Hypothalamic-pituitary-adrenal axis dysregulation in depersonalization disorder

The role of the immune system in depersonalisation disorder

OBJECTIVES

Depersonalisation-derealization disorder (DPD) is a dissociative disorder that impairs cognitive function and occupational performance. Emerging evidence indicate the levels of tumour necrosis factor-α and interleukin associated with the dissociative symptoms. In this study, we aimed to explore the role of the immune system in the pathology of DPD.

METHODS

We screened the protein expression in serum samples of 30 DPD patients and 32 healthy controls. Using a mass spectrometry-based proteomic approach, we identified differential proteins that were verified in another group of 25 DPD patients and 30 healthy controls using immune assays. Finally, we performed a correlation analysis between the expression of differential proteins and clinical symptoms of patients with DPD.

RESULTS

We identified several dysregulated proteins in patients with DPD compared to HCs, including decreased levels of C-reactive protein (CRP), complement C1q subcomponent subunit B, apolipoprotein A-IV, and increased levels of alpha-1-antichymotrypsin (SERPINA3). Moreover, the expression of CRP was positively correlated with visuospatial memory and the ability to inhibit cognitive interference of DPD. The expression of SERPINA3 was positively correlated with the ability to inhibit cognitive interference and negatively correlated with the perceptual alterations of DPD.

CONCLUSIONS

The dysregulation of the immune system may be the underlying biological mechanism in DPD. And the expressions of CRP and SERPINA3 can be the potential predictors for the cognitive performance of DPD.

Spatial anxiety contributes to the dizziness-related handicap of adults with peripheral vestibular disease

In subjects with peripheral vestibular disease and controls, we assessed: 1. The relationship between spatial anxiety and perceived stress, and 2. The combined contribution of spatial anxiety, spatial perspective-taking, and individual cofactors to dizziness-related handicap. 309 adults participated in the study (153 with and 156 without peripheral vestibular disease), including patients with bilateral vestibular deficiency, unilateral deficiency (evolution <3 or ≥3 months), Meniere's disease, and Benign Paroxysmal Positional Vertigo. Assessments included: general health, personal habits, spatial anxiety (3-domains), perceived stress, spatial perspective-taking, dizziness-related handicap (3-domains), unsteadiness, sleep quality, motion sickness susceptibility, trait anxiety/depression, state anxiety, depersonalization/derealization. After bivariate analyses, analysis of covariance was performed (p ≤ 0.05). Spatial anxiety was related to unsteadiness and perceived stress, with an inverse relationship with trait anxiety (ANCoVA, adjusted R2 = 0.27-0.30, F = 17.945-20.086, p < 0.00001). Variability on perspective-taking was related to vestibular disease, trait and state anxiety, motion sickness susceptibility, and age (ANCoVA, adjusted R2 = 0.18, F = 5.834, p < 0.00001). All domains of spatial anxiety contributed to the Physical domain of dizziness-related handicap, while the Navigation domain contributed to the Functional domain of handicap. Handicap variability was also related to unsteadiness, spatial perspective-taking, quality of sleep, and trait anxiety/depression (ANCoVA, adjusted R2 = 0.66, F = 39.07, p < 0.00001). Spatial anxiety is related to perceived stress in adults both with and without vestibular disease, subjects with trait anxiety rated lower on spatial anxiety. State anxiety and acute stress could be helpful for recovery after peripheral vestibular lesion. Spatial anxiety and perspective-taking contribute to the Physical and Functional domains of dizziness-related handicap, possibly because it discourages behavior beneficial to adaptation.

Glyphosate: Impact on the microbiota-gut-brain axis and the immune-nervous system, and clinical cases of multiorgan toxicity

Glyphosate (GLP) and GLP-based herbicides (GBHs), such as polyethoxylated tallow amine-based GLP surfactants (GLP-SH), developed in the late 70', have become the most popular and controversial agrochemicals ever produced. Nowadays, GBHs have reached 350 million hectares of crops in over 140 countries, with an annual turnover of 5 billion and 11 billion USD in the U.S.A. and worldwide, respectively. Because of the highly efficient inhibitory activity of GLP targeted to the 5-enolpyruvylshikimate-3-phosphate synthase pathway, present in plants and several bacterial strains, the GLP-resistant crop-based genetic agricultural revolution has decreased famine and improved the costs and quality of living in developing countries. However, this progress has come at the cost of the 50-year GBH overuse, leading to environmental pollution, animal intoxication, bacterial resistance, and sustained occupational exposure of the herbicide farm and companies' workers. According to preclinical and clinical studies covered in the present review, poisoning with GLP, GLP-SH, and GBHs devastatingly affects gut microbiota and the microbiota-gut-brain (MGB) axis, leading to dysbiosis and gastrointestinal (GI) ailments, as well as immunosuppression and inappropriate immunostimulation, cholinergic neurotransmission dysregulation, neuroendocrinal system disarray, and neurodevelopmental and neurobehavioral alterations. Herein, we mainly focus on the contribution of gut microbiota (GM) to neurological impairments, e.g., stroke and neurodegenerative and neuropsychiatric disorders. The current review provides a comprehensive introduction to GLP's microbiological and neurochemical activities, including deviation of the intestinal Firmicutes-to-Bacteroidetes ratio, acetylcholinesterase inhibition, excitotoxicity, and mind-altering processes. Besides, it summarizes and critically discusses recent preclinical studies and clinical case reports concerning the harmful impacts of GBHs on the GI tract, MGB axis, and nervous system. Finally, an insightful comparison of toxic effects caused by GLP, GBH-SH, and GBHs is presented. To this end, we propose a first-to-date survey of clinical case reports on intoxications with these herbicides.

Stress response in dissociation and conversion disorders: A systematic review

Dissociative disorders (DD) and conversion disorders (CD) are frequent in general and psychiatric populations. Some evidence suggest that the hypothalamic-pituitary axis (HPA) and autonomic nervous system (ANS) are dysregulated in both disorders. We carried out a systematic review of the literature to summarize the existing knowledge on the stress response, via HPA and/or ANS, in patients with DD, CD, or dissociative symptoms. We systematically searched Medline and Web of Science using the Medical Subject Headings related to stress axis, CD, DD, and dissociative symptoms following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results suggest that in participants without psychiatric history, high cortisol secretion is related to high dissociation scores. Conversely the stress system might be blunted in patients with post-traumatic stress disorder who develop dissociative symptoms. Stress response changes seem to be associated with the emergence and persistence of dissociative and conversion disorders. Hence, monitoring the stress response and examining closely the history of stress exposure in DD and CD should be encouraged in future larger studies.

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.

Interoception, Stress, and Physical Symptoms in Stress-Associated Diseases

Abstract. The brain and peripheral bodily organs continuously exchange information. Exemplary, interoception refers to the processing and perception of ascending information from the body to the brain. Stress responses involve a neurobehavioral cascade, which includes the activation of peripheral organs via neural and endocrine pathways and can thus be seen as an example for descending information on the brain-body axis. Hence, the interaction of interoception and stress represents bi-directional communication on the brain-body axis. The main hypothesis underlying this review is that the dysregulation of brain-body communication represents an important mechanism for the generation of physical symptoms in stress-related disorders. The aims of this review are, therefore, (1) to summarize current knowledge on acute stress effects on different stages of interoceptive signal processing, (2) to discuss possible patterns of abnormal brain-body communication (i.e., alterations in interoception and physiological stress axes activation) in mental disorders and chronic physical conditions, and (3) to consider possible approaches to modify interoception. Due to the regulatory feedback loops underlying brain-body communication, the modification of interoceptive processes (ascending signals) may, in turn, affect physiological stress axes activity (descending signals), and, ultimately, also physical symptoms.

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.

Stress and the vestibular system

In this chapter we review the existing literature regarding the interactions between stress and the mechanisms that maintain balance. Evidence suggests that the interplay between neuro-endocrine and psychological factors may have a significant role in balance function. For example, in healthy individuals vestibular stimulation has been shown to trigger the stress response as indicated by increased blood cortisol levels, whereas in patients with vestibular pathology factors such as resilience and anxiety may be the key focus of interactions with stress. Critically, factors such as anxiety are known to influence clinical outcomes, despite our mechanistic understanding of these processes remaining in their infancy.

What was once essential, may become detrimental: The mediating role of depersonalization in the relationship between childhood emotional maltreatment and psychological distress in adults

Depersonalization (DP) is a dissociative phenomenon, characterized by feeling "unreal" or detached from one's own emotions, thoughts, and behavior (APA, 2013). It is considered to be a defense mechanism, employed in response to overwhelming events, whereby thoughts and emotions are suppressed in order to enhance the individual's capacity to function in traumatic environments. DP has been found to co-occur with anxiety and depressive disorders, and childhood emotional maltreatment (EM) has been identified as an important predisposing factor. The study's primary aim was to investigate the mediating role of DP in the relationship between childhood EM and psychological distress in young adults. Additionally, it aimed to confirm that a history of childhood EM (emotional abuse and emotional neglect) predicted current levels of DP and to explore how both a person's attitude towards experiencing and expressing emotions (with an emphasis on the affect phobia model) and their current attachment security are related to current DP. A cross-sectional design was employed, which included young adults (N = 761) aged between 18 and 25 years. Participants completed an online survey that comprised of several self-report measures. Regression and mediation analyses were conducted. The results indicated that: (1) DP significantly mediated the relationship between childhood EM and current psychological distress; (2) that a history of EM, but no other forms of childhood abuse, significantly predicted current DP experiences; and (3) EM, attachment-related anxiety, and negative attitudes toward emotions predicted clinical cutoff levels of DP. The results are discussed in detail, including clinical implications and direction for future research.

A human exposure based mixture of persistent organic pollutants affects the stress response in female mice and their offspring

Persistent organic pollutants (POPs) are found in the food chain of both humans and animals and exert a wide spectrum of potentially adverse effects. The present experiment aimed to investigate whether a defined mixture of 29 POPs, based on the dietary intake of Scandinavians, could affect the stress response in female mice exposed through ingestion, and in their offspring. Female mice 129:C57BL/6F0 hybrids were exposed from weaning, throughout pregnancy, and up until necropsy, to either 5000 × or 100 000 × the estimated daily intake for Scandinavians. The offspring were fed a reference diet containing no POPs. Both the mothers and their offspring were tested for basal and stress responsive corticosterone levels, and in an open field test to measure locomotor activity and anxiety-like behaviours. We found mothers to have elevated basal corticosterone levels, as well as a prolonged stress response following POP exposure. In the offspring, there was no effect of POPs on the stress response in females, but the exposed males had an over-sensitised stress response. There was no effect on behaviour in either the mothers or the offspring. In conclusion, we found a human relevant POP mixture can lead to subtle dysregulation of the hypothalamus-pituitary-adrenal axis in mice. As HPA axis dysregulation is commonly associated with neurological disorders, further studies should explore the relevance of this outcome for humans.

Depersonalization, adversity, emotionality, and coping with stressful situations

Depersonalization is defined as persistent or recurrent episodes of feeling detached or estranged from a sense of self and the world. This study addressed the primary question: Do nonclinical individuals who endorse high symptomatic depersonalization have inherently more intense emotional responses, along with more childhood adversity and past trauma? In this IRB approved study, participants who met clinical levels of depersonalization (n = 43, 16.3%) were compared to a group without clinical levels of depersonalization (n = 221, 83.7%). Adverse childhood experiences, adult traumatic events, emotional overexcitability, coping strategies under stress, and anxiety were examined in both groups. The variables to assess depersonalization severity included the Dissociative Experience Scale-II, Cambridge Depersonalization Scale, and Multiscale Dissociation Inventory. The results indicated that clinical levels of depersonalization were identified in 16.3% of the sample. The high depersonalization group had significantly more adverse childhood experiences, in particular, emotional abuse and neglect. They also experienced more adult traumatic events, higher levels of anxiety, more emotional overexcitability, and they employed a less adaptive emotion-oriented coping strategy under stress. It is recommended that treating depersonalization symptoms should include examining childhood adversity, especially emotional abuse and neglect. Based on study findings, emotion regulation skills should be promoted to help individuals with elevated depersonalization manage their emotion-oriented coping strategies, anxiety, and emotional overexcitability.

Emotion regulation strategies moderate the relationship of fatigue with depersonalization and derealization symptoms

BACKGROUND

The aim of the present study was to investigate the relationships of common emotion regulation strategies (suppression and reappraisal) to self-reported fatigue and depersonalization/derealization symptoms. Specifically, we tested the moderating effect of suppression and reappraisal on the link of fatigue with depersonalization and derealization symptoms. Opposite effects were expected for both emotion regulation strategies assuming that cognitive reappraisal has an adaptive buffering effect, while suppression intensifies the association of fatigue and depersonalization/derealization experiences.

METHODS

In a representative study (N = 2524) we assessed emotion regulation strategies, fatigue, depersonalization/derealization, distress, and demographic variables via questionnaires. 55.5% of the participants were female, mean age was 49.4 (SD = 18.2) years with age groups represented in comparable proportions.

RESULTS

In line with the assumptions, moderated regression analyses revealed an interaction effect of emotion regulation strategies and fatigue. Simple slope analyses indicated a buffering effect of cognitive reappraisal on the positive relation of fatigue with depersonalization and derealization symptoms. In contrast, suppression fosters the positive correlation of fatigue and depersonalization and derealization experiences.

LIMITATIONS

Our study is limited to these two habitual emotion regulation strategies employing a cross sectional design.

CONCLUSION

Our findings provide comprehensive empirical data investigating depersonalization/derealization symptoms from the perspective of emotion regulation research. Cognitive reappraisal might help people suffering from fatigue to prevent depersonalization and derealization tendencies.

Understanding and treating depersonalisation disorder

Depersonalisation disorder involves an unpleasant, chronic and disabling alteration in the experience of self and environment. In addition to these classic features of depersonalisation and derealisation, symptoms may also encompass alterations in bodily sensation and a loss of emotional reactivity. Primary depersonalisation disorder is probably more common than previously thought, and here we discuss the diagnosis, assessment and treatment of the condition, with particular reference to our experiences in a specialist depersonalisation clinic. We also consider psychological and biological aspects of the condition. Although there is as yet no recognised treatment for this disorder, various pharmacological interventions, particularly a combination of lamotrigine and a selective serotonin reuptake inhibitor, have shown promise. We discuss these drug treatments, together with psychological approaches, in particular a recent cognitive–behavioural conceptualisation and treatment approach.

Neurobiological Development in the Context of Childhood Trauma

Neurobiological systems may be particularly susceptible to deleterious impact of childhood trauma, and the impact of childhood trauma on development and subsequent functional outcomes across the lifespan has been well-documented. The current review addresses the neurobiological impact of exposure to interpersonal trauma in childhood in the context of executive function, emotion regulation, and dissociation/interoceptive awareness. Subsequent risk for PTSD and depression is also discussed. The pathway of risk from childhood trauma to these cognitive, emotional, and psychiatric outcomes is addressed in terms of potential structural and functional alterations within the hippocampus, prefrontal cortex, and amygdala resulting from chronic or repeated activation of the hypothalamic-pituitary-adrenal (HPA) axis and its interaction with and influence on genetic and epigenetic processes during sensitive periods of development. Implications for practice are discussed.

Depersonalization: An exploratory factor analysis of the Italian version of the Cambridge Depersonalization Scale

BACKGROUND

"Depersonalization" (DP) is a common symptom in the general population and psychiatric patients (Michal et al., 2011 [1]). DP is characterized by an alteration in the experience of the self, so that one feels detached from his or her own mental processes or body (or from the world), feeling as being an outside observer of his or her own self, and loosing the experience of unity and identity (American Psychiatric Association, 2013 [2]).

AIM

We performed an exploratory factor analysis of the Cambridge Depersonalization Scale Italian version (CDS-IV).

METHODS

We enrolled 149 inpatients and outpatients of psychiatric services located in two Italian regions, Lazio and Campania. Patients were aged between 15 and 65 and diagnosed with schizophrenic, depressive or anxiety disorders.

RESULTS

Four factors accounted for 97.4% of the variance. Factor 1 (10, 24, 26, 1, 13, 23, 9, 2, 5, and 11), called "Detachment from the Self", captures experiences of detachment from actions and thoughts. Factor 2 (19, 20, 27, 3, 12, 23, 22, and 11), called "Anomalous bodily experiences", refers to unusual bodily experiences. Factor 3 (7, 28, 25, 6, 9, and 2), named "Numbing", describes the dampening of affects. Factor 4 (14, 17, and 16), named "Temporal blunting", refers to the subjective experience of time. We did not find any specific factor that refers to derealization; this suggests that the constructs of depersonalization/derealization (DP/DR) were strongly related to each other.

CONCLUSIONS

Our results show that the constructs of DP/DR subsume several psychopathological dimensions; moreover, the above mentioned factors were broadly consistent with prior literature.

Altered patterns of heartbeat-evoked potentials in depersonalization/derealization disorder: neurophysiological evidence for impaired cortical representation of bodily signals

OBJECTIVE

Core features of depersonalization/derealization disorder (DPD) are emotional numbing and feelings of disembodiment. Although there are several neurophysiological findings supporting subjective emotional numbing, the psychobiology of disembodiment remains unclear.

METHODS

Heartbeat-evoked potentials (HEPs), which are considered psychophysiological indicators for the cortical representation of afferent signals originating from the cardiovascular system, were assessed in 23 patients with DPD and 24 healthy control individuals during rest and while performing a heartbeat perception task.

RESULTS

Absolute HEP amplitudes did not differ between groups. Nevertheless, healthy individuals showed higher HEPs during the heartbeat perception task than during rest, whereas no such effect was found in patients with DPD (p = .031). Patients with DPD had higher total levels of salivary α-amylase than did healthy individuals (9626.6 [8200.0] versus 5344.3 [3745.8] kU min/l; p = .029), but there were no group differences in cardiovascular measures (heart rate = 76.2 [10.1] versus 74.3 [7.5] beats/min, p = .60; normalized low-frequency heart rate variability = 0.63 [0.15] versus 0.56 [0.15] normalized units, p = .099; low frequency/high frequency ratio = 249.3 [242.7] versus 164.8 [108.8], p = .10), salivary cortisol (57.5 [46.7] versus 55.1 [43.6] nmol min/l, p = .86), or cortisone levels (593.2 [260.3] versus 543.8 [257.1] nmol min/l, p = .52).

CONCLUSIONS

These results suggest altered cortical representation of afferent signals originating from the cardiovascular system in patients with DPD, which may be associated with higher sympathetic tone. These findings may reflect difficulties of patients with DPD to attend to their actual bodily experiences.

Multimodal assessment of emotional reactivity in borderline personality pathology: the moderating role of posttraumatic stress disorder symptoms

Emotional reactivity has been theorized to play a central role in borderline personality (BP) pathology. Although growing research provides evidence for subjective emotional reactivity in BP pathology, research on physiological or biological reactivity among people with BP pathology is less conclusive. With regard to biological reactivity in particular, research on cortisol reactivity (a neurobiological marker of emotional reactivity) in response to stressors among individuals with BP pathology has produced contradictory results and highlighted the potential moderating role of PTSD-related pathology. Thus, this study sought to examine the moderating role of PTSD symptoms in the relation between BP pathology and both subjective (self-report) and biological (cortisol) emotional reactivity to a laboratory stressor. Participants were 171 patients in a residential substance use disorder treatment center. Consistent with hypotheses, results revealed a significant main effect of BP pathology on subjective emotional reactivity to the laboratory stressor. Furthermore, results revealed a significant interaction between BP pathology and PTSD symptoms in the prediction of cortisol reactivity, such that BP pathology was associated with heightened cortisol reactivity only among participants with low levels of PTSD symptoms. Similar findings were obtained when examining the interaction between BP pathology and the reexperiencing and avoidance/numbing symptoms of PTSD specifically. Results highlight the moderating role of PTSD symptoms in the BP-reactivity relation.

Dissociative disorders in DSM-5

BACKGROUND

We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining diagnostic criteria.

METHODS

This paper reviews clinical, phenomenological, epidemiological, cultural, and neurobiological data related to the DDs in order to generate an up-to-date, evidence-based set of DD diagnoses and diagnostic criteria for DSM-5. First, we review the definitions of dissociation and the differences between the definitions of dissociation and conceptualization of DDs in the DSM-IV-TR and the ICD-10, respectively. Also, we review more general conceptual issues in defining dissociation and dissociative disorders. Based on this review, we propose a revised definition of dissociation for DSM-5 and discuss the implications of this definition for understanding dissociative symptoms and disorders.

RESULTS

We make the following recommendations for DSM-5: 1. Depersonalization Disorder (DPD) should include derealization symptoms as well. 2. Dissociative Fugue should become a subtype of Dissociative Amnesia (DA). 3. The diagnostic criteria for DID should be changed to emphasize the disruptive nature of the dissociation and amnesia for everyday as well as traumatic events. The experience of possession should be included in the definition of identity disruption. 4. Dissociative Trance Disorder should be included in the Unspecified Dissociative Disorder (UDD) category.

CONCLUSIONS

There is a growing body of evidence linking the dissociative disorders to a trauma history, and to specific neural mechanisms.

Dissociative disorders in DSM-5

BACKGROUND

We present recommendations for revision of the diagnostic criteria for the Dissociative Disorders (DDs) for DSM-5. The periodic revision of the DSM provides an opportunity to revisit the assumptions underlying specific diagnoses and the empirical support, or lack of it, for the defining diagnostic criteria.

METHODS

This paper reviews clinical, phenomenological, epidemiological, cultural, and neurobiological data related to the DDs in order to generate an up-to-date, evidence-based set of DD diagnoses and diagnostic criteria for DSM-5. First, we review the definitions of dissociation and the differences between the definitions of dissociation and conceptualization of DDs in the DSM-IV-TR and the ICD-10, respectively. Also, we review more general conceptual issues in defining dissociation and dissociative disorders. Based on this review, we propose a revised definition of dissociation for DSM-5 and discuss the implications of this definition for understanding dissociative symptoms and disorders.

RESULTS

We make the following recommendations for DSM-5: 1. Depersonalization Disorder (DPD) should derealization symptoms as well. 2. Dissociative Fugue should become a subtype of Dissociative Amnesia (DA). 3. The diagnostic criteria for DID should be changed to emphasize the disruptive nature of the dissociation and amnesia for everyday as well as traumatic events. The experience of possession should be included in the definition of identity disruption. 4. Should Dissociative Trance Disorder should be included in the Unspecified Dissociative Disorder (UDD) category.

CONCLUSIONS

There is a growing body of evidence linking the dissociative disorders to a trauma history, and to specific neural mechanisms.

Psychogenic non-epileptic seizures: a model of their pathogenic mechanism

Psychogenic non-epileptic seizures (PNES) consist of paroxystic events facilitated by a dysfunction in emotion processing. Models explaining the pathogenic mechanisms leading to these seizure-like episodes are limited. In this article, evidence that supports dysfunction at the level of arousal tolerance, cognitive-emotional information processing and volitional control is reviewed. A hypothetical pathophysiological mechanism is discussed based on functional neuroimaging evidence from PNES-related conditions and traits. This pathophysiological model suggests an alteration in the influence and connection of brain areas involved in emotion processing onto other brain areas responsible for sensorimotor and cognitive processes. Integrating this information, PNES are conceptualized as brief episodes facilitated by an unstable cognitive-emotional attention system. During the episodes, sensorimotor and cognitive processes are modified or not properly integrated, allowing the deployment of autonomous prewired behavioral tendencies. Finally, I elaborate on how therapeutic applications could be modified based on the proposed hypothetical model, potentially improving clinical outcomes.

Depersonalization disorder

PURPOSE OF REVIEW

There is increasing interest in depersonalization disorder, in part because of the increased community awareness of the condition via the Internet. The disorder may be more prevalent than schizophrenia but is often misdiagnosed; hence, an update is timely.

RECENT FINDINGS

Recent research has included characterization of the nosology and phenomenology of the disorder, whereas emerging evidence demonstrates a neurophysiological dampening down in addition to psychological dampening in the face of emotional stimulation.

SUMMARY

Greater understanding of the clinical characteristics of this disorder will improve the reliability of diagnosis and aid the development of neurobiological and psychological models for empirical testing. Although response to current treatments has been disappointing, recent research has identified the basis for the development of new pharmacological and psychological treatments.

Cognitive-affective neuroscience of depersonalization

Depersonalization disorder (DPD) is characterized by a subjective sense of detachment from one's own being and a sense of unreality. An examination of the psychobiology of depersonalization symptoms may be useful in understanding the cognitive-affective neuroscience of embodiment. DPD may be mediated by neurocircuitry and neurotransmitters involved in the integration of sensory processing and of the body schema, and in the mediation of emotional experience and the identification of feelings. For example, DPD has been found to involve autonomic blunting, deactivation of sub-cortical structures, and disturbances in molecular systems in such circuitry. An evolutionary perspective suggests that attenuation of emotional responses, mediated by deactivation of limbic structures, may sometimes be advantageous in response to inescapable stress.

Dissociation versus posttraumatic stress: cortisol and physiological correlates in adults highly exposed to the World Trade Center attack on 9/11

Nine months on average after the World Trade Center (WTC) attack, 21 highly exposed adults and 10 healthy controls without major exposure did not differ in cortisol and physiologic measures. Dissociation and posttraumatic stress symptoms were quantified in the exposed group. Dissociation was associated with greater peritraumatic dissociation and, marginally, childhood trauma, lower plasma cortisol levels at 08.00h, and blunted heart rate reactivity to psychosocial stress. Posttraumatic stress was associated with exposure, peritraumatic distress, and early posttraumatic stress, and marginally associated with peritraumatic dissociation; it was not associated with cortisol or physiologic measures. Urinary cortisol differed significantly in its relationship to dissociation versus posttraumatic stress. This small study emphasizes the importance of dissecting the neurobiology of posttraumatic stress versus dissociative traumatic responses.

Dissociative disorders

The dissociative disorders, including "psychogenic" or "functional" amnesia, fugue, dissociative identity disorder (DID, also known as multiple personality disorder), and depersonalization disorder, were once classified, along with conversion disorder, as forms of hysteria. The 1970s witnessed an "epidemic" of dissociative disorder, particularly DID, which may have reflected enthusiasm for the diagnosis more than its actual prevalence. Traditionally, the dissociative disorders have been attributed to trauma and other psychological stress, but the existing evidence favoring this hypothesis is plagued by poor methodology. Prospective studies of traumatized individuals reveal no convincing cases of amnesia not attributable to brain insult, injury, or disease. Treatment generally involves recovering and working through ostensibly repressed or dissociated memories of trauma; at present, there are few quantitative or controlled outcome studies. Experimental studies are few in number and have focused largely on state-dependent and implicit memory. Depersonalization disorder may be in line for the next "epidemic" of dissociation.

Hypothalamic-pituitary-adrenal axis function in dissociative disorders, post-traumatic stress disorder, and healthy volunteers

BACKGROUND

This study investigated basal and stress-induced hypothalamic-pituitary-adrenal (HPA)-axis alterations in dissociative disorders (DDs).

METHODS

Forty-six subjects with DD without lifetime post-traumatic stress disorder (PTSD), 35 subjects with PTSD, and 58 healthy comparison (HC) subjects, free of current major depression, were studied as inpatients. After a 24-hour urine collection and hourly blood sampling for ambient cortisol determination, a low-dose dexamethasone suppression test was administered, followed by the Trier Social Stress Test.

RESULTS

The DD group had significantly elevated urinary cortisol compared with the HC group, which was more pronounced in the absence of lifetime major depression, whereas the PTSD and HC groups did not differ. The DD group demonstrated significantly greater resistance to, and faster escape from, dexamethasone suppression compared with the HC group, whereas the PTSD and HC groups did not differ. The three groups did not differ in cortisol stress reactivity, but both psychiatric groups demonstrated a significant inverse correlation between dissociation severity and cortisol reactivity, after controlling for all other symptomatology. The PTSD subgroup with comorbid DD tended to have blunted stress reactivity compared with the HC group.

CONCLUSIONS

The study demonstrates a distinct pattern of HPA-axis dysregulation in DDs, emphasizing the importance of further study of stress-response systems in dissociative psychopathology.

Depersonalization experiences in undergraduates are related to heightened stress cortisol responses

The relationship between dissociative tendencies, as measured with the Dissociative Experiences Scale and its amnesia, absorption/imaginative involvement, and depersonalization/derealization subscales, and HPA axis functioning was studied in 2 samples of undergraduate students (N = 58 and 67). Acute stress was induced by means of the Trier Social Stress Test. Subjective and physiological stress (i.e., cortisol) responses were measured. Individuals high on the depersonalization/derealization subscale of the Dissociative Experiences Scale exhibited more pronounced cortisol responses, while individuals high on the absorption subscale showed attenuated responses. Interestingly, subjective stress experiences, as indicated by the Tension-Anxiety subscale of the Profile of Mood States, were positively related to trait dissociation. The present findings illustrate how various types of dissociation (i.e., depersonalization/derealization, absorption) are differentially related to cortisol stress responses.

The neurobiology and clinical significance of depersonalization in mood and anxiety disorders: a critical reappraisal

Depersonalization and derealization occur on a continuum of situations, from healthy individuals to a severely debilitating disorder where the symptoms can persist chronically. Since 1960s, different neurobiological models have been hypothesized and they have been associated with the temporal lobes. Recent advances in the functioning of the limbic system and the application of Geschwind's concept of disconnection in the cortico-limbic networks, pointed the role of the amygdala and its connections with medial prefrontal cortex and anterior cingulate cortex, the same structures that are strictly interlinked with the neurobiology of emotions and affective disorders. In this paper, we hypothesize that depersonalization may represent a clinical index of disease severity, poorer response to treatment and high level of comorbidity, in mood and anxiety disorders, discussing the neurobiology of depersonalization and the available clinical evidence.

A preliminary study of cortisol and norepinephrine reactivity to psychosocial stress in borderline personality disorder with high and low dissociation

The goal of the current study was to investigate subjective and neurohormonal reactivity to acute psychosocial stress in borderline personality disorder (BPD) as a function of dissociative symptoms. Five BPD subjects with high dissociation, 8 BPD subjects with low dissociation, and 11 healthy control subjects were compared in basal urinary cortisol and norepinephrine, as well as in plasma cortisol and norepinephrine reactivity to the Trier Social Stress Test (TSST). Subjective stress rating and emotional response to the TSST were also measured. The three groups differed significantly in cortisol stress reactivity, with the high-dissociation BPD group demonstrating the most robust response. The three groups did not significantly differ in norepinephrine stress reactivity. In the combined BPD sample, dissociation severity tended to be inversely correlated with basal urinary norepinephrine, was positively correlated with norepinephrine stress reactivity. Childhood trauma was inversely correlated with basal urinary cortisol. In conclusion, despite its small sample size this pilot study suggests that dissociative symptomatology may be a marker of heightened biological vulnerability to stress in BPD, and merits further study.

[Depersonalization--current data]

OBJECTIVE

Depersonalization is a fascinating clinical phenomenon referring to a self-consciousness disorder, characterized by emotional detachment from one's own feelings, thoughts, or actions. This article intends to summarize the current literature in this area.

METHOD

Using the Medline data base, we reviewed literature addressing the clinical, etiology, nosology, physiopathology, and treatment of depersonalization.

CONCLUSIONS

Derealization means that perception of the world and of external reality are altered. These 2 phenomena are often associated. They are not specific to any psychiatric entity and are reported in many different psychiatric syndromes. Many factors, including use of different substances, are involved in their onset. The physiopathology is still little known. However, some conceptual models suggest partial amygdala inhibition combined with activation of other amygdaloid structures. A serotoninergic functioning impairment is indicated in different pharmacologic studies. Different psychotropic drugs, especially serotoninergic antidepressants, have been proposed for pharmacotherapy; however, there are no conclusive randomized studies, and the contribution of psychotherapy in treating these patients is still questioned.

Depersonalisation disorder: a contemporary overview

Depersonalisation disorder is characterised by prominent depersonalisation and often derealisation, without clinically notable memory or identity disturbances. The disorder has an approximately 1 : 1 gender ratio with onset at around 16 years of age. The course of the disorder is typically long term and often continuous. Mood, anxiety and personality disorders are often comorbid with depersonalisation disorder but none predict symptom severity. The most common immediate precipitants of the disorder are severe stress, depression and panic, and marijuana and hallucinogen ingestion. Depersonalisation disorder has also been associated with childhood interpersonal trauma, in particular emotional maltreatment. Neurochemical findings have suggested possible involvement of serotonergic, endogenous opioid and glutamatergic NMDA pathways. Brain imaging studies in depersonalisation disorder have revealed widespread alterations in metabolic activity in the sensory association cortex, as well as prefrontal hyperactivation and limbic inhibition in response to aversive stimuli. Depersonalisation disorder has also been associated with autonomic blunting and hypothalamic-pituitary-adrenal axis dysregulation. To date, treatment recommendations and guidelines for depersonalisation disorder have not been established. There are few studies assessing the use of pharmacotherapy in this disorder. Medication options that have been reported include clomipramine, fluoxetine, lamotrigine and opioid antagonists. However, it does not appear that any of these agents have a potent anti-dissociative effect. A variety of psychotherapeutic techniques has been used to treat depersonalisation disorder (including trauma-focused therapy and cognitive-behavioural techniques), although again none of these have established efficacy to date. Overall, novel therapeutic approaches are clearly needed to help individuals experiencing this refractory disorder.

Basal norepinephrine in depersonalization disorder

In contrast to the noradrenergic dysregulation described in PTSD, little is known regarding noradrenergic function in dissociative disorders. The purpose of this preliminary study was to investigate basal norepinephrine in depersonalization disorder (DPD). Nine subjects with DSM-IV DPD, without lifetime PTSD, were compared to nine healthy comparison (HC) subjects. Norepinephrine was measured via 24-h urine collection and three serial plasma determinations. Groups did not differ significantly in plasma norepinephrine levels. Compared to the HC group, the DPD group demonstrated significantly higher urinary norepinephrine, only prior to covarying for anxiety. The DPD group also demonstrated a highly significant inverse correlation between urinary norepinephrine and depersonalization severity (r=-0.88). Norepinephrine and cortisol levels (reported in a prior study) were not intercorrelated. We concluded that although dissociation accompanied by anxiety was associated with heightened noradrenergic tone, there was a marked basal norepinephrine decline with increasing severity of dissociation. The findings are in concordance with the few reports on autonomic blunting in dissociation and merit further investigation.

A novel specific bioassay for the determination of glucocorticoid bioavailability in human serum

OBJECTIVE

Some patients develop side-effects even on relatively low doses of topically administered glucocorticoids (GCs), while others appear to be less sensitive to GCs. We have developed and validated a bioassay which can measure glucocorticoid bioavailability directly from small amounts of human serum to help elucidate underlying mechanisms.

METHODS

We have stably transfected the human embryonic kidney cell line HEK293 with a plasmid expressing the glucocorticoid receptor, and a plasmid containing the luciferase gene preceded by three concatenated steroid response elements, bringing luciferase expression under control of the liganded glucocorticoid receptor.

RESULTS

The assay, with an intra- and interassay coefficient of variance (CV) better than 10%, showed the expected difference in potency between different GCs (fluticasone propionate > budesonide > dexamethasone > hydrocortisone). No cross-reactivity was detected with other steroid hormones such as progesterone, testosterone and oestradiol. The bioassay easily detects the rise and subsequent fall of bioavailable GCs in human serum following ingestion of only 0.5 mg dexamethasone, and clearly reflects the diurnal cortisol rhythm. Moreover, systemic availability following inhalation of 2 x 250 micro g fluticasone propionate using a pressure dose inhaler could be demonstrated.

CONCLUSIONS

This assay can be used to determine levels of bioavailable GCs in serum, both endogenous and administered, and thus may help in optimizing treatment regimens. The small amount of serum needed to perform an analysis makes this assay applicable even to infants.