Cognitive load and autonomic response patterns under negative priming demand in depersonalization-derealization disorder

Behavioural, autonomic, and neural responsivity in depersonalisation-derealisation disorder: A systematic review of experimental evidence

Depersonalisation-derealisation disorder (DDD) is characterised by distressing experiences of separation from oneself and/or one's surroundings, potentially resulting from alterations in affective, cognitive, and physiological functions. This systematic review aimed to synthesise current experimental evidence of relevance to proposed mechanisms underlying DDD, to appraise existing theoretical models, and to inform future research and theoretical developments. Studies were included if they tested explicit hypotheses in DDD samples, with experimental manipulations of at least one independent variable, alongside behavioural, subjective, neurological, affective and/or physiological dependent variables. Some evidence for diminished subjective responsivity to aversive images and sounds, and hyperactivation in neurocircuits associated with emotional regulation when viewing aversive images emerged, corroborating neurobiological models of DDD. Inconsistencies were present regarding behavioural and autonomic responsivity to facial expressions, emotional memory, and self-referential processing. Common confounds included small sample sizes, medication, and comorbidities. Alterations in affective reactivity and regulation appear to be present in DDD; however, further research employing more rigorous research designs is required to provide stronger evidence for these possible mechanisms.

Dissociative Symptoms and Interoceptive Integration

Dissociative symptoms and disorders of dissociation are characterised by disturbances in the experience of the self and the surrounding world, manifesting as a breakdown in the normal integration of consciousness, memory, identity, emotion, and perception. This paper aims to provide insights into dissociative symptoms from the perspective of interoception, the sense of the body's internal physiological state, adopting a transdiagnostic framework.Dissociative symptoms are associated with a blunting of autonomic reactivity and a reduction in interoceptive precision. In addition to the central function of interoception in homeostasis, afferent visceral signals and their neural and mental representation have been shown to shape emotional feeling states, support memory encoding, and contribute to self-representation. Changes in interoceptive processing and disrupted integration of interoceptive signals into wider cognition may contribute to detachment from the body and the world, blunted emotional experience, and altered subjective recall, as experienced by individuals who suffer from dissociation.A better understanding of the role of altered interoceptive integration across the symptom areas of dissociation could thus provide insights into the neurophysiological mechanisms underlying dissociative disorders. As new therapeutic approaches targeting interoceptive processing emerge, recognising the significance of interoceptive mechanisms in dissociation holds potential implications for future treatment targets.

Depersonalization/Derealization Disorder and Neural Correlates of Trauma-related Pathology: A Critical Review

Depersonalization and derealization refer to an estranged state of mind that involves a profound feeling of detachment from one's sense of self and the surrounding environment, respectively. The phenomena co-occur on a continuum of severity, ranging from a transient experience as a normal reaction to a traumatic event to a highly debilitating condition with persistent symptoms, formally described as depersonalization/derealization disorder (DPDR). Lack of awareness of DPDR is partly due to a limited neurobiological framework, and there remains a significant risk of misdiagnosis in clinical practice. Earlier literature has focused on several brain regions involved in the experience of depersonalization and derealization, including adaptive responses to stress via defense cascades comprising autonomic functioning, the hypothalamic-pituitary-adrenal (HPA) axis, and various other neurocircuits. Recent evidence has also demonstrated the role of more complex mechanisms that are bolstered by dissociative features, such as emotional dysregulation and disintegration of the body schema. This review intends to abridge the prevailing knowledge regarding structural and functional brain alterations associated with DPDR with that of its heterogenic manifestations. DPDR is not merely the disruption of various sensory integrations, but also of several large-scale brain networks. Although a comprehensive antidote is not available for DPDR, a holistic route to the neurobiological context in DPDR may improve general understanding of the disorder and help afflicted individuals re-establish their sense of personal identity. Such information may also be useful in the development of novel pharmacological agents and targeted psychological interventions.

Functional Neuroimaging in Dissociative Disorders: A Systematic Review

Background: Dissociative disorders encompass loss of integration in essential functions such as memory, consciousness, perception, motor control, and identity. Nevertheless, neuroimaging studies, albeit scarce, have suggested the existence of particular brain activation patterns in patients belonging to this diagnostic category. The aim of this review is to identify the main functional neuroimaging correlates of dissociative disorders. Methods: we searched the PubMed database to identify functional neuroimaging studies conducted on subjects with a diagnosis of a dissociative disorder, following the PRISMA guidelines. In the end, we included 13 studies in this systematic review, conducted on 51 patients with dissociative identity disorder (DID), 28 subjects affected by depersonalization disorder, 24 with dissociative amnesia, and 6 with other or not specified dissociative disorders. Results: Prefrontal cortex dysfunction seems prominent. In addition, changes in the functional neural network of the caudate are related to alterations of identity state and maintenance of an altered mental status in DID. Another role in DID seems to be played by a dysfunction of the anterior cingulate gyrus. Other regions, including parietal, temporal, and insular cortices, and subcortical areas were reported to be dysfunctional in dissociative disorders. Conclusions: Prefrontal dysfunction is frequently reported in dissociative disorders. Functional changes in other cortical and subcortical areas can be correlated with these diagnoses. Further studies are needed to clarify the neurofunctional correlations of each dissociative disorder in affected patients, in order to identify better tailored treatments.

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

BACKGROUND

Neuroimaging 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.

METHODS

Overall, 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.

RESULTS

Patients 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.

CONCLUSION

The 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.

Dissociation in Borderline Personality Disorder: Recent Experimental, Neurobiological Studies, and Implications for Future Research and Treatment

PURPOSE OF REVIEW

The aim of this review article is to give an overview over recent experimental neurobiological research on dissociation in borderline personality disorder (BPD), in order to inform clinicians and to stimulate further research. First, we introduce basic definitions and models that conceptualize dissociation from a transdiagnostic perspective. Then, we discuss recent findings in BPD.

RECENT FINDINGS

Stress-related dissociation is a key symptom of BPD, closely linked to other core domains of the disorder (emotion dysregulation, identity disturbances, and interpersonal disturbances). The understanding of neurobiological correlates of dissociation across different psychiatric disorders (e.g., dissociative disorders, post-traumatic stress disorder) is steadily increasing. At the same time, studies explicitly focusing on dissociation in BPD are still scarce. There is evidence for adverse effects of dissociation on affective-cognitive functioning (e.g., interference inhibition), body perception, and psychotherapeutic treatment response in BPD. On the neural level, increased activity in frontal regions (e.g., inferior frontal gyrus) and temporal areas (e.g., inferior and superior temporal gyrus) during symptom provocation tasks and during resting state was observed, although findings are still diverse and need to be replicated. Conceptual differences and methodological differences in study designs and sample characteristics (e.g., comorbidities, trauma history) hinder a straightforward interpretation and comparison of studies. Given the potentially detrimental impact of dissociation in BPD, more research on the topic is strongly needed to deepen the understanding of this complex clinical condition.

From brooding to detachment: Rumination longitudinally predicts an increase in depersonalization and derealisation

OBJECTIVES

Depersonalization-derealization (DEP-DER) is a dissociative experience which is related to psychopathology and distress. Yet, the aetiological factors leading to DEP-DER are not sufficiently clear. In this study, we suggest rumination as one possible antecedent. Thus, the goal of the study was to explore the longitudinal relationship between rumination and DEP-DER.

DESIGN

Longitudinal self-report study; mixed clinical and community sample.

METHODS

The study was conducted on 98 participants, 49 of them were diagnosed with depression, anxiety disorders, or obsessive-compulsive disorder, and the other 49 were healthy, matched community controls. The participants underwent a structured clinical interview and completed a battery of questionnaires. Then, the participants completed the same battery again once a month, for five additional assessment points (6 months in total). The data were analysed using multilevel linear modelling with time-lag analysis.

RESULTS

We found that levels of rumination and DEP-DER increased and decreased simultaneously, meaning that on assessments in which people reported that they tended to ruminate, they also reported higher levels of DEP-DER symptoms. In addition, we found support for a unidirectional association, consistent with our theoretical hypothesis. Specifically, rumination levels on a certain month longitudinally predicted a higher likeliness for reporting DEP-DER on the following month, even when controlling for the contemporaneous relationship. Conversely, DEP-DER symptoms did not longitudinally predict increased rumination.

CONCLUSIONS

These findings suggest that rumination may be an antecedent of DEP-DER, but not vice versa. Possible mechanisms to explain this link are discussed.

PRACTITIONER POINTS

Rumination and DEP-DER oscillate together over time; additionally, rumination predicts a longitudinal increase in DEP-DER. Clinicians noticing ruminative thought followed by decreased emotionality should distinguish between an authentic decrease of distress versus detachment. The findings provide one possible explanation for the frequency of DEP-DER symptoms in anxiety and depressive disorders. Poor sleep quality and emotion regulation difficulties should be explored as potential mediators explaining this link.

Biomarkers of Pathological Dissociation: A Systematic Review

Pathological dissociation is a severe, debilitating and transdiagnostic psychiatric symptom. This review identifies biomarkers of pathological dissociation in a transdiagnostic manner to recommend the most promising research and treatment pathways in support of the precision medicine framework. A total of 205 unique studies that met inclusion criteria were included. Studies were divided into four biomarker categories, namely neuroimaging, psychobiological, psychophysiological and genetic biomarkers. The dorsomedial and dorsolateral prefrontal cortex, bilateral superior frontal regions, (anterior) cingulate, posterior association areas and basal ganglia are identified as neurofunctional biomarkers of pathological dissociation and decreased hippocampal, basal ganglia and thalamic volumes as neurostructural biomarkers. Increased oxytocin and prolactin and decreased tumor necrosis factor alpha (TNF-α) are identified as psychobiological markers. Psychophysiological biomarkers, including blood pressure, heart rate and skin conductance, were inconclusive. For the genetic biomarker category studies related to dissociation were limited and no clear directionality of effect was found to warrant identification of a genetic biomarker. Recommendations for future research pathways and possible clinical applicability are provided.

Emotional response in depersonalization: A systematic review of electrodermal activity studies

BACKGROUND

Depersonalization is a complex phenomenological experience initially described as a psychological disturbance of self-awareness. Among the different dimensions underlying depersonalization, emotional numbing appears to be a key symptom but remains a poorly understood phenomenon.

METHOD

We conducted a systematic review, following PRISMA guidelines, of studies investigating electrodermal activity, a well-documented marker of bodily arousal expression of emotion. Studies were selected from the PubMed, Scopus, Web of Science and PsychINFO databases.

RESULTS

Among the 64 studies initially identified, 11 were finally included, involving 148 patients with depersonalization disorder and 173 healthy subjects for whom depersonalization symptoms were assessed. The main results of these studies suggest that depersonalization is marked by a high skin conductance level and attenuated skin conductance responses to negative stimuli.

LIMITATIONS

Due to discrepancies in methodology, we were not able to conduct quantitative analyses. Moreover, the studies included had limited sample sizes, restricting the generalizability of the results.

CONCLUSION

Though further evidence is required, it appears from electrodermal studies that depersonalization is associated with hypervigilance and emotional detachment during threatening situations. However, because emotional numbing might not be restricted to negative events, we proposed perspectives for future research, stressing the need to explore emotional responses of patients with depersonalization to positive situations.

Structural and functional brain alterations in psychiatric patients with dissociative experiences: A systematic review of magnetic resonance imaging studies

INTRODUCTION

There is currently no general agreement on how to best conceptualize dissociative symptoms and whether they share similar neural underpinnings across dissociative disorders. Neuroimaging data could help elucidate these questions.

OBJECTIVES

The objective of this review is to summarize empirical evidence for neural aberrations observed in patients suffering from dissociative symptoms.

METHODS

A systematic literature review was conducted including patient cohorts diagnosed with primary dissociative disorders, post-traumatic stress disorder (PTSD), or borderline personality disorder.

RESULTS

Results from MRI studies reporting structural (gray matter and white matter) and functional (during resting-state and task-related activation) brain aberrations were extracted and integrated. In total, 33 articles were included of which 10 pertained to voxel-based morphology, 2 to diffusion tensor imaging, 10 to resting-state fMRI, and 11 to task-related fMRI. Overall findings indicated aberrations spread across diverse brain regions, especially in the temporal and frontal cortices. Patients with dissociative identity disorder and with dissociative PTSD showed more overlap in brain activation than each group showed with depersonalization/derealization disorder.

CONCLUSION

In conjunction, the results indicate that dissociative processing cannot be localized to a few distinctive brain regions but rather corresponds to differential neural signatures depending on the symptom constellation.

Trapped in a Glass Bell Jar: Neural Correlates of Depersonalization and Derealization in Subjects at Clinical High-Risk of Psychosis and Depersonalization-Derealization Disorder

BACKGROUND

Depersonalization (DP) and derealization (DR) are symptoms of a disruption of perceptual integration leading to an altered quality of subjective experiences such as feelings of unreality and detachment from the self (DP) or the surroundings (DR). Both DP and DR often occur in concert with other symptoms, for example in subjects at clinical high-risk (CHR) for psychosis, but also appear isolated in the form of DP/DR disorder. Despite evidence that DP/DR causes immense distress, little is known about their neurobiological underpinnings. Therefore, we investigated the neural correlates of DP/DR using pseudo-continuous arterial spin labeling MRI.

METHODS

We evaluated the frequency of DP/DR symptoms in a clinical sample (N = 217) of help-seeking individuals from the Early Detection and Intervention Centre for Mental Crisis (CHR, n = 97; clinical controls (CC), n = 91; and first-episode psychosis (FEP), n = 29). Further, in a subsample of those CHR subjects who underwent MRI, we investigated the resting-state regional cerebral blood flow (rCBF). Here, individuals with (n = 21) and without (n = 23) DP/DR were contrasted. Finally, rCBF was measured in a small independent second sample of patients with DP/DR disorder (n = 6) and healthy controls (HC, n = 6).

RESULTS

In the complete clinical sample, significantly higher frequency of DP/DR was found in CHR compared to CC (50.5 vs. 16.5%; χ² ₍₂₎ = 24.218, p ≤ 0.001, Cramer's V = 0.359) as well as in FEP compared to CC (37.9 vs. 16.5%; χ² ₍₂₎ = 5.960, p = 0.015, Cramer's V = 0.223). In MRI, significantly lower rCBF was detected in the left orbitofrontal cortex in CHR with vs. without DP/DR (x/y/z = -16/42/-22, p < 0.05, FWE corrected). In patients with DP/DR disorder, significantly higher rCBF was detected in the left caudate nucleus (x/y/z = -18/-32/18, p < 0.05) compared to HC.

CONCLUSIONS

This study shows that DP/DR symptoms are frequently found in CHR subjects. Investigating two separate DP/DR populations with an identical neuroimaging technique, our study also indicates that there may be divergent pathophysiological mechanisms-decreased neuronal activity in the orbitofrontal cortex, but increased activity within the caudate nucleus-leading to a final common pathway with similar psychopathological symptoms. This suggests that both top-down (orbitofrontal cortex) and bottom-up (caudate nucleus) mechanisms could contribute to the emergence of DP/DR.

Current Understanding of the Neural Mechanisms of Dissociation in Borderline Personality Disorder

Purpose of Review

In this article, we aim to give an overview over recent neuroimaging research on dissociation in borderline personality disorder (BPD). Stress-related dissociation is highly prevalent in BPD, while so far only little is known about its neural underpinnings.

Recent Findings

Based on research in depersonalization and the dissociative subtype of posttraumatic stress disorder, it has been proposed that dissociation involves alterations in a cortico-limbic network. In BPD, neuroimaging research explicitly focusing on dissociation is still scarce.

Summary

Functional neuroimaging studies have provided preliminary evidence for an altered recruitment and interplay of fronto-limbic regions (amygdala, anterior cingulate, inferior frontal gyrus, medial and dorsolateral prefrontal cortices) and temporoparietal areas (superior temporal gyrus, inferior parietal lobule, fusiform gyrus), which may underlie disrupted affective-cognitive processing during dissociation in BPD. More neuroimaging research with larger samples, clinical control groups, and repeated measurements is needed to deepen the understanding of dissociation in BPD.

Dissociation and Alterations in Brain Function and Structure: Implications for Borderline Personality Disorder

Dissociation involves disruptions of usually integrated functions of consciousness, perception, memory, identity, and affect (e.g., depersonalization, derealization, numbing, amnesia, and analgesia). While the precise neurobiological underpinnings of dissociation remain elusive, neuroimaging studies in disorders, characterized by high dissociation (e.g., depersonalization/derealization disorder (DDD), dissociative identity disorder (DID), dissociative subtype of posttraumatic stress disorder (D-PTSD)), have provided valuable insight into brain alterations possibly underlying dissociation. Neuroimaging studies in borderline personality disorder (BPD), investigating links between altered brain function/structure and dissociation, are still relatively rare. In this article, we provide an overview of neurobiological models of dissociation, primarily based on research in DDD, DID, and D-PTSD. Based on this background, we review recent neuroimaging studies on associations between dissociation and altered brain function and structure in BPD. These studies are discussed in the context of earlier findings regarding methodological differences and limitations and concerning possible implications for future research and the clinical setting.