Skin conductance and memory fragmentation after exposure to an emotional film clip in depersonalization 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.

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.

Perception of Our Own Body Influences Self-Concept and Self-Incoherence Impairs Episodic Memory

How does our body affect the way we think about our personality? We addressed this question by eliciting the perceptual illusion that pairs of friends swapped bodies with each other. We found that during the illusion, the participants rated their own personality characteristics more similarly to the way they previously rated their friend's personality, and this flexible adjustment of self-concept to the "new" bodily self was related to the strength of illusory ownership of the friend's body. Moreover, a subsequent memory test showed that personality traits rated during the friend-body-swap illusion were generally remembered worse than traits rated during the control conditions; importantly, however, this impairment of episodic recognition memory was reduced for the participants who considerably adjusted their self-concept during the illusory body swapping. These findings demonstrate that our beliefs about own personality are dynamically shaped by the perception of our body and that coherence between the bodily and conceptual self-representations is important for the normal encoding of episodic memories.

Symptoms of depersonalisation/derealisation disorder as measured by brain electrical activity: A systematic review

Depersonalisation/derealisation disorder (DPD) refers to frequent and persistent detachment from bodily self and disengagement from the outside world. As a dissociative disorder, DPD affects 1-2 % of the population, but takes 7-12 years on average to be accurately diagnosed. In this systematic review, we comprehensively describe research targeting the neural correlates of core DPD symptoms, covering publications between 1992 and 2020 that have used electrophysiological techniques. The aim was to investigate the diagnostic potential of these relatively inexpensive and convenient neuroimaging tools. We review the EEG power spectrum, components of the event-related potential (ERP), as well as vestibular and heartbeat evoked potentials as likely electrophysiological biomarkers to study DPD symptoms. We argue that acute anxiety- or trauma-related impairments in the integration of interoceptive and exteroceptive signals play a key role in the formation of DPD symptoms, and that future research needs analysis methods that can take this integration into account. We suggest tools for prospective studies of electrophysiological DPD biomarkers, which are urgently needed to fully develop their diagnostic potential.

"Seat of the soul"? The structure and function of the pineal gland in women with alleged spirit possession-Results of two experimental studies

BACKGROUND

Cultural traditions attribute to pineal gland an important role for spiritual experiences. Mediumship and spirit possession are cultural phenomena found worldwide which have been described as having dissociative and psychotic-like characteristics, but with nonpathological aspects. A sympathetic activation pattern in response to spirit possession has been reported in some studies, but empirical data on pineal gland is scarce in this context.

METHODS

We aimed to investigate pineal gland and pituitary volumes, as well as urinary 6-sulfatoxymelatonin levels in 16 alleged mediums (Medium Group-MG) compared with 16 healthy nonmedium controls (Control Group) (Experiment 1). Furthermore, we aimed to evaluate urinary 6-sulfatoxymelatonin and stress reactivity in GM (n = 10) under different physiological conditions (Experiment 2).

RESULTS

In Experiment 1, MG presented higher scores of anomalous experiences, but there were no between-group differences regarding mental health or subjective sleep quality. Similar pineal gland and pituitary volumes were observed between groups. There were no between-group differences in urinary 6-sulfatoxymelatonin collected under equivalent baseline conditions. In Experiment 2, the rise of anxiety and heart rate in response to mediumistic experience was intermediate between a nonstressful control task (reading) and a stressful control task (Trier Social Stress Test-TSST). No significant differences were observed in 6-sulfatoxymelatonin urinary levels between the three conditions. The pattern of stress reactivity during the TSST was normal, but with an attenuated salivary cortisol response.

CONCLUSION

The normal neuroimaging and stress reactivity findings in MG contrast with the abnormal results usually observed in subjects with psychotic and dissociative disorders.

The Body-Threat Assessment Battery (BTAB): A new instrument for the quantification of threat-related autonomic affective responses induced via dynamic movie clips

We present a new instrument for the assessment of responses to threat-related imagery directed towards a human body - the Body-Threat Assessment Battery (BTAB). The BTAB consists of a series of high-definition dynamic clips depicting body-threats and matched non-threat baseline behaviours. For body-threat stimuli a perspective manipulation was included to assess the effects of viewing threats from the point-of-view of the observer (POV) or from an external/exocentric perspective (EXO). Green-screen technology was used so that extraneous background information could be removed and standardised in post-production. Categorical normative data for psychological ratings (valence, arousal and pain), psychophysiological, phasic skin conductance responses (SCRs) and tonic skin conductance levels (SCLs) were obtained for all stimuli. Body-threat stimuli evoked significantly higher psychological ratings of arousal and pain, with more negative ratings of valence, relative to baseline stimuli. In addition, threat stimuli also had an increased efficacy at evoking SCRs, and these were significantly stronger relative to baseline stimuli. There were no effects of perspective on psychophysiological or psychological responses to threat imagery. The findings are discussed in the context of the utility and scope of the BTAB for supporting neurocognitive investigations of aversive imagery and body-threats specifically in the study of embodiment, body-processing and self-consciousness.

A study of dissociation in survivors of 5 disasters

This study examined dissociation as an outcome to disaster in dissociative data collected from 423 highly-exposed survivors of 5 different disasters using consistent methodology. Ten items selected for conceptual relevance to disaster experience were administered from the Dissociative Disorders Interview Schedule, a structured interview for lifetime dissociative disorders. Structured psychiatric interviews provided data on incident somatization symptoms, disaster-related PTSD, and lifetime predisaster psychopathology. The Temperament and Character Inventory assessed personality. Observed levels of dissociation were low and not usually postdisaster. Dissociation level was associated with female sex, number of incident somatization symptoms, personality (underdeveloped executive functioning), PTSD, and predisaster psychopathology in bivariate analyses. In multiple linear regression models, dissociation was associated with the low number of incident somatoform symptoms observed independent of the effects of PTSD, hyperarousal specifically (but not intrusion or avoidance/numbing), personality, predisaster psychopathology, and demographic variables which were not independently associated with dissociation. The low levels of dissociation found in this study and the lack of association between dissociation and indicators of psychopathology point to a largely nonpathological nature of the dissociative phenomena measured. These findings do not indicate the development of dissociative psychopathology as a prevalent mental health outcome of disasters.

Exposure and response prevention therapy augmented with naltrexone in kleptomania: a controlled case study using galvanic skin response for monitoring

BACKGROUND

Kleptomania is a disease that shares features with obsessive compulsive spectrum disorders (OCD) and with substance abuse disorders (SAD). This is underlined by therapeutic approaches in kleptomania ranging from cognitive behavioural therapy and selective serotonin reuptake inhibitors that are effective in OCD, and opioid antagonists that are currently being used in SAD. However, almost no literature exists about exposure and response prevention (ERP) therapy in kleptomania. Furthermore, there is a clear lack of objective markers that would allow a therapeutic monitoring.

AIM

To show the effectiveness of ERP therapy in kleptomania in a single case report.

METHOD

An ERP therapy under real-world conditions and later augmentation with the opioid antagonist naltrexone is described. Continuous measurements of galvanic skin response (GSR) before, during and after therapy sessions are reported in association with changes of the Kleptomania Symptom Assessment Scale (KSAS) self-questionnaire.

RESULTS

While KSAS scores showed a clear treatment response to ERP sessions, the GSR was significantly lower during ERP treatment in comparison with baseline measures. However, during augmentation with naltrexone, GSR measures increased again and clinical severity did not further improve.

CONCLUSIONS

This case shows the possible usefulness of ERP-like approaches and therapy monitoring using electrophysiological markers of arousal for individualized treatment in kleptomania.

The depersonalized brain: New evidence supporting a distinction between depersonalization and derealization from discrete patterns of autonomic suppression observed in a non-clinical sample

Depersonalization and Derealization are characterised by feelings of detachment from one's bodily self/surroundings and a general emotional numbness. We explored predisposition to trait-based experiences of depersonalization/derealization-type experiences and autonomic arousal toward simulated body-threats, which were delivered to the participant's own body (i.e. Self) and when observed being delivered to another individual (i.e. Other). Ninety participants took part in an "Implied Body-Threat Illusion" task (Dewe, Watson, & Braithwaite, 2016) and autonomic arousal was recorded via standardised skin conductance responses and finger temperature. Autonomic suppression in response to threats delivered to the Self correlated with increases in trait-based depersonalization-type experiences. In contrast, autonomic suppression for threats delivered to Others correlated with trait-based derealization-like experiences. Body-temperature and anticipatory arousal did not correlate reliably with predisposition to depersonalization- or derealization-type experiences. The theoretical implications of these findings are discussed in terms of a fronto-limbic autonomic suppression mechanism.

Frightened by the perpetrator's voice: Startle responsivity and cognitive processing predict earwitness speaker identification

This study was inspired by the case of a robbery victim who was startled and reminded of the crime upon hearing a stranger's voice, while not clearly recognizing the speaker. To investigate whether specific voices can modulate startle reactions and thereby predict speaker identification, we presented an audio hijack scenario to 84 participants and afterwards asked them to identify the perpetrator among neutral and negative speech fragments, while measuring flash-evoked eye-blink startle responses. Furthermore, we addressed data-driven cognitive processing during the audio scenario as a potential moderator in voice discrimination. Negative speech and the perpetrator's voice led to potentiated startle. Enhanced startle was positively associated with voice discrimination, but only in neutral speech fragments. In negative fragments, this association was weakened as a function of self-reported levels of data-driven processing during encoding. Thus, startle responses can generally predict accurate voice recognition, but speech emotionality and cognitive processing moderate this relationship.

Emotion regulation strategies in trauma-related disorders: pathways linking neurobiology and clinical manifestations

Emotion regulation impairments with traumatic origins have mainly been studied from posttraumatic stress disorder (PTSD) models by studying cases of adult onset and single-incident trauma exposure. The effects of adverse traumatic experiences, however, go beyond the PTSD. Different authors have proposed that PTSD, borderline personality, dissociative, conversive and somatoform disorders constitute a full spectrum of trauma-related conditions. Therefore, a comprehensive review of the neurobiological findings covering this posttraumatic spectrum is needed in order to develop an all-encompassing model for trauma-related disorders with emotion regulation at its center. The present review has sought to link neurobiology findings concerning cortico-limbic function to the field of emotion regulation. In so doing, trauma-related disorders have been placed in a continuum between under- and over-regulation of affect strategies. Under-regulation of affect was predominant in borderline personality disorder, PTSD with re-experiencing symptoms and positive psychoform and somatoform dissociative symptoms. Over-regulation of affect was more prevalent in somatoform disorders and pathologies characterized by negative psychoform and somatoform symptoms. Throughout this continuum, different combinations between under- and over-regulation of affect strategies were also found.

What happened first? Working memory and negative emotion tell you better: evidence from a temporal binding task

Emotionally arousing events may disrupt the ability to bind together different features of items to their context; this holds true both for spatial binding (i.e. remembering the locations of previously presented items) and temporal binding (i.e. remembering the order in which different items were previously presented). Nonetheless, memory for emotional events may be enhanced in certain situations. A key factor that might explain the memory-emotion relation is represented by individual differences in cognition. The present study investigated temporal binding for neutral and negative events in a group of 50 undergraduate students, focusing on the role of individual differences in working memory (measured through forward and backward digit span tasks). Temporal binding was assessed with sorting accuracy of various pictorial scripted events, 24 h after encoding. Results showed that higher backward digit span predicted higher binding accuracy; importantly, this was qualified by the interaction with valence, such that higher backward digit span predicted better performance for negative, but not neutral, events. It is concluded that working memory facilitates binding of emotional events to their temporal context during encoding, creating a strong representation, and favouring later retrieval of such bound representations.

Cardiac modulation of startle is altered in depersonalization-/derealization disorder: Evidence for impaired brainstem representation of baro-afferent neural traffic

Patients with depersonalization-/derealization disorder (DPD) show altered heartbeat-evoked brain potentials, which are considered psychophysiological indicators of cortical representation of visceral-afferent neural signals. The aim of the current investigation was to clarify whether the impaired CNS representation of visceral-afferent neural signals in DPD is restricted to the cortical level or is also present in sub-cortical structures. We used cardiac modulation of startle (CMS) to assess baro-afferent signal transmission at brainstem level in 22 DPD and 23 healthy control individuals. The CMS paradigm involved acoustic startle stimuli (105dB(A), 50ms) elicited 0, 100, 200, 300, 400 and 500ms after a cardiac R-wave. In healthy control individuals, we observed lower startle responses at 100 and 300ms than at 0 and 400ms after an R-wave. In DPD patients, no effect of the cardiac cycle on startle response magnitude was found. We conclude that the representation of visceral-afferent neural signals at brainstem level may be deficient in DPD. This effect may be due to increased peripheral sympathetic tone or to dysregulated signal processing at brainstem level.

Sleep loss increases dissociation and affects memory for emotional stimuli

BACKGROUND AND OBJECTIVES

Because of their dreamlike character, authors have speculated about the role that the sleep-wake cycle plays in dissociative symptoms. We investigated whether sleep loss fuels dissociative symptoms and undermines cognitive efficiency, particularly memory functioning.

METHODS

Fifty-six healthy undergraduate students were randomly assigned to an experimental group (n = 28) and a control group (n = 28). The experimental group was deprived of sleep for 36 h in a sleep laboratory; the control group had a regular night of sleep. Sleepiness, mood, and dissociative symptoms were assessed 6 times in the experimental group (control group: 4 times). Several cognitive tasks were administered.

RESULTS

Sleep deprivation led to an increase in dissociative symptoms, which was mediated by levels of general distress. Feelings of sleepiness preceded an increase of dissociative symptoms and deterioration of mood. Finally, sleep loss also undermined memory of emotional material, especially in highly dissociative individuals.

LIMITATIONS

Limitations included moderate reliability of the mood scale, limited generalizability due to student sample, and a relatively short period of intensive sleep deprivation rather than lengthy but intermittent sleep loss, representative of a clinical population.

CONCLUSIONS

We found that sleep deprivation had significant effects on dissociation, sleepiness, and mood. Specifically, sleepiness and dissociation increased during the night, while mood deteriorated. Our findings stress the importance of sleep deficiencies in the development of dissociative symptoms. They support the view that sleep disruptions fuel distress, but also degrade memory and attentional control. It is against this background that dissociative symptoms may arise.

Preliminary physiological evidence for impaired emotion regulation in depersonalization disorder

Depersonalization disorder is associated with emotional responding deficits. Ability to regulate emotion was measured by heart rate, skin conductance, and subjective responses to pictures. Compared to controls, depersonalized participants were better able to suppress, but not enhance, emotions irrespective of valence (heart rate). Emotion regulation in depersonalization merits further study.

Depersonalization disorder: disconnection of cognitive evaluation from autonomic responses to emotional stimuli

BACKGROUND

Patients with depersonalization disorder (DPD) typically complain about emotional detachment. Previous studies found reduced autonomic responsiveness to emotional stimuli for DPD patients as compared to patients with anxiety disorders. We aimed to investigate autonomic responsiveness to emotional auditory stimuli of DPD patients as compared to patient controls. Furthermore, we examined the modulatory effect of mindful breathing on these responses as well as on depersonalization intensity.

METHODS

22 DPD patients and 15 patient controls balanced for severity of depression and anxiety, age, sex and education, were compared regarding 1) electrodermal and heart rate data during a resting period, and 2) autonomic responses and cognitive appraisal of standardized acoustic affective stimuli in two conditions (normal listening and mindful breathing).

RESULTS

DPD patients rated the emotional sounds as significantly more neutral as compared to patient controls and standardized norm ratings. At the same time, however, they responded more strongly to acoustic emotional stimuli and their electrodermal response pattern was more modulated by valence and arousal as compared to patient controls. Mindful breathing reduced severity of depersonalization in DPD patients and increased the arousal modulation of electrodermal responses in the whole sample. Finally, DPD patients showed an increased electrodermal lability in the rest period as compared to patient controls.

CONCLUSIONS

These findings demonstrated that the cognitive evaluation of emotional sounds in DPD patients is disconnected from their autonomic responses to those emotional stimuli. The increased electrodermal lability in DPD may reflect increased introversion and cognitive control of emotional impulses. The findings have important psychotherapeutic implications.

Early emotional processing deficits in depersonalization: an exploration with event-related potentials in an undergraduate sample

Emotional stimuli may draw attention to such an extent that they hamper the processing of subsequent signals, a phenomenon termed emotion-induced blindness (EIB). As depersonalization is associated with self-reported attenuated emotional responses, the present study explored whether individuals scoring high on the Cambridge Depersonalization Scale (CDS; n=15) exhibit a diminished EIB effect relative to low CDS scoring individuals (n=15), and whether attentional processes reflected in event-related potentials (ERPs) are implicated in this effect. We obtained an EIB effect such that emotional distractors that preceded targets with a lag of 200ms reduced correct detection of targets. Although the magnitude of this effect was similar for high and low CDS participants, high CDS participants exhibited a significantly lower ERP amplitude at the frontal lead in the 200-300ms window than did low CDS individuals to targets that followed emotional versus neutral distractors. This latter effect was significantly related to the Alienation factor of the CDS. This pattern suggests that difficulties in the discrimination between emotional and neutral stimuli relate to the feeling of unreality in depersonalization.

The efficiency of reappraisal and expressive suppression in regulating everyday affective experiences

A widespread assumption in research and clinical practice is that cognitive reappraisal is a healthy and successful emotion regulation strategy, while expressive suppression is ineffective and has non-favourable consequences (e.g., decreased positive affect, higher physiological arousal). However, little is known about the consequences of reappraisal and expressive suppression for everyday affect. We investigated affective consequences of habitual reappraisal and expressive suppression in undergraduates (n=87), and sampled affect characteristics for 24h. Moreover, we quantified affective recovery from viewing an aversive video fragment. Habitual reappraisal was associated with lowered emotional arousal (but not valence), both in terms of diurnal affect levels and positive and negative responses to the emotional provocation task. This pattern contravenes the popular assumption that reappraisal has generally favourable consequences. Additionally, in contrast to the alleged non-favourable consequences of habitual expressive suppression, the current study failed to find a relation between expressive suppression, diurnal affect levels and affective recovery. This suggests that the detrimental effects of expressive suppression are limited in duration. Collectively, our results emphasise that the everyday consequences of emotion regulation for affect merits systematic research, for instance by using more naturalistic and prolonged interventions.

Psychophysiological investigations in depersonalization disorder and effects of electrodermal biofeedback

Previous studies investigating depersonalization disorder (DPD) report a lower baseline skin conductance level (SCL) and attenuated skin conductance response (SCR) to emotive stimuli. We hypothesized that increasing physiological arousal levels via electrodermal biofeedback may ameliorate disembodiment and emotional numbing symptomatology. Real-time versus sham biofeedback yielded a significant SCL increase after just 3 real-time biofeedback sessions in healthy volunteers. Subsequently, a randomized controlled biofeedback trial was administered with DPD patients. Findings were not replicated as SCL tended to fall, curiously more substantially in the real-time condition, concomitant with increased low- and high-frequency heart rate variability. To further investigate abnormal autonomic regulation in DPD, we compared basal autonomic activity between patients and healthy volunteers and found the former to be significantly more labile, indexed by greater nonspecific SCRs and higher resting SCLs. Rather than low sympathetic arousal, DPD might be better characterized by abnormal autonomic regulation affecting emotional and physiological responsivity.