Dissociative symptoms mediate the relation between PTSD symptoms and functional impairment in a sample of military members, veterans, and first responders with PTSD

Investigating the dissociative subtype of post-traumatic stress disorder in single- and multi-event trauma-exposed youth: Prevalence, course, prognosis, severity and functional impairment

OBJECTIVES

This study aimed, following both single- and multi-event trauma, to ascertain prevalence and course of the dissociative subtype of post-traumatic stress disorder (PTSD-DS) in youth; how well early PTSD-DS predicts later PTSD; and whether dissociation accounts for unique variance in post-traumatic stress symptoms (PTSS) and functional impairment over and above the effect of other post-trauma cognitive processing factors and PTSS respectively.

DESIGN AND METHODS

This study is a secondary analysis of data from the Acute Stress Programme for Children and Teenagers study (n = 234) and the Coping in Care After Trauma study (n = 110) in which children had experienced single- and multi-event trauma respectively.

RESULTS

PTSD-DS diagnosis was common in children with PTSD regardless of trauma experienced (>39.0%). PTSD-DS showed a similar trajectory of natural recovery to PTSD, and it was similarly predictive of later PTSD following single-event trauma. Finally, dissociation was a significant factor in PTSS and functional impairment.

CONCLUSIONS

These results should be viewed in the context of several limitations including narrow sample of participants which reduces the generalizability of results, concerns around children's ability to conceptualize challenging concepts such as dissociation and the use of self-report measures to form diagnostic groups. The PTSD-DS diagnosis may offer clinical utility to the extant PTSD diagnosis in children and adolescents, as dissociation has been shown to be a contributory factor in the maintenance of both PTSS and functional impairment. Further research is required to inform further editions of the DSM and other diagnostic systems.

Enhancing post-traumatic stress disorder patient assessment: leveraging natural language processing for research of domain criteria identification using electronic medical records

BACKGROUND

Extracting research of domain criteria (RDoC) from high-risk populations like those with post-traumatic stress disorder (PTSD) is crucial for positive mental health improvements and policy enhancements. The intricacies of collecting, integrating, and effectively leveraging clinical notes for this purpose introduce complexities.

METHODS

In our study, we created a natural language processing (NLP) workflow to analyze electronic medical record (EMR) data and identify and extract research of domain criteria using a pre-trained transformer-based natural language model, all-mpnet-base-v2. We subsequently built dictionaries from 100,000 clinical notes and analyzed 5.67 million clinical notes from 38,807 PTSD patients from the University of Pittsburgh Medical Center. Subsequently, we showcased the significance of our approach by extracting and visualizing RDoC information in two use cases: (i) across multiple patient populations and (ii) throughout various disease trajectories.

RESULTS

The sentence transformer model demonstrated high F1 macro scores across all RDoC domains, achieving the highest performance with a cosine similarity threshold value of 0.3. This ensured an F1 score of at least 80% across all RDoC domains. The study revealed consistent reductions in all six RDoC domains among PTSD patients after psychotherapy. We found that 60.6% of PTSD women have at least one abnormal instance of the six RDoC domains as compared to PTSD men (51.3%), with 45.1% of PTSD women with higher levels of sensorimotor disturbances compared to men (41.3%). We also found that 57.3% of PTSD patients have at least one abnormal instance of the six RDoC domains based on our records. Also, veterans had the higher abnormalities of negative and positive valence systems (60% and 51.9% of veterans respectively) compared to non-veterans (59.1% and 49.2% respectively). The domains following first diagnoses of PTSD were associated with heightened cue reactivity to trauma, suicide, alcohol, and substance consumption.

CONCLUSIONS

The findings provide initial insights into RDoC functioning in different populations and disease trajectories. Natural language processing proves valuable for capturing real-time, context dependent RDoC instances from extensive clinical notes.

A latent class analysis of dissociative PTSD subtype among Chinese adolescents following the COVID-19 pandemic and lockdown

BACKGROUND

The COVID-19 pandemic and related policies have amplified the vulnerability of adolescents to the development of posttraumatic stress disorder (PTSD) and dissociation symptoms. This study sought to explore the profile patterns and psychopathological characteristics of co-occurring PTSD and dissociation symptoms in Chinese adolescents.

METHODS

A total of 57,984 junior and senior high school students in Deyang City, China were recruited between July 13 and July 19, 2020. PTSD and dissociation symptoms, risk factors, and functional impairment variables were assessed using the Global Psychotrauma Screen for Teenagers (GPS-T) instrument. Latent class analysis (LCA) was employed to examine the phenomenology and risk factors of co-occurring PTSD and dissociation symptoms. Analysis of Variance (ANOVA) was utilized to investigate differences in COVID-19 pandemic-related exposure and functional impairment across distinct symptom profiles.

RESULTS

A 4-class model was selected as the optimal solution, comprising subgroups of low symptom, predominant PTSD symptom, predominant dissociation symptom, and PTSD-dissociation symptom. Class membership could be significantly predicted by other stressful experiences, social support, childhood maltreatment and psychiatric histories. The PTSD-dissociation symptom class exhibited the most severe COVID-19 pandemic-related exposure and functional impairment among all classes.

LIMITATIONS

The cross-sectional design, Chinese cultural background, online survey method and oversimple measurements were the limitations.

CONCLUSIONS

Our findings extend existing knowledge about the coexisting patterns of PTSD and dissociation symptoms in adolescents, which could assist in identifying high-risk youths. Furthermore, our findings offer recommendations for shaping public health policies and formulating effective clinical interventions for adolescents following the COVID-19 pandemic and lockdown.

The Psychological Impact of Exposure to Battle on Medics: A Cross-Sectional Study of Ex-Soldiers Who Sought Help From the IDF Combat Reaction Unit

INTRODUCTION

The present study's central aim was to examine two questions: (1) Will there be differences in mental health outcomes between medics and non-medics who sought help at the Israeli Combat Reaction Unit (CRU)? (2) Will there be differences in mental health outcomes between combatants and non-combatants?

MATERIALS AND METHODS

This cross-sectional study included files of 1,474 Israeli Defense Forces ex-service members (89% combatants, of whom 13% were medics; 11% non-combatants, of whom 6% were medics), who filled out questionnaires on admission for evaluation at the CRU.Dependent variables were mental health measures and included two PTSD measures (Clinician-Administered PTSD Scale and PTSD Checklist for DSM-5), Beck Depression Inventory, Dissociative Experience Scale, and Brief Symptom Inventory. Military profession (medics vs. non-medics) and status (combatant vs. non-combatant) were the independent variables. Background variables were also examined.

RESULTS

We found no substantial differences between medics and non-medics in the mental health measures. When looking at combat and non-combat separately, the non-combat medics (CMs), in general, were in better mental health conditions than the other three groups- CMs, non-medic combatants, and non-medic non-combatants-all of whom had similar scores in the mental health measures. However, compared to the rest, non-CMs took considerably longer years before approaching the CRU.

CONCLUSIONS

The elapsed time to seek help for non-MCs was explained by their reluctance to seek help, not being combatants, and being medics who are portrayed as resilient. Recommendations for encouraging this subgroup to seek help were given.

The independent and combined impact of moral injury and moral distress on post-traumatic stress disorder symptoms among healthcare workers during the COVID-19 pandemic

Background: Healthcare workers (HCWs) across the globe have reported symptoms of Post-Traumatic Stress Disorder (PTSD) during the COVID-19 pandemic. Moral Injury (MI) has been associated with PTSD in military populations, but is not well studied in healthcare contexts. Moral Distress (MD), a related concept, may enhance understandings of MI and its relation to PTSD among HCWs. This study examined the independent and combined impact of MI and MD on PTSD symptoms in Canadian HCWs during the pandemic.Methods: HCWs participated in an online survey between February and December 2021, with questions regarding sociodemographics, mental health and trauma history (e.g. MI, MD, PTSD, dissociation, depression, anxiety, stress, childhood adversity). Structural equation modelling was used to analyze the independent and combined impact of MI and MD on PTSD symptoms (including dissociation) among the sample when controlling for sex, age, depression, anxiety, stress, and childhood adversity.Results: A structural equation model independently regressing both MI and MD onto PTSD accounted for 74.4% of the variance in PTSD symptoms. Here, MI was strongly and significantly associated with PTSD symptoms (β = .412, p < .0001) to a higher degree than MD (β = .187, p < .0001), after controlling for age, sex, depression, anxiety, stress and childhood adversity. A model regressing a combined MD and MI construct onto PTSD predicted approximately 87% of the variance in PTSD symptoms (r2 = .87, p < .0001), with MD/MI strongly and significantly associated with PTSD (β = .813, p < .0001), after controlling for age, sex, depression, anxiety, stress, and childhood adversity.Conclusion: Our results support a relation between MI and PTSD among HCWs and suggest that a combined MD and MI construct is most strongly associated with PTSD symptoms. Further research is needed better understand the mechanisms through which MD/MI are associated with PTSD.

Daily Sleep-Stress Reactivity and Functional Impairment in World Trade Center Responders

BACKGROUND

How sleep is impacted by stress ("sleep reactivity to stress") and how stress is impacted by sleep ("stress reactivity to sleep") are trait-like characteristics of individuals that predict depression, anxiety, and insomnia. However, pathways between reactivity and functional impairment (e.g., impairment in social relationships and interpersonal functioning) have not been explored, which may be a critical pathway in understanding the link between reactivity and the development of psychological disorders.

PURPOSE

We examined associations between reactivity and changes in functional impairment among a cohort of 9/11 World Trade Center responders.

METHODS

Data from 452 responders (Mage = 55.22 years; 89.4% male) were collected between 2014 and 2016. Four baseline sleep and stress reactivity indices (i.e., sleep duration and efficiency reactivity to stress; stress reactivity to sleep duration and efficiency) were calculated from 14 days of sleep and stress data using random slopes from multilevel models. Functional impairment was assessed approximately 1 year and 2 years after baseline via semi-structured interviews. Latent change score analyses examined associations between baseline reactivity indices and changes in functional impairment.

RESULTS

Greater baseline sleep efficiency reactivity to stress was associated with decreases in functioning (β = -0.05, p = .039). In addition, greater stress reactivity to sleep duration (β = -0.08, p = .017) and sleep efficiency (β = -0.22, p < .001) was associated with lower functioning at timepoint one.

CONCLUSION

People who are more reactive to daily fluctuations in stress and sleep have poorer interpersonal relationships and social functioning. Identifying individuals with high reactivity who could benefit from preventative treatment may foster better social integration.

Persistent Dissociation and Its Neural Correlates in Predicting Outcomes After Trauma Exposure

OBJECTIVE

Dissociation, a disruption or discontinuity in psychological functioning, is often linked with worse psychiatric symptoms; however, the prognostic value of dissociation after trauma is inconsistent. Determining whether trauma-related dissociation is uniquely predictive of later outcomes would enable early identification of at-risk trauma populations. The authors conducted the largest prospective longitudinal biomarker study of persistent dissociation to date to determine its predictive capacity for adverse psychiatric outcomes following acute trauma.

METHODS

All data were part of the Freeze 2 data release from the Advancing Understanding of Recovery After Trauma (AURORA) study. Study participants provided self-report data about persistent derealization (N=1,464), a severe type of dissociation, and completed a functional MRI emotion reactivity task and resting-state scan 2 weeks posttrauma (N=145). Three-month follow-up reports were collected of posttraumatic stress, depression, pain, anxiety symptoms, and functional impairment.

RESULTS

Derealization was associated with increased ventromedial prefrontal cortex (vmPFC) activation in the emotion reactivity task and decreased resting-state vmPFC connectivity with the cerebellum and orbitofrontal cortex. In separate analyses, brain-based and self-report measures of persistent derealization at 2 weeks predicted worse 3-month posttraumatic stress symptoms, distinct from the effects of childhood maltreatment history and current posttraumatic stress symptoms.

CONCLUSIONS

The findings suggest that persistent derealization is both an early psychological and biological marker of worse later psychiatric outcomes. The neural correlates of trauma-related dissociation may serve as potential targets for treatment engagement to prevent posttraumatic stress disorder. These results underscore dissociation assessment as crucial following trauma exposure to identify at-risk individuals, and they highlight an unmet clinical need for tailored early interventions.

Functional Limitations, Post-Traumatic Stress Disorder, and College Adjustment in Student Veterans: A Mediation Analysis Study

Purpose

The purpose of this study was to examine whether functional limitations mediate the relation between PTSD symptoms and college life adjustment in student veterans with PTSD symptoms.

Methods

A total of 232 student veterans with PTSD symptoms were recruited for this study. Participants were predominantly male (84.5%; females = 15.5%). Participants’ ages ranged from 18 to 54 years (M = 28.43, SD = 5.42). Correlational analyses were conducted to calculate the relationships among study variables. We also conducted a mediation analysis to examine whether functional limitations mediate the relationship between PTSD symptoms and college life adjustment.

Results

The mediation analysis indicated that the effect of PTSD symptoms on college adjustment can be partially explained by functional limitations.

Conclusion

Our results have potentially important implications for rehabilitation counseling researchers and clinicians in the COVID-19 era.

Dissociative symptomatology mediates the relation between posttraumatic stress disorder severity and alcohol-related problems

Background

Up to 50% of individuals with posttraumatic stress disorder (PTSD) endorse problematic alcohol use. Typically, these individuals present with more complex and often more severe PTSD symptoms than those who do not report problematic alcohol use. Emerging literature suggests that heightened symptoms of dissociation are likewise associated with greater PTSD symptom severity. Despite this knowledge, the role of dissociation in the relation between PTSD severity and alcohol‐related problems has yet to be examined. Here, we explore the mediating role of dissociative symptomatology on the association between PTSD severity and alcohol‐related problems within a PTSD treatment‐seeking sample.

Methods

Structural equation modeling was used to test the mediating role of dissociative symptomatology between PTSD severity and alcohol‐related problems. Participants [N = 334; mean age (SD) = 44.29 (9.77), 50% female] were drawn from a clinical intake battery database for PTSD in‐patient treatment services at Homewood Health Care, Guelph, ON, Canada. A subset of battery measures assessing PTSD severity, dissociative symptomatology, and alcohol‐related problems were submitted to analysis.

Results

A significant positive association emerged between PTSD severity and alcohol‐related problems (β = 0.127, p < 0.05) in the absence of dissociative symptomatology. Critically, however, when added to this model, dissociative symptomatology (six unique facets of dissociation assessed by the Multiscale Dissociation Inventory) mediated the relation between PTSD severity and alcohol‐related problems. Specifically, greater PTSD severity was associated with greater dissociative symptomatology (β = 0.566, p < 0.0001), which was in turn associated with greater alcohol‐related problems (β = 0.184, p < 0.05).

Conclusions

These results suggest that dissociative symptomatology plays a key role in explaining the relation between PTSD severity and alcohol‐related problems. Future studies should examine the impact of targeting dissociative symptomatology specifically in treating individuals with PTSD who endorse alcohol‐related problems.

The Role of Implicit Memory in the Development and Recovery from Trauma-Related Disorders

Post-traumatic Stress Disorder is a chronic condition that occurs following a traumatic experience. Information processing models of PTSD focus on integrating situationally triggered sensory-emotional memories with consciously accessible autobiographical memories. Review of the nature of implicit memory supports the view that sensory-emotional memories are implicit in nature. Dissociation was also found to be associated with the development and severity of PTSD, as well as deficits in autobiographical memory. Moreover, disorganized attachment (DA) was associated with greater degrees of dissociation and PTSD, and like the defining neural activation in PTSD, was found to be associated with basal ganglia activity. In addition, subcortical neuroception of safety promotes a neurophysiological substrate supportive of social engagement and inhibition of fear-based responses. Furthermore, activation of representations of co-created imagined scenes of safety and secure attachment are associated with increases in this neurophysiological substrate. Repeated priming of secure attachment imagery was associated with modification of internal working models of DA along with reductions in dissociation and recovery from complex PTSD. In conclusion, it is posited that adequate recovery from extensive trauma experiences requires more than conscious elaboration of traumatic autobiographical memories and that the application of implicit nonconscious memory modification strategies will facilitate more optimal recovery.

A Psychometric Investigation of Racial Trauma Symptoms Using a Semi-Structured Clinical Interview With a Trauma Checklist (UnRESTS)

The term racial trauma is used to describe the cumulative distressing and traumatizing effects of racism in all of its forms, and it closely resembles the construct of posttraumatic stress disorder (PTSD). This investigation aims to increase our understanding of racial trauma by comparing the characteristics of those with a clinically-relevant diagnosis of racial trauma to those without, based on the findings of a clinical semi-structured interview and symptom checklist for assessing racial trauma, the University of Connecticut Racial Ethnic Stress and Trauma Survey (UnRESTS), administered to a diverse group of adults (N = 97). This paper extends prior work on racial trauma by examining the correlations between racial trauma and validated self-report measures of discriminatory distress, controlling for racialization. We examine the correlation between a clinically-relevant diagnosis of racial trauma and racial/ethnic identity. We also compare racism-related PTSD symptoms in those with and without racial trauma to inform clinical assessment. Finally, we examine the factor structure of racial trauma symptoms using the 24 items from the UnRESTS PTSD symptom checklist and compare these to current DSM-5 models. The structure of racial trauma symptoms differed from the DSM-5 4-factor model, as do other PTSD models in the research literature. Clinical and research implications are discussed.

Altered basal forebrain BOLD signal variability at rest in posttraumatic stress disorder: A potential candidate vulnerability mechanism for neurodegeneration in PTSD

Individuals with posttraumatic stress disorder (PTSD) are at increased risk for the development of various forms of dementia. Nevertheless, the neuropathological link between PTSD and neurodegeneration remains unclear. Degeneration of the human basal forebrain constitutes a pathological hallmark of neurodegenerative diseases, such as Alzheimer's and Parkinson's disease. In this seed-based resting-state (rs-)fMRI study identifying as outcome measure the temporal BOLD signal fluctuation magnitude, a seed-to-voxel analyses assessed temporal correlations between the average BOLD signal within a bilateral whole basal forebrain region-of-interest and each whole-brain voxel among individuals with PTSD (n = 65), its dissociative subtype (PTSD+DS) (n = 38) and healthy controls (n = 46). We found that compared both with the PTSD and healthy controls groups, the PTSD+DS group exhibited increased BOLD signal variability within two nuclei of the seed region, specifically in its extended amygdaloid region: the nucleus accumbens and the sublenticular extended amygdala. This finding is provocative, because it mimics staging models of neurodegenerative diseases reporting allocation of neuropathology in early disease stages circumscribed to the basal forebrain. Here, underlying candidate etiopathogenetic mechanisms are neurovascular uncoupling, decreased connectivity in local- and large-scale neural networks, or disrupted mesolimbic dopaminergic circuitry, acting indirectly upon the basal forebrain cholinergic pathways. These abnormalities may underpin reward-related deficits representing a putative link between persistent traumatic memory in PTSD and anterograde memory deficits in neurodegeneration. Observed alterations of the basal forebrain in the dissociative subtype of PTSD point towards the urgent need for further exploration of this region as a potential candidate vulnerability mechanism for neurodegeneration in PTSD.

Post-traumatic stress disorder in train crash survivors in Italy: the role of mood spectrum dysregulations and intrusiveness

BACKGROUND

To explore relationships among post-traumatic stress disorder (PTSD), depressive spectrum symptoms, and intrusiveness in subjects who survived the crash of a train derailed carrying liquefied petroleum gas and exploded causing a fire.

METHODS

A sample of 111 subjects was enrolled in Viareggio, Italy. AMOS version 21 (IBM Corp, 2012) was utilized for a structural equation model-path analysis to model the direct and indirect links between the exposure to the traumatic event, the occurrence of depressive symptoms, and intrusiveness. Subjects were administered with the SCID-IV (Structured Clinical Interview for DSM-IV), the Questionnaire for Mood Spectrum (MOODS-SR)-Last Month version, the Trauma and Loss Spectrum Questionnaire (TALS-SR), and the Impact of Event Scale-Revised version (IES-R).

RESULTS

Sixty-six (66/111; 59.4%) subjects met SCID-IV criteria for PTSD. Indices of goodness of fit were as followed: χ2/df = 0.2 P = .6; comparative fit index = 1 and root mean square error of approximation = 0.0001. A significant path coefficient for direct effect of potential traumatic events on depressive symptoms (β = 0.25; P < .04) and from depressive symptoms to intrusiveness (β = 0.34; P < .003) was found. An indirect effect was also observed: standardized value of potential traumatic events on intrusiveness was 0.86. The mediating factor of this indirect effect path was represented by depressive symptoms. Potential traumatic events explained 6.2% of the variance of depressive symptoms; 11.8% of the variance of intrusiveness was accounted for traumatic event and depressive symptoms.

CONCLUSIONS

Path analysis led us to speculate that depression symptoms might have mediated the relationship between the exposure to potential traumatic events and intrusiveness for the onset of PTSD.

Victimization profiles in girls involved in the juvenile justice system: A latent class analysis

BACKGROUND

Previous research has demonstrated that youth involved in the juvenile justice system endorse diverse patterns of victimization. However, previous research investigating victimization profiles among youth involved in the juvenile justice system has primarily consisted of boys.

OBJECTIVE

This study investigated victimization profiles and correlates of victimization exposure, including posttraumatic stress symptoms and risk behaviors, in a sample of girls involved in the juvenile justice system.

PARTICIPANTS AND SETTING

Participants were 245 girls involved in the juvenile justice system (Mage = 15.57, SD = 1.13) participating in a dating violence prevention program. The sample was racially diverse, and 48 % self-identified as Hispanic/Latina.

METHOD

Prior to participating in the intervention, participants completed self-report measures of adversity and victimization exposure, posttraumatic stress symptoms, and risk behaviors.

RESULTS

Results of latent class analysis identified three distinct victimization profiles. The first class (n = 106) was characterized by low levels of victimization. The second class (n = 98) experienced predominantly emotional victimization (i.e., emotional dominant). The third class (n = 41) was characterized by exposure to polyvictimization (i.e., polyvictimization predominant). Girls categorized into the polyvictimization dominant class evidenced the greatest levels of posttraumatic stress symptoms, substance use, suicidal behaviors, and sexual risk behaviors.

CONCLUSIONS

Girls involved in the juvenile justice system report distinct patterns of victimization, which are differentially associated with posttraumatic stress symptoms and risk behaviors. The present study underscores the importance of implementing trauma-informed assessment and intervention practices within juvenile justice systems.

Dissociative symptoms predict severe illness presentation in Canadian public safety personnel with presumptive post-traumatic stress disorder (PTSD)

BACKGROUND

Post-traumatic stress disorder affects 9% of individuals across their lifetime and increases nearly fourfold to 35% in Canadian public safety personnel (PSP). On-the-job experiences of PSP frequently meet criteria for traumatic events, making these individuals highly vulnerable to exposures of trauma and the negative consequences of PTSD. Few studies have reported on the clinical characteristics of Canadian samples of PSP and even fewer have examined the dissociative subtype of PTSD, which is associated with more severe, chronic traumatic experiences, and worse outcomes.

OBJECTIVE

This study aimed to characterize dissociative symptoms, PTSD symptom severity, and other clinical variables among Canadian PSP with presumptive PTSD.

METHODS

We sampled current and past PSP in Canada from both inpatient and outpatient populations (N = 50) that were enrolled in a psychological intervention. Only baseline testing data (prior to any intervention) were analysed in this study, such as PTSD symptom severity, dissociative symptoms, emotion dysregulation, and functional impairment.

RESULTS

In our sample, 24.4% self-reported elevated levels of dissociation, specifically symptoms of depersonalization and derealization. Depersonalization and derealization symptoms were associated with more severe PTSD symptoms, greater emotion dysregulation, and functional impairment.

CONCLUSIONS

Nearly a quarter of this sample of Canadian PSP reported experiencing elevated levels of PTSD-related dissociation (depersonalization and derealization). These high levels of depersonalization and derealization were consistently positively associated with greater illness severity across clinical measures. It is imperative that dissociative symptoms be better recognized in patient populations that are exposed to chronic traumatic events such as PSP, so that treatment interventions can be designed to target a more severe illness presentation.

Peripersonal Space and Bodily Self-Consciousness: Implications for Psychological Trauma-Related Disorders

Peripersonal space (PPS) is defined as the space surrounding the body where we can reach or be reached by external entities, including objects or other individuals. PPS is an essential component of bodily self-consciousness that allows us to perform actions in the world (e.g., grasping and manipulating objects) and protect our body while interacting with the surrounding environment. Multisensory processing plays a critical role in PPS representation, facilitating not only to situate ourselves in space but also assisting in the localization of external entities at a close distance from our bodies. Such abilities appear especially crucial when an external entity (a sound, an object, or a person) is approaching us, thereby allowing the assessment of the salience of a potential incoming threat. Accordingly, PPS represents a key aspect of social cognitive processes operational when we interact with other people (for example, in a dynamic dyad). The underpinnings of PPS have been investigated largely in human models and in animals and include the operation of dedicated multimodal neurons (neurons that respond specifically to co-occurring stimuli from different perceptive modalities, e.g., auditory and tactile stimuli) within brain regions involved in sensorimotor processing (ventral intraparietal sulcus, ventral premotor cortex), interoception (insula), and visual recognition (lateral occipital cortex). Although the defensive role of the PPS has been observed in psychopathology (e.g., in phobias) the relation between PPS and altered states of bodily consciousness remains largely unexplored. Specifically, PPS representation in trauma-related disorders, where altered states of consciousness can involve dissociation from the body and its surroundings, have not been investigated. Accordingly, we review here: (1) the behavioral and neurobiological literature surrounding trauma-related disorders and its relevance to PPS; and (2) outline future research directions aimed at examining altered states of bodily self-consciousness in trauma related-disorders.

The Mediating Role of Alexithymia in the Association Between Adverse Childhood Experiences and Postdeployment Mental Health in Canadian Armed Forces Personnel

Recent studies showing an association between adverse childhood experiences and the development of alexithymia in military personnel have generated interest regarding the role of alexithymia in the pathway linking childhood trauma exposure to mental health disorders. Accordingly, the current study was conducted to (a) examine the associations among adverse childhood experiences, alexithymia, and symptoms of depression and posttraumatic stress disorder (PTSD) among recently deployed Canadian military personnel and (b) assess the mediating role of alexithymia in these associations. Data collected from 2,927 members of the Canadian Armed Forces at baseline and after their return from an overseas deployment were subjected to a prospective path analysis. The results of the path analysis, R² = .35, pointed to a significant direct effect of childhood adversity on postdeployment mental health symptoms. Contrary to our expectations, the results also pointed to a negative indirect effect of childhood neglect, suggesting that childhood neglect contributed to lower levels of postdeployment depression and PTSD symptoms through the dimension of alexithymia related to difficulty in describing feelings. These patterns of associations, for the most part, persisted even when accounting for combat exposure during recent deployments, R² = .42. The present results are discussed in light of study limitations and methodological considerations, and policy and clinical implications are noted.

Can service members with mild traumatic brain injury learn to develop implementation intentions for self-identified goals?

PURPOSE

Goal achievement relies heavily on executive functions, which may be compromised following mild traumatic brain injury (mTBI). Implementation intentions (II) have been found to help people act in accordance with their goals. II are written statements that describe a behavior that a person plans to enact when they encounter some form of anticipated trigger or stimulus. We evaluated the feasibility of teaching participants with mTBI to develop II for self-identified goals within the context of cognitive rehabilitation.

METHODS

Soldiers with mTBI were recruited from a traumatic brain injury clinic. During the intervention, participants were assigned to develop an II for one of three self-identified goals every day. Descriptive methods were used to examine implementability and acceptability of the II training protocol as well as the extent to which participants learned to develop II for their own goals.

RESULTS

The II training protocol was found to be highly implementable and acceptable to participants. Overall, participants (n = 16) were able to develop II related to their self-identified goals, which primarily focused on managing cognitive problems. For the most part, participants developed II that involved event- rather than time- or somatic/feeling-based triggers.

CONCLUSION AND IMPLICATIONS

Participants with mTBI were able to learn to develop II for their self-identified goals. Further study is needed to determine whether adding II to cognitive rehabilitation advances patient goal achievement.IMPLICATIONS FOR REHABILITATIONIt is feasible to incorporate training in implementation intentions (predetermined "if/when-then" plans that are intended to link specific situational triggers with actions) in metacognitive strategy instruction for patients with mild traumatic brain injury.Participants with mild traumatic brain injury in this study demonstrated that they were able to develop implementation intentions for multiple self-identified rehabilitation goals, which holds promise for also teaching patients with mild cognitive impairment from other conditions.Learning to develop implementation intentions may help patients with mild traumatic brain injury initiate a range of other cognitive strategies in their everyday lives.Implementation intentions have the potential to help patients enact goal behaviors associated with their rehabilitation goals, making cognitive rehabilitation more "customizable" and relevant to clients' specific needs.

Pain perception and processing in individuals with posttraumatic stress disorder: a systematic review with meta-analysis

Posttraumatic stress disorder (PTSD) is a known risk factor for the development of chronic pain conditions, and almost 1 in 5 individuals with chronic pain fulfills the criteria for PTSD. However, the relationship between PTSD and pain is poorly understood and studies on pain perception in patients with PTSD show inconsistent results suggesting that different sensory profiles exist among individuals with PTSD. Here, we (1) systematically summarize the current literature on experimentally evoked pain perception in patients with PTSD compared to subjects without PTSD, and (2) assess whether the nature of the traumatic event is associated with different patterns in pain perception. The main outcome measures were pain threshold, pain tolerance, and pain intensity ratings as well as measures of temporal summation of pain and conditioned pain modulation. A systematic search of MEDLINE, EMBASE, Web of Science, PsycINFO, and CINAHL identified 21 studies for the meta-analysis, including 422 individuals with PTSD and 496 PTSD-free controls. No main effect of PTSD on any outcome measure was found. However, stratification according to the nature of trauma revealed significant differences of small to medium effect sizes. Combat-related PTSD was associated with increased pain thresholds, whereas accident-related PTSD was associated with decreased pain thresholds. No clear relationship between PTSD and experimentally evoked pain perception exists. The type of trauma may affect pain thresholds differently indicating the presence of different subgroups with qualitative differences in pain processing.

Classifying heterogeneous presentations of PTSD via the default mode, central executive, and salience networks with machine learning

Intrinsic connectivity networks (ICNs), including the default mode network (DMN), the central executive network (CEN), and the salience network (SN) have been shown to be aberrant in patients with posttraumatic stress disorder (PTSD). The purpose of the current study was to a) compare ICN functional connectivity between PTSD, dissociative subtype PTSD (PTSD+DS) and healthy individuals; and b) to examine the use of multivariate machine learning algorithms in classifying PTSD, PTSD+DS, and healthy individuals based on ICN functional activation. Our neuroimaging dataset consisted of resting-state fMRI scans from 186 participants [PTSD (n = 81); PTSD + DS (n = 49); and healthy controls (n = 56)]. We performed group-level independent component analyses to evaluate functional connectivity differences within each ICN. Multiclass Gaussian Process Classification algorithms within PRoNTo software were then used to predict the diagnosis of PTSD, PTSD+DS, and healthy individuals based on ICN functional activation. When comparing the functional connectivity of ICNs between PTSD, PTSD+DS and healthy controls, we found differential patterns of connectivity to brain regions involved in emotion regulation, in addition to limbic structures and areas involved in self-referential processing, interoception, bodily self-consciousness, and depersonalization/derealization. Machine learning algorithms were able to predict with high accuracy the classification of PTSD, PTSD+DS, and healthy individuals based on ICN functional activation. Our results suggest that alterations within intrinsic connectivity networks may underlie unique psychopathology and symptom presentation among PTSD subtypes. Furthermore, the current findings substantiate the use of machine learning algorithms for classifying subtypes of PTSD illness based on ICNs.

Resolution of Dissociated Ego States Relieves Flashback-Related Symptoms in Combat-Related PTSD: A Brief Mindfulness Based Intervention

A novel understanding and therapeutic approach to the treatment of PTSD-related flashback triggers are described. Triggered responses are conceptualized as the result of latent dissociative structures of neural organization and psychodynamic functioning activated by current events. The dissociative structure - here described as a dissociated ego state (DES) - reflects a fracturing of executive functioning resulting in a delimited aspect of self that is not under cognitive control or subject to cognitive inhibition by the self of daily experience, and is the psychological construct behind intrusive PTSD symptoms. Use of a mindful attentional state permits regulated access to the DES (therapeutic engagement without risk of emotional dysregulation) so that dissociated cognitive resources can be recovered and the dissociated structure deactivated. This may relieve maladaptive responses and behaviors associated with the DES in a profound and durable way, without the need for exposure to or recovery of traumatic memories. Based on this understanding, a 9-step intervention is introduced with a case example of a Vietnam veteran suffering PTSD symptoms for 49 years with significant gains maintained at 21 months follow up. These findings demonstrate rapid and durable resolution of chronic PTSD symptoms through a mindfulness-based approach that focused on deactivation of dissociated ego states, in contrast to targeting trauma memories. If proven efficacious, this novel approach may result in reduced treatment costs and improved outcomes for veterans suffering with PTSD.

The Dissociative Subtype of PTSD Interview (DSP-I): Development and Psychometric Properties

The inclusion of the dissociative subtype of post-traumatic stress disorder (PTSD-DS) in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) reflects the importance of assessing PTSD-DS. We developed the Dissociative Subtype of PTSD Interview (DSP-I). This clinician-administered instrument assesses the presence and severity of PTSD-DS (i.e., symptoms of depersonalization or derealization) and contains a supplementary checklist that enables assessment and differentiation of other trauma-related dissociative symptoms (i.e., blanking out, emotional numbing, alterations in sensory perception, amnesia, and identity confusion). The psychometric properties were tested in 131 treatment-seeking individuals with PTSD and histories of multiple trauma, 17.6 % of whom met criteria for PTSD-DS in accordance with the DSP-I. The checklist was tested in 275 treatment-seeking individuals. Results showed the DSP-I to have high internal consistency, good convergent validity with PTSD-DS items of the CAPS-5, and good divergent validity with scales of somatization, anxiety and depression. The depersonalization and derealization scales were highly associated. Moreover, the DSP-I accounted for an additional variance in PTSD severity scores of 8% over and above the CAPS-5 and number of traumatic experiences. The dissociative experiences of the checklist were more strongly associated with scales of overall distress, somatization, depression, and anxiety than scales of depersonalization and derealization. In conclusion, the DSP-I appears to be a clinically relevant and psychometrically sound instrument that is valuable for use in clinical and research settings.

Severity and Symptom Trajectory in Combat-Related PTSD: a Review of the Literature

PURPOSE OF REVIEW

Combat-related posttraumatic stress disorder is increasingly recognized as having a variable course in returning veterans. Relatively few studies have identified predictors of illness duration or severity in this population. This review sought to synthesize the existing literature.

RECENT FINDINGS

The existing literature remains limited and heterogeneous. However, several studies identified hyperarousal and pre-deployment dissociation as predictive of disease severity, and re-experiencing as predictive of suicidality in veterans with combat-related PTSD. No other pre-, peri-, or posttraumatic psychosocial predictors of individual symptoms or overall disease severity have been identified in replicated studies. Important clinical factors to explore in the assessment of PTSD in combat veterans may now include hyperarousal and a history of dissociation as these may predict disease severity, and re-experiencing as this has been identified as a significant predictor of suicidality. Further study into this topic may reveal biological or more sensitive psychosocial markers predicting illness severity and prognosis.

Rumination as a Mediator of the Associations Between Moral Injury and Mental Health Problems in Combat-Wounded Veterans

Moral injury is hypothesized to develop from witnessing or engaging in events that violate one's beliefs about themselves and has been shown to be associated with negative mental health symptoms. Although there has been an increase in research examining moral injury among military veterans, mechanisms that link moral injury to mental health outcomes are not well understood. The present study examined rumination subcomponents (problem-focused thoughts, counterfactual thinking, repetitive thoughts, and anticipatory thoughts) as possible mediators of the associations between moral injury (both self-directed and other-directed symptoms) and negative mental health symptoms (i.e., depression, anxiety, suicidality, sleep disturbance, memory problems, and posttraumatic stress disorder symptoms). Participants were 189 combat wounded veterans (180 men; Mean age = 43.14 years) who had experienced one or more deployments (defined as 90 days or more). Nearly all participants reported a service-connected disability (n = 176, 93.1%), with the average participant reporting a 90% total VA disability ranking, and most participants had received a purple heart (n = 163, 86.2%). Within our comprehensive mediation model, we found eight significant mediation effects with the most consistent mediator being problem-focused thoughts. Specifically, both self-directed and other- directed moral injury were associated with increased problem-focused thoughts, which in turn was associated with higher reported symptoms of depression, anxiety, and posttraumatic stress disorder. Taken together, rumination, and in particular, problem-focused thoughts, is relevant to understand the increased vulnerability of military veterans to exhibit poor mental health outcomes when experiencing moral injury.

The relation between adverse childhood experiences and moral injury in the Canadian Armed Forces

Background: There is increasing evidence that moral injuries (MIs) may affect the mental health of Canadian Armed Forces (CAF) members and veterans. Despite knowledge suggesting that MIs are related to multiple negative mental health outcomes, including the onset of post-traumatic stress disorder (PTSD), it is unknown whether pre-traumatic variables, including the presence of childhood abuse, are related to MIs. Objective: This study seeks to investigate the potential relationship between adverse childhood experiences and later onset MI in military members. Methods: Thirty-three patients newly admitted to an inpatient unit for treatment of trauma-related disorders received a standardized self-assessment package, including the PTSD Checklist for DSM-5 (PCL-5), the Moral Injury Events Scale (MIES; adapted for the Canadian context), and the Adverse Childhood Experiences Questionnaire (ACE-Q), which is a retrospective measure of childhood abuse. Results: Analyses revealed a significant relation between childhood emotional abuse and the presence of MI in adulthood. Specifically, emotional abuse during childhood was correlated with total score on the MIES (p = 0.006) and with its two subscales, perceived betrayals (p = 0.022) and perceived transgressions (p = 0.016). These correlations remained significant when controlling for age and gender. Conclusions: Among CAF members and veterans, childhood events are related to the presence of MI during adulthood. These preliminary data are provocative in suggesting that emotional abuse during childhood may increase the likelihood of endorsing MI during adult military service. Further work is needed to identify pre-traumatic variables that may serve to increase risk or enhance resilience to the development of MI in military members.