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Posttraumatic stress symptoms and dissociation between childhood trauma and two different types of psychosis-like experience
Child Abuse & Neglect 72 (2017) 404–410
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Posttraumatic stress symptoms and dissociation between childhood trauma and two different types of psychosis-like experience
MARK
Ji Young Choi Department of Psychiatry, Sanggye Paik Hospital, Inje University, 1342, Dongilro, Nowon-gu, Seoul, Republic of Korea
AR TI CLE I NF O
AB S T R A CT
Keywords: Childhood trauma Persecutory ideation Aberrant experience Posttraumatic stress symptoms Dissociation Non-psychotic psychiatric patients
This study examined the roles of posttraumatic stress (PTS) symptoms and dissociation in the relationship between childhood trauma and two different types of psychosis-like experience, including persecutory ideation and aberrant experience, in non-psychotic psychiatric patients. From August 2015 to August 2016, among psychiatric out patients seeking treatment at the Department of Psychiatry at a major teaching medical hospital in Seoul, Korea, 169 patients who had never been diagnosed with a psychotic disorder, including schizophrenia spectrum disorder, bipolar disorder, and/or depressive disorder with psychotic features, completed the Korean Childhood Trauma Questionnaire, the Korean version of the Impact of Event Scale-Revised, the modified Korean version of the Peritraumatic Dissociation Experiences Questionnaire, and the Korean Minnesota Multiphasic Personality Inventory-2 (MMPI-2). The RC 6 (Ideas of Persecution) and RC 8 (Aberrant Experiences) of the restructured scales of the MMPI-2 were used as a measure of persecutory ideation and aberrant experience. Structural equation modeling analyses confirmed a partial mediation model in which PTS symptoms partially mediated the relationship between childhood trauma and persecutory ideation, and dissociation partially mediated the relationship between childhood trauma and aberrant experience. This implies that there are distinct mechanisms depending on the type of psychosis-like experience in relation to childhood trauma.
Childhood trauma has been widely accepted as one of the most significant environmental factors associated with the development of psychosis. There is copious evidence that childhood trauma significantly increases the risk for severe mental illnesses such as schizophrenia spectrum disorder, bipolar disorder, and depressive disorder with psychotic features (Janssen et al., 2004; Kessler et al., 2010; Vares et al., 2012). Childhood trauma has been suggested to be a predictor of psychosis later in life that often occurs in a dose-response manner, suggesting that psychosis worsens as the severity of trauma increases (Janssen et al., 2004; Schenkel, Spaulding, DiLillo, & Silverstein, 2005). Studies have also found that childhood trauma was related to sub-clinical psychosis, such as paranoid thinking and hallucinatory experience, in non-psychotic psychiatric patients and in the general population (Cole, NewmanTaylor, & Kennedy, 2016; Shah et al., 2014; van Nierop et al., 2014). Despite evidence for a relationship between childhood trauma and psychotic experience, the underlying mechanisms involved remain unclear. Posttraumatic stress (PTS) symptoms and dissociation have been suggested and explored as possible mediating factors by many researchers, because they are understood as responses to traumatic experiences (Evans et al., 2015; Vogel et al., 2011). Posttraumatic stress disorder (PTSD), which includes intrusion, arousal, and avoidance as diagnostic criteria, is a typical response after traumatic experience. Dissociation has also been commonly understood as the manifestation of automatic defense mechanisms that serve to mitigate the impact of traumatic experiences (van Ijzendoorn & Schuengel, 1996). Studies have
E-mail address: [email protected]. http://dx.doi.org/10.1016/j.chiabu.2017.08.023 Received 6 January 2017; Received in revised form 19 July 2017; Accepted 19 August 2017 0145-2134/ © 2017 Elsevier Ltd. All rights reserved.
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demonstrated that childhood trauma is associated with the experience of chronic PTS symptoms, which in turn increases the likelihood of psychosis in schizophrenia patients or broad psychotic disorder patients (Choi et al., 2015; Vogel et al., 2011). Dissociation has received more attention as the mediating factor in the relationship between childhood trauma and psychosis. As dissociation causes impaired reality testing, individuals who cope with trauma via dissociation are more likely to subsequently experience psychosis, not only in patients with severe mental illness, but also in the general population (Evans et al., 2015; Hammersley, Read, Woodall, & Dillon, 2008; Kilcommons & Morrison, 2005). However, there has been no attempt to test if PTS symptoms and dissociation play distinct roles as mediating factors in developing a psychotic experience. It is purported that the size of their contribution on a psychotic experience would be different, especially when considering that PTS symptoms and dissociation are somewhat different responses to traumatic experience (Hetzel and McCanne, 2005). Therefore, there is a need to explore whether these factors play distinct roles in the relationship between childhood trauma and psychotic experience. The severity of psychotic symptoms has generally been assessed by both hallucinations and delusions in studies targeting schizophrenia spectrum disorder. On some occasions, psychotic symptoms have included subjective thought disorder or confusion in addition to hallucinations and delusions (Choi et al., 2015). Although a psychotic experience can typically be divided into hallucinations and paranoid delusions, few studies have analyzed them separately (Cole et al., 2016; Muenzenmaier et al., 2015). It is possible that the effect of childhood trauma on paranoid thinking and proneness to hallucination differs, and PTS symptoms and dissociation fulfill different roles in the association between childhood trauma and the two types of psychotic experiences. Muenzenmaier et al. (2015) suggested that although dissociation appears to mediate the relation between stressful childhood experiences and hallucination, the relationship between delusions and cumulative trauma does not seem to be mediated by dissociative symptoms in people with psychosis disorders. Read, Fosse, Moskowitz, and Perry (2014) proposed that trauma-related affect regulation (as assessed by PTS symptoms) mediates the association between trauma and persecutory delusion. Recently, Cole et al. (2016) reported that dissociation mediates the relationship of early maltreatment and hallucination proneness with delusional ideation in the general population. Despite the limitation that the mediating roles of dissociation and PTS could not be compared with each other, these studies suggest the possibility of different mediating roles of dissociation and PTS symptoms in the relationship between childhood trauma and different types of psychotic experience. It has been reported that the incidence of paranoid thinking or hallucinatory experience in the general population is up to 20–30% (Moritz, Göritz, McLean, Westermann, & Brodbeck, 2017; Westermann & Lincoln, 2011). Paranoid thinking is associated with more severe depression and mood regulation difficulties, and hallucinatory experiences not only cause not subjective perturbations, but they also diminish coping abilities in relation to more arousals and difficulties of judgment (Altman, Clooins, & Mundy, 1997; Klaassen et al., 2012). Because psychosis-like experience is an important factor affecting adjustment levels in nonpsychotic psychiatric patients, it is important to explore the underlying mechanisms affecting the association between childhood trauma and psychotic experiences, targeting both patients with and without psychosis. The purpose of the current study was to test the distinct mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and two representative types of psychosis-like experiences, persecutory ideation and aberrant experiences, in a non-psychotic clinical sample. Aberrant experiences include bizarre sensitive and perceptual experiences, hallucination, and odd thought processes. The main hypothesis was that both PTS symptoms and dissociation play mediating roles, but they have different effect sizes depending on the type of psychotic experience. The model hypothesized that PTS symptoms, including fear, arousal, and mistrust toward others and toward the world have a stronger mediating effect between childhood trauma and persecutory ideation, while experiences of dissociated consciousness during and after traumatic events have more effects on unrealistic or bizzare perceptual and sensitive experiences.
1. Methods 1.1. Participants and procedure Participants included outpatients aged 18–65 years, visiting the psychiatry department of a major medical hospital in Seoul from August 2015 to August 2016. Among 347 patients, who underwent psychological evaluation, 169 adult outpatients met the following inclusion criteria finally participated in the study: (a) never being diagnosed with psychosis, with the potential of being accompanied by psychotic symptoms such as schizophrenia spectrum disorder bipolar disorders, major depressive disorder with psychotic features, psychotic disorder, or disorders that were not otherwise specified; (b) absence of organic brain dysfunction or other medical conditions, as determined by the psychiatrist’s opinion based history taking and medical exams, (c) not being diagnosed with PTSD and/ or acute stress disorder after experiencing recent traumatic events, to minimize confusion between the effects of childhood trauma and recent traumatic events, and (d) as indicated in the MMPI-2 manual, have more than 30 no-response items, and a T score of over 80 on the validity scales. Those individuals who provided informed consent to participate in the present study completed the measures as part of their evaluation. Usually, the outpatients in this study completed the assessment within two weeks of their initial consultation. Official diagnoses were made by staff psychiatrists based on the Diagnostic and Statistical Manual 4th Edition (DSM-IV). The study was approved by the hospital’s Institutional Review Board. The mean age of the sample was 35.53 years (SD = 16.59) with range of 18–60 years. The participants included 96 males (56.8%) and 73 females (43.2%).
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1.2. Measures 1.2.1. Korean childhood trauma questionnaire The Korean version of the Childhood Trauma Questionnaire was developed by Yu, Park, Ryu, and Ha (2009), who translated the original version (Berstein & Fink, 1998). This questionnaire comprises the 5 subscales of emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect, and 3 items pertaining to the validity scale (minimization/denial scale). Each item is scored on a 5-point Likert scale, with higher scores representing a more severe degree of abuse. Internal consistency of the Korean version was 0.79, and the Cronbach’s alpha across the 5 subscales was 0.80 (emotional abuse), 0.82 (physical abuse), 0.79 (sexual abuse), 0.89 (emotional neglect), and 0.51 (physical neglect; Yu et al., 2009). The Cronbach’s alpha values for the present study were 0.86 for physical abuse, 0.67 for physical neglect, 0.81 for emotional abuse, 0.87 for emotional neglect, and 0.78 for sexual abuse. 1.2.2. Korean version of the impact of event scale-Revised (IES-R-K) The Impact of Event Scale was originally developed as a self-report measure by Horowitz, Whiner, and Alvarez (1979), to measure the central features of PTSD, such as trauma-related symptoms of intrusion and avoidance. Weiss and Marmar (1997) revised it to include symptoms of hyperarousal. The IES-R consists of 22 items representing the subscales of intrusion, avoidance, numbing and dissociation, and hyperarousal, with each item scored on a 5-point Likert scale. The IES-R was translated into Korean and validated by Eun, Kwon, Lee, Kim, Choi, and Cho (2005). The overall internal consistency in the validation study in Korea was 0.77 and that for each subscale was between 0.69 and 0.83 (Eun et al., 2005). In the present study, the internal consistency was 0.94 for intrusion, 0.92 for avoidance, 0.85 for hyperarousal, and 0.76 for numbing and dissociation. 1.2.3. Korean version of modified version of the peritraumatic dissociation questionnaire (K-PDEQ) The PDEQ, modified by Marshall, Orlando, Jaycox, Foy, and Belzberg (2002) from the original PDEQ (Marmar, Weiss & Melzler, 1997), is an eight-item measure that retrospectively assesses dissociative phenomena that occur during a potentially traumatic event, using a 5-point scale. The K-PDEQ, translated and validated by Choi (2006), modified the direction to evaluate dissociative experiences lasting until the time of testing, and not only during traumatic events. These dissociative phenomena include altered time perception, depersonalization, and derealization. The internal consistency of the Korean version was 0.85 (Choi, 2006) and that in the present study was 0.91. 1.2.4. RC 6 (Ideas of persecution) and RC 8 (Aberrant experiences) of the restructured clinical (RC) scales of the minnesota multiphasic personality inventory-2 (MMPI-2) The MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) is widely used to assess symptoms and diagnostic possibilities comprehensively in clinical populations. The MMPI-2 has been standardized in Korea, with acceptable reliability and validity (Kim, Han, Lim, Lee, Min, & Moon, 2005). The restructured clinical scales were developed to minimize common factors and to improve their discriminant validity. The RC 6 scale consists of 17 items that assess paranoid ideation, persecutory ideas, or delusional thought. A higher score on this scale indicates a tendency toward paranoid ideation. The RC 8 consists of 18 items that assess symptoms of hallucination, bizarre sensory experiences, odd thought processes, and loss of reality testing. Higher scores on this scale indicate a tendency to experience bizarre sensations and perceptual experiences, beliefs not shared by others, and/or unrealistic fears of danger or harm (Ben-Porath & Tellegen, 2008). The validation study in Korea indicated an internal consistency of 0.71 for the RC 6 (Ideas of Persecution) and 0.72 for the RC 8 (Aberrant Experiences) (Kim et al., 2005). In the present study, the internal consistency was 0.78 for the RC 6 and 0.82 for the RC 8. 1.3. Data analysis Partial correlational analyses were conducted to examine the relationship between childhood trauma, PTS symptoms, dissociation, ideation of persecution, and aberrant experience after controlling for age and gender. Next, an SEM with a maximum likelihood estimation method was conducted using Amos 17.0 (Arbuckle, 2008), to examine the mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and the two types of psychosis-like experiences. For assessment of model fit, we used the Comparative Fit Index (CFI), the Bentler-Bonett Normed Fit Index (NFI), and the Root Mean Square Error of Approximation (RMSEA). Generally, a CFI and NFI greater than 0.90 and an RMSEA less than 0.10 indicate appropriate model fit (Byrne, 2010; Kline, 2005). The statistical significance of the mediating and indirect effects was assessed using the boostrapped bias-corrected percentile that is based on the confidence interval based on 1000 bootstrap draws (Preacher & Hayes, 2008). If zero was not within the 95% confidence intervals of the bootstrapped samples, then the mediating/indirect effect was considered statistically significant. 2. Results 2.1. Sample characteristics The primary psychiatric diagnoses of participants were as follows: 96 participants were diagnosed with depressive disorder (56.8%), 25 with anxiety disorder (14.8%), 7 with somatoform disorder (4.1%), 7 diagnosed with adjustment disorder (4.1%), and 22 with various issues, including impulse control disorder, substance use disorder, and personality disorder. Twelve participants were not specifically diagnosed. There were no gender difference in the variables, except for sexual abuse, F (1, 168) = 25.32, p = 0.000. 406
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Table 1 Partial Correlation among Variables. 1 1. 2. 3. 4. 5. 6. 7. 8. 9.
Physical Abuse Physical Neglect Emotional Abuse Emotional Neglect Sexual Abuse IES-R-K PDEQ RC6 of MMPI-2 RC8 of MMPI-2 Mean SD
2
3 ***
10.09 5.19
4 ***
5 ***
6 **
7 **
8
9 **
0.46
0.66 0.58***
0.47 0.67*** 0.65***
0.26 0.38*** 0.30*** 0.20**
0.21 0.27** 0.34*** 0.24** 0.17*
0.13 0.19* 0.22** 0.14 0.18* 0.65***
0.24 0.35*** 0.43*** 0.36*** 0.28*** 0.50*** 0.37***
0.25** 0.31*** 0.34*** 0.25** 0. 27*** 0.44*** 0.58*** 0.63***
9.78 4.08
9.85 4.94
13.38 5.35
6.93 3.27
58.29 22.42
14.83 7.43
54.31 12.46
54.21 13.14
Note. IES-R-K = Korean version of the Impact of Event Scale-revised; PDEQ = Peritraumatic Dissociation Experience Questionnaire; RC6 = Ideation of Persecution, RC8 = Aberrant Experience. * p < 0.05. ** p < 0.01. *** p < 0.001.
Means and standard deviations, along with a correlation matrix for all variables, have been presented in Table 1. None of the study variables were severely skewed or kurtotic. 2.2. Partial correlational analyses Table 1 shows the results of the partial correlational analyses. After controlling for age and gender, all types of maltreatment showed a moderate level of correlation with ideation of persecution and aberrant experiences, as measured by the RC scales of the MMPI-2 (r = 0.24–0.43, p < 0.001). The degree of each type of maltreatment was also significantly correlated with PTS symptoms (Physical Abuse [PA] r = 0.21, p = 0.005; Physical Neglect [PN] r = 0.27, p = 0.001; Emotional Abuse [EA] r = 0.34, p = 0.000; Emotional Neglect [EN] r = 0.24, p = 0.002; Sexual Abuse [SA] r = 0.17, p = 0.029). Physical neglect, emotional abuse, and sexual abuse showed modest but significant correlations with dissociation symptoms (PN: r = 0.19, p = 0.013; EA: r = 0.22, p = 0.004; SA: r = 0.18, p = 0.019). PTS symptoms and dissociation were very closely related with the two types of psychosis-like experiences (r = 0.37–.58, p = 0.000). 2.3. Structural equation modeling (SEM) To explore the mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and the two types of psychosis-like experiences in a nonpsychotic psychiatric sample, an SEM was conducted. First, the full mediation model was tested, wherein it was examined if PTS symptoms and dissociation fully mediated the relationship between childhood trauma and the two types of psychosis-like experiences. Next, a partial mediation model, with direct paths from childhood trauma to ideation of persecution and aberrant experience, was compared to the full mediation model (Kline, 2005). The full mediation SEM models did not demonstrate acceptable fit, χ2 (df = 23, N = 169) = 67.34, p = 0.000; CFI = 0.93; NFI = 0.90; RMSEA = 0.107 (90% CI = 0.078–.137). The partial mediation model (see Fig. 1) showed an acceptable fit, χ2 (df = 21, N = 169) = 39.05, p = 0.010; CFI = 0.97; NFI = 0.94; RMSEA = 0.072 (90% CI = 0.035–.106). Thus, the partial mediation model was deemed the most appropriate model for the relationship between childhood trauma, PTS symptoms, dissociation, and the two types of psychosis-like experiences examined. Childhood trauma was directly related to each psychosis-like experience (RC 6 β = 0.38, p < 0.001; RC 8 β = 0.28, p < 0.001). Childhood trauma had a significant indirect relationship with ideation of persecution, which was mediated by PTS symptoms (indirect combined β = 0.36, and β = 0.29, p < 0.001), but the indirect relationship between childhood trauma and aberrant experience via PTS symptoms was not significant. Meanwhile, childhood trauma displayed a significant indirect relationship with aberrant experience through dissociation (indirect combined β = 0.24, and β = 0.51, p < 0.001), but childhood trauma had no indirect relationship with ideation of persecution through dissociation. Further, respectively, 41.0% and 50.4% of the variance in ideation of persecution and aberrant experience was accounted for by the model. In the analysis using bootstrapped 95% confidence intervals, confidence intervals that do not include zero would indicate the presence of significant indirect effects. The indirect effect of childhood trauma on persecutory ideation through PTS symptoms (β = 0.13, 95% confidence interval = 0.06 to 0.22) as well as that of childhood trauma on aberrant experience through dissociation (β = 0.13, 95% confidence interval = 0.02 to 0.23) were significant. 3. Discussion This study attempted to test different mediating effects of PTS symptoms and dissociation in the relationship between childhood 407
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Fig. 1. The partial mediation model (N = 169). Path coefficients were standardized. Note. PA = Physical Abuse; PN = Physical Neglect; EA = Emotional Abuse; EN = Emotional Neglect; SA = Sexual Abuse; PTS = Posttraumatic Stress. ** p < 0.01, ***p < 0.001
trauma and two representative types of psychosis-like experiences, in a non-psychotic psychiatric sample. While previous research examining the relationship between childhood trauma and psychosis has typically focused on the comprehensive psychotic experience, we divided psychotic experiences into persecutory ideation and aberrant experience. Furthermore, it was hypothesized that different responses to trauma, like PTS symptoms and dissociation, play distinct roles according to the type of psychotic experience. The potential hypothesis is that PTS symptoms would play a more important role in the relationship between childhood trauma and persecutory ideation, and dissociation would play a more significant role in the relationship between childhood trauma and aberrant experiences. The use of SEM in the present study allowed simultaneous examination of two types of psychosis-like experiences and two mediating factors. The current analysis revealed that childhood trauma was directly and indirectly related to two types of psychosis-like experiences. All types of childhood trauma were highly correlated with persecutory ideation and aberrant experience. Such results are consistent with the findings of prior studies that childhood trauma affects the degree of psychotic symptoms, and that psychosis-like symptoms are associated with childhood trauma in both non-psychotic clinical and community samples (Cole et al., 2016; Janssen et al., 2004; Lardinois, Lataster, Mengelers, van Os, & Myin-Germeys, 2011). On the other hand, these findings are also consistent with a series of prior studies that suggested that childhood cumulative trauma predicts complex PTSD symptoms, including alteration in attention or consciousness and alteration in perception of others (Herman, 1992; Pelcovitz et al., 1997). The present SEM results indicated that both PTS symptoms and dissociation play distinct mediating roles in the relationship between childhood trauma and the two different types of psychotic-like experiences examined. The PTS symptoms partially mediated the relationship of childhood trauma with ideation of persecution, but not that with aberrant experience. Additionally, dissociation partially mediated the relationship of childhood trauma with aberrant experience, but not that with persecutory ideation. Previous research had already suggested that PTS symptoms and dissociation in response to trauma might play a causal role in the development of psychosis and subclinical psychosis (Evans et al., 2015; Vogel et al., 2009). More recently, some studies have explored the role of PTS symptoms and dissociation as underlying mediating factors between childhood trauma and psychotic experience in both clinical and nonclinical samples, and have tried to divide psychosis experience into hallucination and delusion (Cole et al., 2016; Hardy et al., 2016; Humpston et al., 2016). Methodologically, however, a test of potentially distinct mediation was not conducted in one model. Although it is difficult to compare our result with that of previous studies directly, the result is relevant with Muenzenmaier et al.’s (2015) study, which revealed that the association between stressful childhood experiences and hallucination completely lost significance when dissociation was controlled, but the association between stressful childhood experiences and delusion was significant independent of dissociation. The result that PTS symptom is a more important mediator in relationship with persecutory ideation is also relevant with the previous suggestion that childhood victimization results in neurodevelopmental changes such as hyperactivity of the hypothalamic-pituitary axis through PTS symptoms, and that it may render people more vulnerable to interpret external cues as negative (Read et al., 2014). However, when we consider that Hardy et al. (2016) hypothesized more specific mechanisms, including posttraumatic avoidance and numbing, intrusive trauma memory, and negative belief between childhood trauma type and type of psychotic experience in psychosis, we hypothesized that PTS symptoms included two 408
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comprehensive symptoms as a mediator of persecutory ideation. Therefore, it is necessary to explore the mediating role of more specified PTS symptoms. Although more detailed explorations of the relationship between childhood trauma and psychotic experience are needed, our result about potentially distinct mediating roles suggests the intervention points for people with subclinical psychotic symptoms. According to the type of psychosis-like experiences, focusing on dissociation or PTS symptoms could help reduce psychotic experiences. In case of aberrant experience, it is more helpful to focus on reprocessing and contextualizing the trauma-related memory, but in persecutory ideation, it is more helpful to learn how to stabilize or soothe lasting hyperarousal in addition to reconstructing the negative belief about others. Limitations of this study include the use of retrospective self-reports, small sample size, and relative low reliability of one subscale of the CTQ, which limits the generalization of the present findings. Moreover, because of the cross-sectional design, no firm conclusions can be made about causal relationships. Second, although we tried to minimize the confusion of the effects of childhood trauma and recent traumatic events by excluding individuals diagnosed with PTSD, we could not control the effect of various adulthood traumas. Another concern is related to the fact that there could be an overlap between dissociation and aberrant experience in the non-psychosis sample, although the two scale assess distinct constructs. Fourth, we were not able to examine the potential differences attributable to different types of childhood trauma. Based on the results of the partial correlation analysis, all types of childhood trauma were significantly related to PTS symptoms, but physical abuse and neglect were not significantly related to dissociation. In this study, we focused on overall childhood trauma, however, in future, it is necessary to explore whether that relationship between dissociation and aberrant experience differs according to the type of childhood trauma. Despite these limitations, the results of the present study highlight the distinct mediating effects of PTS symptoms and dissociation in the relationship between childhood trauma and two different types of psychosis-like experiences in a nonpsychotic clinical sample. Although some previous studies have explored the mediating role of PTS symptoms or dissociation respectively, this study was the first attempt to test the underlying mechanisms between two mediating factors and two types of psychosis-like experiences, simultaneously. This has the clinical implication that interventions for childhood trauma related to PTS symptoms and dissociation are useful to help various non-psychotic patients suffering from psychosis-like experiences to develop insight and controllability of symptoms. Meanwhile, it is hoped that the mechanism in the path from childhood trauma to the two types of psychotic symptoms, via PTS symptoms and dissociation, can be confirmed by replicating the findings of the current study in a sample of patients with severe mental illness, whose psychotic symptoms receive more clinical attention. The comparison between non-psychosis and psychosis samples could suggest theoretical and clinical implications. Funding information This research did not receive any specific grant from funding agencies in the public commercial, or not −for-profit sectors. Competing interests The authors declare that they have no competing interests. References Altman, H., Collins, M., & Mundy, P. (1997). Subclinical hallucinations and delusions in nonpsychotic adolescents. Journal of Child Psychology & Psychiatry, 38, 413–420. http://dx.doi.org/10.1111/j.1469-7610.1997.tb01526.x. Arbuckle, J. L. (2008). AMOS 17.0 user’s guide. New York: SPSS Inc. Ben-Porath, Y. S., & Tellegen, A. (2008). MMPI-2-RF (Minnesota multiphasic personality inventory-2 restructured form) manual for administration, scoring, and interpretation. Minneapolis: University of Minnesota Press. Berstein, D., & Fink, L. (1998). Childhood trauma questionnaire: A retrospective self-reportSan Antonio, TX: Psychological Corporation. Butcher, J. N., Dahlstrom, W. G., Graham, J. R., Tellegen, A., & Kaemmer, B. (1989). Minnesota multiphasic personality inventory-2 (MMPI-2): Manual for administration, scoring, and interpretation. Minneapolis, MN: University of Minnesota Press. Byrne, B. M. (2010). Structural equation modeling with AMOS: Basic concepts, applications, and programming (2nd ed.). New York, NY: Routledge. Choi, J. Y., Choi, Y. M., Kim, B., Lee, D. W., Gim, M. S., & Park, S. H. (2015). The effects of childhood abuse on self-reported psychotic symptoms in severe mental illness: Mediating effects of posttraumatic stress symptoms. Psychiatry Research, 229, 389–393. http://dx.doi.org/10.1016/j.psychres.2015.05.112. Choi, H. (2006). The impact of dissociative experiences on traumatic stress in prostituted women with prolonged trauma. Seoul, Republic of Korea: Seoul National University [Unpublished master’s thesis]. Cole, C. L., Newman-Tayler, K., & Kennedy, F. (2016). Dissociation mediates the relationship between childhood maltreatment and subclinical psychosis. Journal of Trauma & Dissociation, 17, 577–592. http://dx.doi.org/10.1080/15299732.2016.1172537. Eun, H. J., Kwon, T. W., Lee, S. M., Kim, T. H., Choi, M. R., & Cho, S. J. (2005). A study on reliability and validity of the Korean version of Impact of Event ScaleRevised. Journal of the Korean Neuropsychiatric Association, 44, 303–310. Evans, G. J., Reid, G., Preston, P., Palmier-Claus, J., & Sellwood, W. (2015). Trauma and psychosis: The mediating role of self-concept clarity and dissociation. Psychiatry Research, 228, 626–632. http://dx.doi.org/10.1016/j.psychres.2015.04.053. Hammersley, P., Read, J., Woodall, S., & Dillon, J. (2008). Childhood trauma and psychosis: The genie is out of the bottle. Journal of Psychological Trauma, 6, 7–20. http://dx.doi.org/10.1300/j513v06n02_02. Hardy, A., Emsley, R., Freeman, D., Bebbington, P., Garety, P. A., Kuipers, E. E., et al. (2016). Psychological mechanisms mediating effects between trauma and psychotic symptoms: The role of affect regulation, intrusive trauma memory, belief, and depression. Schizophrenia Bulletin, . 42, s34–s43. Herman, J. L. (1992). Complex PTSD: A syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5, 377–391. http://dx.doi.org/10.1007/ bf00977235. Hetzel, M. D., & McCanne, T. R. (2005). The roles of peritraumatic dissociation, child physical abuse, and child sexual abuse in the development of posttraumatic stress disorder and adult victimization. Child Abuse & Neglect, 29, 915–930. http://dx.doi.org/10.1016/j.chiabu.2004.11.008. Horowitz, M., Wilner, N. J., & Alvarez, W. (1979). Impact of events scale: A measure of subjective stress. Psychosomatic Medicine, 41, 209–218. http://dx.doi.org/10.
409
Child Abuse & Neglect 72 (2017) 404–410
J.Y. Choi
1097/00006842-197905000-00004. Humpston, C. S., Walsh, E., Oakley, D. A., Mehat, M. A., Bell, V., & Deeley, Q. (2016). The relationship between different types of dissociation and psychosis-like experience in a non-clinical sample. Consciousness & Cognition, 41, 83–92. http://dx.doi.org/10.1016/j.concog.2016.02.009. Janssen, I., Krabbendam, L., Bak, M., Hanssen, M., Vollebergh, W., de Graaf, R., et al. (2004). Childhood abuse as a risk factor for psychotic experiences. Acta Psychiatrica Scandinavica, 109, 38–45. http://dx.doi.org/10.1046/j.0001-690x.2003.00217.x. Kessler, R. C., McLaughlin, K. A., Green, J. G., Gruber, M. J., Sampson, N. A., Zaslavsky, A. M., et al. (2010). Childhood adversities and adult psychopathology in the WHO world mental health surveys. British Journal of Psychiatry, 197, 378–388. Kilcommons, A. M., & Morrison, A. P. (2005). Relationship between trauma and psychosis: An exploration of cognitive and dissociative factors. Acta Psychiatrica Scandinavica, 112, 351–359. http://dx.doi.org/10.1111/j.1600-0447.2005.00623.x. Kim, J. S., Han, K., Lim, J. Y., Lee, J. H., Min, B. B., & Moon, K. J. (2005). The korean version of minnesota multiphasic personality inventory-2. manual. Seoul, Korea: Maumsarang Ltd. Klaassen, R. M. C., Heins, M., Luteijn, L. B., van der Gaag, M., van Beveren, N. J. M., et al. (2012). Depressive symptoms are associated with (sub)clinical psychotic symptoms in patients with non-affective psychotic disorder, sibling and healthy controls. Psychological Medicine, 43, 747–756. http://dx.doi.org/10.1017/ s0033291712001572. Kline, R. E. (2005). Principle and practice of structural equation modeling. New York, NY: Guilford Press. Lardinois, M., Lataster, T., Mengelers, R., van Os, J., & Myin-Germeys, I. (2011). Childhood trauma and increased stress sensitivity in psychosis. Acta Psychiatry Scandinavia, 123, 28–35. http://dx.doi.org/10.1111/j.1600-0447.2010.01594.x. Marmar, C. R., Weiss, D. S., & Metzler, T. J. (1997). The peritraumatic dissociative experience questionnare. In J. P. Wilson, & T. M. Keane (Eds.). Assessing psychological trauma and PTSD: A practioner’s handbook (pp. 412–429). New York: Guilford Press. http://dx.doi.org/10.1037/t07470-000. Marshall, G. N., Orlando, M., Jaycox, L., Foy, D. W., & Belzberg, H. (2002). Development and validation of a modified version of the peritraumatic dissociative experience questionnaire. Psychological Assessment, 14, 12–134. http://dx.doi.org/10.1037//1040-3590.14.2.123. Moritz, S., Göritz, A. S., McLean, B., Westermann, S., & Brodbeck, J. (2017). Do depressive symptoms predict paranoia or vice versa? Journal of Behavior Therapy and Experimental Psychiatry, 56, 113–121. http://dx.doi.org/10.1016/j.jbtep.2016.10.002. Muenzenmaier, K. H., Seixas, A. A., Schneeberger, A. R., Castille, D. M., Battaglia, J., & Link, B. G. (2015). Cumulative effects of stressful childhood experiences on delusion and hallucinations. Journal of Trauma & Dissociation, 16, 442–462. http://dx.doi.org/10.1080/15299732.2015.1018475. Pelcovitz, D., van der Kolk, B., Roth, S., Mandel, F., Kaplan, S., & Resick, P. (1997). Development of a criteria set and a structured interview for disorders of extreme stress (SIDES). Journal of Traumatic Stress, 10, 3–16. http://dx.doi.org/10.1002/jts.2490100103. Preacher, K. L., & Hayes, A. F. (2008). Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models. Behavior Research Methods, 40, 879–891. http://dx.doi.org/10.3758/BRM.40.3.879. Read, J., Fosse, R., Moskowitz, A., & Perry, B. (2014). The traumagenic neurodevelopmental model of psychosis revisited. Neuropsychiatry, 4, 65–79. http://dx.doi.org/ 10.2217/npy.13.89. Schenkel, L. S., Spaulding, W. D., DiLillo, D., & Silverstein, S. M. (2005). Histories of childhood maltreatment in schizophrenia: Relationships with premorbid functioning, symptomatology, and cognitive deficits. Schizophrenia Research, 76, 273–286. http://dx.doi.org/10.1016/j.schres.2005.03.003. Shah, S., Mackinnon, A., Galletly, C., Carr, V., McGrath, J. J., Stain, H. J., et al. (2014). Prevalence and impact of childhood abuse in people with a psychotic illness. Data from the second Australian national survey of psychosis. Schizophrenia Research, 159, 20–26. http://dx.doi.org/10.1016/j.schres.2014.07.011. Vogel, M., Schatz, D., Spitzer, G., Kuwert, P., Moller, N., Freyberger, H. J., et al. (2009). A more proximal impact of dissociation than of trauma and posttraumatic stress disorder on Schneiderian symptoms in patients diagnosed with schizophrenia. Comprehensive Psychiatry, 50, 128–134. http://dx.doi.org/10.1016/j. comppsych.2008.06.007. Vogel, M., Meier, J., Gronke, S., Waage, M., Schneider, W.l., Freyberger, H. J., et al. (2011). Differential effects of childhood abuse and neglect: Mediation by posttraumatic distress in neurotic disorder and negative symptoms in schizophrenia? Psychiatry Research, 189, 121–127. http://dx.doi.org/10.1016/j.psychres. 2011.01.008. Weiss, D. S., & Marmar, C. R. (1997). The impact of event scale-Revised. In J. P. Wilson, & T. M. Keane (Eds.). Assessing psychological trauma and PTSD (pp. 399–411). New York: Guilford Press. http://dx.doi.org/10.1037/t12199-000. Westermann, S., & Lincoln, T. (2011). Emotion regulation difficulties are relevant to persecutory ideation. Psychology And. Psychotherapy, . Theory, Research, and Practice, 84, 273–287. http://dx.doi.org/10.1348/147608310x523019. Yu, J. H., Park, J. S., Park, D. H., Ryu, S. H., & Ha, J. H. (2009). Validation of the Korean childhood trauma questionnaire: The practical use in counseling and therapeutic intervention. The Korean Journal of Health Psychology, 14, 563–578. http://dx.doi.org/10.17315/kjhp.2009.14.3.006. van Ijzendoorn, M. H., & Schuengel, C. (1996). The measurement of dissociation in normal and clinical populations: Meta-analytic validation of the dissociative experiences scale (DES). Clinical Psychology Review, 16, 365–382. http://dx.doi.org/10.1016/0272-7358(96)00006-2. van Nierop, M., van, O. S. J., Gunther, N., van Zelst, C., de Graaf, R., ten Have, M., et al. (2014). Does social defeat mediate the association between childhood trauma and psychosis? Evidence from the NEMESIS-2 Study. Acta Psychiatrica Scandinavica, 129, 467–476. http://dx.doi.org/10.1111/acps.12212.
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Posttraumatic stress symptoms and dissociation between childhood trauma and two different types of psychosis-like experience
MARK
Ji Young Choi Department of Psychiatry, Sanggye Paik Hospital, Inje University, 1342, Dongilro, Nowon-gu, Seoul, Republic of Korea
AR TI CLE I NF O
AB S T R A CT
Keywords: Childhood trauma Persecutory ideation Aberrant experience Posttraumatic stress symptoms Dissociation Non-psychotic psychiatric patients
This study examined the roles of posttraumatic stress (PTS) symptoms and dissociation in the relationship between childhood trauma and two different types of psychosis-like experience, including persecutory ideation and aberrant experience, in non-psychotic psychiatric patients. From August 2015 to August 2016, among psychiatric out patients seeking treatment at the Department of Psychiatry at a major teaching medical hospital in Seoul, Korea, 169 patients who had never been diagnosed with a psychotic disorder, including schizophrenia spectrum disorder, bipolar disorder, and/or depressive disorder with psychotic features, completed the Korean Childhood Trauma Questionnaire, the Korean version of the Impact of Event Scale-Revised, the modified Korean version of the Peritraumatic Dissociation Experiences Questionnaire, and the Korean Minnesota Multiphasic Personality Inventory-2 (MMPI-2). The RC 6 (Ideas of Persecution) and RC 8 (Aberrant Experiences) of the restructured scales of the MMPI-2 were used as a measure of persecutory ideation and aberrant experience. Structural equation modeling analyses confirmed a partial mediation model in which PTS symptoms partially mediated the relationship between childhood trauma and persecutory ideation, and dissociation partially mediated the relationship between childhood trauma and aberrant experience. This implies that there are distinct mechanisms depending on the type of psychosis-like experience in relation to childhood trauma.
Childhood trauma has been widely accepted as one of the most significant environmental factors associated with the development of psychosis. There is copious evidence that childhood trauma significantly increases the risk for severe mental illnesses such as schizophrenia spectrum disorder, bipolar disorder, and depressive disorder with psychotic features (Janssen et al., 2004; Kessler et al., 2010; Vares et al., 2012). Childhood trauma has been suggested to be a predictor of psychosis later in life that often occurs in a dose-response manner, suggesting that psychosis worsens as the severity of trauma increases (Janssen et al., 2004; Schenkel, Spaulding, DiLillo, & Silverstein, 2005). Studies have also found that childhood trauma was related to sub-clinical psychosis, such as paranoid thinking and hallucinatory experience, in non-psychotic psychiatric patients and in the general population (Cole, NewmanTaylor, & Kennedy, 2016; Shah et al., 2014; van Nierop et al., 2014). Despite evidence for a relationship between childhood trauma and psychotic experience, the underlying mechanisms involved remain unclear. Posttraumatic stress (PTS) symptoms and dissociation have been suggested and explored as possible mediating factors by many researchers, because they are understood as responses to traumatic experiences (Evans et al., 2015; Vogel et al., 2011). Posttraumatic stress disorder (PTSD), which includes intrusion, arousal, and avoidance as diagnostic criteria, is a typical response after traumatic experience. Dissociation has also been commonly understood as the manifestation of automatic defense mechanisms that serve to mitigate the impact of traumatic experiences (van Ijzendoorn & Schuengel, 1996). Studies have
E-mail address: [email protected]. http://dx.doi.org/10.1016/j.chiabu.2017.08.023 Received 6 January 2017; Received in revised form 19 July 2017; Accepted 19 August 2017 0145-2134/ © 2017 Elsevier Ltd. All rights reserved.
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demonstrated that childhood trauma is associated with the experience of chronic PTS symptoms, which in turn increases the likelihood of psychosis in schizophrenia patients or broad psychotic disorder patients (Choi et al., 2015; Vogel et al., 2011). Dissociation has received more attention as the mediating factor in the relationship between childhood trauma and psychosis. As dissociation causes impaired reality testing, individuals who cope with trauma via dissociation are more likely to subsequently experience psychosis, not only in patients with severe mental illness, but also in the general population (Evans et al., 2015; Hammersley, Read, Woodall, & Dillon, 2008; Kilcommons & Morrison, 2005). However, there has been no attempt to test if PTS symptoms and dissociation play distinct roles as mediating factors in developing a psychotic experience. It is purported that the size of their contribution on a psychotic experience would be different, especially when considering that PTS symptoms and dissociation are somewhat different responses to traumatic experience (Hetzel and McCanne, 2005). Therefore, there is a need to explore whether these factors play distinct roles in the relationship between childhood trauma and psychotic experience. The severity of psychotic symptoms has generally been assessed by both hallucinations and delusions in studies targeting schizophrenia spectrum disorder. On some occasions, psychotic symptoms have included subjective thought disorder or confusion in addition to hallucinations and delusions (Choi et al., 2015). Although a psychotic experience can typically be divided into hallucinations and paranoid delusions, few studies have analyzed them separately (Cole et al., 2016; Muenzenmaier et al., 2015). It is possible that the effect of childhood trauma on paranoid thinking and proneness to hallucination differs, and PTS symptoms and dissociation fulfill different roles in the association between childhood trauma and the two types of psychotic experiences. Muenzenmaier et al. (2015) suggested that although dissociation appears to mediate the relation between stressful childhood experiences and hallucination, the relationship between delusions and cumulative trauma does not seem to be mediated by dissociative symptoms in people with psychosis disorders. Read, Fosse, Moskowitz, and Perry (2014) proposed that trauma-related affect regulation (as assessed by PTS symptoms) mediates the association between trauma and persecutory delusion. Recently, Cole et al. (2016) reported that dissociation mediates the relationship of early maltreatment and hallucination proneness with delusional ideation in the general population. Despite the limitation that the mediating roles of dissociation and PTS could not be compared with each other, these studies suggest the possibility of different mediating roles of dissociation and PTS symptoms in the relationship between childhood trauma and different types of psychotic experience. It has been reported that the incidence of paranoid thinking or hallucinatory experience in the general population is up to 20–30% (Moritz, Göritz, McLean, Westermann, & Brodbeck, 2017; Westermann & Lincoln, 2011). Paranoid thinking is associated with more severe depression and mood regulation difficulties, and hallucinatory experiences not only cause not subjective perturbations, but they also diminish coping abilities in relation to more arousals and difficulties of judgment (Altman, Clooins, & Mundy, 1997; Klaassen et al., 2012). Because psychosis-like experience is an important factor affecting adjustment levels in nonpsychotic psychiatric patients, it is important to explore the underlying mechanisms affecting the association between childhood trauma and psychotic experiences, targeting both patients with and without psychosis. The purpose of the current study was to test the distinct mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and two representative types of psychosis-like experiences, persecutory ideation and aberrant experiences, in a non-psychotic clinical sample. Aberrant experiences include bizarre sensitive and perceptual experiences, hallucination, and odd thought processes. The main hypothesis was that both PTS symptoms and dissociation play mediating roles, but they have different effect sizes depending on the type of psychotic experience. The model hypothesized that PTS symptoms, including fear, arousal, and mistrust toward others and toward the world have a stronger mediating effect between childhood trauma and persecutory ideation, while experiences of dissociated consciousness during and after traumatic events have more effects on unrealistic or bizzare perceptual and sensitive experiences.
1. Methods 1.1. Participants and procedure Participants included outpatients aged 18–65 years, visiting the psychiatry department of a major medical hospital in Seoul from August 2015 to August 2016. Among 347 patients, who underwent psychological evaluation, 169 adult outpatients met the following inclusion criteria finally participated in the study: (a) never being diagnosed with psychosis, with the potential of being accompanied by psychotic symptoms such as schizophrenia spectrum disorder bipolar disorders, major depressive disorder with psychotic features, psychotic disorder, or disorders that were not otherwise specified; (b) absence of organic brain dysfunction or other medical conditions, as determined by the psychiatrist’s opinion based history taking and medical exams, (c) not being diagnosed with PTSD and/ or acute stress disorder after experiencing recent traumatic events, to minimize confusion between the effects of childhood trauma and recent traumatic events, and (d) as indicated in the MMPI-2 manual, have more than 30 no-response items, and a T score of over 80 on the validity scales. Those individuals who provided informed consent to participate in the present study completed the measures as part of their evaluation. Usually, the outpatients in this study completed the assessment within two weeks of their initial consultation. Official diagnoses were made by staff psychiatrists based on the Diagnostic and Statistical Manual 4th Edition (DSM-IV). The study was approved by the hospital’s Institutional Review Board. The mean age of the sample was 35.53 years (SD = 16.59) with range of 18–60 years. The participants included 96 males (56.8%) and 73 females (43.2%).
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1.2. Measures 1.2.1. Korean childhood trauma questionnaire The Korean version of the Childhood Trauma Questionnaire was developed by Yu, Park, Ryu, and Ha (2009), who translated the original version (Berstein & Fink, 1998). This questionnaire comprises the 5 subscales of emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect, and 3 items pertaining to the validity scale (minimization/denial scale). Each item is scored on a 5-point Likert scale, with higher scores representing a more severe degree of abuse. Internal consistency of the Korean version was 0.79, and the Cronbach’s alpha across the 5 subscales was 0.80 (emotional abuse), 0.82 (physical abuse), 0.79 (sexual abuse), 0.89 (emotional neglect), and 0.51 (physical neglect; Yu et al., 2009). The Cronbach’s alpha values for the present study were 0.86 for physical abuse, 0.67 for physical neglect, 0.81 for emotional abuse, 0.87 for emotional neglect, and 0.78 for sexual abuse. 1.2.2. Korean version of the impact of event scale-Revised (IES-R-K) The Impact of Event Scale was originally developed as a self-report measure by Horowitz, Whiner, and Alvarez (1979), to measure the central features of PTSD, such as trauma-related symptoms of intrusion and avoidance. Weiss and Marmar (1997) revised it to include symptoms of hyperarousal. The IES-R consists of 22 items representing the subscales of intrusion, avoidance, numbing and dissociation, and hyperarousal, with each item scored on a 5-point Likert scale. The IES-R was translated into Korean and validated by Eun, Kwon, Lee, Kim, Choi, and Cho (2005). The overall internal consistency in the validation study in Korea was 0.77 and that for each subscale was between 0.69 and 0.83 (Eun et al., 2005). In the present study, the internal consistency was 0.94 for intrusion, 0.92 for avoidance, 0.85 for hyperarousal, and 0.76 for numbing and dissociation. 1.2.3. Korean version of modified version of the peritraumatic dissociation questionnaire (K-PDEQ) The PDEQ, modified by Marshall, Orlando, Jaycox, Foy, and Belzberg (2002) from the original PDEQ (Marmar, Weiss & Melzler, 1997), is an eight-item measure that retrospectively assesses dissociative phenomena that occur during a potentially traumatic event, using a 5-point scale. The K-PDEQ, translated and validated by Choi (2006), modified the direction to evaluate dissociative experiences lasting until the time of testing, and not only during traumatic events. These dissociative phenomena include altered time perception, depersonalization, and derealization. The internal consistency of the Korean version was 0.85 (Choi, 2006) and that in the present study was 0.91. 1.2.4. RC 6 (Ideas of persecution) and RC 8 (Aberrant experiences) of the restructured clinical (RC) scales of the minnesota multiphasic personality inventory-2 (MMPI-2) The MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) is widely used to assess symptoms and diagnostic possibilities comprehensively in clinical populations. The MMPI-2 has been standardized in Korea, with acceptable reliability and validity (Kim, Han, Lim, Lee, Min, & Moon, 2005). The restructured clinical scales were developed to minimize common factors and to improve their discriminant validity. The RC 6 scale consists of 17 items that assess paranoid ideation, persecutory ideas, or delusional thought. A higher score on this scale indicates a tendency toward paranoid ideation. The RC 8 consists of 18 items that assess symptoms of hallucination, bizarre sensory experiences, odd thought processes, and loss of reality testing. Higher scores on this scale indicate a tendency to experience bizarre sensations and perceptual experiences, beliefs not shared by others, and/or unrealistic fears of danger or harm (Ben-Porath & Tellegen, 2008). The validation study in Korea indicated an internal consistency of 0.71 for the RC 6 (Ideas of Persecution) and 0.72 for the RC 8 (Aberrant Experiences) (Kim et al., 2005). In the present study, the internal consistency was 0.78 for the RC 6 and 0.82 for the RC 8. 1.3. Data analysis Partial correlational analyses were conducted to examine the relationship between childhood trauma, PTS symptoms, dissociation, ideation of persecution, and aberrant experience after controlling for age and gender. Next, an SEM with a maximum likelihood estimation method was conducted using Amos 17.0 (Arbuckle, 2008), to examine the mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and the two types of psychosis-like experiences. For assessment of model fit, we used the Comparative Fit Index (CFI), the Bentler-Bonett Normed Fit Index (NFI), and the Root Mean Square Error of Approximation (RMSEA). Generally, a CFI and NFI greater than 0.90 and an RMSEA less than 0.10 indicate appropriate model fit (Byrne, 2010; Kline, 2005). The statistical significance of the mediating and indirect effects was assessed using the boostrapped bias-corrected percentile that is based on the confidence interval based on 1000 bootstrap draws (Preacher & Hayes, 2008). If zero was not within the 95% confidence intervals of the bootstrapped samples, then the mediating/indirect effect was considered statistically significant. 2. Results 2.1. Sample characteristics The primary psychiatric diagnoses of participants were as follows: 96 participants were diagnosed with depressive disorder (56.8%), 25 with anxiety disorder (14.8%), 7 with somatoform disorder (4.1%), 7 diagnosed with adjustment disorder (4.1%), and 22 with various issues, including impulse control disorder, substance use disorder, and personality disorder. Twelve participants were not specifically diagnosed. There were no gender difference in the variables, except for sexual abuse, F (1, 168) = 25.32, p = 0.000. 406
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Table 1 Partial Correlation among Variables. 1 1. 2. 3. 4. 5. 6. 7. 8. 9.
Physical Abuse Physical Neglect Emotional Abuse Emotional Neglect Sexual Abuse IES-R-K PDEQ RC6 of MMPI-2 RC8 of MMPI-2 Mean SD
2
3 ***
10.09 5.19
4 ***
5 ***
6 **
7 **
8
9 **
0.46
0.66 0.58***
0.47 0.67*** 0.65***
0.26 0.38*** 0.30*** 0.20**
0.21 0.27** 0.34*** 0.24** 0.17*
0.13 0.19* 0.22** 0.14 0.18* 0.65***
0.24 0.35*** 0.43*** 0.36*** 0.28*** 0.50*** 0.37***
0.25** 0.31*** 0.34*** 0.25** 0. 27*** 0.44*** 0.58*** 0.63***
9.78 4.08
9.85 4.94
13.38 5.35
6.93 3.27
58.29 22.42
14.83 7.43
54.31 12.46
54.21 13.14
Note. IES-R-K = Korean version of the Impact of Event Scale-revised; PDEQ = Peritraumatic Dissociation Experience Questionnaire; RC6 = Ideation of Persecution, RC8 = Aberrant Experience. * p < 0.05. ** p < 0.01. *** p < 0.001.
Means and standard deviations, along with a correlation matrix for all variables, have been presented in Table 1. None of the study variables were severely skewed or kurtotic. 2.2. Partial correlational analyses Table 1 shows the results of the partial correlational analyses. After controlling for age and gender, all types of maltreatment showed a moderate level of correlation with ideation of persecution and aberrant experiences, as measured by the RC scales of the MMPI-2 (r = 0.24–0.43, p < 0.001). The degree of each type of maltreatment was also significantly correlated with PTS symptoms (Physical Abuse [PA] r = 0.21, p = 0.005; Physical Neglect [PN] r = 0.27, p = 0.001; Emotional Abuse [EA] r = 0.34, p = 0.000; Emotional Neglect [EN] r = 0.24, p = 0.002; Sexual Abuse [SA] r = 0.17, p = 0.029). Physical neglect, emotional abuse, and sexual abuse showed modest but significant correlations with dissociation symptoms (PN: r = 0.19, p = 0.013; EA: r = 0.22, p = 0.004; SA: r = 0.18, p = 0.019). PTS symptoms and dissociation were very closely related with the two types of psychosis-like experiences (r = 0.37–.58, p = 0.000). 2.3. Structural equation modeling (SEM) To explore the mediating roles of PTS symptoms and dissociation in the relationship between childhood trauma and the two types of psychosis-like experiences in a nonpsychotic psychiatric sample, an SEM was conducted. First, the full mediation model was tested, wherein it was examined if PTS symptoms and dissociation fully mediated the relationship between childhood trauma and the two types of psychosis-like experiences. Next, a partial mediation model, with direct paths from childhood trauma to ideation of persecution and aberrant experience, was compared to the full mediation model (Kline, 2005). The full mediation SEM models did not demonstrate acceptable fit, χ2 (df = 23, N = 169) = 67.34, p = 0.000; CFI = 0.93; NFI = 0.90; RMSEA = 0.107 (90% CI = 0.078–.137). The partial mediation model (see Fig. 1) showed an acceptable fit, χ2 (df = 21, N = 169) = 39.05, p = 0.010; CFI = 0.97; NFI = 0.94; RMSEA = 0.072 (90% CI = 0.035–.106). Thus, the partial mediation model was deemed the most appropriate model for the relationship between childhood trauma, PTS symptoms, dissociation, and the two types of psychosis-like experiences examined. Childhood trauma was directly related to each psychosis-like experience (RC 6 β = 0.38, p < 0.001; RC 8 β = 0.28, p < 0.001). Childhood trauma had a significant indirect relationship with ideation of persecution, which was mediated by PTS symptoms (indirect combined β = 0.36, and β = 0.29, p < 0.001), but the indirect relationship between childhood trauma and aberrant experience via PTS symptoms was not significant. Meanwhile, childhood trauma displayed a significant indirect relationship with aberrant experience through dissociation (indirect combined β = 0.24, and β = 0.51, p < 0.001), but childhood trauma had no indirect relationship with ideation of persecution through dissociation. Further, respectively, 41.0% and 50.4% of the variance in ideation of persecution and aberrant experience was accounted for by the model. In the analysis using bootstrapped 95% confidence intervals, confidence intervals that do not include zero would indicate the presence of significant indirect effects. The indirect effect of childhood trauma on persecutory ideation through PTS symptoms (β = 0.13, 95% confidence interval = 0.06 to 0.22) as well as that of childhood trauma on aberrant experience through dissociation (β = 0.13, 95% confidence interval = 0.02 to 0.23) were significant. 3. Discussion This study attempted to test different mediating effects of PTS symptoms and dissociation in the relationship between childhood 407
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Fig. 1. The partial mediation model (N = 169). Path coefficients were standardized. Note. PA = Physical Abuse; PN = Physical Neglect; EA = Emotional Abuse; EN = Emotional Neglect; SA = Sexual Abuse; PTS = Posttraumatic Stress. ** p < 0.01, ***p < 0.001
trauma and two representative types of psychosis-like experiences, in a non-psychotic psychiatric sample. While previous research examining the relationship between childhood trauma and psychosis has typically focused on the comprehensive psychotic experience, we divided psychotic experiences into persecutory ideation and aberrant experience. Furthermore, it was hypothesized that different responses to trauma, like PTS symptoms and dissociation, play distinct roles according to the type of psychotic experience. The potential hypothesis is that PTS symptoms would play a more important role in the relationship between childhood trauma and persecutory ideation, and dissociation would play a more significant role in the relationship between childhood trauma and aberrant experiences. The use of SEM in the present study allowed simultaneous examination of two types of psychosis-like experiences and two mediating factors. The current analysis revealed that childhood trauma was directly and indirectly related to two types of psychosis-like experiences. All types of childhood trauma were highly correlated with persecutory ideation and aberrant experience. Such results are consistent with the findings of prior studies that childhood trauma affects the degree of psychotic symptoms, and that psychosis-like symptoms are associated with childhood trauma in both non-psychotic clinical and community samples (Cole et al., 2016; Janssen et al., 2004; Lardinois, Lataster, Mengelers, van Os, & Myin-Germeys, 2011). On the other hand, these findings are also consistent with a series of prior studies that suggested that childhood cumulative trauma predicts complex PTSD symptoms, including alteration in attention or consciousness and alteration in perception of others (Herman, 1992; Pelcovitz et al., 1997). The present SEM results indicated that both PTS symptoms and dissociation play distinct mediating roles in the relationship between childhood trauma and the two different types of psychotic-like experiences examined. The PTS symptoms partially mediated the relationship of childhood trauma with ideation of persecution, but not that with aberrant experience. Additionally, dissociation partially mediated the relationship of childhood trauma with aberrant experience, but not that with persecutory ideation. Previous research had already suggested that PTS symptoms and dissociation in response to trauma might play a causal role in the development of psychosis and subclinical psychosis (Evans et al., 2015; Vogel et al., 2009). More recently, some studies have explored the role of PTS symptoms and dissociation as underlying mediating factors between childhood trauma and psychotic experience in both clinical and nonclinical samples, and have tried to divide psychosis experience into hallucination and delusion (Cole et al., 2016; Hardy et al., 2016; Humpston et al., 2016). Methodologically, however, a test of potentially distinct mediation was not conducted in one model. Although it is difficult to compare our result with that of previous studies directly, the result is relevant with Muenzenmaier et al.’s (2015) study, which revealed that the association between stressful childhood experiences and hallucination completely lost significance when dissociation was controlled, but the association between stressful childhood experiences and delusion was significant independent of dissociation. The result that PTS symptom is a more important mediator in relationship with persecutory ideation is also relevant with the previous suggestion that childhood victimization results in neurodevelopmental changes such as hyperactivity of the hypothalamic-pituitary axis through PTS symptoms, and that it may render people more vulnerable to interpret external cues as negative (Read et al., 2014). However, when we consider that Hardy et al. (2016) hypothesized more specific mechanisms, including posttraumatic avoidance and numbing, intrusive trauma memory, and negative belief between childhood trauma type and type of psychotic experience in psychosis, we hypothesized that PTS symptoms included two 408
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comprehensive symptoms as a mediator of persecutory ideation. Therefore, it is necessary to explore the mediating role of more specified PTS symptoms. Although more detailed explorations of the relationship between childhood trauma and psychotic experience are needed, our result about potentially distinct mediating roles suggests the intervention points for people with subclinical psychotic symptoms. According to the type of psychosis-like experiences, focusing on dissociation or PTS symptoms could help reduce psychotic experiences. In case of aberrant experience, it is more helpful to focus on reprocessing and contextualizing the trauma-related memory, but in persecutory ideation, it is more helpful to learn how to stabilize or soothe lasting hyperarousal in addition to reconstructing the negative belief about others. Limitations of this study include the use of retrospective self-reports, small sample size, and relative low reliability of one subscale of the CTQ, which limits the generalization of the present findings. Moreover, because of the cross-sectional design, no firm conclusions can be made about causal relationships. Second, although we tried to minimize the confusion of the effects of childhood trauma and recent traumatic events by excluding individuals diagnosed with PTSD, we could not control the effect of various adulthood traumas. Another concern is related to the fact that there could be an overlap between dissociation and aberrant experience in the non-psychosis sample, although the two scale assess distinct constructs. Fourth, we were not able to examine the potential differences attributable to different types of childhood trauma. Based on the results of the partial correlation analysis, all types of childhood trauma were significantly related to PTS symptoms, but physical abuse and neglect were not significantly related to dissociation. In this study, we focused on overall childhood trauma, however, in future, it is necessary to explore whether that relationship between dissociation and aberrant experience differs according to the type of childhood trauma. Despite these limitations, the results of the present study highlight the distinct mediating effects of PTS symptoms and dissociation in the relationship between childhood trauma and two different types of psychosis-like experiences in a nonpsychotic clinical sample. Although some previous studies have explored the mediating role of PTS symptoms or dissociation respectively, this study was the first attempt to test the underlying mechanisms between two mediating factors and two types of psychosis-like experiences, simultaneously. This has the clinical implication that interventions for childhood trauma related to PTS symptoms and dissociation are useful to help various non-psychotic patients suffering from psychosis-like experiences to develop insight and controllability of symptoms. Meanwhile, it is hoped that the mechanism in the path from childhood trauma to the two types of psychotic symptoms, via PTS symptoms and dissociation, can be confirmed by replicating the findings of the current study in a sample of patients with severe mental illness, whose psychotic symptoms receive more clinical attention. The comparison between non-psychosis and psychosis samples could suggest theoretical and clinical implications. Funding information This research did not receive any specific grant from funding agencies in the public commercial, or not −for-profit sectors. Competing interests The authors declare that they have no competing interests. References Altman, H., Collins, M., & Mundy, P. (1997). Subclinical hallucinations and delusions in nonpsychotic adolescents. Journal of Child Psychology & Psychiatry, 38, 413–420. http://dx.doi.org/10.1111/j.1469-7610.1997.tb01526.x. Arbuckle, J. L. (2008). AMOS 17.0 user’s guide. New York: SPSS Inc. Ben-Porath, Y. S., & Tellegen, A. (2008). MMPI-2-RF (Minnesota multiphasic personality inventory-2 restructured form) manual for administration, scoring, and interpretation. Minneapolis: University of Minnesota Press. Berstein, D., & Fink, L. (1998). Childhood trauma questionnaire: A retrospective self-reportSan Antonio, TX: Psychological Corporation. Butcher, J. N., Dahlstrom, W. G., Graham, J. R., Tellegen, A., & Kaemmer, B. (1989). Minnesota multiphasic personality inventory-2 (MMPI-2): Manual for administration, scoring, and interpretation. Minneapolis, MN: University of Minnesota Press. Byrne, B. M. (2010). Structural equation modeling with AMOS: Basic concepts, applications, and programming (2nd ed.). New York, NY: Routledge. Choi, J. Y., Choi, Y. M., Kim, B., Lee, D. W., Gim, M. S., & Park, S. H. (2015). The effects of childhood abuse on self-reported psychotic symptoms in severe mental illness: Mediating effects of posttraumatic stress symptoms. Psychiatry Research, 229, 389–393. http://dx.doi.org/10.1016/j.psychres.2015.05.112. Choi, H. (2006). The impact of dissociative experiences on traumatic stress in prostituted women with prolonged trauma. Seoul, Republic of Korea: Seoul National University [Unpublished master’s thesis]. Cole, C. L., Newman-Tayler, K., & Kennedy, F. (2016). Dissociation mediates the relationship between childhood maltreatment and subclinical psychosis. Journal of Trauma & Dissociation, 17, 577–592. http://dx.doi.org/10.1080/15299732.2016.1172537. Eun, H. J., Kwon, T. W., Lee, S. M., Kim, T. H., Choi, M. R., & Cho, S. J. (2005). A study on reliability and validity of the Korean version of Impact of Event ScaleRevised. Journal of the Korean Neuropsychiatric Association, 44, 303–310. Evans, G. J., Reid, G., Preston, P., Palmier-Claus, J., & Sellwood, W. (2015). Trauma and psychosis: The mediating role of self-concept clarity and dissociation. Psychiatry Research, 228, 626–632. http://dx.doi.org/10.1016/j.psychres.2015.04.053. Hammersley, P., Read, J., Woodall, S., & Dillon, J. (2008). Childhood trauma and psychosis: The genie is out of the bottle. Journal of Psychological Trauma, 6, 7–20. http://dx.doi.org/10.1300/j513v06n02_02. Hardy, A., Emsley, R., Freeman, D., Bebbington, P., Garety, P. A., Kuipers, E. E., et al. (2016). Psychological mechanisms mediating effects between trauma and psychotic symptoms: The role of affect regulation, intrusive trauma memory, belief, and depression. Schizophrenia Bulletin, . 42, s34–s43. Herman, J. L. (1992). Complex PTSD: A syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5, 377–391. http://dx.doi.org/10.1007/ bf00977235. Hetzel, M. D., & McCanne, T. R. (2005). The roles of peritraumatic dissociation, child physical abuse, and child sexual abuse in the development of posttraumatic stress disorder and adult victimization. Child Abuse & Neglect, 29, 915–930. http://dx.doi.org/10.1016/j.chiabu.2004.11.008. Horowitz, M., Wilner, N. J., & Alvarez, W. (1979). Impact of events scale: A measure of subjective stress. Psychosomatic Medicine, 41, 209–218. http://dx.doi.org/10.
409
Child Abuse & Neglect 72 (2017) 404–410
J.Y. Choi
1097/00006842-197905000-00004. Humpston, C. S., Walsh, E., Oakley, D. A., Mehat, M. A., Bell, V., & Deeley, Q. (2016). The relationship between different types of dissociation and psychosis-like experience in a non-clinical sample. Consciousness & Cognition, 41, 83–92. http://dx.doi.org/10.1016/j.concog.2016.02.009. Janssen, I., Krabbendam, L., Bak, M., Hanssen, M., Vollebergh, W., de Graaf, R., et al. (2004). Childhood abuse as a risk factor for psychotic experiences. Acta Psychiatrica Scandinavica, 109, 38–45. http://dx.doi.org/10.1046/j.0001-690x.2003.00217.x. Kessler, R. C., McLaughlin, K. A., Green, J. G., Gruber, M. J., Sampson, N. A., Zaslavsky, A. M., et al. (2010). Childhood adversities and adult psychopathology in the WHO world mental health surveys. British Journal of Psychiatry, 197, 378–388. Kilcommons, A. M., & Morrison, A. P. (2005). Relationship between trauma and psychosis: An exploration of cognitive and dissociative factors. Acta Psychiatrica Scandinavica, 112, 351–359. http://dx.doi.org/10.1111/j.1600-0447.2005.00623.x. Kim, J. S., Han, K., Lim, J. Y., Lee, J. H., Min, B. B., & Moon, K. J. (2005). The korean version of minnesota multiphasic personality inventory-2. manual. Seoul, Korea: Maumsarang Ltd. Klaassen, R. M. C., Heins, M., Luteijn, L. B., van der Gaag, M., van Beveren, N. J. M., et al. (2012). Depressive symptoms are associated with (sub)clinical psychotic symptoms in patients with non-affective psychotic disorder, sibling and healthy controls. Psychological Medicine, 43, 747–756. http://dx.doi.org/10.1017/ s0033291712001572. Kline, R. E. (2005). Principle and practice of structural equation modeling. New York, NY: Guilford Press. Lardinois, M., Lataster, T., Mengelers, R., van Os, J., & Myin-Germeys, I. (2011). Childhood trauma and increased stress sensitivity in psychosis. Acta Psychiatry Scandinavia, 123, 28–35. http://dx.doi.org/10.1111/j.1600-0447.2010.01594.x. Marmar, C. R., Weiss, D. S., & Metzler, T. J. (1997). The peritraumatic dissociative experience questionnare. In J. P. Wilson, & T. M. Keane (Eds.). Assessing psychological trauma and PTSD: A practioner’s handbook (pp. 412–429). New York: Guilford Press. http://dx.doi.org/10.1037/t07470-000. Marshall, G. N., Orlando, M., Jaycox, L., Foy, D. W., & Belzberg, H. (2002). Development and validation of a modified version of the peritraumatic dissociative experience questionnaire. Psychological Assessment, 14, 12–134. http://dx.doi.org/10.1037//1040-3590.14.2.123. Moritz, S., Göritz, A. S., McLean, B., Westermann, S., & Brodbeck, J. (2017). Do depressive symptoms predict paranoia or vice versa? Journal of Behavior Therapy and Experimental Psychiatry, 56, 113–121. http://dx.doi.org/10.1016/j.jbtep.2016.10.002. Muenzenmaier, K. H., Seixas, A. A., Schneeberger, A. R., Castille, D. M., Battaglia, J., & Link, B. G. (2015). Cumulative effects of stressful childhood experiences on delusion and hallucinations. Journal of Trauma & Dissociation, 16, 442–462. http://dx.doi.org/10.1080/15299732.2015.1018475. Pelcovitz, D., van der Kolk, B., Roth, S., Mandel, F., Kaplan, S., & Resick, P. (1997). Development of a criteria set and a structured interview for disorders of extreme stress (SIDES). Journal of Traumatic Stress, 10, 3–16. http://dx.doi.org/10.1002/jts.2490100103. Preacher, K. L., & Hayes, A. F. (2008). Asymptotic and resampling strategies for assessing and comparing indirect effects in multiple mediator models. Behavior Research Methods, 40, 879–891. http://dx.doi.org/10.3758/BRM.40.3.879. Read, J., Fosse, R., Moskowitz, A., & Perry, B. (2014). The traumagenic neurodevelopmental model of psychosis revisited. Neuropsychiatry, 4, 65–79. http://dx.doi.org/ 10.2217/npy.13.89. Schenkel, L. S., Spaulding, W. D., DiLillo, D., & Silverstein, S. M. (2005). Histories of childhood maltreatment in schizophrenia: Relationships with premorbid functioning, symptomatology, and cognitive deficits. Schizophrenia Research, 76, 273–286. http://dx.doi.org/10.1016/j.schres.2005.03.003. Shah, S., Mackinnon, A., Galletly, C., Carr, V., McGrath, J. J., Stain, H. J., et al. (2014). Prevalence and impact of childhood abuse in people with a psychotic illness. Data from the second Australian national survey of psychosis. Schizophrenia Research, 159, 20–26. http://dx.doi.org/10.1016/j.schres.2014.07.011. Vogel, M., Schatz, D., Spitzer, G., Kuwert, P., Moller, N., Freyberger, H. J., et al. (2009). A more proximal impact of dissociation than of trauma and posttraumatic stress disorder on Schneiderian symptoms in patients diagnosed with schizophrenia. Comprehensive Psychiatry, 50, 128–134. http://dx.doi.org/10.1016/j. comppsych.2008.06.007. Vogel, M., Meier, J., Gronke, S., Waage, M., Schneider, W.l., Freyberger, H. J., et al. (2011). Differential effects of childhood abuse and neglect: Mediation by posttraumatic distress in neurotic disorder and negative symptoms in schizophrenia? Psychiatry Research, 189, 121–127. http://dx.doi.org/10.1016/j.psychres. 2011.01.008. Weiss, D. S., & Marmar, C. R. (1997). The impact of event scale-Revised. In J. P. Wilson, & T. M. Keane (Eds.). Assessing psychological trauma and PTSD (pp. 399–411). New York: Guilford Press. http://dx.doi.org/10.1037/t12199-000. Westermann, S., & Lincoln, T. (2011). Emotion regulation difficulties are relevant to persecutory ideation. Psychology And. Psychotherapy, . Theory, Research, and Practice, 84, 273–287. http://dx.doi.org/10.1348/147608310x523019. Yu, J. H., Park, J. S., Park, D. H., Ryu, S. H., & Ha, J. H. (2009). Validation of the Korean childhood trauma questionnaire: The practical use in counseling and therapeutic intervention. The Korean Journal of Health Psychology, 14, 563–578. http://dx.doi.org/10.17315/kjhp.2009.14.3.006. van Ijzendoorn, M. H., & Schuengel, C. (1996). The measurement of dissociation in normal and clinical populations: Meta-analytic validation of the dissociative experiences scale (DES). Clinical Psychology Review, 16, 365–382. http://dx.doi.org/10.1016/0272-7358(96)00006-2. van Nierop, M., van, O. S. J., Gunther, N., van Zelst, C., de Graaf, R., ten Have, M., et al. (2014). Does social defeat mediate the association between childhood trauma and psychosis? Evidence from the NEMESIS-2 Study. Acta Psychiatrica Scandinavica, 129, 467–476. http://dx.doi.org/10.1111/acps.12212.
410