Temporo-parietal junction stimulation in the treatment of depersonalization disorder

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

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

Obsessive-compulsive symptoms and dissociative experiences: Suggested underlying mechanisms and implications for science and practice

A strong and specific link between obsessive-compulsive disorder or symptoms (OCD/S) and a tendency for dissociative experiences (e.g., depersonalization-derealization, absorption and imaginative involvement) cannot be explained by trauma and is poorly understood. The present theoretical formulation proposes five different models conceptualizing the relationship. According to Model 1, dissociative experiences result from OCD/S through inward-focused attention and repetition. According to Model 2, dissociative absorption causally brings about both OCD/S and associated cognitive risk factors, such as thought-action fusion, partly through impoverished sense of agency. The remaining models highlight common underlying causal mechanisms: temporo-parietal abnormalities impairing embodiment and sensory integration (Model 3); sleep alterations causing sleepiness and dreamlike thought or mixed sleep-wake states (Model 4); and a hyperactive, intrusive imagery system with a tendency for pictorial thinking (Model 5). The latter model relates to Maladaptive Daydreaming, a suggested dissociative syndrome with strong ties to the obsessive-compulsive spectrum. These five models point to potential directions for future research, as these theoretical accounts may aid the two fields in interacting with each other, to the benefit of both. Finally, several dissociation-informed paths for further developing clinical intervention in OCD are identified.

Factorial Model of Obese Adolescents: The Role of Body Image Concerns and Selective Depersonalization-A Pilot Study

BACKGROUND

The relationship binding body weight to psychological well-being is unclear. The present study aims at identifying the contribution, and specificity, of some dimensions (i.e., eating-related symptoms, body image disorders, eating habits, personality traits, and emotional difficulties) characterizing the psychological profile of obese adolescents (749 participants, 325 females; 58.3% normal-weight, 29.9% overweight, and 11.7% obese; mean age = 16.05, SD = 0.82).

METHODS

By introducing the scores obtained by standardized self-report tools into a generalized linear model, a factorial reduction design was used to detect the best fitting discriminant functions and the principal components explaining the higher proportion of the variance.

RESULTS

We found two discriminant functions correctly classifying 87.1% of normal-weight, 57.2% of overweight, and 68.2% of obese adolescents. Furthermore, two independent factors, explaining 69.68% of the total variance, emerged.

CONCLUSIONS

The first factor, "Body Image Concerns", included the drive for thinness, body dissatisfaction, and interpersonal distrust. The second factor, "Selective Depersonalization", included a trend toward depersonalization and dissatisfaction with the torso. The neurophysiological implications of our findings will be discussed.

Potential Targets for Noninvasive Brain Stimulation on Depersonalization-Derealization Disorder

INTRODUCTION

Non-invasive brain stimulation seems to be beneficial for DPD patients. However, the sites used in previous studies were empirical. Exploring new stimulation locations via functional magnetic resonance imaging may improve the efficacy.

OBJECTIVES

The objective was to find potential locations for non-invasive brain stimulation on the depersonalization-derealization disorder.

METHODS

We explored the potential brain surface regions from three pipelines: pipeline 1: activation likelihood estimation meta-analysis (five studies with 36 foci included); pipeline 2: functional connectivity analysis based on DPD-network (76 subjects included); and pipeline 3: functional connectivity analysis based on DPD regions of interest from the meta-analysis. Potential targets were the 10-20 system coordinates for brain surface regions.

RESULTS

We identified several potential brain surface regions, including the bilateral medial prefrontal cortex, dorsal lateral prefrontal cortex, superior parietal gyrus, superior temporal gyrus, and right ventrolateral prefrontal cortex as potential sites.

CONCLUSION

Our findings of the potential stimulation targets might help clinicians optimize the application of non-invasive brain stimulation therapy in individuals with DPD.

Targeting temporal parietal junction for assessing and treating disembodiment phenomena: a systematic review of TMS effect on depersonalization and derealization disorders (DPD) and body illusions

The temporal-parietal junction (TPJ) is a key structure for the embodiment, term referred to as the sense of being localized within one's physical body and is a fundamental aspect of the self. On the contrary, the sense of disembodiment, an alteration of one's sense of self or the sense of being localized out of one's physical body, is a prominent feature in specific dissociative disorders, namely depersonalization/derealization disorders (DPD). The aims of the study were to provide: 1) a qualitative synthesis of the effect of Transcranial Magnetic Stimulation (TMS), taking into account its use for therapeutic and experimental purposes; 2) a better understanding on whether the use of TMS could support the treatment of DPD and other clinical conditions in which depersonalization and derealization are displayed. To identify suitable publications, an online search of the PubMed, Cochrane Library, Web of science and Scopus databases was performed using relevant search terms. In addition, an in-depth search was performed by screening review articles and the references section of each included articles. Our search yielded a total of 108 records through multiple databases searching and one additional record was identified through other sources. After duplicates removal, title and abstract reading, we retained 16 records for the assessment of eligibility. According to our inclusion criteria, we retained 8 studies. The selected studies showed that TMS targeting the TPJ is a promising technique for treating disembodiment phenomena DPD and for inducing reversible disembodiment states in healthy subjects. These data represent the first step towards a greater understanding of possible treatments to be used in disembodiment disorders. The use of TMS over the TPJ appears to be promising for treating disembodiment phenomena.

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.

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.

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.

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.

Pharmacotherapy for dissociative disorders: A systematic review

BACKGROUND

Dissociative Disorder (DD) is a large group of disorders that shares common psychopathology. Psychopharmacological agents have sparse evidence in the treatment of DD in general. Multiple pharmacotherapy options have been used without conclusive evidence.

METHODS

We conducted a systematic review of data in English language from 1967 to 2019 the protocol of which was registered under PROSPERO (Study ID CRD42019127235). Using PRISMA guidelines, 5 RCTs reporting data on 214 participants providing data on response to pharmacotherapy in dissociative disorder were included.

RESULTS

The treatment response rate of pharmacotherapy group as measured in reduction in dissociative symptoms was 68.42% (n = 65/95), significantly higher than that of 39.49% (n = 47/119) in the control group. And, the pooled RR was 1.59 (95% CI, 0.76-3.30; P = 0.21). The overall effect estimates are favourable to pharmacotherapy group over placebo.

CONCLUSION

It would be apt to conclude that Paroxetine and Naloxone are the only pharmacological agents studied through RCTs and found to have modest evidence for controlling depersonalization symptoms and dissociative symptoms that are comorbid with PTSD and BPD. Results of this meta-analysis should be interpreted with caution in view of high heterogeneity and scanty literature on RCTs on various subtypes of DD.

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

BACKGROUND

Depersonalization/derealization disorder is a dissociative disorder characterized by feelings of unreality and detachment from the self and surroundings. Depersonalization/derealization disorder is classified as a primary disorder, but depersonalization symptoms are frequently observed in mood and anxiety disorders. In the context of major depressive disorder (MDD), depersonalization symptoms are associated with greater depressive severity as indexed by treatment resistance, inpatient visits, and duration of depressive episodes. In the current investigation, we tested four network-based, neural-functional hypotheses of depersonalization in MDD. These hypotheses were framed in terms of functional relationships between 1) extrastriate body area and default mode network (DMN); 2) hippocampus and DMN; 3) medial prefrontal cortex and ventral striatum; and 4) posterior and anterior insular cortex.

METHODS

We conducted functional magnetic resonance imaging during resting state on 28 female patients with MDD and 27 control subjects with no history of a psychiatric disorder. Functional connectivity between seed and target regions as specified by our network-level hypotheses was computed and correlated with scores on the Cambridge Depersonalization Scale. We used a conservative, unbiased bootstrapping procedure to test the significance of neural-behavioral correlations observed under each of the four models tested.

RESULTS

Of the four neural-functional models of depersonalization symptoms tested, only the model proposing that reduced connectivity between the extrastriate body area and DMN predicts higher levels of depersonalization symptoms in MDD was confirmed.

CONCLUSIONS

Our results indicate that depersonalization/derealization disorder symptoms in patients with depression are related to reduced functional connectivity between brain regions that are proposed to support processing of body-related (extrastriate body area) and autobiographical (DMN) information.

White matter network alterations in patients with depersonalization/derealization disorder

BACKGROUND

Depersonalization/derealization disorder (DPD) is a chronic and distressing condition characterized by detachment from oneself and/or the external world. Neuroimaging studies have associated DPD with structural and functional alterations in a variety of distinct brain regions. Such local neuronal changes might be mediated by altered interregional white matter connections. However, to our knowledge, no research on network characteristics in this patient population exists to date.

METHODS

We explored the structural connectome in 23 individuals with DPD and 23 matched, healthy controls by applying graph theory to diffusion tensor imaging data. Mean interregional fractional anisotropy (FA) was used to define the network weights. Group differences were assessed using network-based statistics and a link-based controlling procedure.

RESULTS

Our main finding refers to lower FA values within left temporal and right temporoparietal regions in individuals with DPD than in healthy controls when using a link-based controlling procedure. These links were also associated with dissociative symptom severity and could not be explained by anxiety or depression scores. Using network-based statistics, no significant results emerged. However, we found a trend for 1 subnetwork that may support the model of frontolimbic dysbalance suggested to underlie DPD symptomatology.

LIMITATIONS

To ensure ecological validity, patients with certain comorbidities or psychotropic medication were included in the study. Confirmatory replications are necessary to corroborate the results of this explorative investigation.

CONCLUSION

In patients with DPD, the structural connectivity between brain regions crucial for multimodal integration and emotion regulation may be altered. Aberrations in fibre tract communication seem to be not solely a secondary effect of local grey matter volume loss, but may present a primary pathophysiology in patients with DPD.

Consensus Recommendations for the Clinical Application of Repetitive Transcranial Magnetic Stimulation (rTMS) in the Treatment of Depression

OBJECTIVE

To provide expert recommendations for the safe and effective application of repetitive transcranial magnetic stimulation (rTMS) in the treatment of major depressive disorder (MDD).

PARTICIPANTS

Participants included a group of 17 expert clinicians and researchers with expertise in the clinical application of rTMS, representing both the National Network of Depression Centers (NNDC) rTMS Task Group and the American Psychiatric Association Council on Research (APA CoR) Task Force on Novel Biomarkers and Treatments.

EVIDENCE

The consensus statement is based on a review of extensive literature from 2 databases (OvidSP MEDLINE and PsycINFO) searched from 1990 through 2016. The search terms included variants of major depressive disorder and transcranial magnetic stimulation. The results were limited to articles written in English that focused on adult populations. Of the approximately 1,500 retrieved studies, a total of 118 publications were included in the consensus statement and were supplemented with expert opinion to achieve consensus recommendations on key issues surrounding the administration of rTMS for MDD in clinical practice settings.

CONSENSUS PROCESS

In cases in which the research evidence was equivocal or unclear, a consensus decision on how rTMS should be administered was reached by the authors of this article and is denoted in the article as "expert opinion."

CONCLUSIONS

Multiple randomized controlled trials and published literature have supported the safety and efficacy of rTMS antidepressant therapy. These consensus recommendations, developed by the NNDC rTMS Task Group and APA CoR Task Force on Novel Biomarkers and Treatments, provide comprehensive information for the safe and effective clinical application of rTMS in the treatment of MDD.

Mind the Hype: A Critical Evaluation and Prescriptive Agenda for Research on Mindfulness and Meditation

During the past two decades, mindfulness meditation has gone from being a fringe topic of scientific investigation to being an occasional replacement for psychotherapy, tool of corporate well-being, widely implemented educational practice, and "key to building more resilient soldiers." Yet the mindfulness movement and empirical evidence supporting it have not gone without criticism. Misinformation and poor methodology associated with past studies of mindfulness may lead public consumers to be harmed, misled, and disappointed. Addressing such concerns, the present article discusses the difficulties of defining mindfulness, delineates the proper scope of research into mindfulness practices, and explicates crucial methodological issues for interpreting results from investigations of mindfulness. For doing so, the authors draw on their diverse areas of expertise to review the present state of mindfulness research, comprehensively summarizing what we do and do not know, while providing a prescriptive agenda for contemplative science, with a particular focus on assessment, mindfulness training, possible adverse effects, and intersection with brain imaging. Our goals are to inform interested scientists, the news media, and the public, to minimize harm, curb poor research practices, and staunch the flow of misinformation about the benefits, costs, and future prospects of mindfulness meditation.

Treatment of a Patient With Depersonalization Disorder With Low Frequency Repetitive Transcranial Magnetic Stimulation of the Right Temporo-Parietal Junction in a Private Practice Setting

Depersonalization disorder (DPD) is a debilitating dissociative condition with no proven treatments. Although the pathophysiology of DPD is poorly understood, there are reports of increased excitability of the prefrontal cortex in patients with this condition. The temporo-parietal junction may also play a major role in the conscious experience of the spatial unity of the normal self and body. Repetitive transcranial magnetic stimulation has been shown in some case studies to effectively treat this condition. This report describes an additional such case, a 26-year-old man with a 6-month history of DPD who responded safely and significantly to repetitive transcranial magnetic stimulation to the right temporo-parietal junction.

Treatment of Depersonalization Disorder With Repetitive Transcranial Magnetic Stimulation

High frequency repetitive transcranial magnetic stimulation (rTMS) was approved by the US Food and Drug Administration in 2008 to treat major depressive disorder in those who did not respond to at least 1 antidepressant trial. Previous studies have shown that both high frequency rTMS to the left dorsolateral prefrontal cortex (DLPFC) and low frequency rTMS to the right DLPFC have antidepressant efficacy in treatment-resistant depression. Although rTMS has been widely used in the treatment of depression, very few studies of rTMS in patients with depersonalization disorder (DPD) have been published so far. DPD involves persistent or recurrent experiences of unreality and feelings of detachment causing distress or functional impairment while insight remains intact. The prevalence of DPD is approximately 1% to 2%. Studies of the pharmacological treatment of DPD are limited, and medications have proven to be of limited benefit. We present the case of a 30-year-old man with major depressive disorder and DPD who did not respond to pharmacotherapy. After the patient was treated with low frequency rTMS to the right DLPFC followed by high frequency rTMS to the left DLPFC, there was a significant reduction in his depersonalization symptoms. Given its effectiveness in our patient, the use of both low frequency rTMS to the right DLPFC and high frequency rTMS to the left DLPFC for treatment of DPD should be further explored.

Paying the price for body evolution: The role of evolution in disorders of body representation

Since its beginning, research about cognitive representation of our bodies has debated over multiple representations models. Furthermore, recent years have seen a rise in the study of body representation disorders and related impairments. However, why human beings manifest so many deficits is still a mystery. Considering human evolution, frontal brain regions are well known for their changes in dimensions and connections. Less known is that parietal and temporal lobes encountered similar changes. These areas, especially in the right hemisphere, are crucial for body representation. Our hypothesis is that evolution of these areas determined a more varied and widespread cross wiring between the temporal and parietal lobes, increasing their communication pathways and their reciprocal influence. As such, these connections could lead to an increased probability of interconnected body and emotional disorders in humans. The prediction of this hypothesis is that all body representation disorders have an associated emotional component and vice versa. Evidence supporting the interconnection between emotional and body representation disorders derives from psychiatric diseases such as eating disorders. This hypothesis opens up new directions to understand body representation and points towards innovative solutions for the clinical treatments of body representation/emotional impairments.

Self-specific processing in the meditating brain: a MEG neurophenomenology study

Self-specific processes (SSPs) specify the self as an embodied subject and agent, implementing a functional self/nonself distinction in perception, cognition, and action. Despite recent interest, it is still undetermined whether SSPs are all-or-nothing or graded phenomena; whether they can be identified in neuroimaging data; and whether they can be altered through attentional training. These issues are approached through a neurophenomenological exploration of the sense-of-boundaries (SB), the fundamental experience of being an 'I' (self) separated from the 'world' (nonself). The SB experience was explored in collaboration with a uniquely qualified meditation practitioner, who volitionally produced, while being scanned by magnetoencephalogram (MEG), three mental states characterized by a graded SB experience. The results were then partly validated in an independent group of 10 long-term meditators. Implicated neural mechanisms include right-lateralized beta oscillations in the temporo-parietal junction, a region known to mediate the experiential unity of self and body; and in the medial parietal cortex, a central node of the self's representational system. The graded nature as well as the trainable flexibility and neural plasticity of SSPs may hold clinical implications for populations with a disturbed SB.

Ventrolateral prefrontal cortex repetitive transcranial magnetic stimulation in the treatment of depersonalization disorder: A consecutive case series

Case reports and an open trial have reported promising responses to repetitive transcranial magnetic stimulation (rTMS) to prefrontal and temporo-parietal sites in patients with depersonalization disorder (DPD). We recently showed that a single session of rTMS to the ventrolateral prefrontal cortex (VLPFC) was associated with a reduction in symptoms and increase in physiological arousal. Seven patients with medication-resistant DSM-IV DPD received up to 20 sessions of right-sided rTMS to the VLPFC for 10 weeks. Stimulation was guided using neuronavigation software based on participants' individual structural MRIs, and delivered at 110% of resting motor threshold. A session consisted of 1Hz repetitive TMS for 15min. The primary outcome measure was reduction in depersonalization symptoms on the Cambridge Depersonalization Scale (CDS). Secondary outcomes included scores on the Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI). 20 sessions of rTMS treatment to right VLPFC significantly reduced scores on the CDS by on average 44% (range 2-83.5%). Two patients could be classified as "full responders", four as "partial" and one a non-responder. Response usually occurred within the first 6 sessions. There were no significant adverse events. A randomized controlled clinical trial of VLPFC rTMS for DPD is warranted.

A structural MRI study of cortical thickness in depersonalisation disorder

Depersonalisation disorder (DPD) is characterised by a sense of unreality about the self and the world. Research suggests altered autonomic responsivity and dysfunction in prefrontal and temporal lobe areas in this condition. We report the first structural magnetic resonance imaging study of 20 patients with DPD and 21 controls using the FreeSurfer analysis tool employing both region-of-interest and vertex-based methods. DPD patients showed significantly lower cortical thickness in the right middle temporal region according to both methods of analysis. The vertex-based method revealed additional differences in bilateral temporal lobes, inferior frontal regions, the right posterior cingulate, and increased thickness in the right gyrus rectus and left precuneus. Clinical severity scores were negatively correlated with cortical thickness in middle and right inferior frontal regions. In sum, grey matter changes in the frontal, temporal, and parietal lobes are associated with DPD. Further research is required to specify the functional significance of the findings and whether they are vulnerability or disease markers.

Evidence-based guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS)

A group of European experts was commissioned to establish guidelines on the therapeutic use of repetitive transcranial magnetic stimulation (rTMS) from evidence published up until March 2014, regarding pain, movement disorders, stroke, amyotrophic lateral sclerosis, multiple sclerosis, epilepsy, consciousness disorders, tinnitus, depression, anxiety disorders, obsessive-compulsive disorder, schizophrenia, craving/addiction, and conversion. Despite unavoidable inhomogeneities, there is a sufficient body of evidence to accept with level A (definite efficacy) the analgesic effect of high-frequency (HF) rTMS of the primary motor cortex (M1) contralateral to the pain and the antidepressant effect of HF-rTMS of the left dorsolateral prefrontal cortex (DLPFC). A Level B recommendation (probable efficacy) is proposed for the antidepressant effect of low-frequency (LF) rTMS of the right DLPFC, HF-rTMS of the left DLPFC for the negative symptoms of schizophrenia, and LF-rTMS of contralesional M1 in chronic motor stroke. The effects of rTMS in a number of indications reach level C (possible efficacy), including LF-rTMS of the left temporoparietal cortex in tinnitus and auditory hallucinations. It remains to determine how to optimize rTMS protocols and techniques to give them relevance in routine clinical practice. In addition, professionals carrying out rTMS protocols should undergo rigorous training to ensure the quality of the technical realization, guarantee the proper care of patients, and maximize the chances of success. Under these conditions, the therapeutic use of rTMS should be able to develop in the coming years.

Face processing in depersonalization: an fMRI study of the unfamiliar self

Depersonalization disorder (DPD) is characterized by a core sense of unfamiliarity. Nine DPD participants and 10 healthy controls underwent functional magnetic resonance imaging while viewing self and unfamiliar faces. Compared with control subjects, the DPD group exhibited significantly greater activation in several brain regions in response to self vs. stranger faces. Implications are discussed.

Striking discrepancy of anomalous body experiences with normal interoceptive accuracy in depersonalization-derealization disorder

Background

Disembodiment is a core feature of depersonalization disorder (DPD). Given the narratives of DPD patients about their disembodiment and emotional numbing and neurobiological findings of an inhibition of insular activity, DPD may be considered as a mental disorder with specific impairments of interoceptive awareness and body perception.

Methods

We investigated cardioceptive accuracy (CA) of DPD patients (n = 24) as compared to healthy controls (n = 26) with two different heartbeat detection tasks (“Schandry heartbeat counting task” and “Whitehead heartbeat discrimination task”). Self-rated clearness of body perception was measured by questionnaire.

Results

Contrary to our hypothesis, DPD patients performed similarly to healthy controls on the two different heartbeat detection tasks, and they had equal scores regarding their self-rated clearness of body perception. There was no correlation of the severity of “anomalous body experiences” and depersonalization with measures of interoceptive accuracy. Only among healthy controls CA in the Schandry task was positively correlated with self-rated clearness of body perception. Depersonalization was unrelated to severity of depression or anxiety, while depression and anxiety were highly correlated. Anxiety and depression did not modify the associations of depersonalization with interoceptive accuracy.

Conclusions

Our main findings highlight a striking discrepancy of normal interoception with overwhelming experiences of disembodiment in DPD. This may reflect difficulties of DPD patients to integrate their visceral and bodily perceptions into a sense of their selves. This problem may be considered an important target for psychotherapeutic treatment approaches.

Testing a neurobiological model of depersonalization disorder using repetitive transcranial magnetic stimulation

Background

Depersonalization disorder (DPD) includes changes in subjective experiencing of self, encompassing emotional numbing. Functional magnetic resonance imaging (fMRI) has pointed to ventrolateral prefrontal cortex (VLPFC) inhibition of insula as a neurocognitive correlate of the disorder.

Objective

We hypothesized that inhibition to right VLPFC using repetitive transcranial magnetic stimulation (rTMS) would lead to increased arousal and reduced symptoms.

Methods

Patients with medication-resistant DSM-IV DPD (N = 17) and controls (N = 20) were randomized to receive one session of right-sided rTMS to VLPFC or temporo-parietal junction (TPJ). 1Hz rTMS was guided using neuronavigation and delivered for 15 min. Co-primary outcomes were: (a) maximum skin conductance capacity, and (b) reduction in depersonalization symptoms (Cambridge Depersonalisation Scale (CDS) [state version]). Secondary outcomes included spontaneous fluctuations (SFs) and event-related skin conductance responses.

Results

In patients with DPD, rTMS to VLPFC led to increased electrodermal capacity, namely maximum skin conductance deflections. Patients but not controls also showed increased SFs post rTMS. Patients who had either VLPFC or TPJ rTMS showed a similar significant reduction in symptoms. Event-related electrodermal activity did not change.

Conclusions

A single session of right-sided rTMS to VLPFC (but not TPJ) significantly increased physiological arousal capacity supporting our model regarding the relevance of increased VLPFC activity to emotional numbing in DPD. rTMS to both sites led to reduced depersonalization scores but since this was independent of physiological arousal, this may be a non-specific effect. TMS is a potential therapeutic option for DPD; modulation of VLPFC, if replicated, is a plausible mechanism.

Evidence-based treatment for Depersonalisation-derealisation Disorder (DPRD)

BACKGROUND

Depersonalisation-derealisation disorder (DPRD) is a distressing and impairing condition with a pathophysiology that is not well understood. Nevertheless, given the growing interest in its pathogenesis, and the publication of a number of treatment trials, a systematic review of randomised controlled pharmacotherapy and psychotherapy trials is timely.

METHODS

A systematic search of articles on DPRD published from January 1980 to August 2012, using Cochrane methods, was conducted. All randomised controlled trials (RCTs) of pharmacotherapy, psychotherapy, somatic interventions and a blend of these modalities for the treatment of depersonalisation disorder were included in the review. Searches were carried out on multiple databases. The bibliographies of all identified trials were checked for additional studies and authors were contacted for published trials. No unpublished trials were found and no restrictions were placed on language and setting. Data extraction sheets were further designed to enter specified data from each trial and risk of bias information was identified. PRISMA guidelines were also followed to ensure that our methodology and reporting were comprehensive. Of the unique 1296 papers that were retrieved, four studies met the inclusion criteria and were reviewed.

RESULTS

Four RCTs (all within the duration of 12 weeks or less) met study criteria and were included (180 participants; age range 18-65 years). The four RCTs included two lamotrigine studies, one fluoxetine study and one biofeedback study. Evidence for the treatment efficacy of lamotrigine was found in one study (Cambridge Dissociation Scale, CDC: p < 0.001) with no evidence of effect for lamotrigine in the second study (CDS: p = 0.61 or Present State Examination: p = 0.17). Fluoxetine and biofeedback were not more efficacious than the control condition, although there was a trend for fluoxetine to demonstrate greater efficacy in those with comorbid anxiety disorder. The four studies had 'low' or 'unclear' risk of bias.

CONCLUSION

The limited data from randomised controlled trials on the pharmacotherapy and psychotherapy of DPRD demonstrates inconsistent evidence for the efficacy of lamotrigine, and no efficacy for other interventions. Additional research on this disorder is needed.

Depersonalization experiences are strongly associated with dizziness and vertigo symptoms leading to increased health care consumption in the German general population

This study investigated the association of depersonalization (DP) experiences with dizziness and its impact on subjective impairment and health care use. Trained interviewers surveyed a representative sample of 1287 persons using standardized self-rating questionnaires on dizziness, DP, and mental distress. Symptoms of dizziness were reported by 15.8% (n = 201). Thereof, 62.7% endorsed at least one symptom of DP, 40% reported impairment by symptoms of DP, and 8.5% reported clinically significant DP. Regression analyses identified DP as a significant, independent predictor for dizziness symptom severity, health care use, and impairment by dizziness. With regard to the Vertigo Symptom Scale, DP explained 34.1% (p < 0.001) of the variance for severity of symptoms of dysfunction in the balance system. In conclusion, symptoms of DP, highly prevalent in patients complaining of dizziness and vertigo, were independently associated with increased impairment and health care use. The presence of DP symptoms should actively be explored in patients complaining of dizziness.

Dissociative experiences and quality of life in patients with non-epileptic attack disorder

Dissociative experiences are commonly reported by patients with non-epileptic attack disorder (NEAD). This cross-sectional study examined the prevalence and characteristics of dissociative experiences in patients with NEAD and assessed their association with health-related quality of life (HRQoL). Fifty-three patients diagnosed with NEAD were consecutively recruited (70.0% female, mean age=42 years, 22.0% with comorbid epilepsy) from a specialist neuropsychiatric clinic. Our sample reported high levels of dissociative experiences, with 36.7% of patients scoring ≥30 on the Dissociative Experiences Scale (DES). Significant negative correlations were found between total DES scores and HRQoL, as measured by the QOLIE-31 questionnaire (r=-0.64, p<0.001). This association remained significant when accounting for symptoms of depression and anxiety, other psychiatric comorbidities, and attack frequency and severity. These findings suggest a high prevalence of dissociative experiences in this patient population, highlighting the importance of routinely screening patients for dissociative symptoms and their impact on patients' lives.