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Keywords:

  • Disaster-related Psychological Screening Test;
  • earthquake survivors;
  • post-traumatic stress disorder

Abstract

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

Aims:  To predict the longitudinal course of post-traumatic stress disorder (PTSD) in survivors three years following a catastrophic earthquake using multivariate data presented six months after the earthquake.

Methods:  Trained assistants and psychiatrists used the Disaster-related Psychological Screening Test (DRPST) to interview earthquake survivors 16 years and older and to assess current and incidental psychopathology. A total of 1756 respondents were surveyed over the three-year follow-up period.

Results:  A total of 38 (9.1%) of the original 418 PTSD subjects and 40 of the original 1338 (3.0%) non-PTSD subjects were identified as having PTSD at the 3-year post-earthquake follow up. Younger age, significant financial loss, and memory/attention impairment were predictive factors of unresolved PTSD and delayed PTSD.

Conclusions:  The longitudinal course of PTSD three years after the earthquake could be predicted as early as six months after the earthquake on the basis of demographic data, PTSD-related factors, and putative factors for PTSD.

NATURAL DISASTERS, such as earthquakes and hurricanes, and man-made disasters, such as terrorism and wars, can cause mental trauma with long-lasting consequences. Post-traumatic stress disorder (PTSD) is one of the most common psychiatric disorders in victims of natural disasters1 and is continuing to gain attention in trauma outcome research. According to the DSM-IV diagnostic criteria, PTSD has three core psychopathologies: (i) re-experience; (ii) numbness and avoidance; and (iii) hyper arousal. The DSM-IV diagnostic criteria for PTSD allow clinicians to specify whether or not the disorder is chronic (if the symptoms have lasted three months or more) or exhibits delayed onset (if the onset of the symptoms was six months or more after the stressful event). In a systemic review, Andrews et al. found that delayed-onset PTSD in the absence of any prior symptoms was rare, whereas delayed onsets that represented exacerbations or reactivations of prior symptoms accounted on average for 38.2% and 15.3%, respectively, of military and civilian cases of PTSD.2 Frueh et al. interviewed 747 military veterans and achieved a similar result.3

Earthquake is one of the major natural disasters of the contemporary era.4 Risk factors for PTSD (such as demographic data, psychological factors and psychiatric symptoms) and post-trauma social resource factors have been studied by some researchers.

Demographic data

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

Some studies examining gender differences suggest that female subjects are more likely to develop PSTD than male subjects.5–8 A possible explanation is the specific reactions resulting from feminine characteristics to the traumatic event.9 Old age has been associated with increased risk of developing PTSD in previous studies.10,11 However, a recent study found contradictory results.8 In a review article, Smid et al. found that military combat exposure, Western cultural background, and lower cumulative PTSD incidence were associated with delayed PTSD, and that delayed PTSD represents exacerbations of prior symptoms.12

Psychological factors and psychiatric symptoms

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

Meyer et al. indicated that some psychiatric symptoms and disorders are risk factors for PTSD.13 Some personality traits, like neuroticism and introversion, are associated with risk of PTSD.11,14 Other studies showed that some psychiatric disorders may be predictive of chronic PTSD.15,16 Some studies have examined the long-term course of PTSD. A longitudinal analysis of the mental health of school children after the Great Hanshin Awaji earthquakes indicated that some survivors' psychological reactions emerge early and disappear early, by two years after the disaster; this is contrary to findings of other studies.17 Lazaratou et al. found that the more PTSD symptoms that emerged during the first 6 months after the earthquake, the more they impacted the victims' lives 50 years after the event.8 Koren, Arnon, and Klein18 found that the best predictor of recovery from chronic PTSD was the initial level of post-traumatic reaction immediately after the accident. However, few data are available on the long-term effects caused by the disaster.4

Andrews et al. retrospectively interviewed 142 veterans and found that immediate-onset and delayed-onset PTSD described similar amounts of trauma exposure, but those in the delayed-onset group reported significantly less peritraumatic dissociation, anger, and shame. Both groups were more likely to report major depressive disorder and alcohol abuse prior to PTSD onset than the no PTSD group; and delayed onsets involved more general stress sensitivity and a progressive failure to adapt to continued stress exposure.19

Post-trauma social resource factors

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

Inadequate social support after the trauma adds to the risk of developing PTSD.1,20 Higher levels of post-disaster life events are also related to the risk of PTSD.21 The more social stressors (such as economic or marital disruption, relocation, death of an intimate partner, and other loss problems), the more risk of developing PTSD.

Hobfoll's conservation of resources model has been well supported by previous studies on natural disasters.22 According to Hobfoll's conservation of resources stress theory,4 resource loss is an important determinant of individual stress and physical and mental health including PTSD. Brewin et al.23 also found that the effect size of all the risk factors was modest, but factors operating during or after the trauma, such as trauma severity, lack of social support, and additional life stress, had somewhat stronger effects than pre-trauma factors. Thus, one of the present study purposes is to find the association of the course of PTSD with relevant social resource factors.

We tried to predict the longitudinal course of PTSD in earthquake survivors three years after the disaster using multivariate data including demographic data, psychological factors and PTSD symptoms, and post-trauma social resource factors presented at six months.

METHODS

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

Subjects

The Chi-Chi earthquake, so named because of the location of the epicenter near Chi-Chi township in Nantou County, Taiwan, measured 7.3 on the Richter scale and struck in the early morning of 21 September 1999. More than 10 000 people died or were injured as a result of the earthquake.24 Yu-Chi township was selected for this population survey. The sampling is cluster sampling, not random sampling, as random sampling for selecting the study site is sometimes difficult in a disaster situation. Some predict higher death rates near the epicenter of the earthquake. Although our site was only 17 km from the epicenter, residents typically managed to escape from buildings when the earthquake struck because of the typical house architecture. Consequently, unlike in other townships, there were relatively few deaths (less than 20) and injuries in Yu-Chi township compared to other townships.24 However, residents still suffered from several physical injuries and loss of resources (such as house damage, etc.). Those respondents who sought medical services due to physical injuries or medical problems after the earthquake were more at the risk of PTSD.5

In the first survey conducted six months after the earthquake,24 2107 respondents agreed to participate in a 3-year follow-up survey. Two and half years later (3 years after the earthquake), 1756 (83.3%) of the 2107 respondents were followed up. There were no significant characteristics of the village population as a whole or the respondents.5 Of the 351 participants who were not followed up, 35 (10.0%) had died, 150 (42.7%) had moved away during the follow-up period, 30 (8.5%) lived outside the township of study, and 136 (38.7%) could not be found after we visited their homes three times.

Instrument

The Disaster-related Psychological Screening Test (DRPST) is a list of questionnaires designed by five psychiatrists and two public health professionals. It is used to collect background information on residents (Part I) and to check for psychological symptoms resulting from disaster-related psychiatric disorders (including 17 items of PTSD and nine items of major depressive episode [Part II]) according to DSM-IV criteria. The test is modified to account for local language grammar and a seven-symptom scale was selected for PTSD screening. Scores of 4 or higher on the PTSD scale were used to define a group of survivors with PTSD, which has been validated by previous studies.20,25 Compared with PTSD diagnosed by psychiatrists using the Mini-International Neuropsychiatric Interview, its positive predictive value was 97.2% and its negative predictive value was 97.4%.25

Putative risk factors for PTSD among the survivors were also included in Part I of the DRPST 33-item questionnaire,20,24 which included eight putative risk factors for PTSD: (i) household destruction; (ii) physical injury during the time of the earthquake or when the survey was taken; (iii) loss or injury of a family member; (iv) emotional problems due to the loss of a family member; (v) decrease in social activities; (vi) losing one's job due to the earthquake; (vii) significant financial loss; and (viii) memory/attention impairment. The final item consisted of the sum of the following scores: difficulty in recalling things, difficulty in finding appropriate words to express oneself, forgetting where one put something, concentration impairment, and forgetting to turn off a tap or burner (all items scoring from 1 to 4, from never to often).

Procedure

The psychiatric team conducted a two-week psychiatric training program to train six research assistants who used the DRPST to screen for PTSD among the respondents. The details of this training program have been documented previously.24,25 The study team got the list of family members and the addresses of all the residents from the local government. By door-knocking, the research assistants then used the questionnaires to collect basic information on PTSD-related symptoms and the putative risk factor information from all residents 16 years of age or older. Because 26.9% of the respondents had less than a primary school education, the assistants had to explain the questionnaires and help respondents complete them. A goal of the research project was to explain it in detail before we invited the survivors to join the study and make sure that they would like to join the three-year follow-up survey. Written informed consent forms were obtained from all participants, together with approval from the institutional review board of Kai-Suan Psychiatric Hospital, the local government authorities, and the Taiwanese Department of Health.

Data analysis

Respondents were divided into four groups according to the progression of their PTSD: the recovering group (respondents who had PTSD six months after the earthquake and did not have PTSD three years after), the unresolved PTSD group (respondents who had PTSD both six months and three years after the earthquake), the persistently healthy group (respondents who did not have PTSD six months or three years after the earthquake), and the delayed-PTSD group (respondents who did not have PTSD six months after the earthquake, but who had PTSD three years after).

We compared the unresolved group with the recovery group to explore the risk factors for unresolved PTSD and the delayed onset group with the persistent health group to explore the risk factors for onset of delayed PTSD. We used t-tests to determine whether continuous variables were associated with change in the longitudinal course of PTSD. χ2 analysis was employed for testing the associations of categorical variables. All tests performed were two-sided, with a significance level of α = 0.05. Variables that were associated with the change in the longitudinal course of six-month PTSD at a significant level (P < 0.15) were incorporated as predictors into a multiple logistic regression model. The goodness of fit for the regression models was tested using Hosmer–Lemeshow. spss version 10.0 software was used for all statistical analyses.

RESULTS

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

The average age of the 1756 respondents was 54.5 ± 16.7 (range: 16–98); 54.4% were women (male, 801; female, 905). The educational level was predominantly primary school or below (64.5%). Most respondents (77.5%) were married. Of the 418 participants with PTSD at intake, 38 (9.1%) were unresolved at the follow-up interval. The 418 PTSD-positive participants who were older at intake seemed to be more likely to recover from PTSD. Six of the eight putative risk factors were significantly associated with unresolved PTSD (Table 1). Female subjects and three of 12 PTSD-related symptoms were significantly associated with unresolved PTSD (Table 2). Furthermore, 40 of the 1338 (3%) participants who did not have PTSD at intake had PTSD at follow up (delayed PTSD). Among the 1338 PTSD-negative participants at intake, female gender was a risk factor for developing delayed PTSD. Four of the eight putative risk factors were significantly associated with delayed onset PTSD (Table 3). Of 12 PTSD-related symptoms, two were significantly associated with delayed PTSD at follow up (Table 4).

Table 1.  The association of longitudinal course of six-month PTSD-positive participants with demographic variables, and putative risk factors of the participants
 0.5-year PTSD-positive n = 418
3-year PTSD-negative n = 3803-year PTSD-positive n = 38 (Unresolved)OR95%CITotal
n%n%n%
  • *

    P < 0.05;

  • **

    P < 0.01;

  • ***

    P < 0.001

  • Female = 1 vs male = 0; single = 1, married = 2, divorced & other = 3;§ junior high school or above = 1 vs primary school = 0; yes = 1 vs no = 0. Note: The statistically non-significant PTSD-related symptoms were omitted.

  • CI, confidence interval; OR, odds ratio; NA, not applicable; PTSD, post-traumatic stress disorder.

Demographic data
 Gender
  Female24190.3269.71.250.61–2.5626763.9
 Age (years)
 Mean ± SD59.53 ± 14.154.58 ± 15.640.980.96–1.00*NANA
 Current marital status
  Married32991.4318.60.610.13–2.8436086.1
  Divorced & Other3888.4511.60.860.15–4.944310.3
 Education§
  Junior high school or above9687.31412.71.730.86–3.4711026.3
Putative risk factors for PTSD
 Household destruction
  Yes16687.82312.21.981.00–3.91*18945.2
 Being physically injured
  Yes3183.8616.22.110.82–5.44378.9
 Loss or injury of a family member
  Yes4683.6916.42.251.00–5.06*5513.2
 Emotional problems due to the loss of family member
  Yes2488.9311.11.270.36–4.44276.5
 Decrease in social activities
  Yes5483.11116.92.461.15–5.25*6515.6
 Losing one's job due to the earthquake
  Yes5481.81218.22.791.33–5.85**6615.8
 Significant financial loss
  Yes9076.92723.17.913.77–16.58***11728.0
 Memory/attention impairment (5 to 20, from no to severe)10.60 ± 4.1112.71 ± 3.581.131.04–1.22**10.79 ± 4.11
Table 2.  The association of the longitudinal course of six-month PTSD-positive participants with the comparison of three-year PTSD-positive and -negative participants
 0.5-year PTSD-positive n = 418
3-year PTSD-negative n = 3803-year PTSD-positive n = 38 (Unresolved)OR95%CITotal
n%n%n%
  1. * P < 0.05;**P < 0.01; ***P < 0.001. yes = 1 vs no = 0.

  2. Note: The statistically non-significant PTSD-related symptoms were omitted.

  3. CI, confidence interval; OR, odds ratio; PTSD, post-traumatic stress disorder.

0.5-year PTSD-related symptoms
 Experienced threat to life
  Yes7685.41314.62.081.02–4.26*8921.3
 Distressing dreams of the event
  Yes15490.1179.91.190.61–2.3317140.9
 Reliving the experience
  Yes24288.63111.42.531.08–5.89*27365.3
 Efforts to avoid thoughts and feelings associated with the trauma
  Yes15392.2137.80.770.38–1.5616639.7
 Efforts to avoid activities, places, people that arouse recollections of the trauma
  Yes10592.197.90.810.37–1.7811427.3
 Diminished interest in activities
  Yes28890.6309.41.200.53–2.7131876.1
 Feeling detachment from others
  Yes6683.51316.52.471.20–5.09*7918.9
 Difficulty falling or staying asleep
  Yes25989.33110.72.070.89–4.8329069.4
 Irritability or outbursts of anger
  Yes27190.03010.01.510.67–3.3930172.0
 Difficulty concentrating
  Yes33790.3369.72.300.53–9.8837389.2
 Hypervigilance
  Yes36291.2358.80.580.16–2.0739795.0
 Exaggerated startled response
  Yes36190.7379.31.950.25–14.9639895.2
Table 3.  The association of longitudinal course of six-month PTSD-negative participants with demographic variables, and putative risk factors of the participants
 0.5-year PTSD-negative n = 1338
3-year PTSD-negative n = 12983-year PTSD-positive n = 40 (Delayed onset)OR95%CITotal
n%n%n%
  1. * P < 0.05;**P < 0.01; ***P < 0.001.

  2. Female = 1 vs male = 0; single = 1, married = 2, divorced & other = 3;§ junior high or above = 1 vs primary school = 0; yes = 1 vs no = 0. Note: The statistically non-significant PTSD-related symptoms were omitted.

  3. CI, confidence interval; NA, not applicable; OR, odds ratio; PTSD, post-traumatic stress disorder.

Demographic data        
 Gender        
  Female66095.9284.12.261.14–4.47*68851.4
 Age        
  Mean ± SD54.03 ± 17.2750.08 ± 19.620.990.97–1.01NANA
 Current marital status        
  Married107597.2312.80.790.27–2.27110682.7
  Divorced & Other11495.854.21.200.31–4.571198.9
 Education§        
  Junior high school or above49396.1203.91.630.87–3.0751338.3
Putative risk factors for PTSD        
 Household destruction        
  Yes47195.9204.11.760.94–3.3049136.7
 Being physically injured        
  Yes4495.724.31.500.35–6.42463.4
 Loss or injury of a family member        
  Yes9494.066.02.260.93–5.521007.5
 Emotional problems due to the loss of family member        
  Yes4183.7816.37.673.33–17.66***493.7
 Decrease in social activities        
  Yes15890.8169.24.812.50–9.25***17413.0
 Losing one's job due to the earthquake        
  No114397.1342.9NANA117788.0
  Yes11596.363.71.30.54–3.1516112.0
 Significant financial loss        
  Yes25693.8176.23.011.58–5.72***27320.4
 Memory/attention impairment (5 to 20, from no to severe)8.98 ± 3.5512.08 ± 4.861.231.13–1.33***9.07 ± 3.63
Table 4.  The association of the longitudinal course of six-month PTSD-negative participants with the comparison of three-year PTSD-positive and -negative participants
 0.5-year PTSD-negative n = 1338
3-year PTSD-negative n = 12983-year PTSD-positive (Delayed onset) n = 40OR95%CITotal
n%n%n%
  1. * P < 0.05; ** P < 0.01;***P < 0.001. yes = 1 vs no = 0.

  2. Note: The statistically non-significant PTSD-related symptoms were omitted.

  3. CI, confidence interval; OR, odds ratio; PTSD, post-traumatic stress disorder.

0.5-year PTSD-related symptoms
 Experienced threat to life
  Yes4994.235.82.070.62–6.94523.9
 Distressing dreams of the event
  Yes10299.011.00.300.04–2.211037.7
 Reliving the experience
  Yes21796.483.61.250.57–2.7422516.8
 Efforts to avoid thoughts and feelings associated with the trauma
  Yes8296.533.51.200.36–3.98856.4
 Efforts to avoid activities, places, people that arouse recollections of the trauma
  Yes7098.611.40.450.06–3.32715.3
 Diminished interest in activities
  Yes10395.454.61.660.64–4.321088.1
 Feeling detachment from others
  Yes3391.738.33.110.91–10.59362.7
 Difficulty falling or staying asleep
  Yes22093.2166.83.271.71–6.25**23617.6
 Irritability or outbursts of anger
  Yes21197.262.80.910.38–2.1921716.2
 Difficulty concentrating
  Yes30596.8103.21.090.53–2.2531523.5
 Hypervigilance
  Yes44296.5163.51.290.68–2.4645834.2
 Exaggerated startled response
  Yes54795.8244.22.061.08–3.91*57142.7

Prediction model: When forward stepwise logistic regression analysis was applied to the uncontrolled data, significant associations were found between unresolved PTSD and ‘younger age’, ‘being physically injured’, ‘significant financial loss’, ‘memory/attention impairment’, and ‘reliving the experience’ (Table 5).

Table 5.  Regression models for the prediction of unresolved PTSD and onset of delayed PTSD
 Unresolved PTSDOnset of delayed PTSD
Adjusted odds95%CIAdjusted odds95%CI
  • *

    P < 0.05;

  • **

    P < 0.01;

  • ***

    P < 0.001.

  • yes = 1 vs no = 0.

  • AUC, area under the receiver–operator characteristic curve; CI, confidence interval; NS, not significant; PTSD, post-traumatic stress disorder.

Demographic data    
 Age0.960.93–0.98**0.970.95–0.99**
Putative risk factors for PTSD    
 Being physically injured3.051.06–8.78*NS
 Emotional problems due to the loss of a family memberNS4.231.61–11.15**
 Decrease in social activitiesNSNS2.451.15–5.22*
 Significant financial loss7.163.30–15.55***2.271.13–4.58*
 Memory/attention impairment (from never to often = 5–20)1.211.09–1.34***1.241.13–1.36***
Six-month PTSD-related symptoms    
 Reliving the experience2.981.20–7.44*NS
 Difficulty falling or staying asleepNS2.561.24–5.27*
 Exaggerated startled responseNS2.041.01–4.10*
Goodness of fit0.290.22
AUC with the 95%CI (in brackets)0.820(0.739–0.902)0.821(0.752–0.890)

The other logistic regression showed that ‘younger age’, ‘emotional problems due to the loss of a family member’, ‘decrease in social activities’, ‘significant financial loss’, ‘memory/attention impairment’, ‘difficulty falling or staying asleep’, and ‘exaggerated startled response’ were independent predictors of onset of delayed PTSD (Table 5).

DISCUSSION

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

In this study, 418 (23.8%) of the participating earthquake survivors exhibited PTSD six months after the earthquake. This estimated rate of PTSD is consistent with previous reports on PTSD,1,26–28 and the findings support the idea that PTSD is a common response after exposure to a natural disaster.15,29,30

After adjusting for other factors, older age was a protective factor for unresolved and delayed PTSD, which is in accordance with a previous study finding that previous exposure to traumatic events may allow some elderly persons to cope more effectively with subsequent trauma, and increased age at the time of a natural disaster trauma may even offer protection against the disorder.31

These eight putative factors are peritraumatic and post-traumatic factors, not prior characteristics. They are not only the predictors of PTSD23,32 but also predictors of unresolved and delayed PTSD in our studies. The type of event, such as injury, is a strong predictor of levels of intrusive and avoidance symptoms after a traumatic event33 and our study suggested that ‘being physically injured’ was also a predictor for unresolved PTSD. ‘The loss or injury of a family member’ did not predict unresolved PTSD, nor did it predict delayed PTSD. However, ‘emotional problems due to the loss of a family member’ was a predictor of delayed PTSD. Some participants were less affected by the death of their family member because they did not live together and they did not have a close relationship,34 so ‘the loss of a family member’ did not predict the course of PTSD. Instead, ‘emotional problems due to the loss of a family member’ was a predictor of delayed PTSD. ‘Decrease in social activities’ was significantly associated with both unresolved and delayed PTSD and it was also a predictor of delayed PTSD. An important finding in this field study was that those suffering from severe psychiatric illness did not ask for help by themselves; instead, they stayed at home and did not participate in social activities. ‘Losing one's job due to the earthquake’ was significantly associated with unresolved PTSD, but after adjusting all other associated factors, it was not an independent predictor. Only those who experienced significant financial loss developed unresolved and delayed PTSD. Financial loss from earthquakes was associated with higher distress and the presence of PTSD symptoms20,24,35 and it was a predictor of unresolved and delayed PTSD in our study.

Yehuda et al.36 suggested in a previous study that PTSD subjects showed impairments in learning and short-term and delayed retention compared to unexposed subjects; survivors without PTSD did not. The most robust impairment observed in PTSD was in verbal learning, which may be a risk factor for, or consequence of, chronic PTSD. Studies with animals have shown that the hippocampus, a brain area involved in learning and memory, is sensitive to stress. Kitayama et al.37 found smaller hippocampal volume in adult subjects with chronic PTSD in a meta-analytic study. This is in accordance with our finding that memory/attention impairment is not only a predictor of unresolved PTSD but also a predictor of delayed PTSD.

Brauchle38 suggests that persistent dissociation is a main predictor of chronic PTSD in disaster workers. One study on veterans suggests that the avoidance cluster, especially its numbing symptoms, was most strongly associated with chronic PTSD, and less strongly but also significantly associated was the hyper arousal cluster.39 However, ‘reliving the experience’, a symptom of experiencing cluster, is the only PTSD-related symptom to predict unresolved PTSD in our study. Many participants told us that the aftershocks or even the sound of a passing truck would cause panic for them, which could be why we found different PTSD-related symptoms as predictors of unresolved PTSD. Carty, O'Donnell, and Creamer40 suggested that clinicians should consider subthreshold diagnoses as potential risk factors for delayed-onset PTSD, and we found that ‘difficulty falling or staying asleep’ and ‘exaggerated startled response’ were important predictors of delayed PTSD.

Because the survivors received government support if the earthquake destroyed their houses, 38.7% of the respondents claimed that their houses were destroyed, although in some cases their houses looked fine to our research assistants. This β error (type II error) caused the ‘household destruction’ to not be associated with unresolved PTSD or delayed PTSD.

The present findings indicate that clinical evaluation of individuals exposed to an earthquake should include specific evaluation of PTSD symptoms and putative risk factors for PTSD. Early mental health intervention may serve to prevent the chronicity of PTSD or the development of delayed PTSD. Because the occurrences of unresolved and delayed PTSD in earthquake survivors is rare, it is important to predict the high-risk group so that limited resources may be used for intervention.

However, there are two limitations to this study. First, we used a valid screening instrument rather than a diagnostic interview. Second, we might have mistaken the cases that had recovered from delayed PTSD before the secondary survey for persistently healthy cases, and those who were identified as being in the unresolved PTSD group could have been in remission for a while during the post-earthquake 3-year follow-up interval. We might have mistaken those cases that had recovered from delayed PTSD prior to the secondary survey for persistently healthy cases, and those who were identified as being in the unresolved PTSD group could have been in remission for a while during the post-earthquake three-year follow-up period. The recovered cases represent those in both partial and full recovery, and the delayed cases among them do not actually represent delay in the onset of PTSD, but rather slowness in achieving full diagnostic criteria.

CONCLUSIONS

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

The longitudinal course of PTSD three years after an earthquake may be predicted as early as six months following the disaster on the basis of psychosocial predictors.

Younger age, significant financial loss, and memory/attention impairment were predictive factors of these two predictive regression models. Thus, early evaluation, social resource support and treatment of PTSD among high-risk earthquake survivors may be important components of public health efforts targeting job offers and mental health rehabilitation in the first few months after an earthquake, thereby helping victims to recover from PTSD, and prevent the onset of delayed PTSD.

ACKNOWLEDGMENTS

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES

This study was supported by grants from the National Science Council, Republic of China (NSC 93-2625-Z-280-001).

REFERENCES

  1. Top of page
  2. Abstract
  3. Demographic data
  4. Psychological factors and psychiatric symptoms
  5. Post-trauma social resource factors
  6. METHODS
  7. RESULTS
  8. DISCUSSION
  9. CONCLUSIONS
  10. ACKNOWLEDGMENTS
  11. REFERENCES