Acute dissociation as part of the defense cascade: Associations with behavioral, autonomic, and experiential threat responses in posttraumatic stress disorder.

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. Here, we explored associations between dissociative and behavioral, physiological, and experiential threat responses as well as effects of dissociative responding on PTSD symptom course. Individuals with PTSD (N = 71) participated in a preregistered script-driven imagery study including exposure to standardized, detail-enriched 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. 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. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Psychometric properties of the dissociative subtype of posttraumatic stress disorder scale: replication and extension in two German-speaking samples.

Background: The fifth version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) introduced the dissociative subtype of posttraumatic stress disorder (D-PTSD). To assess this subtype, the Dissociative Subtype of PTSD Scale (DSPS), a 15-item self-report measure to identify lifetime and current dissociative symptoms of D-PTSD, was developed. However, so far, the scale has only been validated in war veterans. Moreover, criterion validity and diagnostic utility have not been examined yet.Objective: We aimed to validate the DSPS in two samples of civilian trauma-exposed German-speaking participants.Methods: In Study 1, a pre-registered online study, participants with and without PTSD symptoms (N = 558) answered questionnaires about traumatic experiences, dissociation, PTSD, depression, generalized anxiety disorder, somatic symptom disorder, alcohol use disorder, absorption, and dissociative responding to trauma-related questionnaires. In Study 2, which used secondary data of a pre-registered clinical study, participants with a PTSD diagnosis (N = 71) answered questionnaires about traumatic experiences, dissociation, PTSD, depression, generalized anxiety disorder, somatic symptom disorder, and dissociative responding to standardized trauma exposure. Moreover, PTSD, D-PTSD, and other diagnoses were assessed with structured clinical interviews.Results: Analyses confirmed a three-factor structure as well as high internal consistency, and high convergent, discriminant, and criterion validity of the DSPS. Moreover, the scale was able to identify a latent D-PTSD group and individuals with D-PTSD diagnosis.Conclusions: The DSPS constitutes a reliable and valid tool to assess D-PTSD symptoms in clinical practice and research and thereby may contribute to a better understanding of these debilitating symptoms.

Many individuals with posttraumatic stress disorder (PTSD) suffer from dissociative symptoms which can be assessed with the Dissociative Subtype of PTSD Scale (DSPS; Wolf et al., 2017).The DSPS demonstrated good psychometric properties in two German-speaking trauma-exposed samples and hence might be used to assess D-PTSD symptoms in research and clinical practice.Complementing the original English version, a German version of the DSPS is provided in the Supplements.