Psychiatry Research 228 (2015) 598–605

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Relationships between posttraumatic stress disorder (PTSD), dissociation, quality of life, hopelessness, and suicidal ideation among earthquake survivors Osman Ozdemir a, Murat Boysan b, Pinar Guzel Ozdemir a,n, Ekrem Yilmaz a a b

Yüzüncü Yıl University, Department of Psychiatry, Dursun Odabas Medical Center, Van, Turkey Yüzüncü Yıl University, Department of Psychology, Faculty of Arts, Van, Turkey

art ic l e i nf o

a b s t r a c t

Article history: Received 2 December 2014 Received in revised form 10 April 2015 Accepted 3 May 2015 Available online 10 June 2015

Researches have demonstrated that Posttraumatic stress disorder (PTSD) is one of the most common stress reactions in the face of disasters and significantly associated with a broad range of trauma-induced sequelaes including anxiety, depression, suicidality as well as functional impairments. To date, though many aspects of risk factors with respect to the development and maintenance of PTSD have been addressed, mediating role of dissociation has received relatively less attention. In the present study, we examined relations of PTSD with quality of life, hopelessness, suicidal ideation, and mediational effect of pathological dissociation in these connections. 583 subjects most of whom experienced a severe earthquake participated in the study after two years of the disaster. We found that being female, being single, earthquake exposure, and having greater suicidal ideation were significant predictors of PTSD symptom severity. Role-Physical, Bodily-Pain, General Health and Role-Emotional subscales of the SF-36 were inversely associated with PTSD symptom severity. Pathological dissociation significantly mediated the substantial associations between predictors and PTSD symptom clusters. Chronic dissociation appears to put trauma exposed individuals in jeopardy of prolonged posttraumatic reactions by mediating the negative influences of risk factors in the face of experienced earthquake. & 2015 Elsevier Ireland Ltd. All rights reserved.

Keywords: Posttraumatic syndrome Dissociative disorders Depression Suicidality Well-being Disability

1. Introduction Epidemiological studies have shown that exposure to disasters i.e. earthquakes, floods, or hurricanes etc. are not rare among people and result in a broad range of mental and physical health consequences (Norris et al., 2002). Posttraumatic stress disorder (PTSD) is one of the most common stress reactions and presumably the most debilitating condition in case of trauma exposure, specifically disasters (Galea et al., 2005). Most individuals exposed to aversive life events experience a natural recovery process in the aftermath of the trauma and emotional regulation comes back to a level prior to the incident. Nevertheless, a substantial minority fail to extinguish eliciting various stress responses that perpetuate trauma-induced acute reactions in chronic suffering from severe symptoms, particularly PTSD (Breslau, 2002; Kessler et al., 1995). Although defining the construct of dissociative phenomena is a matter of various debates because of its multifaceted characteristics, trauma-induced dissociation can be defined as a disruption in the

n Correspondence to: Yüzüncü Yıl University, Faculty of Medicine, Department of Psychiatry, Van 65200, TURKEY. Tel.: þ 90 4322150474, fax: þ 90 4322168352. E-mail address: [email protected] (P. Guzel Ozdemir).

http://dx.doi.org/10.1016/j.psychres.2015.05.045 0165-1781/& 2015 Elsevier Ireland Ltd. All rights reserved.

usually integrated functions of mental processes including sense perceptions, thoughts, feelings, experiences, and memories (DePrince and Freyd, 2007). Significant linkages between the trauma and dissociation have also been well-established. Research has shown that dissociative symptoms have an important role in the development and maintenance of posttraumatic stress disorder (PTSD) (Galatzer-Levy et al., 2011; Stein et al., 2013; Wolf et al., 2012). Nonetheless, cooccurring dissociation is not peculiar to PTSD rather a broad range of dissociative symptomatology could be commonly observed among patients with other psychiatric disorders and even in general population (Giesbrecht et al., 2004; Maaranen et al., 2005; Mulder et al., 1998). Patients with dissociative symptoms have significantly higher rates of comorbid psychiatric conditions including depression, borderline personality disorder, and self-mutilation and suicide attempts (Ebrinc et al., 2008; Maaranen et al., 2005; Zoroglu et al., 2003). Also, it has been consistently demonstrated that dissociative experiences were associated with impaired quality of life such as physical and social functioning (Mitchell et al., 2012). Bremner (1999) proposed a dualistic model of posttraumatic reactions is that psychological manifestations in response to traumatic events can be best understood by grouping posttraumatic syndrome into two lines: one predominantly dissociative and the other characterized by hyperarousal states. Experiencing

O. Ozdemir et al. / Psychiatry Research 228 (2015) 598–605

dissociative symptoms during the adverse events strongly predicts latter onset of persistent PTSD (Friedman, 2013; Ozer et al., 2003) and dissociative symptoms such as numbing are a necessary condition for acute and posttraumatic stress disorder diagnosis in DSM-5 (American Psychiatric Association, 2013). Due to the stress–diathesis model of dissociation, dissociative mechanisms are implicated in either buffering stress-related extreme responses or disrupting affect regulation (Butler et al., 1996). Briere et al. (2005) submitted a distinction between peritraumatic and chronic pathological dissociation that, in comparison to the former, the latter was likely to represent a more pathological subtype of dissociation with worse psychological outcomes. Recent advances in PTSD research have provided supportive evidence for that dissociative symptomatology central to PTSD; whereas a sizable minority of individuals with persistent PTSD at about 30% seem to have a tendency to elicit more severe dissociative symptoms relative to the other subset of PTSD patients experiencing primarily hyperarousal states with relatively low dissociative inclination in response to reminders of trauma memory (Lanius et al., 2012). Moreover, the premise that dissociative phenomena convey both buffering and maladaptive effects among trauma exposed person was plainly demonstrated in a representative sample by Boysan (2014) that normal dissociation characterized by lower levels of dissociative experiences was negatively associated with measures of detrimental affective states; on the other extreme, greater levels of dissociative symptomatology was a significant predictor of elevations in affective symptoms. Over and above, pathological dissociation was not only a significant antecedent for persistent PTSD but also a mediator of significant associations of PTSD symptoms with other predictors as a risk factor (Kadak et al., 2013; Özdemir et al., In press). In the epidemiological studies of psychopathology, PTSD has exhibited an excessively discrete pattern of comorbidity relative to other psychiatric disorders and consistently detected to be cooccuring with other nosological entities to an extent to a higher of 92% (Keane et al., 2007). Significant linkages between PTSD and suicidal behaviors have long been recognized and an increase in research interest focusing on these relation has been carried on. Comorbid psychiatric conditions have been found to be conferring PTSD affected people at higher risk of suicidality across different populations, such as war veterans, survivors of disasters, victims of childhood and/or adult trauma (Krysinska and Lester, 2010; Panagioti et al., 2009; 2012). Some authors have postulated that traumatization result in disruption of basic psychobiological constructs that constitute personality (Hulette et al., 2011; Mauritz et al., 2013). These formulations suggest that traumatized individuals could exhibit behavioral problems, such as impulsivity, aggression, substance abuse, and self-injurious acts, as well as internalization problems including symptoms of depression and anxiety (Stein et al., 2013). In addition, commonly found was specifically major depression which seems to have a central role in a tendency to suicidal behaviors. Leiner et al. (2008) evidenced for mediational influence of comorbid depressive disorder in accounting the substantial relations between suicidal ideation and PSTD. A comprehensive meta-analysis put forth a series of considerable suggestions that significant correlates of PTSD were suicidal ideation and suicidal behaviors rather than completed suicides, and these relations were sustained irrespective of subtypes of traumatic experiences and of samples recruited from either psychiatric or community populations (Panagioti et al., 2012). Despite suicide has long being a matter of intense interest and the extensive clinical and epidemiological literature, there are still huge gaps in our understanding of factors associated with suicidality and suicidal thought (Silverman, 2011). To the best of our knowledge, suicidality may be a relatively stable vulnerability for some individuals and unlike suicidal behaviors, suicidal ideation

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by its own may be a specific cognitive susceptibility factor for development of psychopathology rather than co-occuring with psychopathology, such as depression or PTSD. Poor problem solving capabilities, greater impulsivity (Windfuhr and Kapur, 2011), and deficiencies in interpersonal skills, conceptualized as burdensomeness and thwarted relatedness (Ribeiro and Joiner, 2011), have been suggested to be the hallmark features of suicidal individuals. Suicidal behavior is one of pathological manifestations which represents incapability in dealing with stressful situations coupled with emotional regulation deficits. General coping deficiencies in conjunction with emotional dysregulation may lead to both a failure in extinguishing acute stress responses and suicidal behaviors along with the psychopathology in the face of traumatic events. Turning to higher order cognitive information processing in suicide, the perception of defeat and entrapment are speculated to be significant correlates of suicidal behaviors (Johnson et al., 2008) which seem reminiscent of the conceptualization of mental defeat in the cognitive model of PTSD proposed by Ehlers and Clark (2000). Overlapping cognitive mechanisms in suicide and PTSD still remain elusive and need further investigations. To date, several models have been proposed to explain the relationship between dissociation, and self-destructive behaviors that are important in suicide attempts. First, self mutilation might be related to regulate overwhelming discomfort of dissociative experiences, sensations, emotions or feelings resulting from immature and maladaptive coping strategies (Chang et al., 2010). Second, dissociative mechanisms may be upholding the pain threshold and pain tolerance during the self-injury behaviors (Orbach, 1994). Third, dissociative symptoms often accompany to psychiatric disorders, particularly major depression, and borderline personality disorder in which higher rates of suicidal behaviors are observed (Chang et al., 2010; Grabe et al., 1999; Klonsky and Moyer, 2008). Although, suicidal thoughts and proneness to suicidal behaviors generally suggested to be a function of mood regulation problems and psychopathology, to the best of our knowledge, these relations are likely to be reciprocally determined that suicidality may also be an important antecedent of mood symptoms and self-regulation problems. In a preliminary study, Selvi et al. (2010) demonstrated that, by using multi-sample path modeling, suicidal ideation was not predicted by depressive symptomatology but rather depressive symptoms were a product of suicidal ideation. In this vein, suicidality may be the antecedent of PTSD as a function of mediational effect of pathological dissociation. In a recent study conducted amongst a representative community sample, Sareen et al. (2007) plainly provided convincing evidence for that PTSD remains a significant predictor of physical health problems after controlling for socio-demographic features and other mental disorders. PTSD was also predictive of suicide attempts, poor quality of life, and short- and long-term disability after adjusting for socio-demographic factors, mental disorders, and severity of physical disorders. Previous studies have consistently reported poor health status and functional impairment among disaster survivors. Lai et al. (2004) examined the differences in a set of demographic and clinical features between full, partial and non-PTSD groups after 10 months of a severe earthquake in Taiwan and found that individuals with either full or partial PTSD reported significantly greater levels of suicidality, general psychopathology, disability; and impaired well-being relative to individuals with non-PTSD. Injured victims of earthquake reported higher levels of PTSD symptoms compared to individuals with no injury due to the disaster (Kuo et al., 2007). Six months after the devastating floods and mudslides in Mexico, acute PTSD reactions were found to mediate the relations between disaster exposure and physical health problems in a sample of adults. Regardless of whether physical health was medically

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verifiable, subjective health was inversely associated with PTSD symptom severity (Norris et al., 2006). In October 2011, an earthquake with a magnitude of 7.2 struck to Van Province in the eastern part of Turkey and caused severe damage. A great many aftershocks occurred after the earthquake and many people sought help in mental health services. In the present study conducted 2 years after the earthquake, our utmost aim was to examine the relations of PTSD symptom clusters with demographic characteristics, dissociation, quality of life, hopelessness, and suicidal ideation among a community sample, most of which experienced the disaster. The current study differentiates from prior investigations in several ways that in the literature, to date, various strands of research has partially focused on such relations in PTSD and moderately addressed these issues among individuals who experienced severe disasters. Given the variables of suicidality and dimensions of health status, previous surveillance has often been designed with such a formation of investigating co-occurrence of suicidality and health problems with PTSD or possible influence of posttraumatic syndromes on these conditions as outcomes. Moreover, as mentioned above, it appears that specifically the role of depression in PTSD symptom severity in response to traumatic experiences in disasters has been widely examined. However, potential influence of dissociation central to PTSD pathology has been increasingly recognized in recent advances but received less attention specifically in the epidemiology of disasters. In the present work, we put forth several hypothesis: (i) as the perceived symptom severity and metaworry such as anxiety sensitivity is a risk factor for persistent PTSD (Kadak et al., 2013; Taylor, 2009), co-occurring mental and physical health problems such as depression, poor quality of life, and disability would significantly contribute to persistence of PTSD; (ii) individuals who were more prone to pathological dissociation would report more deteriorations in physical and mental health; and (iii) pathological dissociation would be not only predictive in PTSD symptom severity but also would mediate the relations between risk factors and PTSD.

2. Methods 2.1. Participants Participants were 611 subjects recruited from Van, Turkey where was hit by a 7.2 magnitude earthquake on October 23rd, 2011. Due to missing data, 28 subjects were excluded from the analysis that the final sample consisted of 583 participants (428 male; 73.4%). Their mean age was 24.9 years (S.D. ¼ 6.5) and age of the sample ranged between 17 and 67 years. 261 participants (44.8%) experienced the earthquake. 71 participants had a psychiatric disorder (12.2%), 40 participants (6.9%) reported family psychopathology in their first degree relatives, 90 participants (15.4%) had prior self-mutilation and 35 participants (6%) had prior suicide attempt at least once at a time. One fourth of the participants (24.4%) was grouped into DEStaxon membership (N ¼144) which represents a proneness to have dissociative disorders. Demographic and clinical characteristics of the sample are shown in Table 1. 2.2. Procedure The survey was conducted two years after the earthquake in 2013. Participants were recruited from community in Van, Turkey. The study was a household survey that random sampling procedure was used. A sample size of 550 households, representative for Van were chosen. A random sample of 100 alternative addresses were also determined in case of nobody was present at home when visited by research team. One respondent participated in from each household and we collected data from 611 subjects and 28 participants were not included in the data analysis process. Each participant was completely informed about the aim of the study and taken written informed consent. Then, volunteers were administered a socio-demographic questionnaire, the Dissociative Experiences Scale (DES), Short Form Health Survey Questionnaire (SF-36), Posttraumatic Diagnostic Scale (PTDS), Beck Depression Inventory (BDI), Beck Hopelessness Scale (BHS), and Scale for Suicide Ideation (SSI). The study procedure was received an approval from Ethical Committee of Yüzüncü Yıl University School of Medicine.

Table 1 Demographic and clinical characteristics of the sample (N ¼583).

Sex (male vs female) Education

Group (adult vs student) Marital status (single vs married) Income

DES-taxon membership Earthquake exposure Presence of any psychiatric disorders Presence of family psychopathology Prior self-mutilation Prior suicide attempt

Male Primary school Secondary school High school University Adult Single Low Average Upper

N

%

428 56 59 144 324 251 407 194 321 68 144 261 71 40 90 35

73.41 9.61 10.12 24.70 55.57 39.96 69.81 33.28 55.06 11.66 24.70 44.77 12.18 6.86 15.44 6.00

2.3. Psychometric instruments Dissociative Experiences Scale (DES) The Dissociative Experiences Scale (DES) is a 28-item self-report questionnaire developed for screening dissociative experiences among community sample. (Bernstein and Putnam, 1986) The Turkish version of the DES was demonstrated to have good reliability and validity almost equal to its original form. The Turkish had an alpha of α ¼ 0.97 and test–retest correlation coefficient was r ¼0.77 (Yargic et al., 1995). Health Survey Questionnaire (SF-36) The short form Health Survey is a self-administered questionnaire consisting of 36 items, requiring about 5–10 min to complete. The SF-36 is one of the most widely used tools for exploring the health-related quality of life. The lower the scores the greater the disability (Kopjar, 1996). Turkish version of the instrument was shown to have good discriminant and construct validity and excessively high internal consistency ranging from 0.81 to 0.98 with exception of Vitality and Mental Health sub-scales. Cronbach's alphas were 0.65 and 0.64 for these subscales, respectively (Demiral et al., 2006). Posttraumatic Diagnostic Scale, Self Report Version (PTDS-SR) Posttraumatic Diagnostic Scale, Self-Report version (PTDS-SR) is a 17 items self report questionnaire reflecting DSM-IV symptoms of PTSD which are rated on a 4point Likert type scale (Foa et al., 1997). The validation study of the Turkish version of the PTDS-SR was performed by Aydin et al. (2012). Original three-factor derived in the initial validation study was replicated. Cronbach's alphas for the symptom clusters ranged between 0.72 and 0.82. Beck Depression Inventory (BDI) The Beck Depression Inventory (BDI) is a 21-item self report measure of depressive symptom severity. Each item is rated on a 0–3 and the total scores range from 0 to 63, with higher values indicating more severe depressive symptoms.(Beck et al., 1961) The validity and reliability of the Turkish version of the BDI was good. Internal consistency of the scale was α ¼0.80 (Hisli, 1989). The Beck Hopelessness Scale (BHS) The Beck Hopelessness Scale (BHS) consists of 20 true/false items self-report inventory that is designed to measure three major aspects of hopelessness: negative feelings about the future, loss of motivation, and expectations (Beck et al., 1994). The Turkish version had an internal reliability of α ¼0.86 and test– retest reliability was r ¼0.73 (Seber et al., 1993). The Scale for Suicide Ideation (SSI) The Scale for Suicidal Ideation (SSI) was developed by Beck et al. (1997) in order to assess the intensity, pervasiveness, and characteristics of suicidal ideation. The scale contains 20 items: 15 items scored 0 to 2, 5 items not scored. The validity and reliability study of the Turkish version of the SSI was performed by Dilbaz et al. (1995). 2.4. Statistical analysis Initially, we computed descriptive statistics to indicate demographic characteristics of the sample. Scale scores of psychological variables were compared between high dissociation group characterized by DES-taxon membership and low

O. Ozdemir et al. / Psychiatry Research 228 (2015) 598–605 dissociation group. DES-Taxon, first proposed by Waller et al. (1996), includes 8 items of the DES which are indicative of having dissociative disorders. DES-taxon membership was determined using the formulation of Waller and Ross (1997): one was assigned to the DES-taxon membership if his or her computed probability which was derived from his or her item responses exceeded a critical threshold score of 0.90. Multiple regression analyses were run in order to explore the partial associations of PTSD symptom clusters with demographic and psychological variables. Finally, mediating role of pathological dissociation between PTSD symptom severity and predictor variables were investigated with a multivariate analysis of covariance (MANCOVA). The statistical significance threshold was held at p o0.05.

3. Results To explore the differences in posttraumatic symptoms, depression, hopelessness and suicidal ideation as well as physical, social and emotional functioning in terms of the SF-36 sub-scales between individuals with a high tendency of pathological dissociation and without such an inclination, mean scale scores of participants in the DES-taxon group were compared with the scale scores of participants with no pathological dissociation by running one-way analysis of variance models. Individuals who revealed high levels of pathological dissociation reported greater scores on three posttraumatic symptom clusters of reexperiencing, avoidance and hyperarousal as well as depression, hopelessness, and suicidal ideation. Furthermore, participants with lower levels of pathological dissociation had better scores on all eight components of the SF-36 which are indicators of good physical and mental health as compared to individuals with high pathological dissociation. Results are shown in Table 2. Predictive values of demographic variables such as age, sex, level of education, marital status, income and indexes of vulnerability to extreme stress response in terms of experienced earthquake, presence of a psychiatric disorder, presence of family psychopathology, prior self-mutilation, prior suicide attempt as well as psychological variables in terms of DES-taxon membership, scale scores of the BDI, BHS, SIS, and SF-36 sub-scales on PTSD symptom severity were investigated by using multiple regression analyses. In the multiple regression models, predictor variables were regressed onto global and subscale scores of the Posttraumatic Diagnostic Scale (PTDS). As seen in Table 3, relations of PTSD symptom clusters with demographical characteristics, DES-taxon membership, the Beck Depression Inventory, Beck Hopelessness Scale, Suicidal Ideation Scale and subscales of the General Health

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Questionnaire were assessed by using five multiple regression models. In the first regression model where the PTDS-SR global scores was the dependent variable, we found that being female, being single, earthquake exposure, having dissociative disorders and greater levels of suicidal ideation were significant predictors of PTDS-SR global symptom severity. Considering the relations between PTDS-SR global scores and general health, the RolePhysical, Bodily-Pain, General Health and Role-Emotional subscales of the SF-36 were inversely associated with PTSD symptom severity. In the second regression model, reexperiencing symptom cluster of PTSD was dependent variable. Age, being female, higher levels of education, being single, earthquake exposure, DES-taxon membership, and greater levels of suicidal ideation significant contributed to variance of reexperiencing symptoms. Lower levels of General-Health and Role-Emotional subscale scores of the SF-36 were significantly associated with elevations in reexperiencing symptoms. In the third regression model in which avoidance symptoms of the PTDS-SR was the dependent variable, higher levels of education, being single, and DES-taxon membership significantly contributed to increase in avoidance symptoms; whilst Role-Physical, General Health and Role-Emotional scales of the SF-36 were inversely associated with this scale of the PTDS-SR. Hyperarousal was positively associated with being single, DEStaxon membership, and suicidal ideation and was negatively linked to Role-Physical, Bodily Pain and Role-Emotional scales of the SF-36 in the fourth regression model. The fifth regression model in which functional impairment scores was the dependent variable demonstrated that depression, suicidal ideation, poor physical and social functioning were significant predictors of functional impairment in PTSD. To uncover the multivariate associations between PTSD symptom clusters and DES-taxon membership after controlling for covariates of demographical characteristics and psychological variables as well as indexes of vulnerability to extreme stress response such as experienced earthquake, presence of a psychiatric disorder, presence of family psychopathology, prior selfmutilation and prior suicide attempt, we conducted multivariate analysis of covariance (MANCOVA). A MANCOVA model permits assessing significant multivariate connections between a set of dependent variables and independent covariates mediated by a fixed independent variable. To do so, we run a MANCOVA model to

Table 2 ANOVA comparisons of psychological variables between DES-taxon membership and no membership (N ¼583).

Dissociative Experiences Scale PTSD Global Re-experiencing Avoidance Hyperarousal Functional impairment Beck Depression Inventory Beck Hopelessness Scale Suicidal Ideation Scale Physical Functioning (SF-36) Role-Physical (SF-36) Bodily Pain (SF-36) General Health (SF-36) Vitality (SF-36) Social Functioning (SF-36) Role-Emotional (SF-36) Mental Health (SF-36)

No membership (n¼ 439)

DES-taxon Membership (n¼ 144)

Mean

S.D.

Mean

S.D.

d.f.

F

P

η2

16.63 14.30 4.19 5.83 4.28 2.97 14.40 7.51 4.07 79.75 71.23 68.43 57.86 55.39 63.83 62.86 55.36

10.72 10.38 3.44 4.64 3.53 3.01 12.15 4.36 4.17 22.31 33.22 19.74 15.92 17.10 21.18 36.37 16.93

46.33 24.62 7.11 10.41 7.10 4.28 24.23 9.49 7.39 62.34 53.01 58.60 50.43 48.82 54.46 44.99 47.60

12.27 10.32 3.32 4.76 3.63 2.66 14.97 3.36 4.19 27.15 32.66 21.64 15.89 17.02 21.05 31.21 15.76

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,

773.444 104.927 77.782 101.641 66.488 21.313 59.822 24.163 67.352 57.145 32.209 25.445 21.469 15.657 20.631 27.719 22.923

0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

0.571 0.155 0.120 0.151 0.104 0.036 0.097 0.041 0.107 0.092 0.053 0.043 0.039 0.027 0.035 0.046 0.039

Significant p Values are indicated using bold figures.

581 572 572 572 572 572 560 568 563 563 570 571 534 570 562 570 565

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Table 3 Multiple regression analyses (N ¼583). PTSD Global

Age Sex Education Marital status Income Experienced earthquake Presence of a psychiatric disorder Presence of family psychopathology Prior self  mutilation Prior suicide attempt Des  taxon membership Beck Depression Inventory Beck Hopelessness Scale Suicidal Ideation Scale Physical Functioning (SF-36) Role-Physical (SF-36) Bodily Pain (SF-36) General Health (SF-36) Vitality (SF-36) Social Functioning (SF-36) Role-Emotional (SF-36) Mental Health (SF-36) Model R Square Model F(22, 443)

β 0.10 0.09 0.07  0.15 0.04 0.08  0.01  0.02 0.01  0.01 0.26 0.10 0.01 0.11  0.02  0.10  0.10  0.12  0.03 0.06  0.12  0.04

t 1.74 2.43 1.83  2.64 0.98 2.12  0.14  0.39 0.18  0.21 6.16 1.93 0.02 2.40  0.49  2.38  2.21  2.61  0.60 1.19  2.93  0.76 0.42 14.308

P 0.083 0.016 0.068 0.009 0.326 0.035 0.890 0.698 0.855 0.831 0.000 0.055 0.986 0.017 0.622 0.018 0.028 0.009 0.548 0.236 0.004 0.449

Reexperiencing β 0.12 0.12 0.09  0.14 0.06 0.11  0.02  0.04 0.05  0.02 0.21 0.10  0.03 0.10  0.02  0.06  0.07  0.10  0.10 0.02  0.13 0.01

t 2.02 2.99 2.01  2.34 1.46 2.79  0.53  0.91 1.15  0.44 4.76 1.95  0.63 2.09  0.46  1.39  1.33  2.07  1.89 0.48  3.08 0.09 0.36 11.377

Avoidance

P 0.044 0.003 0.045 0.020 0.146 0.005 0.596 0.363 0.252 0.660 0.000 0.051 0.531 0.037 0.643 0.166 0.183 0.040 0.059 0.634 0.002 0.932

β 0.10 0.07 0.09  0.13 0.03 0.08  0.03 0.01 0.00  0.02 0.29 0.09 0.06 0.08  0.03  0.09  0.08  0.14 0.03 0.05  0.09  0.01

t 1.79 1.70 2.05  2.23 0.68 1.92  0.74 0.25 0.00  0.56 6.53 1.76 1.23 1.57  0.69  1.98  1.65  2.86 0.51 0.96  2.10  0.22 0.36 11.206

Hyperarousal P 0.075 0.090 0.041 0.026 0.496 0.055 0.458 0.800 0.998 0.575 0.000 0.079 0.221 0.118 0.492 0.049 0.099 0.004 0.609 0.336 0.037 0.829

β 0.04 0.07 0.02  0.14 0.02 0.03 0.05  0.02  0.03 0.02 0.18 0.06  0.05 0.13 0.00  0.13  0.14  0.08  0.03 0.08  0.11  0.11

t 0.60 1.74 0.53  2.23 0.49 0.77 1.09  0.57  0.56 0.56 4.13 1.23  0.99 2.68  0.03  2.75  2.74  1.60  0.58 1.60  2.53  1.92 0.34 10.174

P 0.547 0.083 0.599 0.026 0.627 0.443 0.275 0.570 0.576 0.578 0.000 0.221 0.325 0.008 0.973 0.006 0.006 0.111 0.563 0.111 0.012 0.056

Functional impairment β 0.00  0.01 0.00 0.05 0.05 0.05  0.02  0.07 0.04 0.00 0.02 0.19  0.03 0.13  0.12  0.04  0.01  0.01  0.07  0.14 0.00  0.08

t  0.04  0.26 0.00 0.86 1.24 1.07  0.41  1.68 0.81  0.08 0.38 3.39  0.57 2.47  2.53  0.92  0.17  0.25  1.21  2.67  0.01  1.32 0.28 7.825

P 0.967 0.794 0.996 0.389 0.214 0.286 0.684 0.093 0.416 0.940 0.707 0.001 0.567 0.014 0.012 0.360 0.868 0.800 0.225 0.008 0.992 0.189

Sex ¼ 0:Male, 1: Female; Marital status ¼0:Single, 1: Married; Significant p Values are indicated using bold figures.

evaluate the mediating role of pathological dissociation in the multivariate relations of three PTSD symptom clusters with depression, hopelessness, suicidal ideation, physical and mental health, demographic characteristics, and indexes of vulnerability to stress response. In the MANCOVA model we observed that the multivariate association of pathological dissociation in terms of DES-taxon membership with each PTSD symptom category was substantial when the effects of covariate variables were adjusted. Regarding the relations between covariant variables and PTSD symptoms, significant linkages were mediated by pathological dissociation. Specifically, two variables of being single and problems with work or other daily activities as a result of emotional dysregulation (Role-emotional) were associated with all three types of posttraumatic stress response. Age, being female, and earthquake exposure were significant correlates of only reexperiencing symptoms. Individuals who had higher levels of education and evaluated their personal health as poor along with negative beliefs, including it was likely to get worse (General health) reported greater scores on reexperiencing and avoidance subscales. Participants who scored higher bodily pain were more prone to experience arousal states; whereas individuals experiencing problems with work or daily activities due to their physical health scored higher on both hyperarousal and avoidance symptom clusters. Suicidal ideation was a significant predictor of reexperiencing and hyperarousal symptoms. Significant connections derived in the MANCOVA model are shown in Table 4.

Table 4 Multivariate analysis of covariance (MANCOVA) of subscale scores of the PTDS-SR as dependent variables according to the DES-taxon membership status. Dependent

DES-taxon membership

Covariates Age Sex Education Marital status

Experienced earthquake Suicide ideation Role-Physical Pain General Health Role- Emotional

In the current study, we examined the associations between PTSD, dissociation, quality of life, hopelessness, and suicidal ideation among earthquake survivors. The results of this study demonstrated that individuals with pathological dissociation have elevated depression, more severe PTSD symptoms, greater levels of suicidal ideation and hopelessness as well as lower quality of life compared to low dissociation group. Our findings suggested that there were significant linkages between pathological dissociation in terms of DES-taxon

B C

F (1, 443)

P

Partial η2

195.737

22.666

0.000 0.049

Avoidance HyperarousalC

730.569 167.567

42.608 17.075

0.000 0.088 0.000 0.037

Reexperiencing Reexperiencing Reexperiencing Avoidance Reexperiencing Avoidance Hyperarousal Reexperiencing

35.241 77.068 34.941 71.928 47.332 85.610 48.641 67.259

4.081 8.924 4.046 4.195 5.481 4.993 4.957 7.788

0.044 0.003 0.045 0.041 0.020 0.026 0.026 0.005

0.009 0.020 0.009 0.009 0.012 0.011 0.011 0.017

Reexperiencing Hyperarousal Avoidance Hyperarousal Hyperarousal Reexperiencing Avoidance Reexperiencing Avoidance Hyperarousal

37.656 70.623 66.978 74.226 73.646 36.809 140.227 81.757 75.220 62.660

4.360 7.197 3.906 7.564 7.505 4.262 8.178 9.467 4.387 6.385

0.037 0.008 0.049 0.006 0.006 0.040 0.004 0.002 0.037 0.012

0.010 0.016 0.009 0.017 0.017 0.010 0.018 0.021 0.010 0.014

A B

A

4. Discussion

Reexperiencing

Mean square

Adjusted R2 ¼ 0.33; Adjusted R2 ¼ 0.33; Adjusted R2 ¼ 0.31.

membership and adverse outcomes on a broad range such as PTSD, poor quality of life, hopelessness, suicidal ideation and depression. In addition, we found that PTSD symptom severity in the face of earthquake exposure was significantly associated with older age, being female, earthquake exposure, higher level of education, being single, having greater suicidal ideation, poor general health, and negativistic perception of physical and emotional functioning but not

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depression. Presumably the most salient result of the study was that significant connections between PTSD symptom severity and predictor variables were mediated by pathological dissociation. Bremner (1999) proposed a distinction within trauma-induced stress responses: one is primarily dissociative which is characterized by hypo arousal states and the other is hypervigilant which is characterized by hyper-arousal states. Such conceptualization for the heterogeneity of emotional regulation difficulties in response to trauma exposure is in agreement with early considerations, reflecting complex nature of trauma-related syndromes (Foa and Hearst-Ikeda, 1996; Herman, 1992; Horowitz, 2002). Psychobiological research has provided supportive evidence for a dissociative subtype of posttraumatic stress response that trauma exposed individuals with PTSD could be subsumed into two groups: dissociative PTSD and non-dissociative PTSD. This categorization reflects a distinction in clinical presentations and emotional regulation difficulties peculiar to these subtypes that nondissociative or reexperiencing/hyperarousal PTSD individuals were more prone to emotional undermodulation marked by hyper responsiveness in amygdala and failure in top down control of prefrontal cortex that is implicated in failure of extinguishing symptom generation. On the contrary, individuals with dissociative PTSD were more prone to emotional overmodulation marked by hypo responsiveness in amygdala and preponderance of prefrontal control over temporal lobe structures that is implicated in detachment and compartmentalization symptoms during reminders of the original traumatic experience (Lanius et al., 2010). To the best of our understanding, dissociative subtype distinction in PTSD can be attributed to a cognitive suppression mechanism in an attempt to eschew from impairing effects of intrusive and hyper-arousal emotional states. Thus, pathological dissociation in PTSD can be interpreted in a way that greater dissociative symptomatology in response to trauma clues which refers to a maladaptive coping and presumably associated with higher symptom severity. Kadak et al. (2013) pointed out that dissociation is a significant predictor of PTSD among earthquake survivors. Baker et al. (2003) found high rates of comorbid depression among patients with depersonalization disorder. Furthermore, another study determined that dissociative experiences are best predicted by anxiety and depression among women who were survivors of trauma and life threatening events (Sar et al., 2007). Our findings were in line with our hypothesis and previous research that individuals categorized in DES-taxon membership, an indicator of pathological dissociation, reported significantly more severe symptoms of PTSD, greater depression, higher levels of hopelessness and suicidal ideation as well as poorer mental and physical health. Significant connections between PTSD and suicidality have long been recognized. Research has pointed out co-occurring depressive symptoms confer people with PTSD at greater risk of suicidality (Panagioti et al., 2012). Nonetheless, to date, the role of dissociative symptomatology in suicidal behaviors and ideation among individuals with PTSD has remained elusive to an extent. So far several investigations have demonstrated that suicidal behaviors were significantly linked to pathological dissociation across different populations consisting of high school students, community samples and patients with dissociative disorders (Ebrinc et al., 2008; Maaranen et al., 2005; Zoroglu et al., 2003). Self-mutilative behaviors were almost ubiquitous (82%) among patients with dissociative disorders (Ebrinc et al., 2008). On the other hand, there has been a dearth of research addressing the relations between PTSD, dissociative states and suicidality. Our study provided support for and extended prior empirical and theoretical considerations that suicidal ideation was a significant predictor of hyper-arousal states of intrusions and hypervigilance symptom clusters and these relations were mediated by hypo

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arousal dissociative states. This process also can be interpreted in a way that suicidal thoughts culminate with more severe reexperincing/hyperarousal responses that lead to a maladaptive compensation mechanism of excessive levels of hypo arousal emotional states characterized by pathological dissociation. However, results were odds with prior investigations that we could not find any significant linkages between depression and PTSD symptom severity. A possible explanation for this observation may be due to the research design of prior investigations addressing risk factors for PTSD. It seems like that previous studies have consistently overlooked the possible influence of dissociation on PTSD rather have focused on relationships with depression and anxiety. However, in a community sample of children and adolescents, Kadak et al. (2013) reported significant partial relations of PTSD with depression and dissociation after 10 months of the same earthquake. Another explanation for unsubstantial partial effects of depression on PTSD symptom clusters in the current study may be that severity of posttraumatic stress syndromes including PTSD, dissociation, anxiety and depression may have attenuated due to amount of time passed after the experienced disaster (Galea et al., 2005). Pathological dissociation may also be more persistent relative to depressive symptoms in response to disaster exposure. Further studies with longitudinal research design are needed to more accurately understand the risk factors for persistent PTSD in the face of trauma, particularly disasters. This study showed that pathological dissociation was strongly predictive of poorer quality of life in all domains. DES-Taxon members reported significantly lower scores on eight scales of SF-36 compared to low dissociative subjects. These findings were mostly in consonance with the prior studies that Mitchell et al. (2012) reported a negative correlation between high levels of dissociative experiences and health-related quality of life (HRQoL) in patients with non-epileptic attack disorder. The significant associations also remained after controlling for symptoms of depression and anxiety, other psychiatric comorbidities, and attack frequency and severity. The relationship between dissociation and quality of life needs further research. Evren et al. (2011) investigated the impact of lifetime PTSD, dissociation on quality of life among men with alcohol dependency. They found that the lifetime PTSD group exhibited severe impairments on physical and mental components of quality of life. In multivariate covariance analysis, both dissociation and lifetime PTSD predicted impairment in physical functioning, general health, vitality, and mental health components of quality of life. On the contrary, Latalova et al. (2010) could not find any significant correlations between dissociation and quality of life in patients with bipolar affective disorders in remission. Although meaning and interpretations about traumatic events are more consequential in terms of development of persistent PTSD, negative inferential style involving in severity of posttraumatic symptoms and impairments in functioning either physically or mentally may lead to poorer outcomes in the course of the disorder (Asmundson et al., 2002; Ehlers and Clark, 2000; Taylor, 2009). Our findings with respect to the relations of PTSD severity and mental and physical health were in accordance with the clinical and theoretical considerations in the literature. Roleemotional subscale referring to problems with work or daily activities in life which emerge from emotional problems was significantly associated with all three symptom clusters of PTSD. Perceived problems with work or daily activities which result from physical problems and perceived impairment in general health were also significantly connected with specifically avoidance symptoms as well as hyper-arousal states. Pain was mainly associated with hypervigilance symptoms. Asmundson et al. (2002) focused on hyperarousal symptoms to describe cooccurring physical disability and PTSD. Hypervigilance for external

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stimuli and exaggerated startle responses were suggested to be resulting in the extreme sensitivity to painful sensations. Our investigation provided further support for the importance of functionality in the aftermath of the adverse events that, more presumably, perceived impairments in emotional and physical well-being ensue deteriorations in PTSD symptom severity and should be more comprehensively evaluated in assessing posttraumatic stress responses among individuals who exposed to trauma. Moreover, pathological dissociation mediated the significant connections of PTSD symptoms with mental and physical well-being indicators. Even if dissociation was found to have a mediator role in these relations, the concept of dissociative phenomena involve in somatic components refers to somatoform dissociation. Further studies addressing somatoform dissociation along with mental dissociation would be beneficial of more clearly understanding the connections between PTSD, dissociation and physical functioning. This study has several limitations. First, research design of the investigation was cross-sectional but a longitudinal design research would have been more informative in understanding the relations between variables in the course of the posttraumatic process. Second, researchers focused on the earthquake exposure and posttraumatic reactions in response to the event that other types of traumatic experiences were not assessed in the research procedure. Therefore, our results should be interpreted with caution that if possible influences of prior traumatic incidences and early adverse experiences were included in the study, these traumatic experiences might have been accounting for a part of the variances of PTSD symptom clusters. Finally, this community survey was conducted 2 years after the earthquake. Greater levels of posttraumatic stress reactions are more likely to be seen immediate to trauma exposure relative to later times, particularly in natural disasters (Galea et al., 2005). That is, our results should be interpreted and generalized with caution.

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