SEARCH

SEARCH BY CITATION

Keywords:

  • depression;
  • Great East Japan Earthquake;
  • nuclear power plant accidents;
  • post-traumatic stress disorder;
  • resilience

Abstract

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References

Aim

A mega-earthquake and tsunami struck the northeastern coast of Japan, and many survivors were forced to evacuate to temporary housing due to rising radiation levels. The aims of this study were to investigate the prevalence of symptoms of post-traumatic stress disorder (PTSD), depression, and poor general health among survivors, to test the predictive roles of resilience on mental and physical health, and to examine the predictive sociodemographic factors on resilience.

Methods

Two hundred and forty-one evacuees (men/women: 116/125) from Hirono, Fukushima participated in the study. They were asked to complete the Connor–Davidson Resilience Scale, the Zung Self-Rating Depression Scale, the Impact of Events Scale-Revised, and a demographic questionnaire.

Results

Among all participants, 53.5% exhibited the clinically concerning symptoms of PTSD, and among them 33.2% indicated clinical PTSD symptoms. Additionally, 66.8% reported symptoms of depression, and among them 33.2% showed mildly depressive symptoms, while 19.1% and 14.5% demonstrated moderate and severe depressive symptoms, respectively. Resilience was a significant buffer for depression, PTSD, and general health. Additionally, employment status, eating/exercise habits, and drinking habits predicted resilience.

Conclusion

The results indicated that depression and PTSD are prevalent among the survivors of massive earthquakes, tsunamis, and accidents from nuclear power plants. However, the results also showed that some survivors managed to endure the traumatic events relatively well, and resilience was a significant protective factor in dealing with such events. Therefore, it is crucial to assist survivors in improving their resilience by providing job opportunities and encouraging a healthy lifestyle.

A mega-earthquake and tsunami struck the northeastern coast of Japan on 11 March 2011. The most devastating property damages occurred in Fukushima, Miyagi, Iwate, and Ibaraki prefectures. The vast majority of the fatalities and damage came not from the earthquake itself, but from the resulting tsunami. Tsunami waves in excess of 10 m (33 feet) swept away almost every home, structure, vehicle, and area of vegetation in their path. This earthquake, with a magnitude of 9.0 on the Richter scale, was the worst and the most devastating disaster in Japan since the end of World War II.[1] Furthermore, the event led to a Level 7 nuclear power plant disaster at the Fukushima Daiichi complex, the largest nuclear accident since the 1986 Chernobyl disaster.[2] As a result, a country battling national crisis endured the additional threat of nuclear contamination. These simultaneous natural and manmade disasters inevitably had negative effects not only on the survivors, but also on Japanese society as a whole.

Natural disasters or disasters due to natural hazards, such as earthquakes and tsunamis, can have substantial detrimental effects on the physical and mental health of victims.[3] Previous studies indicated the presence of emotional distress and psychiatric disorders among adult disaster victims.[4] For instance, psychiatric disorders, such as post-traumatic stress disorder (PTSD) or major depressive disorder, increased in the aftermath of earthquakes in Italy,[5] China,[6] Turkey,[7] and Southeast Asia.[8] Survivors of natural disasters also experience enormous stress, due to relocations and the loss of families, communities, and properties. It is well documented that such stress is strongly associated with not only one's psychological well-being, but also one's physical health.[9, 10] Examination of the survivors' mental and physical health after these massive natural and manmade disasters is indispensable in order to provide needed and effective assistance to them.

Individuals respond to disasters differently, and numerous studies have documented that a number of factors influence how people react following disasters. For instance, Phifer[11] found that some sociodemographic factors, such as sex, occupational status, and age, were all associated with amplified psychological symptoms. In particular, he concluded that within this older adult sample, men, those with lower occupational status, and persons aged 55–64 years were at significantly greater risk than their counterparts. Other researchers have found that unmarried persons and those with low levels of education and income have been found to be more susceptible to adverse mental health effects after stressful events than others.[12, 13] Recently, however, a growing number of studies have presented evidence that individuals' efforts to cope with extreme stress also significantly positively affect the psychological outcomes of those involved.[14, 15] One aspect of individual effort is psychological resilience. Resilience has been defined as a protective factor against mental problems and as a dynamic process of adaptation to changes in life circumstances.[16] Previously, some researchers described resilience as a characteristic trait that buffers against the negative outcomes from stressors.[17] However, the recent literature supports the conceptualization that resilience is most commonly understood as a process, not a trait of an individual.[18] Thus, the current view of resilience has been theorized as a dynamic process that can be acquired at any point throughout the lifespan.[19]

Vast numbers of studies concluded that resilience is a protective factor against the development of psychiatric disorders, such as PTSD,[20] and depression.[21] However, those studies have been conducted primarily outside of Japan. Given that resilience may be influenced by cultural components,[22] investigating the role of resilience for survivors of natural disasters in Japan is worthy of study. Therefore, the focus of this study is to explore the prevalence of symptoms of PTSD, depression, and general health among the residents of Hirono who have been affected by the Great East Japan Earthquake and the nuclear power plant accident. This study also examined the factors that influence increased psychological resilience in those survivors.

Methods

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References

Participants and procedure

Participants of this study were the residents of Hirono in Fukushima Prefecture, which is located within a 20-km (12 miles) radius of the Fukushima Nuclear Power Plant. According to the 2010 Census, there were 5418 residents in Hirono.[23] Records show that two residents died, one is still missing, and many experienced damage to their homes and properties from the earthquake and tsunami.[24] However, another tragedy of the residents of Hirono is that they were all forced to relocate to temporary housing due to rising radiation from the compromised nuclear power plant. This survey was part of a larger investigation requested by the Japanese Ministry of Education and the mayor of Hirono to assess the survivors' general health conditions. Participants were informed by the housing support staff of this purpose, and also that participating in this study was completely voluntary, confidential, and anonymous, and that the results of this study would be disclosed to them. The support staff visited all residents in the temporary housing units individually to explain the above information orally; support staff also delivered during these visits a written document that included the same information. Only people who decided to participate completed the survey and dropped it off in a box in a communal meeting place.

A total of 458 survey packages were distributed to the residents, and a total of 241 participants (125 women, 116 men, average age 58.0 ± 16.5 years of age) participated in this study with a response rate of 53%. We excluded some individuals who moved from the temporary housing and individuals who did not answer the majority of the questionnaires. This study took place 9 months after the earthquake, during the period from 16 to 25 December 2011. The participants were asked to complete the Connor–Davidson Resilience Scale (CD-RISC), the Zung Self-Rating Depression Scale (ZSDS), the Impact of Events Scale-Revised (IES-R-J), the Short Form-36 (SF-36)v2 (Japanese version), and a demographic questionnaire.

Questionnaires

SF-36v2 (Japanese version)

The SF-36v2 is designed to measure self-estimated parameters of general health. The SF-36 health survey questionnaire yields on eight scale profiles, and they are hypothesized to form two distinct clusters: physical and mental health. The physical health cluster includes physical functioning (PF), role-physical (RP), body pain (BP), and general health (GH); the mental health cluster contains vitality (V), social functioning (SF), role-emotional (RE), and mental health (MH). This scale is widely used internationally, and Japanese versions of the SF-36 have been developed[25] and validated by Fukuhara et al.[26] The scores range from zero to 100, with higher scores representing better levels of physical and mental well-being. The internal consistencies for the subscales of PF, RP, BP, GH, V, SF, RE, and MH were 0.93, 0.93, 82, 0.86, 0.87, 79, 0.94, and 0.86, respectively.

CD-RISC

The CD-RISC was developed to assess an individual's ability to cope with traumatic stress.[27] It contains 25 items, all of which have a 5-point Likert scale response ranging from 0 (‘not true at all’) to 4 (‘true nearly all of the time’). The scale is rated based on how the subject has felt over the past month. The total score ranges from 0 to 100, with higher scores reflecting greater resilience. Cronbach's alpha of this scale in the present study was 0.87.

ZSDS

The ZSDS was developed by Zung[28] to assess depressive symptomatology and has been validated in Japan.[29] It contains 20 items that participants rate on a 4-point Likert scale, ranging from 1 (a little of the time), 2 (some of the time), 3 (good part of the time), and 4 (most of the time). The scores range from 25–100. The cut-offs for categorizing depression level are as follows: 25–49 (normal range), 50–59 (mildly depressed), 60–69 (moderately depressed), 70 and above (severely depressed). The internal consistency of this scale in the present study was 0.87.

IES-R-J

PTSD was evaluated using the IES-R, which is a widely used, well-validated, and reliable measure.[30] This 22-item measure of traumatic stress probes the intensity of responses to a particular event based on the level of traumatic experience in the past 7 days on a 5-point scale from 0 (not at all) to 4 (extremely). The IES-R yields three subscales (avoidance, intrusion and hyperarousal) and a total score. Higher scores indicate increased levels of post-traumatic distress. The IES-R was not designed to make a categorical diagnosis; however, in the study by Creamer et al., a cut-off score of 24 has been identified as indicating significant PTSD symptoms of clinical concern, and a score of 33 has been noted to meet the criteria of clinical PTSD.[31] Given that the IES has been translated and validated in Japan by Asukai et al.,[30] we used the same cut-off score of 25, which was used to identify PTSD symptoms.

Ethical considerations

This study was approved by the institutional review board of Junshin Gakuen University. All participants provided written informed consent after the procedure had been fully explained to them. Before the questionnaire was completed, the aims and procedures of the study were explained clearly and simply by the interviewers using written materials. Verbal consent was obtained from the participants due to unfamiliarity of culture when dealing with written consent.

Statistical analysis

Non-paired t-tests, χ2-tests, regression analyses, and simultaneous multiple regression analyses were performed to test the hypotheses. Two-tailed P < 0.05 was considered statistically significant.

Results

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References

Prevalence of depression and PTSD

Among survivors who participated in the present study, it was found that symptoms of clinical concern for PTSD were reported by 53.5% (n = 129), and among them, 33.2% (n = 80) indicated clinical PTSD symptoms. As for depression, 66.8% (n = 161) reported symptoms of depression. Among them, 33.2% showed mildly depressive symptoms, while 19.1% and 14.5% demonstrated moderate and severe depressive symptoms, respectively. Table 1 displays the means and SD for depression, PTSD, and general health.

Table 1. Summary of means and SD for depression, PTSD, general health, and resiliency scales
SF-36v2Mean ± SD
  1. BP, bodily pain; CD-RISC, Connor–Davidson Resilience Scale; GH, general health; IES-R, Impact of Events Scale-Revised; MH, mental health; PF, physical functioning; PTSD, post-traumatic stress disorder; RE, role-emotional; RP, role-physical; SF, social functioning; SF-36v2, Short Form-36v2; VT, vitality; Zung, Zung Self-Rating Depression Scale.

PF77.3 ± 23.4
RP71.2 ± 26.5
BP66.1 ± 25.3
GH52.2 ± 18.6
VT50.3 ± 24.5
SF70.6 ± 27.0
RE70.7 ± 27.1
MH54.8 ± 23.0
Zung Total score54.5 ± 12.9
IES-R Total score26.7 ± 17.9
CD-RISC Total score50.80 ± 19.6

Demographic factors on mental and physical health

The results of non-paired t-tests indicated that respondents who were younger than 60 years of age (t = 2.02, P< 0.05), female (t = 2.72, P< 0.01), unemployed (t = 2.39, P< 0.05), had poor eating (t = 2.27, P< 0.05)/exercise habits (t = 3.09, P< 0.01), did not drink alcohol (t = −3.00, P< 0.01), and slept less than 6 h (t = 3.09, P< 0.01) tended to be more depressed than their counterparts. Age 60 was selected as a cut-off age due to the fact that both the World Health Organization and the United Nations use this criterion.[32] As for PTSD, respondents who were unemployed (t = 2.45, P< 0.05), separated from their families after the disaster (t = 2.43, P< 0.05) and had a history of physical illness before the disaster (t = 2.17, P< 0.05) were more likely to show symptoms of PTSD than their counterparts (see Table 2).

Table 2. Differing patterns of demographic characteristics on depression and PTSD
Demographicn (%), Mean ± SD [Range]ZSDS scoret-valueP-valueIES-R scoret-valueP-value
Mean ± SDMean ± SD
  1. a

    ‘Eating habits’ was calculated by adding the number of ‘yes’ responses to six items: (1) Eat breakfast everyday, (2) Eat in moderation, (3) Eat balanced meals, (4) Eat reduced-salt meals, (5) Chew well, and (6) Eat plenty of vegetables.

  2. IES-R, Impact of Events Scale-Revised; PTSD, post-traumatic stress disorder; ZSDS, Zung Self-Rating Depression Scale.

Age (years) (n = 241)58.0 ± 16.5 [19 – 74]      
<60113 (46.9)56.3 ± 12.32.020.04525.3 ± 17.91.1270.261
>60128 (53.1)53.0 ± 13.227.9 ± 17.8
Sex (n = 241)       
Male116 (48.1)52.2 ± 12.92.7220.00724.3 ± 17.01.4970.136
Female125 (51.9)56.7 ± 12.524.9 ± 18.7
No. of family members (n = 239)3.4 ± 1.7 [1 − 8]      
1–296 (40.2)54.4 ± 13.70.1240.90228.9 ± 18.71.5560.121
3+143 (59.8)54.6 ± 12.225.3 ± 17.3
Marital status (n = 239)       
Married/with partner167 (69.9)53.5 ± 12.71.7170.08726.3 ± 17.90.3610.718
No partner/divorced or separated72 (30.2)56.6 ± 13.027.2 ± 18.0
Employment status (n = 238)       
Paid worker, agriculture, home worker137 (53.4)52.9 ± 11.92.3850.01824.3 ± 17.62.4460.015
Non-employed, student101 (42.7)56.8 ± 13.730.0 ± 17.8
Education (n = 226)       
Primary school76 (33.6)53.6 ± 13.90.3280.74428.4 ± 16.61.6090.109
>High school150 (66.4)54.2 ± 12.224.6 ± 17.3
Income (n = 203),¥       
<2 million126 (62.1)54.0 ± 13.11.160.24727.0 ± 16.81.430.154
2–<5 million77 (37.9)51.9 ± 12.523.4 ± 18.1
History of illness (n = 240)       
Yes178 (74.2)54.8 ± 13.00.8260.41028.0 ± 18.52.1740.031
No62 (25.8)53.3 ± 12.122.4 ± 15.2
Eating habitsa (n = 241)       
0–2157 (65.1)55.9 ± 12.82.270.02426.6 ± 17.60.1150.909
3–684 (34.9)52.0 ± 12.826.9 ± 18.5
Exercise habits (n = 238)       
Yes95 (39.9)51.6 ± 12.73.0870.00227.4 ± 16.70.5310.596
No14360.156.7 ± 12.526.2 ± 18.8
Smoking habit (n = 240)       
Yes60 (25.0)54.3 ± 13.4-0.080.93628.7 ± 20.51.0830.280
No18054.5 ± 12.625.8 ± 16.7
Drinking habit (n = 239)       
Yes89 (55.9)51.1 ± 13.72.9990.00323.9 ± 18.51.7170.087
No15044.156.6 ± 11.828.0 ± 17.3
Sleeping habits (n = 241)       
>7 h173 (71.8)53.0 ± 12.43.0870.00226.6 ± 18.00.1350.893
<6 h68 (28.2)58.5 ± 13.326.9 ± 17.6
Live together after disaster (n = 233)       
Separated87 (37.3)56.4 ± 13.01.5990.11130.2 ± 19.02.4310.016
Live together146 (62.7)53.6 ± 12.824.4 ± 16.7
Change of employment (n = 206)       
No employment or change68 (33.0)54.7 ± 13.00.6800.49727.8 ± 19.11.0610.290
No change138 (67.0)53.4 ± 12.925.0 ± 17.6

Predictive roles of resilience on mental and physical health

Regression analyses were performed to investigate the predictive effects of resilience on depression, PTSD, and general health. The results indicated that all tested variables were significant (see Table 3). That is, individuals with greater resilience predicted the presence of fewer symptoms of depression (β = −0.67, P< 0.001) and PTSD (β = −0.29, P< 0.001), better physical functioning (β = 0.24, P< 0.001), fewer role limitations caused by physical and emotional problems (β = 0.33 and β = 0.34, P< 0.001, respectively) and bodily pain (β = 0.20, P< 0.01), greater perceived general and mental health (β = 0.47 and β = 0.51, P< 0.001, respectively), more vitality (β = 0.55, P< 0.001), and better social functioning (β = 0.25, P< 0.001).

Table 3. Summary of regression analysis of resilience on depression, PTSD, and general health
 BSEβt-valueP-value95%CI
  1. BP, bodily pain; CI, confidence interval; GH, general health; IES-R, Impact of Events Scale-Revised; MH, mental health; PF, physical functioning; PTSD, post-traumatic stress disorder; RE, role-emotional; RP, role-physical; SF, social functioning; VT, vitality; Zung, Zung Self-Rating Depression Scale.

Zung total−0.4350.032−0.663−13.6970.001−0.498−0.372
IES-R total−0.2660.056−0.291−4.6960.001−0.376−0.154
PF0.2880.0750.2423.860.0010.1410.436
RP0.4190.0820.3315.4290.0010.2580.611
BP0.2530.0820.1963.0910.0020.0920.414
GH0.4440.0540.4688.1930.0010.3380.551
VT0.6820.0670.54910.1490.0010.5510.816
SF0.3460.0860.2524.0280.0010.1770.517
RE0.4710.0840.3415.5980.0010.3050.636
MH0.5960.0650.5119.1790.0010.4690.725

Furthermore, we tested the differences between high-resilience and low-resilience groups on demographic factors, depression, PTSD, and all subscales of perceived general health. We first divided the participants into high- and low-resilience groups by using the mid-point of the scores. The results indicated that the high-resilience group tended to be married/have a partner (χ2 = 6.37, P< 0.05), were employed (χ2 = 5.34, P< 0.05), had good eating and exercise habits (χ2 = 9.80, P< 0.01; χ2 = 4.38, P< 0.05, respectively), showed fewer symptoms of depression (t = 9.13, P< 0.001) and PTSD (t = 3.66, P< 0.001), and had overall good general health in comparison to their counterparts (see Table 4).

Table 4. Differences between high and low resiliency on demographic factors, depression, PTDS, and general health
 Low CD-RISC group (n = 125)High CD-RISC group (n = 116)χ2-value or t-valueP-value
n (%), Mean ± SD
  1. a

    χ2-test.

  2. b

    ‘Eating habits’ was calculated by adding the number of ‘yes’ responses to six items: (1) Eat breakfast everyday, (2) Eat in moderation, (3) Eat balanced meals, (4) Eat reduced-salt meals, (5) Chew well, and (6) Eat plenty of vegetables.

  3. c

    Non-paired t-test.

  4. Mid-point of 58.5 was used to create low versus high CD-RISC groups.

  5. BP, bodily pain; GH, general health; IES-R, Impact of Events Scale-Revised; MH, mental health; PF, physical functioning; RE, role-emotional; RP, role-physical; SF, social functioning; SF-36v2, Short-Form 36v2; VT, vitality; ZSDS, Zung Self-Rating Depression Scale.

Age (n = 241)a    
<6062.0 (54.9%)51 (45.1%)χ2 = 0.7670.381
>6063.0 (49.2%)65 (50.8%)
Sex (n = 241)a    
Male59 (50.9%)57 (49.1%)χ2 = 0.0910.764
Female66 (52.8%)59 (47.2%)
No. of family members (n = 239)a    
1–256 (58.3%)40 (41.7%)χ2 = 0.0300.082
3+67 (46.9%)76 (53.1%)
Marital status (n = 239)a    
Married/with partner77 (46.1%)90 (53.9%)χ2 = 6.3680.012
No partner/divorced or separated46 (63.9%)26 (36.1%)
Employment status (n = 238)a    
Paid worker, agriculture, home worker62 (45.3%)75 (54.7%)χ2 = 5.3370.021
Non-employed, student61 (60.4%)40 (39.6%)
Education (n = 226)a    
Primary school39 (51.3%)37 (48.7%)χ2 = 0.0350.852
>High school75 (50.0%)75 (50.0%)
Income (n = 203),∼a    
<2 million64 (50.8%)62 (49.2%)χ2 = 0.8430.358
2–<5 million34 (44.2%)43 (55.8%)
History of illness (n = 240)a    
Yes92 (51.7%)86 (48.3%)χ2 = 0.0000.992
No32 (51.6%)30 (48.4%)
Eating habits (n = 240)a,b    
0–293 (59.2%)64 (40.8%)χ2 = 9.7960.002
3–632 (38.1%)52 (61.9%)
Exercise habits (n = 238)a    
Yes42 (44.2%)53 (55.8%)χ2 = 4.3790.036
No83 (58.0%)60 (42.0%)
Smoking habits (n = 240)a    
Yes32 (53.3%)28 (46.7%)χ2 = 0.0890.765
No92 (51.1%)88 (48.9%)
Alcohol habits (n = 239)a    
Yes40 (44.9%)49 (55.1%)χ2 = 2.4140.120
No83 (55.3%)67 (44.7%)
Sleeping habits (n = 241)a    
>7 h90 (52.0%)83 (48.0%)χ2 = 0.0060.938
<6 h35 (51.5%)33 (48.5%)
Live together after disaster (n = 233)    
Separated43 (49.4%)44 (50.6%)χ2 = 0.0050.489
Live together79 (54.1%)67 (45.9%)
Change of employment after disaster (n = 206)a    
No employment or change37 (54.4%)31 (45.6%)χ2 = 1.1770.278
No change64 (46.4%)74 (53.6%)
SF-36v2    
PFc72.8 ± 26.182.2 ± 19.0t = −3.1960.002
RPc63.2 ± 27.579.8 ± 22.5t = −5.1540.001
BPc61.3 ± 24.871.3 ± 24.9t = −3.1110.002
GHc44.7 ± 18.460.2 ± 15.4t = −7.0610.001
VTc40.1 ± 23.161.2 ± 21.0t = −7.4290.001
SFc64.7 ± 27.776.9 ± 24.9t = −3.5970.001
REc63.3 ± 28.478.8 ± 23.3t = −4.6620.001
MHc45.5 ± 21.664.8 ± 20.1t = −7.1720.001
ZSDS total scorec60.8 ± 11.547.8 ± 10.7t = 9.1120.001
IES-R total scorec30.6 ± 18.622.4 ± 16.1t = 3.6530.001

Predictive sociodemographic factors on resilience

To investigate the predictive sociodemographic factors on resilience, we conducted a simultaneous multiple regression analysis using all the measured sociodemographic factors as the independent variables. Job status, eating, exercise, and drinking habits were all predicters of resilience. That is, individuals who were employed (β = 0.24, P< 0.01), had good eating and exercise habits (β = 0.17, P< 0.05; β = 0.22, P< 0.01), and drank alcohol (β = −0.17, P< 0.05) tended to show greater resilience (see Table 5).

Table 5. Predictive factors on resilience
 BSEβt-valueP-value95%CI 
  1. CI, confidence interval.

(Constant)33.3418.672 3.8450.00116.22450.458
Sex−2.2303.246−0.057−0.6870.493−8.6364.176
Age0.1380.1080.1141.2730.205−0.0760.352
Live together−0.5112.960−0.012−0.1730.863−6.3555.332
Marital status2.4173.1640.0560.7640.446−3.8288.662
Employment status9.6723.3510.2412.8860.0043.05816.286
Eating habits7.0532.9630.1732.3810.0181.20612.901
Exercise habits8.6163.0060.2172.8660.0052.68214.550
Smoking habit0.5293.3430.0120.1580.874−6.0697.172
Sleeping habit2.1243.0710.0490.6910.490−3.9398.186
Drinking habits3.9831.410.1962.8240.0051.2036.764
Education0.1993.2240.0050.0620.951−6.1656.653
Income1.6113.3440.0400.4820.630−4.9888.211

Discussion

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References

The foci of this study were: (i) to investigate the prevalence of symptoms of PTSD, depression, and general physical health among survivors of the Great East Japan Earthquake and the nuclear power plant accident; (ii) to test the predictive roles of resilience on mental and physical health; and (iii) to examine the predictive factors of resilience of citizens of Hirono.

Prevalence of PTSD and depression

Regarding the prevalence of PTSD from earthquakes, de la Fuente[33] found that 32% of his sample showed signs of PTSD 10 weeks after the earthquake in Mexico City. In Japan, 9.7% of the sample reported prevalent symptoms of PTSD 4–6 months[34] after the Great Hanshin–Awaji Earthquake and 8.9% did so at 10 months.[35] In this study, 53.5% of the participants exhibited symptoms of clinical concern for PTSD, and among those participants, 33.2% met the clinical criteria of PTSD. Furthermore, looking at the prevalence of depression, 41.1–52.3% of the sample reported symptoms of depression 2 months after an earthquake in Italy,[36] while Lima[37] reported a prevalence rate of depression of 40% 2 months after an earthquake in Ecuador. In Japan, after the Great Hanshin–Awaji Earthquake, a high overall depression rate of 34.1% (17.4% mild, 10.9% moderate, 5.9% severe) was reported. In the present study, the incidence of depression was 66.8% (33.2% mild, 19.1% moderate, 14.5% severe), which was one of the highest prevalence rates reported.

High prevalence of psychological problems may be affected by the numbers of unique regional characteristics of Hirono, Japan. The participants in this study experienced one of the biggest earthquakes ever recorded followed by the devastating effects of a tsunami. Furthermore, the participants were forced to evacuate due to rising levels of radiation coming from the nuclear power plant near Hirono. Consequently, the nuclear power plant accident caused the separation of their families, neighbors, and communities without knowing when they would be able to return to their hometown. It is important to note that Fukushima prefecture is one of Japan's most collectivistic prefectures in which support comes from families, friends, and communities as a whole.[38] Given the breakdown of their major support systems, and subsequent chronic fear related to the nuclear plant, the high prevalence of PTSD and depression is certainly anticipated.

Effects and predictive factors of resilience

As expected, the results of this study indicate that resilience is a significant buffer for depression and PTSD. Indeed, the average level of depression for individuals in this study with high resilience was, in fact, about the normal range for non-clinical samples. Furthermore, highly resilient participants' average PTSD levels also fell in the normal range. These results indicate that it is imperative to provide interventions for survivors that will enhance resilience-promoting factors in the aftermath of a disaster. Contrary to previous findings in a US study,[39] sex and age of the survivors did not predict resilience. Instead, this study showed that employment and a healthy lifestyle, such as good eating and exercise habits, were significantly associated with greater resilience. We conclude, therefore, that encouraging survivors to engage in healthy lifestyles and providing job opportunities may enhance their resilience to cope with these devastating disasters.

Interestingly, this study showed that drinking alcohol more than a couple of times per week was a significant predictor for resilience. It is important to note that culture largely influences attitudes toward drinking behavior, including frequency and volume. For instance, Shimizu et al.[40] concluded that Japanese tend to show tolerance for drinking and that drinking has important social functions and meaning, such as maintaining relationships, in comparison to those of northern European countries and the USA. In the study by Shimizu et al., only 13.6% of their sample did not drink at all, while 44.1% of the participants in this study reported that they did not drink. Therefore, drinking in this case may be an indication of getting back to their normal lives and maintaining social relationships. However, because we did not investigate the amount of alcohol they had, our claim is totally speculative.

Limitations

This study is not free from limitations. Most importantly, due to the sampling issues, the results should be cautiously interpreted. In particular, as we adopted a non-probability sampling method, it is strongly recommended not to over-generalize the findings from this study to the general population. Further, more than half of the respondents were over the age of 60. The majority of young families with school-aged children tended to move to apartments rather than into temporary housing due to availability of schools, etc. Consequently, this study may have a disproportionate rate of older respondents, potentially limiting the external validity of the findings. In addition, caution should be used to interpret the results, given that elderly individuals tend to manifest greater mental illness than younger counterparts. Further study with a more representative age range and randomly selected participants may be crucial to replicating these findings. We also have to note that some important factors (e.g. loss of family members and/or damage of properties) that may be associated with the participants' mental health were not collected and analyzed in this study. Therefore, it is strongly recommended to include such factors to further understand the effects of disasters on mental health and resilience in future studies. Finally, due to the fact that the CD-RISC has not been validated in Japanese, future studies should ensure inclusion of valid measure to assess resilience.

Conclusions

Given that different subgroups of the population are more or less likely to be affected by natural and manmade disasters, psychosocial interventions should be tailored to their unique combination of risk and protective factors. Special attention should be paid to individuals who have numerous risk factors as well as fewer protective factors to prevent further traumatization and chronic mental illness. The Great East Japan Earthquake created large-scale destruction of properties and human lives in many communities. We could not replicate the resilience-promoting factors that were previously found in other nations. Instead, we found some unique components that predicted psychological resilience. As such, further research studies are crucial to identify the protective and risk factors related to resilience because resilience-promoting factors may be different from culture to culture.

Acknowledgment

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References

This work was supported in part by grants from Junshin Gakuen University (No. 23-291-3). The authors declare no conflict of interest.

References

  1. Top of page
  2. Abstract
  3. Methods
  4. Results
  5. Discussion
  6. Acknowledgment
  7. References
  • 1
    United States Geological Survey (USGS). USGS updates magnitude of Japan's 2011 Tōhoku earthquake to 9.0. USGS. [Cited 17 June 2011.] Available from URL: http://www.usgs.gov/newsroom/article.asp?ID=2727&from=rss_home.
  • 2
    Tabuchi H. Japanese officials on defensive as nuclear alert level rises. New York Times. 13 April 2011. [Cited 17 June 2011.] Available from URL: http://www.nytimes.com/2011/04/13/world/asia/13japan.html?pagewanted=all.
  • 3
    Lystad M. Mental Health Response to Mass Emergencies: Theory and Practice. Brunner/Mazel, New York, 1988.
  • 4
    Shore J, Tatum E, Vollner W. Evaluation of mental health effects of disaster, Mount St. Helens eruption. Am. J. Public Health 1986; 76 (Suppl.): 7683.
  • 5
    Priebe S, Grappasonni I, Mari M, Dewey M, Petrelli F, Costa A. Posttraumatic stress disorder six months after an earthquake: Findings from a community sample in a rural region in Italy. Soc. Psychiatry Psychiatr. Epidemiol. 2009; 44: 393397.
  • 6
    Chou FHC, Wu HC, Chou P et al. Epidemiologic psychiatric studies on post-disaster impact among Chi-Chi earthquake survivors in Yu-Chi, Taiwan. Psychiatry Clin. Neurosci. 2007; 61: 370378.
  • 7
    Salcioglu E, Basoglu M, Livanou M. Long-term psychological outcome for non-treatment-seeking earthquake survivors in Turkey. J. Nerv. Ment. Dis. 2003; 191: 154160.
  • 8
    So-kum Tang C. Trajectory of traumatic stress symptoms in the aftermath of extreme natural disaster: A study of adult Thai survivors of the 2004 Southeast Asian earthquake and tsunami. J. Nerv. Ment. Dis. 2007; 195: 5459.
  • 9
    Atkinson RL, Atkinson RC, Smith EE, Ben DJ, Nolen-Hosk-sema S. Introduction to Psychology. Harcourt Brace College Publishers, Fort Worth, 1996.
  • 10
    Smith EE, Nolen-Hoek-sema S, Fredrickson BK, Loftus GR. Introduction to Psychology. Thomson, Tampa, FL, 2003.
  • 11
    Phifer JF. Psychological distress and somatic symptoms after natural disaster: Differential vulnerability among older adults. Psychol. Aging 1990; 5: 412420.
  • 12
    Cronkite RC, Moos RH. The role of predisposing and moderating factors in the stress-illness relationship. J. Health Soc. Behav. 1984; 25: 372393.
  • 13
    Thoits PA. Life stress, social support, and psychological vulnerability: Epidemiological considerations. J. Community Psychol. 1982; 10: 341362.
  • 14
    Moos RH. Coping Responses Inventory – Adult Form Manual. Psychological Assessment Resources, Inc., Lutz, FL, 1993.
  • 15
    Spurrell MT, McFarlane AC. Posttraumatic stress disorder and coping after a natural disaster. Soc. Psychiatry Psychiatr. Epidemiol. 1993; 28: 194200.
  • 16
    Rutter M. Resilience in the face of adversity: Protective factors and resistance to psychiatric disorders. Br. J. Psychiatry 1985; 147: 598611.
  • 17
    Wagnild G. A review of the resilience scale. J. Nurs. Meas. 2009; 17: 105113.
  • 18
    Rutter M. Developing concepts in developmental psychopathology. In: Hudziak JJ (ed.). Developmental Psychopathology and Wellness: Genetic and Environmental Influences. American Psychiatric Publishing, Washington, DC, 2008; 322.
  • 19
    Flach FF. Psychobiologic resilience, psychotherapy, and the creative process. Compr. Psychiatry 1980; 21: 510518.
  • 20
    Bonanno GA. Loss, trauma, and human resilience: Have we underestimated the human capacity to thrive after extremely aversive events? Am. Psychol. 2004; 59: 2028.
  • 21
    Pietrzak RH, Johnson DC, Goldstein MB et al. Psychosocial buffers of traumatic stress, depressive symptoms, and psychosocial difficulties in veterans of Operations Enduring Freedom and Iraqi Freedom: The role of resilience, unit support, and postdeployment social support. J. Affect. Disord. 2010; 120: 188192.
  • 22
    Gunnestad A. Resilience in a cross-cultural perspective: How resilience is generated in different cultures. J. Intercult. Commun. 2006; 11: 120.
  • 23
    Statistics Bureau. Tokyo: Ministry of Internal Affairs and Communications. 2010. http://www.stat.go.jp/. [12 screens]. [Updated 26 October 2011; Cited 17 June 2011.] Available from URL: http://www.stat.go.jp/data/kokusei/2010/kihon1/pdf/gaiyou.pdf.
  • 24
    Fire and Disaster Management Agency. Tokyo: Ministry of Internal Affairs and Communications. 2011. http://www.fdma.go.jp/Timeline. [36 screens]. [Updated 13 March 2012; Cited 17 June 2011.] Available from URL: http://www.fdma.go.jp/bn/higaihou_past_jishin_2311.html.
  • 25
    Fukuhara S. QOL assessment in outcomes research. J. Jpn. Soc. Lumbar Spine Dis. 2002; 8: 3137 (in Japanese).
  • 26
    Fukuhara S, Ware JE, Kosinski M, Wada S, Gandek B. Psychometric and clinical tests of validity of the Japanese SF-36 Health Survey. J. Clin. Epidemiol. 1998; 51: 10451053.
  • 27
    Connor KM, Davidson JR. Development of a new resilience scale: The Connor-Davidson Resilience Scale (CD-RISC). Depress. Anxiety 2003; 18: 7682.
  • 28
    Zung WWK. A self-rating depression scale. Arch. Gen. Psychiatry 1965; 12: 6370.
  • 29
    Fukuda K, Kobayashi S. A study on a self-rating depression scale. Seishin Shinkeigaku Zasshi 1973; 75: 673679.
  • 30
    Asukai N, Kato H, Kawamura N et al. Reliability and validity of the Japanese-language version of the Impact of Event Scale-Revised (IES-R-J): Four studies of different traumatic events. J. Nerv. Ment. Dis. 2002; 190: 175182.
  • 31
    Creamer M, Bell R, Failla S. Psychometric properties of the Impact of Events Scale-Revised. Behav. Res. Ther. 2003; 41: 14891496.
  • 32
    World Health Organization (WHO). Health statistics and health information systems [Internet]. WHO. [Cited 30 August 2013.] Available from URL: http://www.who.int/healthinfo/survey/ageingdefnolder/en/.
  • 33
    De La Fuente R. The mental health consequences of the 1985 earthquake in Mexico. Int. J. Ment. Health 1990; 19: 2129.
  • 34
    Okamoto K, Nakajima H, Nakajima S et al. Analysis of the risk factors for post-traumatic stress disorder in the victims of Hanshin-Awaji earthquake. Jpn. Psychosom. Med. 1998; 38: 607615.
  • 35
    Nagano O, Morimura Y. Depressive symptoms among the inhabitants of Shiya city exposed to the Great Hanshin-Awaji Earthquake. Rinsyoseishinigaku 1999; 28: 309315.
  • 36
    Maj M, Starace F, Crepet P et al. Prevalence of psychiatric disorders among subjects exposed to a natural disaster. Acta Psychiatr. Scand. 1989; 79: 544549.
  • 37
    Lima BR, Chavez H, Samaniego N et al. Disaster severity and emotional disturbance: Implications for primary mental health care in developing countries. Acta Psychiatr. Scand. 1989; 79: 7482.
  • 38
    Yamawaki N. Within-culture variations of collectivism in Japan. J. Cross Cult. Psychol. 2012; 43: 11911204.
  • 39
    Bonanno GA, Galea S, Bucciarelli A, Vlahov D. What predicts psychological resilience after disaster? The role of demographics, resources, and life stress. J. Consult. Clin. Psychol. 2007; 75: 671682.
  • 40
    Shimizu S, Kim DS, Hirota M. Drinking practice and alcohol-related problems: The national representative sample survey for Healthy Japan 21. Nihon Arukoru Yakubutsu Igakkai Zasshi 2004; 39: 189206.