Dissociative Identity Disorder: A Review of Research From 2011 to 2021.

ABSTRACT: Dissociative identity disorder (DID) has historically been one of the most controversial topics in the study of psychopathology. Building on a previous review of empirical research on DID from 2000 to 2010, the present review examined DID research from 2011 to 2021. The research output included 56 case studies and 104 empirical studies. Within the empirical studies, approximately 1354 new cases of DID emerged, which resulted in an average samples of approximately 20. Reanalysis of previous samples was standard in the literature with only 40% of reported cases being new. Studies emerged from dozens of countries across the world, but the majority of cases were from Western counties, especially the United States. Diagnosis primarily relied upon validated measures, but 74% of all new cases came from six research groups. Overall, research on DID is steady but methodologically limited in ways that make generalization, especially about etiology, difficult.

The bidirectional relationship between depression and dissociation: A longitudinal investigation.

Depression is a major public health concern. Recent studies suggest that dissociative symptoms are associated with depressive symptoms, and the concept of "dissociative depression" has been proposed. Yet, only cross-sectional evidence is available in the literature. This study examined the bidirectional relationship between dissociative and depressive symptoms through the use of screening tools in a sample of Chinese young adults (N = 340) over four months. Baseline dissociative symptoms predicted depressive symptoms at follow-up (ß = .262, p < .001), but not the other way around (ß = .065, p = .121). Among different dissociative symptom clusters, identity dissociation was the only significant predictor of subsequent depressive symptoms (ß = .177, p < .001). Furthermore, identity dissociation symptoms partially mediated the relationship between childhood trauma and subsequent depressive symptoms. This preliminary study is the first to test the bidirectional relationship between dissociative and depressive symptoms. The results highlight the importance of taking dissociative symptoms into account when preventing and treating depressive symptoms, especially among childhood trauma survivors.

Sleep-Related Dissociative Disorders.

In sleep-related dissociative disorders, phenomena of the psychiatrically defined dissociative disorders emerge during the sleep period. They occur during sustained wakefulness, either in the transition to sleep or following an awakening from sleep. Behaviors during episodes vary widely, and can result in injury to self or others. Daytime dissociative episodes and a background of trauma are almost always present; there is typically major co-existing psychopathology. Diagnosis is based on both clinical history and polysomnography; differential diagnosis primarily involves other parasomnias and nocturnal seizures. Information available about treatment is limited; in a few reported cases, psychological interventions have proven effective.

What Are the Predictors of Post-traumatic Stress Disorder Among Road Traffic Accident Survivors: A Systematic Review.

ABSTRACT: Traffic accidents put tremendous burdens on the psychosocial aspects of communities. Post-traumatic stress disorder (PTSD), after an accident, is one of the most prevalent and incapacitating psychiatric conditions worldwide. In this systematic review, we aimed to investigate the predictors of PTSD in traffic accident victims. Primary search was conducted in November 2021 and updated in 2023. Studies were excluded if they used any analysis except regression for predictors. Cumulatively, primary and update searches retrieved 10,392 articles from databases, and of these, 87 studies were systematically reviewed. The predictors were categorized into sociodemographics, pretrauma, peritrauma, and post-trauma factors. The PTSD assessment time varied between 2 weeks and 3 years. Being a woman, having depression and having a history of road traffic accidents pretraumatically, peritraumatic dissociative experiences, acute stress disorder diagnosis, rumination, higher injury severity, and involvement in litigation or compensation after the trauma were significant predictors of PTSD.

A Preliminary Longitudinal Analysis of Symptom Management, Post-traumatic Stress, and Depressive Symptoms in Chinese Adults with Dissociative Symptoms.

People with dissociative symptoms are generally poly-symptomatic and require high levels of healthcare resources. Post-traumatic stress disorder (PTSD) and depressive symptoms are two major disabling comorbid symptoms in people with dissociative symptoms. While the sense of control over symptoms may be associated with PTSD and dissociative symptoms, the interplay among these factors over time remains unexplored. This study examined the predictors of PTSD and depressive symptoms in people with dissociative symptoms. Longitudinal data from 61 participants with dissociative symptoms were analyzed. Participants completed self-report measures of dissociative, depressive, and PTSD symptoms and the sense of control over symptoms two times (T1 & T2) with an interval of over one month. PTSD and depressive symptoms were not transient or time-specific, but they persisted over time in our sample. Hierarchical multiple regression analyses revealed that, after controlling for age, treatment usage and baseline symptom severity, T1 symptom management scores (ß = -.264, p = .006) negatively predicted T2 PTSD symptoms, while T1 PTSD symptoms (ß = .268, p = .017) positively predicted T2 depressive symptoms. T1 depressive symptoms (ß = -.087, p = .339) did not predict T2 PTSD symptoms. The findings highlight the importance of improving symptom management skills and treating comorbid PTSD symptoms when working with people with dissociative symptoms.

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).

COULD FAMILY WELL-BEING MODERATE THE RELATIONSHIP BETWEEN ADVERSE CHILDHOOD EXPERIENCES AND SOMATOFORM DISSOCIATION? A PRELIMINARY INVESTIGATION.

The impacts of adverse childhood experiences (ACEs) have been well documented. One possible consequence of ACEs is dissociation, which is a major feature of post-traumatic psychopathology and is also associated with considerable impairment and health care costs. Although ACEs are known to be associated with both psychoform and somatoform dissociation, much less is known about the mechanisms behind this relationship. Little is known about whether social and interpersonal factors such as family environments would moderate the relationship between ACEs and somatoform dissociation. This paper discusses the importance of having a positive and healthy family environment in trauma recovery. We then report the findings of a preliminary study in which we examined whether the association between ACEs and somatoform dissociation would be moderated by family well-being in a convenience sample of Hong Kong adults (N = 359). The number of ACEs was positively associated with somatoform dissociative symptoms, but this association was moderated by the level of family well-being. The number of ACEs was associated with somatoform dissociation only when the family well-being scores were low. These moderating effects were medium. The findings point to the potential importance of using family education and intervention programs to prevent and treat trauma-related dissociative symptoms, but further investigation is needed.

The longitudinal relationship between dissociative symptoms and self-harm in adolescents: a population-based cohort study.

Previous studies have reported that dissociative symptoms (DIS) are associated with self-harm (SH) in adolescents. However, most of these studies were cross-sectional, which limits the understanding of their theoretical relationship. We aimed to investigate the longitudinal relationship between DIS and SH in the general adolescent population. We used data from the Tokyo Teen Cohort study (N = 3007). DIS and SH were assessed at times 1 and 2 (T1 and T2) (12 years of age and 14 years of age, respectively). DIS were assessed using the parent-report Child Behavior Checklist (CBCL), and severe dissociative symptoms (SDIS) were defined as a score above the top 10th percentile. The experience of SH within 1 year was assessed by a self-report questionnaire. The longitudinal relationship between DIS and SH was examined using regression analyses. Using logistic regression analyses, we further investigated the risk for SH at T2 due to persistent SDIS and vice versa. DIS at T1 tended to predict SH at T2 (odds ratio (OR) 1.11, 95% CI 0.99 to 1.25, p = 0.08), while SH at T1 did not predict DIS at T2 (B = - 0.03, 95% CI - 0.26 to 0.20, p = 0.81). Compared with adolescents without SDIS, those with persistent SDIS had an increased risk of SH at T2 (OR 2.61, 95% CI 1.28 to 5.33, p = 0.01). DIS tended to predict future SH, but SH did not predict future DIS. DIS may be a target to prevent SH in adolescents. Intensive attention should be given to adolescents with SDIS due to their increased risk of SH.

Dissociative Symptoms in Complex Posttraumatic Stress Disorder: A Systematic Review.

The 11th revision of the International Classification of Diseases (ICD-11) introduced Complex Posttraumatic Stress Disorder (CPTSD) as a sibling disorder to PTSD. Dissociative symptoms have been implicated in the severity of ICD-11 CPTSD; however, no reviews have investigated how dissociation has been measured in studies investigating CPTSD, nor the relationship between CPTSD and dissociation. This systematic review aimed to identify measures used to assess dissociative symptoms in studies that have assessed CPTSD according to ICD-11 criteria and to synthesize the relationship between these constructs. PsycINFO, PubMed, Scopus and Web of Science were searched on March 31, 2021. Seventeen articles met inclusion criteria. CPTSD was most frequently measured by a version of the International Trauma Questionnaire. Twelve measures were used to assess for dissociative symptoms, the most common being the Dissociative Symptoms Scale and the Dissociative Experiences Scale. The relationship between CPTSD and dissociative symptoms was moderate-to-strong, but inconsistently reported. Further research is needed to determine the most appropriate measure(s) of dissociation in CPTSD.

Posttraumatic symptoms and poor sleep are independent pathways to agency disruptions and dissociation: A longitudinal study with objective sleep assessment.

Dissociation and diminished sense of agency are experiential distortions of disintegration in the perception of self and action. Although one is often implied in the other, they are seldom studied together. Assessing their relationship and shared influences may allow for a more comprehensive and nuanced understanding of dissociative experiences. We aimed to examine their temporal (concurrent or directional) co-occurrence, and to elucidate their etiology, focusing on posttraumatic symptoms (PTS), poor sleep, and their hypothesized joint effect. N = 113 adults oversampled for the existence of trauma exposure history reported PTS and then, for a week, wore an actigraphic sleep monitor, reported subjective sleep quality each morning, and reported state dissociation (depersonalization, derealization, and absorption) and sense of agency four times each day. Data were analyzed using multilevel linear modeling. Higher state dissociation correlated with diminished state sense of agency, but only contemporaneously, not directionally. Both hypothesized etiological factors, namely, PTS (especially complex) and poor sleep (objective and subjective) predicted state dissociation and diminished state sense of agency, but psychological distress seemed to overshadow these main effects. However, robust interactive effects suggested that poor sleep predicted dissociation and disruptions in the sense of agency only among individuals with low PTS. These findings suggest that PTS and poor sleep quality are separate paths to dissociation and impaired sense of agency. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Dissociative Identity Disorder: Between History and Culture.

The Dissociative Identity Disorder has undergone significant transformations over the years. Once regarded as a rare condition, it gained popularity in the 1980s in the United States following the publication of a book on the subject, only to subsequently wane due to extensive controversies. Presently, we are witnessing a resurgence of adolescents who believe they may be afflicted by this disorder. This article delves into the changes that have occurred since the initial surge in 1980, with a particular focus on the role of social media in the dissemination of Dissociative Identity Disorder. The concepts of Mass Social Media-Induced Illness and Munchausen's by Internet are explored to elucidate this phenomenon. Additionally, we examine the criteria essential for distinguishing imitative Dissociative Identity Disorder from genuine cases, with the aim of aiding accurate diagnosis by psychiatrists. Mental health professionals may encounter new challenges when assessing young adults whose presentations are influenced by social media, necessitating awareness of the impact of social media on the dissemination of certain disorders.

Dissociative experiences reduce online problem gambling treatment effectiveness.

AIMS: To determine whether dissociative experiences moderate online problem gambling treatment effectiveness, and to characterize the temporal persistence of the relationship between dissociation and problem gambling. DESIGN: Repeatedly measured self-report data on a guided online cognitive behavioral therapy for problem gambling collected on four occasions: before treatment, after treatment, and at 6- and 12-month follow-ups. SETTING AND PARTICIPANTS: The data (N = 1243, 59.2% males) were collected in Finland between 2019 and 2021. MEASUREMENTS: The primary outcome variable was the self-reported level of problem gambling. The predictors were the treatment phase and dissociative experiences, their interaction, and the demographic covariates of age, education, income, and gender. FINDINGS: Problem gambling scores and dissociative experiences declined significantly following treatment and remained low through the follow-ups (retention rates: 52.6% [post-treatment], 26.3% [at the 6-month follow-up], and 16.1% [at the 12-month follow-up]). However, the treatment was significantly less effective in reducing problem gambling for individuals who kept experiencing dissociation after the treatment. CONCLUSIONS: Dissociation is an integral sign of problem gambling severity and sustained dissociative experiences may significantly reduce the long-term effectiveness of online problem gambling treatments. Treatment efforts should be customized to account for individual differences in dissociative tendencies, and future research should broaden the study of dissociative experiences to other behavioral addictions.

Nocturnal agitation: From sleep state dissociation to sleep-related dissociative state.

Nocturnal agitation refers to a broad spectrum of symptoms from simple movements to aggressive behaviors with partial or complete loss of awareness. An accurate identification of its etiology is critical for appropriate therapeutic intervention. In children and young adults, distinguishing between non-rapid eye movement (NREM) sleep parasomnias and psychogenic non-parasomniac manifestations, a condition known as sleep-related dissociative disorder (SRDD), can be challenging. This review aims to summarize current clinical, neurophysiological, and epidemiological knowledge on NREM parasomnia and SRDD, and to present the pathophysiological hypotheses underlying these nocturnal manifestations. Sleepwalking, sleep terror and confusional arousals are the three main presentations of NREM parasomnias and share common clinical characteristics. Parasomniac episodes generally occur 30minutes to three hours after sleep-onset, they are usually short, lasting no more than few minutes and involve non-stereotyped, clumsy behaviors with frequent amnesia. The prevalence of NREM parasomnia decreases from 15-30% in children to 2-4% in adults. Parasomniac episodes are incomplete awakening from the deepest NREM sleep and are characterized by a dissociated brain activity, with a wake-like activation in motor and limbic structures and a preserved sleep in the fronto-parietal regions. SRDD is a less known condition characterized by dramatic, often very long episodes with frequent aggressive and potentially dangerous behaviors. SRDD episodes frequently occur in quiet wakefulness before falling asleep. These dissociative manifestations are frequently observed in the context of psychological trauma. The pathophysiology of SRDD is poorly understood but could involve transient changes in brain connectivity due to labile sleep-wake boundaries in predisposed individuals. We hypothesize that SRDD and NREM parasomnia are forms of sleep-related dissociative states favored by a sleep-wake state dissociation during sleep-onset and awakening process, respectively.

Development of a Brief Version of the Dissociative Symptoms Scale and the Reliability and Validity of DSS-B Scores in Diverse Clinical and Community Samples.

The Dissociative Symptoms Scale (DSS) was developed to assess moderately severe types of dissociation (depersonalization, derealization, gaps in awareness and memory, and dissociative reexperiencing) that would be relevant to a range of clinical populations, including those experiencing trauma-related dissociation. The current study used data from 10 ethnically and racially diverse clinical and community samples (N = 3,879) to develop a brief version of the DSS (DSS-B). Item information curves were examined to identify items with the most precision in measuring above average levels of the latent trait within each subscale. Analyses revealed that the DSS-B preserved the factor structure and content domains of the full scale, and its scores had strong reliability and validity that were comparable to those of scores on the full measure. DSS-B scores showed high levels of measurement invariance across ethnoracial groups. Results indicate that DSS-B scores are reliable and valid in the populations studied.

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.

Clinical impact and misdiagnosis of functional ophthalmological symptoms: a case report.

BACKGROUND: There is a high prevalence of somatoform disorders and medically unexplained symptoms. When it comes to deciding whether a patient is able to work, it is essential to differentiate a somatoform disorder from a factitious disorder. The case presented demonstrates the impact on disability benefits and the subsequent psychosocial repercussions of misdiagnosing between a factitious disorder and a somatoform disorder. CASE PRESENTATION: A 42-year-old Caucasian woman worked as a 100% fiduciary accountant until the age of 32 when she was placed on medical leave due to persistent trigeminal neuralgia. Afterward, she developed total blindness, not explained by a physiological process, accompanied by distress in a crucial emotional context. We evaluated the patient for a revision of a disability income after a diagnosis of factitious disorder with severe consequences such as disability income suspension and family conflict. Our psychiatric examination concluded the diagnoses of pain disorders related to psychological factors and a dissociative neurological symptom disorder with visual disturbance. CONCLUSIONS: Blindness not explained by a physiological process may accompany trauma and psychological distress. Differentiating this pathology from factitious disorder or simulation is essential from an insurance medicine point of view, but also for its treatment.

A Prospective Study of the Mediating Role of Tonic Immobility and Peritraumatic Dissociation on the 4 DSM-5 Symptom Clusters of Posttraumatic Stress Disorder.

Objective: Tonic immobility (TI) and peritraumatic dissociation (PD) are common peritraumatic reactions associated with psychopathology following trauma. The present study aimed to test whether TI and PD mediated the relationship between perceived threat during an episode of rocket shelling and subsequent posttraumatic stress symptoms.Methods: In a prospective study among 226 Israeli civilians, data were collected both during rocket shelling, between May 14, 2021, until ceasefire on May 21, 2021 (T1) and 1 to 2 months after ceasefire (T2). Measures included the Tonic Immobility Scale, Peritraumatic Dissociative Experiences Questionnaire, and PTSD Checklist for DSM-5. Four mediation models were applied for each posttraumatic stress symptom cluster.Results: Findings showed that a substantial proportion of participants had developed posttraumatic stress disorder (PTSD) symptoms at the time of follow-up (18.8%). Both TI and PD fully mediated the relationship between perceived threat and symptoms of intrusion, avoidance, and negative alterations in mood and cognition, but only PD mediated the relationship with alterations in arousal and reactivity.Conclusions: The present findings suggest that TI and PD may serve as mechanisms underlying the link between individuals' appraisals of threat during the peritraumatic phase and subsequent PTSD symptomatology. Future research should seek to replicate the present findings before any conclusions can be drawn. In particular, the association between PD and arousal and reactivity symptoms should be further explored, given that it might be multifaceted in nature.

The temporal dynamics of dissociation: protocol for an ecological momentary assessment and laboratory study in a transdiagnostic sample.

BACKGROUND: Dissociation is a ubiquitous clinical phenomenon. Dissociative disorders (DD) are primarily characterized by dissociation, and dissociative states are also a criterion for borderline personality disorder (BPD) and the dissociative subtype of post-traumatic stress disorder (PTSD). Dissociative reactions (e.g., depersonalization/derealization or gaps in awareness/memory) across diagnostic categories are believed to be affect contingent and theorized to serve affect regulation functions. What is not clear, however, is how self-reported affect and physiological reactivity unfold within dissociative episodes. To address this issue, the present project aims to investigate the hypothesis (1) whether self-reported distress (as indicated by arousal, e.g., feeling tense/agitated, and/or valence, e.g., feeling discontent/unwell) and physiological reactivity increase before dissociative episodes and (2) whether self-reported distress and physiological reactivity decrease during and after dissociative episodes in a transdiagnostic sample of patients with DD, BPD, and/or PTSD. METHODS: We will use a smartphone application to assess affect and dissociation 12 times per day over the course of one week in everyday life. During this time, heart and respiratory rates will be remotely monitored. Afterwards, participants will report affect and dissociative states eight times in the laboratory before, during, and after the Trier Social Stress Test. During the laboratory task, we will continuously record heart rate, electrodermal activity, and respiratory rate, as well as measure blood pressure and take salivary samples to determine cortisol levels. Our hypotheses will be tested using multilevel structural equation models. Power analyses determined a sample size of 85. DISCUSSION: The project will test key predictions of a transdiagnostic model of dissociation based on the idea that dissociative reactions are affect contingent and serve affect regulation functions. This project will not include non-clinical control participants. In addition, the assessment of dissociation is limited to pathological phenomena.

Childhood experiences and dissociation among high school students in China: Theoretical reexamination and clinical implications.

BACKGROUND: Dissociation remains a controversial topic in terms of its prevalence, cross-cultural validity, and relationship with childhood trauma and adversities. AIMS: This study investigated the prevalence of dissociative symptoms and probable dissociative disorders among Chinese high school students and tested the trauma model of dissociation. METHODS: A total of N = 1,720 high school students completed standardized measures of positive and adverse childhood experiences (PCEs and ACEs), dissociation, depression, and anxiety. RESULTS: The prevalence rates of dissociative symptoms and (probable) DSM-5 dissociative disorders (DDs) were 11.2% and 6.9%, respectively. Dissociation was a reliable construct (ICC = .682 to .752, p < .001) and was moderately correlated with general psychopathology (r = .424 with depressive symptoms, r = .423 with anxiety symptoms). Participants with a probable DD reported more ACEs, fewer PCEs, and more mental health symptoms than those without a probable DD. ACEs were significantly associated with dissociative symptoms (ß = .107, p < .001) even after controlling for age, depressive, and anxiety symptoms. PCEs moderated the relationship between ACEs and dissociative symptoms. CONCLUSIONS: This is the first report of the prevalence of dissociative symptoms and probable DSM-5 DDs among nonclinical children. We provide cross-cultural evidence that dissociation is a reliable and valid clinical phenomenon associated with psychopathology in children across cultures. The findings partly support the trauma model of dissociation. This study contributes to the limited literature on dissociation in children. It also offers empirical data to facilitate the ongoing controversy about (childhood) trauma and dissociation. Our findings imply that dissociation is cross-culturally associated with childhood adversities, but trauma is not the only, sufficient cause. Theoretical and clinical implications are discussed.

Neurobiological and genetic correlates of the dissociative subtype of posttraumatic stress disorder.

Approximately 10%-30% of individuals with posttraumatic stress disorder (PTSD) exhibit a dissociative subtype of the condition defined by symptoms of depersonalization and derealization. This study examined the psychometric evidence for the dissociative subtype of PTSD in a sample of young, primarily male post-9/11-era Veterans (n = 374 at baseline and n = 163 at follow-up) and evaluated its biological correlates with respect to resting state functional connectivity (default mode network [DMN]; n = 275), brain morphology (hippocampal subfield volume and cortical thickness; n = 280), neurocognitive functioning (n = 337), and genetic variation (n = 193). Multivariate analyses of PTSD and dissociation items suggested a class structure was superior to dimensional and hybrid ones, with 7.5% of the sample comprising the dissociative class; this group showed stability over 1.5 years. Covarying for age, sex, and PTSD severity, linear regression models revealed that derealization/depersonalization severity was associated with: decreased DMN connectivity between bilateral posterior cingulate cortex and right isthmus (p = .015; adjusted-p [padj] = .097); increased bilateral whole hippocampal, hippocampal head, and molecular layer head volume (p = .010-.034; padj = .032-.053); worse self-monitoring (p = .018; padj = .079); and a candidate genetic variant (rs263232) in the adenylyl cyclase 8 gene (p = .026), previously associated with dissociation. Results converged on biological structures and systems implicated in sensory integration, the neural representation of spatial awareness, and stress-related spatial learning and memory, suggesting possible mechanisms underlying the dissociative subtype of PTSD. (PsycInfo Database Record (c) 2023 APA, all rights reserved).