Cambridge Depersonalization Scale Research Articles

Examining the association between depersonalisation traits and the bodily self in waking and dreaming

Depersonalisation (DP) is characterized by fundamental alterations to the sense of self that include feelings of detachment and estrangement from one’s body. We conducted an online study in healthy participants (n = 514) with DP traits to investigate and quantify the subjective experience of body and self during waking and dreaming, as the vast majority of previous studies focussed on waking experience only. Investigating dreams in people experiencing DP symptoms may help us understand whether the dream state is a ‘spared space’ where people can temporarily ‘retrieve’ their sense of self and sense of bodily presence. We found that higher DP traits—i.e. higher scores on the Cambridge Depersonalisation Scale (CDS)—were associated with more frequent dream experiences from an outside observer perspective (r = 0.28) and more frequent dream experiences of distinct bodily sensations (r = 0.23). We also found that people with higher CDS scores had more frequent dream experiences of altered bodily perception (r = 0.24), more frequent nightmares (r = 0.33) and higher dream recall (r = 0.17). CDS scores were negatively correlated with body boundary scores (r = − 0.31) in waking states and there was a negative association between CDS scores and the degree of trust in interoceptive signals (r = − 0.52). Our study elucidates the complex phenomenology of DP in relation to bodily selfhood during waking and dreaming and suggests avenues for potential therapeutic interventions in people with chronic depersonalisation (depersonalisation -derealisation disorder).

Unraveling the Complexity: Exploring the Intersection of Panic Disorder, Dissociation, and Complex Post-Traumatic Stress Disorder.

Patients with panic disorder (PD) may experience increased vulnerability to dissociative and anxious phenomena in the presence of repeated traumatic events, and these may be risk factors for the development of complex post-traumatic stress disorder (cPTSD). The present study aims to find out whether the presence of cPTSD exacerbates anxiety symptoms in patients suffering from panic disorder and whether this is specifically associated with the occurrence of dissociative symptoms. One-hundred-and-seventy-three patients diagnosed with PD were recruited and divided into two groups based on the presence (or absence) of cPTSD using the International Trauma Questionnaire (ITQ) scale. Dissociative and anxious symptoms were assessed using the Cambridge Depersonalization Scale (CDS) and Hamilton Anxiety Scale (HAM-A), respectively. Significant differences in re-experienced PTSD (p < 0.001), PTSD avoidance (p < 0.001), PTSD hyperarousal (p < 0.001), and DSO dysregulation (p < 0.001) were found between the cPTSD-positive and cPTSD-negative groups. A statistically significant association between the presence of cPTSD and total scores on the HAM-A (p < 0.001) and CDS (p < 0.001) scales was found using regression analysis. This study highlights the potential link between dissociative symptoms and a more severe clinical course of anxiety-related conditions in patients with PD. Early intervention programs and prevention strategies are needed.

Finding neural correlates of depersonalisation/derealisation disorder via explainable CNN-based analysis guided by clinical assessment scores

Mental health disorders are typically diagnosed based on subjective reports (e.g., through questionnaires) followed by clinical interviews to evaluate the self-reported symptoms. Therefore, considering the interconnected nature of psychiatric disorders, their accurate diagnosis is a real challenge without indicators of underlying physiological dysfunction. Depersonalisation/derealisation disorder (DPD) is an example of dissociative disorder affecting 1–2 % of the population. DPD is characterised mainly by persistent disembodiment, detachment from surroundings, and feelings of emotional numbness, which can significantly impact patients' quality of life. The underlying neural correlates of DPD have been investigated for years to understand and help with a more accurate and in-time diagnosis of the disorder. However, in terms of EEG studies, which hold great importance due to their convenient and inexpensive nature, the literature has often been based on hypotheses proposed by experts in the field, which require prior knowledge of the disorder. In addition, participants' labelling in research experiments is often derived from the outcome of the Cambridge Depersonalisation Scale (CDS), a subjective assessment to quantify the level of depersonalisation/derealisation, the threshold and reliability of which might be challenged. As a result, we aimed to propose a novel end-to-end EEG processing pipeline based on deep neural networks for DPD biomarker discovery, which requires no prior handcrafted labelled data. Alternatively, it can assimilate knowledge from clinical outcomes like CDS as well as data-driven patterns that differentiate individual brain responses. In addition, the structure of the proposed model targets the uncertainty in CDS scores by using them as prior information only to guide the unsupervised learning task in a multi-task learning scenario. A comprehensive evaluation has been done to confirm the significance of the proposed deep structure, including new ways of network visualisation to investigate spectral, spatial, and temporal information derived in the learning process. We argued that the proposed EEG analytics could also be applied to investigate other psychological and mental disorders currently indicated on the basis of clinical assessment scores. The code to reproduce the results presented in this paper is openly accessible at https://github.com/AbbasSalami/DPD_Analysis.

Optimised Multi-Channel Transcranial Direct Current Stimulation (MtDCS) Reveals Differential Involvement of the Right-Ventrolateral Prefrontal Cortex (rVLPFC) and Insular Complex in those Predisposed to Aberrant Experiences

Research has shown a prominent role for cortical hyperexcitability underlying aberrant perceptions, hallucinations, and distortions in human conscious experience – even in neurotypical groups. The rVLPFC has been identified as an important structure in mediating cognitive affective states / feeling conscious states. The current study examined the involvement of the rVLPFC in mediating cognitive affective states in those predisposed to aberrant experiences in the neurotypical population. Participants completed two trait-based measures: (i) the Cortical Hyperexcitability Index_II (CHi_II, a proxy measure of cortical hyperexcitability) and (ii) two factors from the Cambridge Depersonalisation Scale (CDS). An optimised 7-channel MtDCS montage for stimulation conditions (Anodal, Cathodal and Sham) was created targeting the rVLPFC in a single-blind study. At the end of each stimulation session, participants completed a body-threat task (BTAB) while skin conductance responses (SCRs) and psychological responses were recorded. Participants with signs of increasing cortical hyperexcitability showed significant suppression of SCRs in the Cathodal stimulation relative to the Anodal and sSham conditions. Those high on the trait-based measures of depersonalisation-like experiences failed to show reliable effects. Collectively, the findings suggest that baseline brain states can mediate the effects of neurostimulation which would be missed via sample level averaging and without appropriate measures for stratifying individual differences.

Cognitive Behaviour Therapy (CBT) for Depersonalization Derealization Disorder (DDD): a self-controlled cross-over study of waiting list vs. active treatment

ABSTRACT Depersonalisation-Derealisation Disorder (DDD) has a prevalence of around 1% but is under-recognised and often does not respond to medical intervention. We report on a clinical audit of 36 participants with a diagnosis of chronic DDD who were sequentially recruited from a specialist DDD National Health Service clinic in London, United Kingdom, and who completed Cognitive Behavioural Therapy specifically adapted for DDD. The sample population had a mean age of 38.7 years (s.d. = 13.4), 61% were male and 69% were of White ethnicity. Three outcomes were assessed (Cambridge Depersonalisation Scale [CDS], Beck Depression Inventory [BDI], and the Beck Anxiety Inventory [BAI]) at three time points in a naturalistic, self-controlled, cross-over design. Hierarchical longitudinal analyses for outcome response clustered by patient were performed using scores from baseline, beginning, and end of therapy. All scores showed improvement during the treatment period, with medium effect sizes. CBT may be an effective treatment for DDD. However, treatment was not randomly assigned, and the sample was small. More research is needed, including the use of randomisation to assess the efficacy of CBT for DDD.

Online structured dance/movement therapy reduces bodily detachment in depersonalization-derealization disorder

BackgroundDepersonalization-derealization disorder (DDD) is a dissociative disorder encompassing pronounced disconnections from the self and from external reality. As DDD is inherently tied to a detachment from the body, dance/movement therapy could provide an innovative treatment approach. Materials and methodsWe developed two online dance tasks to reduce detachment either by training body awareness (BA task) or enhancing the salience of bodily signals through dance exercise (DE task). Individuals with DDD (n = 31) and healthy controls (n = 29) performed both tasks individually in a cross-over design. We assessed symptom severity (Cambridge Depersonalization Scale), interoceptive awareness (Multidimensional Assessment of Interoceptive Awareness – II), mindfulness (Five Facet Mindfulness Questionnaire), and body vigilance (Body Vigilance Scale) before, during and after the tasks. ResultsAt baseline, individuals with DDD exhibited elevated depersonalization-derealization symptoms alongside lower levels of interoceptive awareness and mindfulness compared to controls. Both tasks reduced symptoms in the DDD group, though dance exercise was perceived as easier. The DE task increased mindfulness in those with DDD more than the BA task, whereas controls showed the opposite pattern. In the DDD group, within-subject correlations showed that lower levels of symptoms were associated with task-specific elevations in interoceptive awareness and mindfulness. ConclusionIndividual and structured dance/movement practice, performed at home without an instructor present, offers an effective tool to reduce symptoms in DDD and can be tailored to address specific cognitive components of a mindful engagement with the body.

The Multidimensional Inventory of Dissociation (MID) in Depersonalization Disorder: General Findings with a Clinical Emphasis on Memory and Identity Disturbances

ABSTRACT The Multidimensional Inventory of Dissociation (MID) was administered to 23 participants diagnosed with DSM-IV-TR Depersonalization Disorder (DDD) by structured interview. The MID has not been previously examined in DDD and does not generate a diagnostic formula for the disorder. Mean MID score for the sample was modestly elevated at 18.54, and was significantly correlated with Dissociative Experiences Scale, Cambridge Depersonalization Scale, and Childhood Trauma Questionnaire scores. Criterion A (General Dissociation) Depersonalization and Depersonalization scale scores were markedly elevated (41.70 and 40.98 respectively), followed by moderate elevations in the Identity Confusion (36.01), Trance (25.44), and Memory Problems (23.30) scales. Criterion B (Intrusions from partly dissociated self-states) mean score was modestly elevated (19.13) and declined to 13.67 once items overlapping with the Depersonalization and Identity Confusion scales were excluded. Criterion C (fully dissociated manifestations of other self-states) mean score was minimally elevated (6.57). Of the 168 pathological dissociation items, 55 were clinically elevated in DDD. Closer examination of the Intrusions and Amnesia items that were modestly elevated in DDD revealed that these items did not reflect the presence of alters, but rather represented known depersonalization-related phenomena. We propose a preliminary formula, based on cutoff scores for Criterion A Depersonalization and/or Derealization, Criterion B, and Criterion C (≥20, ≤28, ≤11) for the sensitive diagnosis of DDD (82.6% of participants), which would require future investigation for replication and determination of specificity vis-à-vis the other dissociative disorders.

Top-Down Influence Leads to a Reduced Sense of Body Ownership in Individuals With Depersonalization Tendencies: A Focus on Full Body Illusion.

Sense of body ownership, that is, the feeling that “my body belongs to me,” has been examined by both the rubber hand illusion (RHI) and full body illusion (FBI). In a study that examined the relationship between RHI and depersonalization, a symptom in which people experience a lower sense of body ownership, people with a high depersonalization tendency experienced RHI through the bottom-up process of visual-tactile integration. Why is it that people with depersonalization feel a lower sense of body ownership over their bodies? Case studies of depersonalization suggest that the top-down cognition in people with depersonalization may make them less likely to feel a sense of body ownership. However, the top-down influence on the sense of body ownership in depersonalization has not yet been experimentally demonstrated. By incorporating top-down manipulation (e.g., instructing participants to regard a fake body as their own) into the FBI procedure, we aimed to clarify the cause of the reduced sense of body ownership in people with a high depersonalization tendency. The FBI procedure was conducted in a virtual reality environment using an avatar as a fake body. The avatar was presented from a third-person perspective, and visual-tactile stimuli were presented to create an illusion. To examine the degree of illusion, we measured the skin conductance responses to the fear stimulus presented after the visual-tactile stimuli presentation. The degree of depersonalization was measured using the Japanese version of the Cambridge Depersonalization Scale. To manipulate the top-down influence, we provided self-association instructions before the presentation of the visual-tactile stimuli. We predicted that the higher the degree of depersonalization, the lower the degree of illusion in the self-association instruction. The results showed that participants with a higher depersonalization tendency had a lower degree of illusion (rho = −0.424, p = 0.035) in the self-association condition. This indicates that in people with a high depersonalization tendency, top-down cognition of the body as their own leads to a decrease in the sense of body ownership.

Psychological aspects of body perception in depression with non-suicidal self-injury

IntroductionEmotional regulation appears to be a key factor in self-injury. But body image also may play an important role in self-harming.ObjectivesAnalysis of the relationship between non-suicidal self-injurious behavior and various aspects of body representation and body perception in adolescents and young women suffering from depression.MethodsThe study involved 85 women with endogenous depression. The answer to the question “Sometimes I purposely injure myself” was used as an indicator of self-harm. The methods include: SCL-90-R, Body Investment Scale (BIS), Physical Appearance Comparison Scale-Revised (PACS-R), Body Satisfaction Scale (BSS), Cambridge Depersonalization Scale (CDS).ResultsThe relationship between self-injurious behavior and emotional, cognitive and behavioral characteristics of the self-body perception was revealed: more negative body image - dissatisfaction with its parts and the whole body (correlation with BSS_head ,238*, BSS_body ,472**, BSS_total_score ,453**), which is accompanied by behavioral manifestations - reduced “Protection” (correlation with BIS -,281**), higher rates of self-surveillance and comparisons of the self-body with others (PACS-R ,323**), depersonalization (CDS ,301**), body dissociation (CDS ABE ,346**), somatization (SCL-90-R ,226*).ConclusionsFor young women with depression, it has been shown that when self-harming, the self-body is “devalued”, perceived as “bad,” and the need to protect it is ignored. The severity of self-harm directly correlates with the phenomena of somatopsychic depersonalization. The results obtained may indicate that rejection of the self-body, “alienated” attitude and deprivation of the body of “subjectivity” can contribute to its use as a tool for solving psychological problems, which is a risk factor for the development, consolidation and aggravation of self-injurious behavior.DisclosureNo significant relationships.

Mindfulness and Depersonalization: a Nuanced Relationship.

ObjectivesAlthough depersonalization has been described as the antithesis of mindfulness, few studies have empirically examined this relationship, and none have considered how it may differ across various facets of mindfulness, either alone or in interaction. The present study examined the relationship between symptoms of depersonalization and facets of dispositional mindfulness in a general population sample.MethodsA total of 296 adult participants (139 male, 155 female, 2 other) were recruited online via Qualtrics and completed the Cambridge Depersonalisation Scale; Depression, Anxiety, and Stress Scale; and Five Facet Mindfulness Questionnaire.ResultsControlling for general distress, depersonalization symptoms were positively associated with Observe, Describe, and Nonreactivity facets and negatively associated with Acting with Awareness and Nonjudgment facets. After controlling for intercorrelations among the facets, depersonalization symptoms remained significantly associated with higher Nonreactivity and lower Acting with Awareness. The overall positive relationship between depersonalization symptoms and the Observe facet was moderated by both Nonjudgment and Nonreactivity. Specifically, higher Observing was related to increased depersonalization symptoms at low levels of Nonjudgment and to decreased symptoms at low levels of Nonreactivity.ConclusionsThe current study provides novel insight into the relationship between depersonalization symptoms and various aspects of mindfulness. Experiences of depersonalization demonstrated divergent relationships with mindfulness facets, alone and in interaction. The results may inform theoretical models of depersonalization and mindfulness-based interventions for depersonalization.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12671-022-01890-y.

White matter abnormalities in first-episode patients with depersonalization/derealization disorder: A tract-based spatial statistics study

BackgroundNeuroimaging studies on depersonalization / derealization disorder (DPD) have revealed that there are structural and functional alterations across numerous brain regions. However, to date, the exact white matter abnormalities that are associated with different clinical symptoms and cognitive impairments in first-episode, drug-naïve patients with DPD remain unclear. MethodsOverall, 25 first-episode, drug-naïve patients with DPD and 23 healthy controls were recruited and underwent DTI scans. The tract-based spatial statistics analysis was conducted in order to determine white matter microstructural changes between the two groups. Correlation analysis was conducted between the fractional anisotropy (FA) of abnormal WM fibers and the total score of the 30-item Cambridge Depersonalization Scale (CDS-30), cognitive assessments. ResultsPatients with DPD demonstrated higher FA in the right corpus callosum (CC), and posterior corona radiate (CR), compared to healthy controls. The FA in the right CC demonstrated a positive correlation with total score of CDS-30, numbing, unreality of self, perceptual alterations, and temporal disintegration, respectively. FA in the right CR region indicated a positive correlation with the total score of CDS-30, unreality of self, perceptual alterations, and temporal disintegration, respectively. Furthermore, FA in the right CR region was found to be negatively correlated with the Continuous Performance Test and the Stroop color-word test. ConclusionThe altered white matter microstructure and cognitive impairments of medication naïve DPD patients were observed. Abnormalities in the integrity of CC and CR were associated with severity of symptoms and cognitive impairments, which may provide a potential biomarker for clinical studies on DPD.

Effectiveness of a Constructive Model of Variables related to Depersonalization- Derealization Disorder of University Students

The aims of this study were to identify the correlation between Depersonalization - Derealization Disorder (DPDR), anxiety, depression, and obsessive-compulsive disorders and to propose a constructive model of anxiety, depression and obsessive- compulsive disorders related to Depersonalization Derealization Disorder of university students. The sample consisted of 344 students (325 female and 19 male), with a mean age of (24.4) years. The study applied the following scales: structured clinical interview for depersonalization-derealization spectrum, Cambridge Depersonalization Scale, Generalised anxiety scale (GAD-7), Hamilton Depression Rating Scale and Maudsley Obsessional–Compulsive Inventory. Results indicated that obsessive-compulsive disorder and depression played a major role in developing DPDR due to a significant positive effect of these disorders, while anxiety had a weak correlation. The study developed a constructive model of variables related to DPDR based on AMOS software. The results illustrated that the contribution of obsessive-compulsive and depression as independent variables in predicting PDRD was 61.8 and 44.9, respectively, while no effect of anxiety was recorded. The findings also developed a model for the causal relationships between anxiety, depression, and obsessive-compulsive influence on DPDR disorder. The results of the causal model test indicated that the obsessive-compulsive variable is hypothesized to be a mediator in influencing the DPDR disorder as it is affected by both anxiety and depression.

Poor sleep efficiency and daytime napping are risk factors of depersonalization disorder in female university students

ObjectivesDepersonalization is characterized by feelings of detachment from reality and has been associated with anxiety and depression, both of which have a bi-directional relationship with sleep. To date, few studies have directly examined the potential relationship between sleep and depersonalization, which was the primary objective of our study. Design/methodsA cross-sectional study of female, Emirati, university students (n = 100) was conducted. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Cambridge Depersonalization Scale (CDS) and the Hospital Anxiety and Depression Scale (HADS). Additionally, 36 of the 100 participants wore wrist actigraphy for two consecutive weekdays. Average sleep duration, and average sleep efficiency (SE; %) across the two nocturnal sleep episodes were calculated. Total number of sleep episodes were obtained from wrist actigraphy and sleep logs. ResultsA significant, positive relationship was observed between PSQI global score and CDS total score (r = 0.21, p = 0.04). Actigraphy-estimated average nocturnal sleep duration was not significantly associated with the CDS. Compared to nocturnal sleepers only, those who undertook daytime naps had almost three times the risk of meeting the criteria for depersonalization disorder (OR = 2.95, 95% CI: 1.04–8.41), after adjustment. For each 1% increase in SE a 23% decreased risk of depersonalization was observed (OR = 0.77, 95% CI: 0.61–0.96), after adjustment. ConclusionsSleep screening in young adults may help to ensure better detection and management of psychological health outcomes. Our findings need to be confirmed prospectively in larger samples and amongst different populations but reiterate the importance of sleep habits pertaining to mental health.

Symptoms of depersonalization/derealization are independent risk factors for the development or persistence of psychological distress in the general population: Results from the Gutenberg health study

BackgroundSymptoms of depersonalization (DP) and derealization (DR) have a high prevalence in patient and community samples. Previous studies suggested that DP/DR symptoms might represent a marker of disease severity and poor prognosis. However, population-based studies investigating the impact of DP/DR symptoms on the course of depression and anxiety are sparse. Therefore, we aimed to analyze whether symptoms of DP/DR are longitudinally associated with the persistence or incidence of elevated symptoms of depression/anxiety. MethodsWe analyzed observational data from a sample of 13.182 participants of the Gutenberg Health Study. The outcomes were elevated symptoms of depression/anxiety at the 2.5 years follow-up as determined by the 2-item depression scale (PHQ-2), the 2-item anxiety scale (GAD-2), and the compound measure PHQ-4 respectively. The predictor was the 2-item Cambridge Depersonalization Scale (CDS-2). Results8.7% of the sample were bothered by symptoms of DP/DR at baseline. They had an increased risk for elevated symptoms of depression/anxiety at the 2.5-year follow-up beyond baseline depression/anxiety and other factors. Each point increment in the CDS-2 scale, ranging from 0-6, was associated with a 21% increase of risk for PHQ-4 ≥ 3 at the follow-up (odds ratio 1.21, 95% confidence interval 1.11-1.32). LimitationsThe study was mostly questionnaire-based. ConclusionSymptoms of DP/DR are independent risk factors for the persistence or incidence of elevated symptoms of depression/anxiety. Symptoms of DP/DR represent an easily assessable risk factor for the course of mental disorders. Treatment and prevention of mental disorders might benefit from the broader recognition of these phenomena.

The Role of Childhood Maltreatment in The Relationship Between Social Anxiety and Dissociation: A Novel Link

ABSTRACTChildren that have been maltreated may experience manifold negative effects later in life. Two such sequelae are social anxiety and dissociation. Recent studies have noted their frequent co-occurrence, but no hypothesis has yet been offered explaining how they interact. College undergraduates (N = 198) completed the Child Trauma Questionnaire, Liebowitz Social Anxiety Scale, and Cambridge Depersonalization Scale. Social anxiety significantly predicted severity of dissociation, and self-reported childhood maltreatment (CM) significantly predicted both social anxiety and dissociation. Notably, emotional abuse was the only significant subtype of CM to predict social anxiety. Furthermore, CM moderated the relationship between social anxiety and dissociation, such that the presence of CM strengthened the predictive effect of social anxiety on dissociation. This study was the first to implicate CM as a mechanism in the social anxiety-dissociation relationship. This study was also the first to note a social anxiety-dissociation link in a non-clinical sample, thus demonstrating the existence of this relationship along a continuum of severity – not solely for those with extreme disturbances.

Dissociative symptoms as measured by the Cambridge Depersonalization Scale in patients with a bipolar disorder

BackgroundThe Cambridge Depersonalization Scale (CDS) characterizes the quality, frequency, and duration of dissociative symptoms. While the psychometric properties of the CDS have been evaluated in primary dissociative disorder, this has been insufficiently addressed among other psychiatric patient groups such as patients with a bipolar disorder (BD). MethodsOutpatients with variable mood (n = 73) responded to a survey that assessed dissociative symptoms and other characteristics. We used factor analysis and McDonald's omega to evaluate psychometric properties of the CDS, and correlations with other characteristics. ResultsPreviously suggested multifactorial models of the CDS were not supported, but the single-dimensional model fit both dichotomized (p = 0.31, CFI = 0.99, RMSEA = 0.02, ECV 70%) and trichotomized CDS responses (p = 0.06, CFI = 0.96, RMSEA = 0.04, ECV 47%). The CDS showed high internal consistency (ω = 0.96). CDS factor scores correlated with symptom severity on the Quick Inventory for Depressive Symptoms (QIDS-SR-16) (ρ = 0.59), the Social Phobia Inventory (ρ = 0.52), the American Association of Psychiatry Severity measure for Panic Disorders (ρ = 0.46), the Childhood Trauma Questionnaire (ρ = 0.44), and the Trauma Screening Questionnaire (ρ = 0.53). Two abbreviated versions of the CDS, retaining the best 14 or 7 items were proposed. LimitationsThe sample size remained moderate. ConclusionsThe CDS is a psychometrically sound, unidimensional measure with clinical impact to detect and characterize dissociative symptoms in BD patients. Establishing the reliability and validity of the abbreviated scales for screening necessitates further study.

The relationship with the voices as a dialogical experience: The role of self-focused attention and dissociation.

The purpose of this article was to study the relationship of self-focused attention and dissociation with the dialogical relationship persons diagnosed with psychosis have with their voices. The DAIMON Scale was applied to 62 persons diagnosed with psychosis to measure the dialogical relationship with their voices, and the Cambridge depersonalization scale, the Tellegen absorption scale, and the self-focused attention scale. The results showed that the dialogical relationship with the voices was associated with high levels of self-focused attention (private and public), depersonalization, and absorption. It was also found that absorption mediated significantly between public self-focused attention and the dialogical relationship with the voices. The role of dissociation and self-focused attention in forming the dialogical relationship a person with psychosis has with the voices is discussed and approaches to treatment are suggested.

The vestibular system and body schema

There is increasing evidence that vestibular disorders evoke complaints reaching far beyond imbalance, oscillopsia and spatial cognition. Yet, how vestibular disorders affect own-body representations has been overlooked. In a first study (1), we measured the occurrence of distorted own-body representations in 60 patients with dizziness (Cambridge Depersonalization Scale). 12% of the patients have experienced distorted own-body representations (their hands or feet felt larger or smaller), 37% reported abnormal sense of agency and 35% reported disownership for the body. These proportions were larger in patients than in healthy controls. In a large prospective study in 210 patients and 210 controls (2), we showed a significantly higher occurrence of out-of-body experiences (illusory sensation of disembodiment) in patients with dizziness (14%) than in healthy participants (5%). A third study (1) aimed at testing whether caloric vestibular stimulation (CVS) produced comparable distortions of own-body representations in healthy volunteers. We compared the effects of Right-warm/Left-cold CVS, Left-warm/Right-cold CVS and sham CVS on internal models of the hands using a pointing task. The perceived length of the dorsum of both hands was increased specifically during Left-warm/Right-cold CVS. Altogether, our studies show a vestibular contribution to own-body representations and should help understand the complex symptomatology of patients with dizziness.(1)Lopez C. et al. 2018. Distorted Own-Body Representations in Patients with Dizziness and during Caloric Vestibular Stimulation. Journal of Neurology 265:86-94.(2)Lopez C. & Elzière M. 2018. Out-of-Body Experience in Vestibular Disorders - A Prospective Study of 210 Patients with Dizziness. Cortex 104:193–206.

The link between childhood trauma and dissociation in frequent users of classic psychedelics and dissociatives

ABSTRACTBackground: Childhood trauma severity is associated with the level of subsequent substance use as well as with the self-reported severity of dissociation. Classic psychedelics and dissociatives target neurotransmitter systems thought to be involved in the onset of dissociative symptoms and may evoke severe and long-lasting symptoms of depersonalization in some users. However, it is currently unclear whether drug use puts people with a history of childhood trauma at higher risk of developing dissociative symptoms.Objectives: The current study investigates whether the one-year prevalence of substance use significantly moderates the link between childhood trauma and the severity of depersonalization.Methods: Participants (n = 297, of which 80.2% were active users) filled out an online self-report questionnaire including the Childhood Trauma Questionnaire (CTQ), the Cambridge Depersonalisation Scale (CDS), and information about their substance use.Results: Results indicate that childhood trauma and substance use are significant individual predictors of dissociation scores in this sample, but no moderation of substance use on the link between childhood trauma and depersonalization was established.Conclusions: It is hypothesized that the quality (particularly the context) of the experience of substance use rather than the sheer quantity may be responsible for the manifestation of depersonalization.

Functional Connectivity Between Extrastriate Body Area and Default Mode Network Predicts Depersonalization Symptoms in Major Depression: Findings From an A Priori Specified Multinetwork Comparison

BackgroundDepersonalization/derealization disorder is a dissociative disorder characterized by feelings of unreality and detachment from the self and surroundings. Depersonalization/derealization disorder is classified as a primary disorder, but depersonalization symptoms are frequently observed in mood and anxiety disorders. In the context of major depressive disorder (MDD), depersonalization symptoms are associated with greater depressive severity as indexed by treatment resistance, inpatient visits, and duration of depressive episodes. In the current investigation, we tested four network-based, neural-functional hypotheses of depersonalization in MDD. These hypotheses were framed in terms of functional relationships between 1) extrastriate body area and default mode network (DMN); 2) hippocampus and DMN; 3) medial prefrontal cortex and ventral striatum; and 4) posterior and anterior insular cortex. MethodsWe conducted functional magnetic resonance imaging during resting state on 28 female patients with MDD and 27 control subjects with no history of a psychiatric disorder. Functional connectivity between seed and target regions as specified by our network-level hypotheses was computed and correlated with scores on the Cambridge Depersonalization Scale. We used a conservative, unbiased bootstrapping procedure to test the significance of neural-behavioral correlations observed under each of the four models tested. ResultsOf the four neural-functional models of depersonalization symptoms tested, only the model proposing that reduced connectivity between the extrastriate body area and DMN predicts higher levels of depersonalization symptoms in MDD was confirmed. ConclusionsOur results indicate that depersonalization/derealization disorder symptoms in patients with depression are related to reduced functional connectivity between brain regions that are proposed to support processing of body-related (extrastriate body area) and autobiographical (DMN) information.