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The Danish Center of Psychotraumatology


Military deployment and combat experiences can lead to invasive psychological, physiological and interpersonal issues manifested in PTSD. However, military deployment and combat experiences alone cannot explain the development of PTSD. In military contexts, it is therefore necessary to screen soldiers before deployment to identify pre-existing vulnerabilities as potential ricofactors for the development of PTSD after deployment.
In recent years, there has been an increased focus on dissociation as a possible pre-existing vulnerability for the development of PTSD. The most characteristic features of dissociation involve negative symptoms such as amnesia, loss of bodily control and loss of somato-sensory awareness (e.g. depersonalisation).
The Danish Center for Psychotraumatology contributes research on dissociation and its role as a pre-existing vulnerability in the development of PTSD. Among other things, studies have been conducted on the connection between this pre-existing vulnerability and the Big Five personality traits as a further contribution to our understanding of the development of PTSD.
Read more about the Center's contributions on this page.



Dissociative experiences are common in traumatized individuals, and can sometimes be mistaken for psychosis. It is difficult to identify pathological dissociation in the treatment of traumatized refugees, because there is a lack of systematic clinical descriptions of dissociative phenomena in refugees. Furthermore, we are currently unaware of how dissociation measures perform in this clinical group. To describe the phenomenology of dissociative symptoms in Bosnian treatment-seeking refugees in Denmark. As a part of a larger study, dissociation was assessed systematically in 86 Bosnian treatment-seeking refugees using a semi-structured clinical interview (Structured Interview for Disorders of Extreme Stress-dissociation subscale; SIDES-D) and a self-report scale (Dissociative Experiences Scale; DES). The SIDES-D indicated twice as high prevalence of pathological dissociation as the DES. According to the DES, 30% of the refugees had pathological dissociation 15 years after their resettlement. On the SIDES-D, depersonalization and derealization experiences were the most common. Also, questions about depersonalization and derealization at times elicited reporting of visual and perceptual hallucinations, which were unrelated to traumatic re-experiencing. Questions about personality alteration elicited spontaneous reports of a phenomenon of "split" pre- and post-war identity in the refugee group. Whether this in fact is a dissociative phenomenon, characteristic of severe traumatization in adulthood, needs further examination. Knowledge of dissociative symptoms in traumatized refugees is important in clinical settings to prevent misclassification and to better target psychotherapeutic interventions. Much development in the measurement of dissociation in refugees is needed.

Palic, S., Carlsson, J., Armour, C. & Elklit A.: (2015). Assessment of dissociation in Bosnian treatment-seeking refugees in Denmark. Nordic Journal of Psychiatry, 69, 307-314. Doi: 10.3109/08039488.2014.977344

Abstract: Childhood sexual abuse (CSA) is an extreme traumatic event associated with numerous long lasting difficulties and symptoms (e.g., Herman, 1992). These include, among other things, the impediment of basic interpersonal structures of attachment (Rumstein-McKean & Hunsley, 2001), as well as impairment of mental integration manifested in dissociation (Van Den Bosch et al., 2003). Theoretically, attachment insecurities and dissociation are closely linked, since dissociation is generated as a way to resolve the conflicted attachment demands faced by the abused child (e.g., Liotti, 1992). Nevertheless, the directionality of association between attachment insecurities and dissociation during treatment of adult CSA survivors remains largely uninvestigated. Filling this gap, the present prospective study assessed female adult survivors of CSA who were outpatients at four treatment centers in Denmark ( n = 407), at the start of treatment (T1), 6 months after starting treatment (T2) and 12 months after starting treatment (T3). Results indicated that both attachment insecurities and dissociation reduced over time during treatment. Elevated attachment insecurities were associated with elevated dissociation at each of the measurements. Moreover, there was a reciprocal association between attachment avoidance and dissociation during treatment. Low levels of attachment avoidance predicted a decline in dissociation and vice versa. Findings suggest that treatment creates a cycle of healing in which rehabilitation of attachment fosters reintegration, which in turn deepens the restoration of attachment.


Lahav, Y. & Elklit, A. (2016). The cycle of healing - dissociation and attachment during treatment of CSA survivors. Child Abuse and Neglect, 60, 67-76. Doi: 10.1016/j.chiabu.2016.09.009


Objective: This study investigated whether pre-deployment dissociation was associated with previously identified post-traumatic stress disorder (PTSD) symptom trajectories from before to 2.5 years after military deployment. Furthermore, it examined whether the tendency to dissociate, pre-deployment personality factors, conceptualized by the Big Five model, and previous trauma represented independent risk factors for post-deployment PTSD symptoms. Method: This prospective study included the entire team of 743 soldiers from the Danish Contingent of the International Security Assistance Force 7 deployed to Afghanistan in 2009. Data consisted of self-report measures and were collected six times: before deployment; during deployment; and 1-3 weeks, 2 months, 7 months and 2.5 years after homecoming. Results: The findings indicate significant associations between pre-deployment dissociation and six PTSD trajectories (p < 0.001, η2 = 0.120). Based on mean differences in dissociation for the six trajectories, two main groups emerged: a group with high dissociation scores at predeployment, which had moderate PTSD symptom levels at pre-deployment and fluctuated over time; and a group with low dissociation scores at pre-deployment, which had low initial PTSD symptom levels and diverged over time. Our study also confirmed previous findings of a positive association between neuroticism and dissociation (r = 0.31, p < 0.001). This suggests that negative emotionality may be a vulnerability that enhances dissociative experiences, although a causal link cannot be concluded from the findings. Finally, pre-deployment dissociation, pre-deployment neuroticism and a history of traumatic events, as independent factors, were significant predictors of post-deployment PTSD (p < 0.001, R2 = 0.158). Conclusions: The study emphasizes the multiplicity of factors involved in the development of PTSD, and group differences in dissociative symptoms support the heterogeneity in PTSD. Further, this study points to specific aspects of personality that may be targeted in a clinical setting and in pre-deployment assessments in the military.


Ponce de Leon, B., Andersen, S. Karstoft, K. & Elklit, A. (2017). Pre-deployment dissociation and personality as risk factors for post-deployment PTSD in Danish soldiers deployed to Afghanistan. European Journal of Psychotraumatology, 9:1, 1443672. Doi: 10.1080/20008198.2018.1443672

While post‐traumatic stress disorder (PTSD) and psychotic disorders are classified as separate disorders, there is increasing evidence that the two may be related. This chapter reviews the literature pertaining to post‐psychotic PTSD by addressing the trauma of psychotic experiences and the trauma of associated hospitalization procedures. It also reviews the literature pertaining to the co‐occurrence of psychotic experiences and PTSD. Shaner and Eth first documented that the experience of schizophrenia could lead to the future development of PTSD symptoms. In the years since the publication of their seminal study, numerous researchers have addressed the contribution made to PTSD symptoms by psychotic symptomatology and hospitalization procedures, such as coercive interventions and involuntary treatment. Dissociation is broadly described as a disruption of the integrated functions relating to consciousness, memory, identity, or perception. Dissociation has long been associated with PTSD. Peri‐traumatic dissociation creates fragmented memories of a trauma event, which are subsequently thought to develop into post‐traumatic symptomatology.


Armour, C., Shevlin, M., Elklit, A. & Houston, J.: Posttraumatic Stress Disorder with psychotic features. In A. Moskowitz, In. Schäfetraumar, & M. J. Dorahy (Eds.): Trauma, Dissociation & Psychosis (pp 257-270). Chicester, UK: Wiley-Blackwell, 2019. Doi: 10.1002/9781118585948.ch16

The current prospective study assessed the temporal relations between dissociation and posttraumatic stress (PTS) in a sample of treatment-seeking female survivors of childhood sexual abuse. PTS refers to symptoms associated with posttraumatic stress disorder (PTSD) in the absence of a clinical diagnosis of PTSD. Initial assessment was on average 23 years after the onset of abuse (N = 405), and participants were followed-up after 6 months (N = 245) and 12 months (N = 119). Findings indicated that dissociative experiences and PTS were highly correlated within each wave of data collection. Cross-lagged panel analysis revealed that at each assessment period dissociative symptoms and PTS levels, respectively, were primarily explained by scores on the same variable at the previous assessment period. Although further reciprocal relations between dissociation and PTS were evident, these associations were relatively weak in magnitude. Current results provide important insights into the temporal relations between dissociative symptoms and PTS. The high correlations between dissociative experiences and PTS several years after trauma exposure have important clinical implications that may affect their treatment and trauma recovery.


Murphy, S., Elklit, A., Murphy, J., Hyland, P. & Shevlin, M. (2017). A Cross-Lagged Panel Study of Dissociation and Posttraumatic Stress in a Treatment-Seeking Sample of Victims of Childhood Sexual Abuse. Journal of Clinical Psychology, 73, 1370-1381. Doi: 10.1002/jclp.22439

Background: Although peritraumatic dissociation (PD) is viewed as a risk factor for posttraumatic stress disorder (PTSD), prospective studies taking into account other well-known risk factors for PTSD have been scarce, and the exploration of potential moderators within the relations between PD and PTSD has been lacking.
Objective: Filling this gap, this prospective study explored the moderating role of perceived threat within the relations between PD and PTSD, above and beyond age, gender, education, and early trauma-related symptoms.
A convenience sample of 200 Israeli civilians filled out self-report questionnaires during the peritraumatic phase (T1) and one to two months after the posttraumatic phase (T2) of being exposed to rocket attacks.
Results: The results showed that perceived threat and PD were associated with early trauma-related symptoms and PTSD symptoms. Moreover, perceived threat moderated the relationship between PD and all PTSD symptom clusters apart from avoidance.
Conclusions: The present results suggest that the implications of PD are shaped by levels of perceived threat, so that detriments of PD are evident when the trauma is appraised as being highly threatening. Therefore, early interventions that aim to decrease PD may be beneficial in preventing PTSD symptoms of intrusion, hyper arousal, and negative alterations in mood and cognition, for individuals who perceive traumatic events as highly threatening.


Relevant Publications:
Dokkedahl, S. B., & Lahav, Y. (2024). Peritraumatic dissociation and posttraumatic stress symptoms: the moderating role of perceived threat. European Journal of Psychotraumatology15(1). DOI: 10.1080/20008066.2024.2338670


Last Updated 29.09.2023