Sleep loss increases dissociation and affects memory for emotional stimuli

Explicit and implicit sense of agency in depersonalisation experiences

The sense of agency, the feeling of controlling one's bodily actions and the world is altered in Depersonalisation (DP), a condition that makes people feel detached from one's self and body. To investigate the link between depersonalisation and both implicit and explicit sense of agency, an online study was conducted using the influential Intentional Binding paradigm in a sample of non-clinical DP participants. The results did not reveal significant differences between individuals with low and high occurrences of DP experiences on the implicit and explicit sense of agency. However, participants with high occurrences of DP experiences showed a more time-sensitive explicit sense of agency and greater temporal distortions for short intervals in the absence of self-initiated motion. These results suggest that there is a discrepancy between implicit and explicit sense of agency in people with high levels of depersonalisation. Altogether, these findings call for further investigations of the key role of time perception on altered sense of self and agency in both non-clinical and clinical populations, to disentangle the mechanisms associated with the explicit and implicit sense of agency.

Associations between disturbed sleep and attenuated psychotic experiences in people at clinical high risk for psychosis

BACKGROUND

Pre-diagnostic stages of psychotic illnesses, including 'clinical high risk' (CHR), are marked by sleep disturbances. These sleep disturbances appear to represent a key aspect in the etiology and maintenance of psychotic disorders. We aimed to examine the relationship between self-reported sleep dysfunction and attenuated psychotic symptoms (APS) on a day-to-day basis.

METHODS

Seventy-six CHR young people completed the Experience Sampling Methodology (ESM) component of the European Union Gene-Environment Interaction Study, collected through PsyMate® devices, prompting sleep and symptom questionnaires 10 times daily for 6 days. Bayesian multilevel mixed linear regression analyses were performed on time-variant ESM data using the brms package in R. We investigated the day-to-day associations between sleep and psychotic experiences bidirectionally on an item level. Sleep items included sleep onset latency, fragmentation, and quality. Psychosis items assessed a range of perceptual, cognitive, and bizarre thought content common in the CHR population.

RESULTS

Two of the seven psychosis variables were unidirectionally predicted by previous night's number of awakenings: every unit increase in number of nightly awakenings predicted a 0.27 and 0.28 unit increase in feeling unreal or paranoid the next day, respectively. No other sleep variables credibly predicted next-day psychotic symptoms or vice-versa.

CONCLUSION

In this study, the relationship between sleep disturbance and APS appears specific to the item in question. However, some APS, including perceptual disturbances, had low levels of endorsement amongst this sample. Nonetheless, these results provide evidence for a unidirectional relationship between sleep and some APS in this population.

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.

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

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

Cross-validation of the ego dissolution scale: implications for studying psychedelics

Introduction

Ego dissolution, variously called Ego-Loss, self-loss, and ego disintegration, is a hallmark of psychedelic drug use. We cross-validated the 10-item Ego Dissolution Scale, which we developed to assess ego dissolution in everyday life, and we included comparator variables that expanded our original assessment of construct validity.

Methods

Undergraduate college student volunteers (N = 527) completed the measures online.

Results

We replicated the original two factor structure (i.e., subfactors: Ego-Loss and Unity/connectedness with others, the world, universe), and we determined that the total score (Cronbach's α = 0.79) and subfactors (Ego-Loss = 78; Unity = 0.83) possessed adequate-to-good reliability and strong convergent validity (e.g., mindfulness, hallucination-predisposition, sleep variables, personality variables, positive/negative affect transliminality, dissociation/depersonalization), while neuroticism, social desirability did not correlate highly with ego dissolution. We identified distinct patterns of relations of measures associated with the Ego-Loss vs. Unity subfactors.

Discussion

We discuss the implications of the use of the EDS for studying everyday aspects of ego dissolution, the long-term effects of psychedelic use, and the value of using the scale in conjunction with measures of the acute effects of psychedelics.

Sleep Quality, Sleep-Related Experiences, and Dissociation in Adult Survivors of Childhood Trauma

OBJECTIVES

Exposure to traumatic stress in childhood increases the risk of sleep disturbances. Preliminary evidence suggests that the relationship between childhood trauma and sleep may depend on trauma chronicity. Additionally, little is known about the relationship between sleep and dissociation, a common symptom in post-traumatic stress disorder. This study examined sleep quality, sleep-related experiences, and dissociation in survivors of childhood trauma with different trauma chronicity.

METHOD

Nine-hundred-and-fourteen community-dwelling adults completed an online survey. They were divided into three groups: no childhood trauma, short-term childhood trauma, and chronic childhood trauma.

RESULTS

We found that survivors of chronic childhood trauma had poorer sleep quality than survivors of short-term childhood trauma and individuals without a history of childhood trauma, controlling for age, number of trauma types experienced, psychological distress, and PTSD symptoms. The relationship between dissociation and sleep quality was moderated by trauma chronicity such that dissociation was associated with better sleep quality only in the chronic trauma group. Dissociation was positively associated with sleep-related experiences regardless of trauma exposure and trauma chronicity.

CONCLUSION

Our findings highlighted the differential impact of acute and chronic traumatic stress on sleep, and suggested that the relationship between dissociation and sleep could depend on trauma chronicity.

Body-and movement-oriented interventions for posttraumatic stress disorder: An updated systematic review and meta-analysis

This study is an update of the meta-analysis we published in 2019 on the effectiveness of body- and movement-oriented interventions (BMOIs) for adults with posttraumatic stress disorder (PTSD) in decreasing PTSD symptoms and secondary outcomes of depressive symptoms, sleep disturbance, and interoceptive awareness. Search terms for BMOIs and PTSD were combined to identify eligible studies in four bibliographical databases. Articles were selected if they included adult participants with a primary diagnosis of PTSD, included BMOI as one of the investigated therapies, were designed as a comparative outcome trial with any control condition, and involved a standardized outcome measure for PTSD symptom severity. This resulted in the addition of 14 new studies compared to the 2019 study. The meta-analysis, which included 29 studies in total, resulted in a mean Hedges' g effect size of 0.50, 95% CI [0.22, 0.79], in decreasing PTSD symptoms, with very high heterogeneity, I2 = 89%. Meta-analyses of secondary outcomes resulted in Hedges' g effect sizes of 0.37, 95% CI [0.08, 0.66] for depressive symptoms; 0.62, 95% CI [0.42, 0.81] for sleep quality; and -0.10, 95% CI [-0.23, 0.43] for interoceptive awareness. The risk of bias analysis resulted in some concerns or high risk of bias in almost all included studies; only one study had a low risk of bias. We conclude that BMOIs may be valuable for patients with PTSD. There is, however, still a lack of high-quality studies with proper control conditions and long-term follow-up periods from which to draw conclusions.

Nocturnal agitation: From sleep state dissociation to sleep-related dissociative state

Nocturnal agitation refers to a broad spectrum of symptoms from simple movements to aggressive behaviors with partial or complete loss of awareness. An accurate identification of its etiology is critical for appropriate therapeutic intervention. In children and young adults, distinguishing between non-rapid eye movement (NREM) sleep parasomnias and psychogenic non-parasomniac manifestations, a condition known as sleep-related dissociative disorder (SRDD), can be challenging. This review aims to summarize current clinical, neurophysiological, and epidemiological knowledge on NREM parasomnia and SRDD, and to present the pathophysiological hypotheses underlying these nocturnal manifestations. Sleepwalking, sleep terror and confusional arousals are the three main presentations of NREM parasomnias and share common clinical characteristics. Parasomniac episodes generally occur 30minutes to three hours after sleep-onset, they are usually short, lasting no more than few minutes and involve non-stereotyped, clumsy behaviors with frequent amnesia. The prevalence of NREM parasomnia decreases from 15-30% in children to 2-4% in adults. Parasomniac episodes are incomplete awakening from the deepest NREM sleep and are characterized by a dissociated brain activity, with a wake-like activation in motor and limbic structures and a preserved sleep in the fronto-parietal regions. SRDD is a less known condition characterized by dramatic, often very long episodes with frequent aggressive and potentially dangerous behaviors. SRDD episodes frequently occur in quiet wakefulness before falling asleep. These dissociative manifestations are frequently observed in the context of psychological trauma. The pathophysiology of SRDD is poorly understood but could involve transient changes in brain connectivity due to labile sleep-wake boundaries in predisposed individuals. We hypothesize that SRDD and NREM parasomnia are forms of sleep-related dissociative states favored by a sleep-wake state dissociation during sleep-onset and awakening process, respectively.

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.

Investigating the effects of sleep and sleep loss on the different stages of episodic emotional memory: A narrative review and guide to the future

For two decades, sleep has been touted as one of the primary drivers for the encoding, consolidation, retention, and retrieval of episodic emotional memory. Recently, however, sleep's role in emotional memory processing has received renewed scrutiny as meta-analyses and reviews have indicated that sleep may only contribute a small effect that hinges on the content or context of the learning and retrieval episodes. On the one hand, the strong perception of sleep's importance in maintaining memory for emotional events may have been exacerbated by publication bias phenomena, such as the "winner's curse" and "file drawer problem." On the other hand, it is plausible that there are sets of circumstances that lead to consistent and reliable effects of sleep on emotional memory; these circumstances may depend on factors such as the placement and quality of sleep relative to the emotional experience, the content and context of the emotional experience, and the probes and strategies used to assess memory at retrieval. Here, we review the literature on how sleep (and sleep loss) influences each stage of emotional episodic memory. Specifically, we have separated previous work based on the placement of sleep and sleep loss in relation to the different stages of emotional memory processing: (1) prior to encoding, (2) immediately following encoding during early consolidation, (3) during extended consolidation, separated from initial learning, (4) just prior to retrieval, and (5) post-retrieval as memories may be restructured and reconsolidated. The goals of this review are three-fold: (1) examine phases of emotional memory that sleep may influence to a greater or lesser degree, (2) explicitly identify problematic overlaps in traditional sleep-wake study designs that are preventing the ability to better disentangle the potential role of sleep in the different stages of emotional memory processing, and (3) highlight areas for future research by identifying the stages of emotional memory processing in which the effect of sleep and sleep loss remains under-investigated. Here, we begin the task of better understanding the contexts and factors that influence the relationship between sleep and emotional memory processing and aim to be a valuable resource to facilitate hypothesis generation and promote important future research.

Zoomed out: digital media use and depersonalization experiences during the COVID-19 lockdown

Depersonalisation is a common dissociative experience characterised by distressing feelings of being detached or 'estranged' from one's self and body and/or the world. The COVID-19 pandemic forcing millions of people to socially distance themselves from others and to change their lifestyle habits. We have conducted an online study of 622 participants worldwide to investigate the relationship between digital media-based activities, distal social interactions and peoples' sense of self during the lockdown as contrasted with before the pandemic. We found that increased use of digital media-based activities and online social e-meetings correlated with higher feelings of depersonalisation. We also found that the participants reporting higher experiences of depersonalisation, also reported enhanced vividness of negative emotions (as opposed to positive emotions). Finally, participants who reported that lockdown influenced their life to a greater extent had higher occurrences of depersonalisation experiences. Our findings may help to address key questions regarding well-being during a lockdown, in the general population. Our study points to potential risks related to overly sedentary, and hyper-digitalised lifestyle habits that may induce feelings of living in one's 'head' (mind), disconnected from one's body, self and the world.

Dissociation and Dissociative Disorders Reconsidered: Beyond Sociocognitive and Trauma Models Toward a Transtheoretical Framework

For more than 30 years, the posttraumatic model (PTM) and the sociocognitive model (SCM) of dissociation have vied for attention and empirical support. We contend that neither perspective provides a satisfactory account and that dissociation and dissociative disorders (e.g., depersonalization/derealization disorder, dissociative identity disorder) can be understood as failures of normally adaptive systems and functions. We argue for a more encompassing transdiagnostic and transtheoretical perspective that considers potentially interactive variables including sleep disturbances; impaired self-regulation and inhibition of negative cognitions and affects; hyperassociation and set shifts; and deficits in reality testing, source attributions, and metacognition. We present an overview of the field of dissociation, delineate uncontested and converging claims across perspectives, summarize key multivariable studies in support of our framework, and identify empirical pathways for future research to advance our understanding of dissociation, including studies of highly adverse events and dissociation. Expected final online publication date for the Annual Review of Clinical Psychology, Volume 18 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dissociative Symptoms are Highly Prevalent in Adults with Narcolepsy Type 1

INTRODUCTION

The core symptoms of narcolepsy such as excessive daytime sleepiness and cataplexy are well known. However, there is mounting evidence for a much broader symptom spectrum, including psychiatric symptoms. Disordered sleep has previously been linked with dissociative symptoms, which may imply that patients with narcolepsy are more prone to develop such symptoms.

OBJECTIVES

To investigate the frequency of dissociative symptoms in adult patients with narcolepsy type 1 compared to population controls.

METHODS

In a retrospective case control study, sixty adult patients fulfilling the criteria for narcolepsy type 1 and 120 matched population control subjects received a structured interview using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) to assess dissociative symptoms and disorders.

RESULTS

A majority of narcolepsy patients reported dissociative symptoms, and even fulfilled the DSM-IV-TR criteria of a dissociative disorder (62% vs 1% in controls, p < .001). Most frequently reported symptoms were "dissociative amnesia" (37% vs 1%, p < .001) and "dissociative disorder of voluntary movement" (32% vs 1%, p < .001).

CONCLUSION

Dissociative symptoms are strikingly prevalent in adult patients with narcolepsy type 1. Although a formal diagnosis of dissociation disorder should not be made as the symptoms can be explained by narcolepsy as an underlying condition, the findings do illustrate the extent and severity of the dissociative symptoms. As for the pathophysiological mechanism, there may be symptom overlap between narcolepsy and dissociation disorder. However, there may also be a more direct link between disrupted sleep and dissociative symptoms. In either case, the high frequency of occurrence of dissociative symptoms should result in an active inquiry by doctors, to improve therapeutic management and guidance.

Dissociation in patients with non-affective psychosis: Prevalence, symptom associations, and maintenance factors

Dissociation is problematic in its own right for patients with psychosis but may also contribute to the occurrence of psychotic experiences. We therefore set out to estimate in a large cohort of patients with psychosis the prevalence of dissociative experiences, and assess using network models the relationships between dissociation, its potential maintenance mechanisms, and mental health symptoms. 902 patients with non-affective psychosis attending UK mental health services participated. Both an undirected model and a partially directed network model were estimated to identify potential relationships between 'felt sense of anomaly' dissociative experiences, paranoia, hallucinations, psychological wellbeing, sleep, and six potential maintenance mechanisms (affect intolerance, perseverative thinking, general self-efficacy, alexithymia, cognitive appraisals, and cognitive-behavioural responses to dissociation). 617 patients (65.4%) had experienced at least one dissociative symptom regularly over the past fortnight, with the average number experienced being 8.9 (SD = 8.0). Dissociation had direct relationships with paranoia, hallucinations, low psychological wellbeing, cognitive appraisals, cognitive-behavioural responses to dissociation, perseverative thinking, and low alexithymia. Dissociation was a probable cause of hallucinations (94.21% of 50,000 sampled directed acyclic graphs), with a trend towards also being a cause of paranoia (86.25% of 50,000 sampled directed acyclic graphs). Approximately two-thirds of patients with psychosis experience regular dissociative experiences. Dissociation is associated with low psychological wellbeing, and it is likely to have a direct causal influence on psychotic symptoms. Catastrophic cognitive appraisals, cognitive-behavioural responses to dissociation, factors related to affect sensitivity, and perseverative thinking may contribute to the occurrence of dissociation.

Nightmare Rescripting: Using Imagery Techniques to Treat Sleep Disturbances in Post-traumatic Stress Disorder

Besides affecting 8% of the general population, nightmares are one of the most frequent symptoms of traumatized individuals. This can be a significant factor in the treatment of post-traumatic disorders; indeed, several studies demonstrated its strong predictive and prognostic value. Sleep disorders, nightmares in particular, could be very distressing for individuals and need targeted interventions, especially if they are associated with a PTSD diagnosis. To date, the best technique for the treatment of traumatic sleep disturbances seems to be Imagery Rehearsal Therapy (IRT), an empirically supported method. Through a review of the literature on this matter, this article aims to outline the incidence and consequences of nightmares in PTSD, illustrate how IRT could prove useful in their treatment, and investigate its clinical applications.

Sleep and Physical Performance: A Case Study of Collegiate Women's Division 1 Basketball Players

In this work, we present a case study to evaluate the connections between sleep, training load, and the perceptions of physical/emotional state of a collegiate, division 1 Women's basketball team. The study took place during the off- (3 weeks) and pre-season (6 weeks) while sleep was tracked using WHOOP wearable straps. Training load was recorded by the strength coach and athletes. Short Recovery and Short Stress (SRSS) questionnaire was used to evaluate the perceptions of athletes on their own emotional and physical states. Our results showed that heart rate measurements are associated with stress levels and recovery perception. We also discovered that the training load was not linked to the sleep variables without the considerations of athletic performance. However, training load may alter perceived stress and recovery which requires further exploration.

A Network Analysis to Identify Associations between PTSD and Dissociation among Teenagers

We conducted a network analysis of measures of dissociation and posttraumatic symptoms (PTS) with a varied sample of adolescents (N = 312), some of them previously exposed to war scenarios. The global measure of dissociation (A-DES) was uniquely linked to the arousal PTS symptom cluster (CRIES-13), in particular sleep problems, but not to the reexperiencing and avoidance clusters. Three of four (i.e., depersonalization/derealization, amnesia, mental partition/compartmentalization) dissociation clusters were uniquely linked to PTS severity, but not absorption. The results with the pooled groups were generally representative of both groups. The DP/DR relation to PTS was based on data from both samples, whereas the link between amnesia and partition/parts might have been driven by the normative group, although the refugee sample had significantly higher scores in those variables. The results replicate some previous findings with adult samples and suggest new paths for research and theory.

The relationship between dissociation symptoms, sleep disturbances, problematic internet use and online gaming in adolescents

Some adolescents admitted to the child and adolescent psychiatry outpatient clinic experience dissociative symptoms, such as hearing strange sounds, temporary blackouts, seeing images, changes in body parts, and looking at themselves from outside themselves. Some may also have sleep disturbances and a history of spending a long time on the internet. This study investigated the relationship between dissociative symptoms and sleep disorders, problematic internet usage (PIU),aggression and digital game addiction in adolescents. Participants completed the State-Trait Anger Expression Inventory (STAXI), Problematic Internet Usage Scale (PIUS), Digital Game Addiction Scale (DGAS-7), Children's Depression Inventory (CDI), Adolescent Dissociative Experiences Scale (A-DES), Pittsburgh Sleep Quality Index (PSQI), Screen for Child Anxiety Related Emotional Disorders Child Version (SCARED), and a sociodemographic form. Regression analyses were performed to identify associations. The sample consisted of 244 adolescents between 14 and 18 years of age (M = 15.93, SD = 0.90), of which 171 (70.1%) were girls and 73 (29.9%) were boys. Fifty-two (21.3%) were classified as having problematic online gaming (POG+), whereas 192 (78.7%) were classified as not having problematic online gaming (POG-). There was a difference between the two groups in all sub-dimensions of the PIUS, STAXI, CDI, and A-DES. Adolescents who had higher scores on the A-DES had a higher risk of sleep disorders and had higher scores on the PIU, CDI, and SCARED. The POG+ group dissociation scores were considerably higher than POG- group scores. Adolescents with high A-DES scores also had higher anger scores and weaker anger control skills. Consequently, sleep disorders, PIU, and POG may increase dissociative symptoms.

Evidence of objective sleep impairment in nonepileptic attack disorder: A naturalistic prospective controlled study using actigraphy and daily sleep diaries over six nights

Poor sleep is reported by many with nonepileptic attack disorder (NEAD) with correlations evident between self-reported sleep quality and mood and functional impairment. However, it is contended that self-reported sleep impairment in NEAD is a subjective phenomenon, which represents a general tendency to over-report symptoms or misinterpret bodily states in those with NEAD. The present study was therefore designed to investigate the extent of subjective and objective sleep impairments in those with NEAD. Over six nights we prospectively recorded comparable nightly objective (actigraphy) and subjective (consensus sleep diary) sleep parameters in a sample of 17 people with NEAD, and an age- and gender-matched normative control group (N = 20). Participants recorded daily measures of attacks, dissociation, and mood. Alongside higher subjective sleep impairment, the NEAD group had significantly worse objective sleep on several metrics compared to the normative controls, characterized by disrupted sleep (frequent awakenings and wake after sleep onset, low efficiency). Exploratory analyses using mixed effects models showed that attacks were more likely to occur on days preceded by longer, more restful sleep. This study, which had good ecological validity, evidences the presence of objective sleep impairment in NEAD, suggesting that in patient reports of problems with sleep should be given careful consideration in clinical practice.

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

OBJECTIVES

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

DESIGN

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

PRACTITIONER POINTS

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

Dissociation in relation to other mental health conditions: An exploration using network analysis

Dissociative experiences, traditionally studied in relation to trauma and PTSD, may be important phenomena across many different psychological conditions, including as a contributory causal factor for psychotic experiences. In this study, the aim was to explore, using network approaches, how dissociative experiences taking the form of a Felt Sense of Anomaly (FSA) relate to both common mental health conditions and psychotic experiences. 6941 individuals from the general population completed online assessments of FSA-dissociation, post-traumatic stress symptoms (PTSS), anxiety, depression, insomnia, worry, distress tolerance, hallucinations, grandiosity, paranoia, and cognitive disorganization. An undirected partial correlation network analysis was used to explore the network structure, then Bayesian inference with Directed Acyclic Graphs (DAGs) was used to identify potential directions of relationships between dissociation and mental health symptoms. Dissociation was found to be highly connected in both network models. Both networks found direct relationships between dissociation and hallucinations, grandiosity, paranoia, cognitive disorganization, anxiety, depression, and PTSS. In the DAGs analysis, the direction of influence between dissociation and hallucinations, PTSS, anxiety and depression was unclear, however it was found to be probable that dissociation influences paranoia (97.66% of sampled DAGs found the direction dissociation to paranoia, versus 2.34% finding the reverse direction), cognitive disorganization (99.74% vs. 0.26%), and grandiosity (93.49% vs. 6.51%). Further, dissociation was found to be a probable influence of insomnia and distress tolerance via indirect pathways. In summary, dissociation is connected to many mental health disorders, and may influence a number of presentations, particularly psychotic experiences. The importance of dissociation in mental health may therefore currently be under-recognised.

The ANT Executive Control Index: No Evidence for Temporal Decrement

OBJECTIVE

This study tested whether indices of executive control, alertness, and orienting measured with Attention Network Test (ANT) are vulnerable to temporal decrement in performance.

BACKGROUND

Developing the resource theory of sustained attention requires identifying neurocognitive processes vulnerable to decrement. Executive control processes may be prone to impairment in fatigue states. Such processes are also highlighted in alternative theories. Determining the role of executive control in vigilance can both advance theory and contribute to practical countermeasures for decrement in human factors contexts.

METHOD

In Study 1, 80 participants performed the standard ANT for an extended duration of about 55 to 60 min. Study 2 (160 participants) introduced manipulations of trial blocking and stimulus degradation intended to increase resource depletion. Reaction time and accuracy measures were analyzed. Subjective stress and workload were assessed in both studies.

RESULTS

In both studies, the ANT induced levels of subjective workload and task disengagement consistent with previous sustained attention studies. No systematic decrement in any performance measure was observed.

CONCLUSION

Executive control assessed by the ANT is not highly vulnerable to temporal decrement, even when task demands are elevated. Future work should differentiate executive control processes; proactive control may be more implicated in sustained attention decrement than in reactive control.

APPLICATION

Designing systems and interfaces to reduce executive control demands may be generally beneficial but will not directly mitigate temporal performance decrement. Enhancing design guidelines and neuroergonomic methods for monitoring operator attention requires further work to identify key neurocognitive processes for decrement.

The path to dissociative experiences: A direct comparison of different etiological models

Severe dissociation is trauma-related, but a range of dissociative experiences are also prevalent in clinical populations that are not necessarily trauma-based (e.g., depression, anxiety disorders, and obsessive-compulsive disorders). These remain poorly understood as the dominant etiological model for dissociation relies on trauma. Importantly, dissociation in such samples predicts poor prognosis and high drop-out rates. We set out to better understand the aetiology of dissociative experiences in a mixed clinical (anxiety and depression) and community sample by exploring between- and within-subjects effects of two domains: psychological distress or negative affectivity (operationalized as anxiety and depression symptoms), and poor sleep quality, including disturbed dreaming. The idea that negative affectivity triggers dissociation (Distress Model) is inspired by the trauma model. The idea that poor sleep and unusual dreaming underlie dissociation (Sleep Model) has been suggested as a competing theory. We examined both models by exploring which domains oscillate alongside dissociative experiences. N = 98 adults, half of them diagnosed with depression and anxiety and half community controls, underwent a structured clinical interview and completed questionnaires monthly for 6 months. Support was found for both models in that each domain had a unique explanatory contribution. Distress evinced consistent effects that could not be explained by sleep or dreaming, both between individuals and across time. Oscillations in dissociation across months, when taking psychological distress into account, were better explained by unusual dreaming than traditional sleep quality measures. These findings cannot be generalized to highly-traumatized samples. A complex, integrated etiological model for dissociative experiences is warranted.

Does Sleep Selectively Strengthen Certain Memories Over Others Based on Emotion and Perceived Future Relevance?

Sleep has been found to have a beneficial effect on memory consolidation. It has furthermore frequently been suggested that sleep does not strengthen all memories equally. The first aim of this review paper was to examine whether sleep selectively strengthens emotional declarative memories more than neutral ones. We examined this first by reviewing the literature focusing on sleep/wake contrasts, and then the literature on whether any specific factors during sleep preferentially benefit emotional memories, with a special focus on the often-suggested claim that rapid eye movement sleep primarily consolidates emotional memories. A second aim was to examine if sleep preferentially benefits memories based on other cues of future relevance such as reward, test-expectancy or different instructions during encoding. Once again, we first focused on studies comparing sleep and wake groups, and then on studies examining the contributions of specific factors during sleep (for each future relevance paradigm, respectively). The review revealed that although some support exists that sleep is more beneficial for certain kinds of memories based on emotion or other cues of future relevance, the majority of studies does not support such an effect. Regarding specific factors during sleep, our review revealed that no sleep variable has reliably been found to be specifically associated with the consolidation of certain kinds of memories over others based on emotion or other cues of future relevance.

Dissociative Symptoms in Bipolar Disorder: Impact on Clinical Course and Treatment Response

Background: Dissociative symptoms are under recognized and scarcely studied by clinicians and researchers in patients with bipolar disorder (BD). We examined the relationship between dissociative symptoms and the psychotic features in patients with BD and assessed clinical and socio-demographic characteristics more frequently associated with dissociative symptoms and treatment response. Methods: Participants were 100 adult outpatients with BD. They were screened with semi-structured interview to collect socio-demographic and clinical characteristics; the Dissociative Experiences Scale-II (DES-II) and the ALDA scale were used to assess dissociative psychopathologies and response to treatment with mood stabilizers, respectively. Results: DES score (mean 31.7 ± 21.7) correlated with clinical variables, BD features, and course of illness. Psychotic symptoms, mixed features, and previous suicide attempts significantly predicted DES score [F _{(3, 47)} = 39.880, p < 0.001, R ² corrected = 0.713]. Dissociative symptoms were inversely correlated with poor response to treatment (r = -0.593; p < 0.001). Limitations: Cross-sectional design with a small sample and backward clinical assessment of psychotic symptoms. Conclusions: Dissociative phenomena are closely related to the presence of psychotic symptoms, mixed features, and previous suicide attempts in BD, especially in BD-I. Given the close association between dissociative and psychotic symptoms, this association could represent a diagnostic indicator of BD-I that may guide the clinician to plan the most appropriate treatment.

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

Objectives

Depersonalization is characterized by feelings of detachment from reality and has been associated with anxiety and depression, both of which have a bi-directional relationship with sleep. To date, few studies have directly examined the potential relationship between sleep and depersonalization, which was the primary objective of our study.

Design/methods

A cross-sectional study of female, Emirati, university students (n = 100) was conducted. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Cambridge Depersonalization Scale (CDS) and the Hospital Anxiety and Depression Scale (HADS). Additionally, 36 of the 100 participants wore wrist actigraphy for two consecutive weekdays. Average sleep duration, and average sleep efficiency (SE; %) across the two nocturnal sleep episodes were calculated. Total number of sleep episodes were obtained from wrist actigraphy and sleep logs.

Results

A significant, positive relationship was observed between PSQI global score and CDS total score (r = 0.21, p = 0.04). Actigraphy-estimated average nocturnal sleep duration was not significantly associated with the CDS. Compared to nocturnal sleepers only, those who undertook daytime naps had almost three times the risk of meeting the criteria for depersonalization disorder (OR = 2.95, 95% CI: 1.04–8.41), after adjustment. For each 1% increase in SE a 23% decreased risk of depersonalization was observed (OR = 0.77, 95% CI: 0.61–0.96), after adjustment.

Conclusions

Sleep screening in young adults may help to ensure better detection and management of psychological health outcomes. Our findings need to be confirmed prospectively in larger samples and amongst different populations but reiterate the importance of sleep habits pertaining to mental health.

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We show a novel relationship between depersonalization and sleep in a non-clinical sample.

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Actigraphy determined poor sleep efficiency was significantly associated with subjective reports of depersonalization.

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Daytime nappers were ~3 times more likely to report depersonalization symptoms and meet the diagnositic criteria.

Losing Control: Sleep Deprivation Impairs the Suppression of Unwanted Thoughts

Unwanted memories often enter conscious awareness when individuals confront reminders. People vary widely in their talents at suppressing such memory intrusions; however, the factors that govern suppression ability are poorly understood. We tested the hypothesis that successful memory control requires sleep. Following overnight sleep or total sleep deprivation, participants attempted to suppress intrusions of emotionally negative and neutral scenes when confronted with reminders. The sleep-deprived group experienced significantly more intrusions (unsuccessful suppressions) than the sleep group. Deficient control over intrusive thoughts had consequences: Whereas in rested participants suppression reduced behavioral and psychophysiological indices of negative affect for aversive memories, it had no such salutary effect for sleep-deprived participants. Our findings raise the possibility that sleep deprivation disrupts prefrontal control over medial temporal lobe structures that support memory and emotion. These data point to an important role of sleep disturbance in maintaining and exacerbating psychiatric conditions characterized by persistent, unwanted thoughts.

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.

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

BACKGROUND

The Cambridge Depersonalization Scale (CDS) characterizes the quality, frequency, and duration of dissociative symptoms. While the psychometric properties of the CDS have been evaluated in primary dissociative disorder, this has been insufficiently addressed among other psychiatric patient groups such as patients with a bipolar disorder (BD).

METHODS

Outpatients with variable mood (n = 73) responded to a survey that assessed dissociative symptoms and other characteristics. We used factor analysis and McDonald's omega to evaluate psychometric properties of the CDS, and correlations with other characteristics.

RESULTS

Previously suggested multifactorial models of the CDS were not supported, but the single-dimensional model fit both dichotomized (p = 0.31, CFI = 0.99, RMSEA = 0.02, ECV 70%) and trichotomized CDS responses (p = 0.06, CFI = 0.96, RMSEA = 0.04, ECV 47%). The CDS showed high internal consistency (ω = 0.96). CDS factor scores correlated with symptom severity on the Quick Inventory for Depressive Symptoms (QIDS-SR-16) (ρ = 0.59), the Social Phobia Inventory (ρ = 0.52), the American Association of Psychiatry Severity measure for Panic Disorders (ρ = 0.46), the Childhood Trauma Questionnaire (ρ = 0.44), and the Trauma Screening Questionnaire (ρ = 0.53). Two abbreviated versions of the CDS, retaining the best 14 or 7 items were proposed.

LIMITATIONS

The sample size remained moderate.

CONCLUSIONS

The CDS is a psychometrically sound, unidimensional measure with clinical impact to detect and characterize dissociative symptoms in BD patients. Establishing the reliability and validity of the abbreviated scales for screening necessitates further study.

The prevalence of Dissociative Disorders and dissociative experiences in college populations: a meta-analysis of 98 studies

This meta-analysis of 31,905 college students includes 12 studies diagnosing Dissociative Disorders (DD) and 92 studies measuring dissociation with the Dissociative Experiences Scale (DES). Prevalence rates were used to separately test the plausibility of the Trauma Model (TM) and the Fantasy Model (FM) of dissociation. Results show 11.4% of students sampled meet criteria for DD, which is consistent with the prevalence of experiencing multiple (types of) trauma during childhood (12%), but is not consistent with the very low prevalence expected from the role of fantasy-proneness proposed in the FM. DES scores varied significantly across the 16 countries and were not higher in North America, but in countries that were comparatively unsafe. The least well-known DD was the most common, which is inconsistent with the FM which holds that the diagnosed person is enacting a familiar social role. There was no evidence that DES scores had decreased over recent decades, which does not support FM assertions that DD were a fad of the 1990s. Three of the five hypotheses tested provided clear support for the TM and a fourth hypothesis provided partial support for the TM. None of the five hypotheses tested supported the FM. The finding that DD were slightly more common in college populations than the general population did not support predictions of either model. The theoretical perspective of the authors moderated DES scores, although this is unlikely due to experimenter bias as studies led by FM theorists had significantly higher DES scores than those led by TM theorists.

Sleep problems and attenuated psychotic symptoms in youth at clinical high-risk for psychosis

There has been growing interest on the effect of sleep problems on psychotic and prodromal symptoms. The current study investigated cross-sectional relations between sleep problems and attenuated psychotic symptoms in a large sample of 740 youth at Clinical High Risk (CHR) for psychosis in an attempt to replicate previous findings and assess whether findings from general population samples and psychotic samples extend to this CHR sample. Sleep problems were found to be significantly positively associated with attenuated psychotic symptom severity. Sleep problems were also found to be more closely associated with certain specific prodromal symptoms (e.g., suspiciousness and perceptual abnormalities) than other attenuated psychotic symptoms. Further, we found that depression mediated the cross-sectional association between sleep problems and paranoid symptoms only. This adds to a growing body of evidence suggesting the mediation role of depression is more pronounced for paranoid-type psychotic symptoms as compared to other psychotic symptoms (e.g., hallucinations).

No Time Like the Present: Thinking About the Past and the Future Is Related to State Dissociation Among Individuals With High Levels of Psychopathological Symptoms

Several short-term pathways have been implicated in relation to dissociative experiences, among them are daily stress, sleepiness, and rumination. In addition, it has been claimed that mechanisms contributing to dissociative experiences may differ, according to specific psychopathological symptoms. Accordingly, this study had two aims. The first was to sample moment-to-moment increases or decreases in current stress, sleepiness, and rumination, in order to assess their temporal relations with state dissociation. Rumination was broken down to its basic two subcomponents: the negative value of the thoughts and thinking about the past (in comparison to present or future), in order to differentiate it from other repetitive thought patterns (e.g., worry). The second goal was to explore whether depression, anxiety, and obsessive–compulsive symptoms may moderate the links between the three mechanisms and specific state dissociation scales [specifically, depersonalization-derealization (DEP-DER) and absorption (ABS)]. Ninety-nine undergraduate students completed trait questionnaires and then answered state items four times a day for 4 days. These experience sampling data were analyzed using multilevel linear modeling (MLM) with Level 1 state measurements and Level 2 demographic and trait variables of the participants. Moments of stress, sleepiness, thinking about the past and negative thoughts were all associated both with state DEP-DER and with state ABS. Dissociation, negative thinking, stress, and sleepiness were positively associated with moments of thinking about the past and the future but inversely associated with moments of thinking about the present. Finally, in accordance with our expectations, the links between DEP-DER and hypothesized mechanisms were mostly moderated by depression and anxiety symptoms, whereas the links between ABS and hypothesized mechanisms were moderated mainly by obsessive–compulsive symptoms. Our findings are in accordance with literature on the efficacy of mindfulness as well as the maladaptive correlates of mind-wandering, as they suggest that dissociative detachment from one’s present occupation is associated with decreased well-being.

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.

Unusual sleep experiences and dissociation as mediators between sleep quality and proneness to hallucinations in a nonclinical population sample: a preliminary study

INTRODUCTION

The purpose of this study was to examine the relationship of sleep quality to proneness to hallucinations and the mediating role of dissociation and unusual sleep experiences in a nonclinical sample.

METHODS

One hundred and seventy-seven participants completed a questionnaire on sleep quality, a dissociative experiences scale, an unusual sleep experiences scale and a hallucination proneness scale.

RESULTS

The results showed a significant positive association between quality of sleep and hallucination proneness, dissociation and unusual sleep experiences, and that dissociation and unusual sleep experiences fully mediated between sleep quality and hallucination proneness.

CONCLUSIONS

Our study highlights the importance of variables related to sleep quality and unusual sleep experiences and dissociation in understanding hallucinations, and the importance of taking these variables into consideration in designing intervention directed at reducing distress caused by hallucinations.

The effects of individual biological rhythm differences on sleep quality, daytime sleepiness, and dissociative experiences

Individuals who differ markedly by sleep chronotype, i.e., morning-type or evening-type also differ on a number of psychological, behavioral, and biological variables. Among several other psychological functions, dissociation may also lead to disruption and alteration of consciousness, which may facilitate dream-like experiences. Our study was aimed at an inquiry into the effects of individual biological rhythm differences on sleep quality and daytime sleepiness in conjunction with dissociative experiences. Participants were 372 undergraduate college students, completed a package of psychological instruments, including the Morningness-Eveningness Questionnaire, Dissociative Experiences Scale, Insomnia Severity Index, and Epworth Sleepiness Scale. Using logistic regression models, direct relations of pathological dissociation with sleepiness, sleep quality and circadian preferences were investigated. Poor sleep quality and sleepiness significantly contributed to the variance of dissociative symptomatology. Although there was no substantial linear association between circadian preferences and pathological dissociation, having evening-type preferences of sleep was indirectly associated with higher dissociation mediated by poor sleep quality. Poor sleep quality and daytime sleepiness seems to be significant antecedents of pathological dissociation. Sleep chronotype preferences underlie this relational pattern that chronobiological characteristics seem to influence indirectly on dissociative tendency via sleep quality.

A preliminary investigation of sleep quality in functional neurological disorders: Poor sleep appears common, and is associated with functional impairment

PURPOSE

Functional neurological disorders (FND) are disabling conditions for which there are few empirically-supported treatments. Disturbed sleep appears to be part of the FND context; however, the clinical importance of sleep disturbance (extent, characteristics and impact) remains largely unknown. We described sleep quality in two samples, and investigated the relationship between sleep and FND-related functional impairment.

METHODS

We included a sample recruited online via patient charities (N=205) and a consecutive clinical sample (N=20). Participants completed validated measures of sleep quality and sleep characteristics (e.g. total sleep time, sleep efficiency), mood, and FND-related functional impairment.

RESULTS

Poor sleep was common in both samples (89% in the clinical range), which was characterised by low sleep efficiency (M=65.40%) and low total sleep time (M=6.05h). In regression analysis, sleep quality was negatively associated with FND-related functional impairment, accounting for 16% of the variance and remaining significant after the introduction of mood variables.

CONCLUSIONS

These preliminary analyses suggest that subjective sleep disturbance (low efficiency, short sleep) is common in FND. Sleep quality was negatively associated with the functional impairment attributed to FND, independent of depression. Therefore, sleep disturbance may be a clinically important feature of FND.

Arousal in Nocturnal Consciousness: How Dream- and Sleep-Experiences May Inform Us of Poor Sleep Quality, Stress, and Psychopathology

The term "sleep experiences," coined by Watson (2001), denotes an array of unusual nocturnal consciousness phenomena; for example, nightmares, vivid or recurrent dreams, hypnagogic hallucinations, dreams of falling or flying, confusional arousals, and lucid dreams. Excluding the latter, these experiences reflect a single factor of atypical oneiric cognitions ("general sleep experiences"). The current study is an opinionated mini-review on the associations of this factor-measured with the Iowa sleep experiences survey (ISES, Watson, 2001)-with psychopathological symptoms and stress. Findings support a strong relation between psychological distress and general sleep experiences. It is suggested that that they should be viewed as a sleep disturbance; they seem to represent involuntary intrusions of wakefulness into sleep, resulting in aroused sleep. These intrusions may stem from excessively thin boundaries between consciousness states (e.g., "transliminality"), or, conversely, they may follow an attempt at disconnecting mental elements (e.g., dissociation), which paradoxically results in a "rebound effect." The extent to which unusual dreaming is experienced as intrusive, rather than controlled, may explain why general sleep experiences are related to psychopathology, whereas lucid dreams are related to psychological resilience. In conclusion, the exploration of the interplay between psychopathology and sleep should be expanded from focusing almost exclusively on quantitative aspects (e.g., sleep efficiency, latency) to including qualitative conscious experiences which may reflect poor sleep quality. Taking into account nocturnal consciousness-including unusual dreaming and permeable sleep-wake boundaries-may unveil rich information on night-time emotional states and broaden our definition of poor sleep quality.

Consciousness across Sleep and Wake: Discontinuity and Continuity of Memory Experiences As a Reflection of Consolidation Processes

The continuity hypothesis (1) posits that there is continuity, of some form, between waking and dreaming mentation. A recent body of work has provided convincing evidence for different aspects of continuity, for instance that some salient experiences from waking life seem to feature in dreams over others, with a particular role for emotional arousal as accompanying these experiences, both during waking and while asleep. However, discontinuities have been somewhat dismissed as being either a product of activation-synthesis, an error within the consciousness binding process during sleep, a methodological anomaly, or simply as yet unexplained. This paper presents an overview of discontinuity within dreaming and waking cognition, arguing that disruptions of consciousness are as common a feature of waking cognition as of dreaming cognition, and that processes of sleep-dependent memory consolidation of autobiographical experiences can in part account for some of the discontinuities of sleeping cognition in a functional way. By drawing upon evidence of the incorporation, fragmentation, and reorganization of memories within dreams, this paper proposes a model of discontinuity whereby the fragmentation of autobiographical and episodic memories during sleep, as part of the consolidation process, render salient aspects of those memories subsequently available for retrieval in isolation from their contextual features. As such discontinuity of consciousness in sleep is functional and normal.

Perspectives on the conceptualization of the dissociative subtype of PTSD and implications for treatment

A dissociative subtype of PTSD was added to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) to denote a distinct presentation of PTSD marked by symptoms of derealization and depersonalization. The subtype has brought renewed interest in the conceptualization of dissociation in PTSD, and raised questions about its treatment. We review the evidence for two models of PTSD-related dissociative symptoms and the treatment approaches that align with each. We find support for the contributions of biologically-based trait-level factors to dissociation, and suggest that empirically supported treatments for PTSD demonstrate efficacy for patients with the subtype.

Modification of Fear Memory by Pharmacological and Behavioural Interventions during Reconsolidation

Background

Dysfunctional fear responses play a central role in many mental disorders. New insights in learning and memory suggest that pharmacological and behavioural interventions during the reconsolidation of reactivated fear memories may increase the efficacy of therapeutic interventions. It has been proposed that interventions applied during reconsolidation may modify the original fear memory, and thus prevent the spontaneous recovery and reinstatement of the fear response.

Methods

We investigated whether pharmacological (propranolol) and behavioural (reappraisal, multisensory stimulation) interventions reduce fear memory, and prevent reinstatement of fear in comparison to a placebo control group. Eighty healthy female subjects underwent a differential fear conditioning procedure with three stimuli (CS). Two of these (CS+) were paired with an electric shock on day 1. On day 2, 20 subjects were pseudo-randomly assigned to either the propranolol or placebo condition, or underwent one of the two behavioural interventions after one of the two CS+ was reactivated. On day 3, all subjects underwent an extinction phase, followed by a reinstatement test. Dependent variables were US expectancy ratings, fear-potentiated startle, and skin conductance response.

Results

Differential fear responses to the reactivated and non-reactivated CS+ were observed only in the propranolol condition. Here, the non-reactivated CS+ evoked stronger fear-potentiated startle-responses compared to the placebo group. None of the interventions prevented the return of the extinguished fear response after re-exposure to the unconditioned stimulus.

Conclusions

Our data are in line with an increasing body of research stating that the occurrence of reconsolidation may be constrained by boundary conditions such as subtle differences in experimental manipulations and instructions. In conclusion, our findings do not support a beneficial effect in using reconsolidation processes to enhance effects of psychotherapeutic interventions. This implies that more research is required before therapeutic interventions may benefit from a combination with reconsolidation processes.

Tracking Potentiating States of Dissociation: An Intensive Clinical Case Study of Sleep, Daydreaming, Mood, and Depersonalization/Derealization

This study examined in real time the role of sleep and daydreaming as potentiating states for subsequent dissociation in depersonalization/derealization disorder (DDD). Research and theory suggests that dissociation may be exacerbated and maintained by a labile sleep-wake cycle in which "dream-like" mentation intrudes into waking life and fuels dissociative symptoms. We explore and extend this idea by examining the state of daydreaming in dissociation. Daydreaming is a state of consciousness between dreaming and waking cognition that involves stimulus-independent and task-unrelated mentation. We report the results of a unique intensive N = 1 study with an individual meeting diagnostic criteria for DDD. Using experience-sampling methodology, the participant rated (six times daily for 40 days) current daydreaming, mood, and dissociative symptoms. At the start of each day sleep quality and duration was also rated. Daydreaming was reported on 45% of occasions and significantly predicted greater dissociation, in particular when daydreams were repetitive and negative (but not fanciful) in content. These relationships were mediated by feelings of depression and anxiety. Sleep quality but not duration was a negative predictor of daily dissociation and also negatively predicted depression but not anxiety. Findings offer initial evidence that the occurrence and content of daydreams may act as potentiating states for heightened, in the moment, dissociation. The treatment implications of targeting sleep and daydreaming for dissociative disorders are discussed.