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Free Webinar November 6th, 7-8.30pm
Unveiling Acute Trauma-Related Dissociation in Body, Brain, and Mind: Novel Evidence from Two Script-Driven Imagery Studies
Yoki L. Mertens, M.Sc., clinical researcher and practitioner, Hamburg, Germany
Title: Neural Correlates of Acute Posttraumatic Dissociation – Findings from an fMRI Script-driven Imagery Study
Yoki Linn Mertens¹, Antje Manthey², Anika Sierk², Henrik Walter², Peter de Jong1, & Judith Daniels¹
¹Department of Clinical Psychology and Experimental Psychopathology, University of Groningen, Netherlands
²Charité Universitätsmedizin Berlin, Berlin, Germany
Abstract
Neurobiological models conceptualize acute posttraumatic dissociation as a frontal-limbic-mediated shutdown response, which follows an initially heightened excitability of the amygdala. This study investigated the causal hypothesis regarding the emergence of dissociation and the associated changes in neural activation using a placebo-controlled, pharmacological challenge paradigm. Functional magnetic resonance imaging (fMRI) data were collected in a large sample of female PTSD patients. Participants were scanned twice, with the order of medication administration (reboxetine vs. placebo) randomly assigned and balanced (double-blind). Brain activations during the exposure to traumatic (vs. neutral) autobiographical memories (i.e., script-driven imagery) were analyzed, and the observed activation patterns were correlated with questionnaires measuring acute and chronic dissociation. Neuroimaging analyses in the placebo condition (N = 51) revealed increased activation found in the occipital gyri, supramarginal gyrus, and amygdala, among others. However, none of the brain activation clusters correlated with dissociative symptoms, despite participants reporting a heightened level of script-elicited acute dissociation during the paradigm. Within-subject comparison of the reboxetine vs. placebo condition (N = 47) did not show any significant differences in whole-brain and amygdala (i.e., (preregistered region-of-interest) activation, hence the pharmacological manipulation was not successful. To conclude, the present investigation did not provide evidence for the cortico-limbic inhibition hypothesis and was unable to replicate previous findings despite the robust sample size and similar methodology employed. In light of the replication crisis, these (null) findings highlight the difficulty in identifying reliable neuromarkers of dissociation
Citations
Mertens, Y. L., Manthey, A., Sierk, A., de Jong, P., Walter, H., & Daniels, J. K. (2023). A pharmacological challenge paradigm to assess neural signatures of script-elicited acute dissociation in women with post-traumatic stress disorder. BJPsych Open, 9(3), e78. http://doi.org//10.1192/bjo.2023.34
Mertens, Y. L., Manthey, A., Sierk, A., Walter, H., & Daniels, J. K. (2022). Neural correlates of acute post-traumatic dissociation: a functional neuroimaging script-driven imagery study. BJPsych Open, 8(4), e109. https://doi.org/10.1192/bjo.2022.65
Yoki L. Mertens
M.Sc.Yoki L. Mertens, M.Sc., is a clinical researcher and practitioner, currently based in Hamburg, Germany. She is interested in trauma-related dissociation, investigated through a neurobiological lens as part of her PhD project at the University of Groningen, NL, and follows a clinical training to become a trauma therapist. Yoki co-founded the early career researcher network “DIS.Connected” (https://disconnected-network.com/) dedicated to promoting exchange between early career dissociation researchers and is part of the DeGPT (https://www.degpt.de) working group for dissociative disorders. You can find her research output here: https://www.researchgate.net/profile/Yoki_Mertens and can contact her via yoki.mertens@gmail.com.
Dr. Sarah K. Danböck, Department of Clinical and Biological Psychology and Psychotherapy at the University of Mannheim
Title: Acute Dissociation as Part of the Defense Cascade: Associations With Behavioral, Autonomic, and Experiential Threat Responses in Posttraumatic Stress Disorder.
Sarah K. Danböck1,2, Michael Liedlgruber2, Laila K. Franke2, Stephan F. Miedl2, Sabrina E. Hettegger2, Rainer-Christian Weber3, Frank H. Wilhelm2
1 Department of Biological and Clinical Psychology and Psychotherapy, University of Mannheim, Germany
2 Division of Clinical Psychology and Psychopathology, Department of Psychology, Paris Lodron University of Salzburg, Austria
3 Center of Psychotraumatology, BG Clinic Bad Reichenhall, Bad Reichenhall, Germany
Abstract
Dissociative symptoms, such as depersonalization and derealization, are experienced by about half of individuals with posttraumatic stress disorder (PTSD). Theoretical models propose that acute dissociation is accompanied by specific behavioral, physiological, and experiential alterations and contributes to unfavorable PTSD symptom course. Yet, empirical evidence is scarce. This talk will present the results of a pre-registered script-driven imagery study in 71 individuals with PTSD that examined associations between dissociative and behavioral, physiological, and experiential responses to trauma-reminders as well as effects of dissociative responding on PTSD symptom course. Participants were exposed to detailed personalized trauma and neutral scripts. Stabilometry, eye-tracking, facial electromyography, autonomic psychophysiology, and self-report data were collected. Moreover, PTSD symptoms were assessed before and 3 months after testing. Analyses did not link acute dissociation to bodily and facial immobility or staring in response to trauma scripts. However, dissociation displayed an inverted U-shaped relationship with heart rate and was linked to higher nonspecific skin conductance fluctuation and higher high-frequency heart rate variability in response to trauma scripts. Moreover, acute dissociation was linked to higher self-reported negative affect responses to trauma scripts and displayed a U-shaped relationship with unfavorable PTSD symptom course over time. While results did not confirm hypothesized behavioral markers of dissociation, they do support defense-cascade model assumptions of an inverted U-shaped relationship between dissociation and psychophysiological arousal resulting from a progression of parasympathetic versus sympathetic dominance with increasing dissociation. On an experiential level, results did not confirm posttraumatic dissociation-induced emotional numbing, questioning theoretical notions. The observed nonlinear associations may help explain the heterogeneity of prior findings and might inform an updated conceptualization of posttraumatic dissociation.
Citations
Danböck, S. K., Liedlgruber, M., Franke, L. K., Miedl, S. F., Hettegger, S. E., Weber, R.-C., & Wilhelm, F. H. (2024). Acute dissociation as part of the defense cascade: Associations with behavioral, autonomic, and experiential threat responses in posttraumatic stress disorder.Journal of Psychopathology and Clinical Science, 133(1), 76–89. https://doi.org/10.1037/abn0000873
Sarah K. Danböck
Dr.Sarah K. Danböck is a postdoctoral researcher in the Department of Clinical and Biological Psychology and Psychotherapy at the University of Mannheim, who has worked at the University of Salzburg and Yale University during her PhD. Sarah’s research focuses on biological mechanisms in the etiology, phenomenology, maintenance, and treatment of trauma-related dissociative symptoms, especially in the context of posttraumatic stress disorder (PTSD). Recognized for her teaching and research, she has received the 2023 Excellence in Teaching Award and the 2023 Young Investigator Award of the University of Salzburg. Sarah also serves as Co-Chair of the early career researcher network “DIS.Connected” (https://disconnected-network.com/) dedicated to promoting exchange between early career dissociation researchers. You can find Sarah’s research output here https://www.researchgate.net/profile/Sarah-Danboeck and can contact her via Sarah.Danboeck@uni-mannheim.de.