Perspectives on the conceptualization of the dissociative subtype of PTSD and implications for treatment

Dissociative Subtype of Posttraumatic Stress Disorder and its Correlates Among Treatment-Seeking Refugees

The dissociative subtype of posttraumatic stress disorder (PTSD-DS) denotes a severe type of PTSD associated with complex trauma exposure and psychiatric comorbidity. Refugees may be at heightened risk of developing PTSD-DS, but research is lacking. This cross-sectional study aimed to examine PTSD-DS and its demographic, trauma-related, and clinical correlates among a convenience sample of refugee patients over 18 years old who were diagnosed with PTSD according to DSM-5. PTSD-DS (Clinician-Administered PTSD Scale for DSM-5), trauma exposure (Life Events Checklist for DSM-5) and general psychopathology (Brief Symptom Inventory) were assessed at intake. T-tests, chi-square tests, and logistical regression analysis were conducted. The final sample consisted of 552 participants (177 (32.1%) women; 375 (67.9%) men; average age 40.0 years (SD = 11.2)) who originated from 63 countries. Of those, 158 (28.6%) met criteria for PTSD-DS. Participants with PTSD-DS scored significantly higher on PTSD symptom severity (t(550)=-5.270, p < .001), number of traumatic event types (t(456)=-3.499, p < .001), and exposure to sexual assault (χ(1) = 6.471, p = .01) than those without PTSD-DS. The odds of having PTSD-DS increased by 14.1% with exposure to each additional traumatic event type (OR = 1.141, CI 0.033-1.260). In conclusion, around 29% of adult treatment-seeking refugees with PTSD met the criteria for PTSD-DS. Those exposed to multiple traumatic event types including sexual assault, regardless of sex, were especially at risk. Having PTSD-DS was associated with more severe PTSD. Prioritizing trauma-focused treatment for those with PTSD-DS is recommended.

Psychometric Properties of the Dissociative Subtype of PTSD Scale: Replication and Extension in a Clinical Sample of Trauma-Exposed Veterans

The addition of the dissociative subtype of posttraumatic stress disorder (PTSD) to the DSM-5 has spurred investigation of its genetic, neurobiological, and treatment response correlates. In order to reliably assess the subtype, we developed the Dissociative Subtype of PTSD Scale (DSPS; Wolf et al., 2017), a 15-item index of dissociative features. Our initial investigation of the dichotomous DSPS lifetime items in a veteran epidemiological sample demonstrated its ability to identify the subtype, supported a three-factor measurement structure, distinguished the three subscales from the normal-range trait of absorption, and demonstrated the greater contribution of derealization and depersonalization symptoms relative to other dissociative symptomatology. In this study, we replicated and extended these findings by administering self-report and interview versions of the DSPS, and assessing personality and PTSD in a sample of 209 trauma-exposed veterans (83.73% male, 57.9% with probable current PTSD). Results replicated the three-factor structure using confirmatory factor analysis of current symptom severity interview items, and the identification of the dissociative subtype (via latent profile analysis). Associations with personality supported the discriminant validity of the DSPS and suggested the subtype was marked by tendencies towards odd and unusual cognitive experiences and low positive affect. Receiver operating characteristic curves identified diagnostic cut-points on the DSPS to inform subtype classification, which differed across the interview and self-report versions. Overall, the DSPS performed well in psychometric analyses, and results support the utility of the measure in identifying this important component of posttraumatic psychopathology.

The Dissociative Subtype of Post-traumatic Stress Disorder: Research Update on Clinical and Neurobiological Features

Recently, a dissociative subtype of post-traumatic stress disorder (PTSD) has been included in the DSM-5. This review focuses on the clinical and neurobiological features that distinguish the dissociative subtype of PTSD from non-dissociative PTSD. Clinically, the dissociative subtype of PTSD is associated with high PTSD severity, predominance of derealization and depersonalization symptoms, a more significant history of early life trauma, and higher levels of comorbid psychiatric disorders. Furthermore, PTSD patients with dissociative symptoms exhibit different psychophysiological and neural responses to the recall of traumatic memories. While individuals with non-dissociative PTSD exhibit an increased heart rate, decreased activation of prefrontal regions, and increased activation of the amygdala in response to traumatic reminders, individuals with the dissociative subtype of PTSD show an opposite pattern. It has been proposed that dissociation is a regulatory strategy to restrain extreme arousal in PTSD through hyperinhibition of limbic regions. In this research update, promises and pitfalls in current research studies on the dissociative subtype of PTSD are listed. Inclusion of the dissociative subtype of PTSD in the DSM-5 stimulates research on the prevalence, symptomatology, and neurobiology of the dissociative subtype of PTSD and poses a challenge to improve treatment outcome in PTSD patients with dissociative symptoms.

The Dynamic Relations Among Peritraumatic Posttraumatic Stress Symptoms: An Experience Sampling Study During Wartime

The associations among peritraumatic posttraumatic stress symptoms (P-PTSS) in the immediate aftermath of trauma exposure, including those in the posttraumatic stress disorder clusters of intrusions, avoidance, negative cognitions and mood (NCM), and arousal, might indicate mechanisms through which enduring PTSD develops. During a period of war, exposed participants (N = 181) were sent twice-daily questionnaires for 30 days via smartphone. We repeatedly assessed the predictive associations between the P-PTSS clusters over time. We performed a multilevel pathway analysis built of multiple triple sequence responses (6,221 cases) on each of the four P-PTSS clusters at a mean time lag of 12 hr (Model A) and 24 hr (Model B) for 181 participants, 85 of whom had been diagnosed with a serious mental illness. Arousal predicted intrusion in Models A and B, b_A = 0.08, 95% CI [0.03, 0.12], p < .001 and b_B = 0.03, 95% CI [0.00, 0.07], p = .051, respectively; and NCM in Models A and B, b_A = 0.09, 95% CI [0.05, 0.12], p < .001 and b_B = 0.06, 95% CI [0.03, 0.09], p < .001, respectively. Intrusion predicted arousal in Model B, b_B = 0.05, 95% CI [0.01, 0.08], p = .010. NCM predicted arousal, b_A = 0.10, 95% CI [0.05, 0.14], p < .001, and avoidance b_A = 0.05, 95% CI [0.00, 0.11], p = .052, in Model A. Avoidance did not predict any other cluster. Arousal seemed to be acting as a hub, strengthening feedback loops to and from NCM and intrusion.

Prevalence and clinical correlates of dissociative subtype of posttraumatic stress disorder at an outpatient trauma clinic in South Korea

Background: Previous studies on of the dissociative subtype of posttraumatic stress disorder (d-PTSD) have relied on specialized statistical methods (i.e. profile or class analyses) for diagnosis than clinical rating available to clinicians. Objective: This study investigated the prevalence and covariates of d-PTSD diagnosed by a semi-structured interview in a cohort of outpatients with DSM-IV PTSD in a specialized trauma clinic in South Korea. Method: Data from 249 patients with civilian PTSD were examined, including demographics, clinical variables, Clinical Global Impression (CGI) Scale, and Clinician-Administered PTSD Scale (CAPS-IV). We defined d-PTSD as the presence of either depersonalization or derealization according to additional dissociative items of the CAPS. About one third (n = 82, 32.9%) of patients were designated as having d-PTSD. Results: Compared to the other patients with PTSD, those with d-PTSD were younger, had more severe PTSD symptoms, frequent interpersonal trauma, and a higher number of comorbid disorders. When these variables and their interactions were entered into a logistic regression model, younger age, severe PTSD symptoms and two or more comorbid conditions remained for the final model. We did not find a significant difference in improvement over the course of treatment between two groups. Conclusions: This study highlights the high prevalence of d-PTSD in a clinical population. Associated features of d-PTSD were similar to those reported in the Euro-American literature. Further studies are needed to better understand mechanisms and treatment options for d-PTSD.

Trauma Memory Processing in Posttraumatic Stress Disorder Psychotherapy: A Unifying Framework

Trauma memory processing (TMP) is an empirically supported approach to psychotherapy for posttraumatic stress disorder (PTSD). However, TMP is not a single, uniform intervention but instead a paradigm that can be operationalized through a variety of component procedures that have not been systematically elucidated and formally tested. Based on findings from phenomenological/structural and neuroimaging research, a central feature of PTSD is theorized to be the involuntary immersion in trauma memories with diminished awareness or negative appraisals of self and current context. Such intrusive reexperiencing-which is epitomized by, but not limited to, flashbacks-is postulated to underlie PTSD's avoidance, altered emotions and cognitions, dissociative, and hyperarousal/hypervigilance symptoms; it is thus a logical target for TMP. The varied approaches to TMP for PTSD are conceptualized as having the common goal of activation of the neural networks in the brain that underlie two key capacities disrupted by intrusive reexperiencing in PTSD: intentional self-referential retrieval of memories and suppression of memory retrieval. Therefore, TMP is postulated to involve two core functions (purposeful reflective remembering and memory awareness in situ) and three essential types (in vivo, imaginal, and cognitive reappraisal). Several implications of this framework for clinical practice and research on TMP for PTSD are discussed.

Neurophysiological Correlates of Collective Trauma Recall in 2009 L'Aquila Earthquake Survivors

In the present study, we aimed to explore neural correlates of survivors of the 2009 L'Aquila, Italy earthquake in response to being shown pictures featuring their own city before and after an earthquake as well as those of an unfamiliar city. Moreover, we explored the associations among psychological variables and brain responses to the pictures of L'Aquila after the earthquake. Our final sample (N = 30 adults) comprised 15 survivors (M age = 31.40 years, SD = 9.42) and 15 controls (M age = 30.53 years, SD = 10.01). Participants' electroencephalographic (EEG) data were recorded during a visual task that included earthquake-related stimuli. Participants were assessed for posttraumatic and dissociation symptoms and event-related potential components, and low-resolution electromagnetic tomography (sLORETA) were analyzed. Compared to the control group, source localization in survivors indicated a lower intensity of the amygdala, hippocampal, parahippocampal, and temporopolar areas in response to visual stimuli concerning the earthquake, p < .001 to p < .0001. Results indicated a reduced limbic activation in response to visual stimuli that evoked the recall of earthquake in survivors. This finding suggests that survivors likely adopted a distancing strategy toward stimuli that may have elicited an emotional activation related to collective trauma.