was similar to the findings of the study of suicide motives following the GEJE [16]. Severe cases of suicide attempts increased immediately after the GEJE [24,25], and the background of those who attempted suicide was related to acute stress and secondary stress reactions such as drastic environmental changes in lifestyle [26]. Clearly, acute stress or drastic environmental changes can pose a challenge to the mental health of evacuees. Notably, it was not only the disaster-related experiences that caused suicide attempts but also reasons indirectly related to the disaster [27].
In summary, these findings indicate that acute stress, drastic environmental changes in life, and psychological factors such as hopelessness and the onset of mental illness were thought to be risk factors for suicide following the disaster. However, because of the complex backdrop of suicide, further accumulation of data is considered necessary to examine more fully the causes of suicide and suicidal behaviors after disasters.

Suicide Prevention Measures Following the GEJE
After the GEJE, numerous disaster-related mental health activities were implemented in the disaster-affected areas [29][30][31][32][33][34]. The basic measures were implemented widely in the affected areas based on the official guidelines [47], as follows: (1) high-risk approaches such as screening evacuees with high psychological distress, binge-drinking or other mental health issues, and ongoing counselling involving home visits, and (2) a community approach, e.g., building social ties among evacuees in the community that has been indicated as a protective factor for suicide in a previous review study [3]. Although practical reports regarding disaster-related mental health activities including outcomes of suicide were limited, these interventions for the evacuees in the affected areas might have been effective for suicide prevention [30][31][32]. However, although this kind of intervention was carried out to a certain extent in all disaster areas after the GEJE on an ongoing basis, and without interruption, the suicide rates in all the affected areas in the Iwate, Miyagi, and Fukushima prefectures showed a delayed increase in the medium-to long-term period following the disaster and increased again in the recovery phase. The reason was uncertain; it might have been related to the small disaster recovery budgets that were reported by the ecological study identified in our review [19].
In any case, it was considered necessary to accumulate knowledge for suicide prevention. It is also important to train counselors to help the evacuees with suicidal ideation in order to prevent suicides in the affected areas, because the counselors who worked with the evacuees with suicidal ideation had a relatively high level of experience [35,36].

Limitations and Strengths of This Literature Study
This literature review has some limitations. Firstly, the identified articles were not sufficiently numerous to enable the findings to be summarized the findings, other than in the case of the descriptive epidemiological studies concerning regional suicide rates. In particular, case reports on individuals who died by suicide or who attempted suicide were extremely limited in terms of understanding the background to the suicidal behavior. Secondly, because the search process was implemented by the author, there is a risk of selection bias even though the search strategy and inclusion/exclusion criteria were set out in advance.
Despite these limitations, this literature review has several strengths, one of which is that it included articles written in Japanese. As a result, more articles written in Japanese than in English were selected (e.g., a descriptive study of those who attempted suicide, practical reports regarding suicide prevention and disaster-related mental health activities, and the review study of counselors' daily records and training interventions for the counselors). It is hoped that more knowledge regarding suicide and suicide prevention can be accumulated for use in any future disaster scenarios.

Conclusions
As a result of this study which reviewed literature following the GEJE, several findings emerged, as follows. (1) Gender differences in suicide rates in the affected areas: the suicide rates in men initially declined and showed a delayed increase, and this was mirrored nationwide. However, the suicide rate in women increased temporarily in the period of two to three years following the GEJE. (2) Suicide rates in the affected areas increased again during the recovery phase. (3) The background to suicide was associated with disaster-related experiences, including acute stress, secondary stress reactions such as drastic environmental changes in lifestyle, as well as to reasons indirectly linked to the GEJE. (4) Intensive intervention combined with the high-risk and community-focused approach could prevent suicides after the disaster. Although it is essential to accumulate further knowledge about suicide and suicide prevention following disasters, the findings of this literature review can contribute to the response, recovery, and preparedness for future disasters.