Absorbed in sleep: Dissociative absorption as a predictor of sleepiness following sleep deprivation in two high-functioning samples

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.

The Self-Absorptive Trait of Dissociative Experience and Problematic Internet Use: A National Birth Cohort Study

Functional and excessive use of internet are hard to distinguish from each other, and internet use can affect adolescents’ development of self-identity. The aim of our study was to investigate the associated relationships between the risk and protective factors for internet use, including parental monitoring, the absorptive dissociative trait, having been bullied, exercise, self-perceived depressive mood, and happiness of 12-year-old adolescents. The Taiwan Birth Cohort Study dataset, which used a national household probability sampling method and included 17,694 12-year-old adolescents, was used for this study. Our results showed that 5.3% of adolescents reported spending more than five hours online during school days. Additionally, adolescents that spent more than five hours online during school days tended to have a higher absorptive trait, perceived less care from mothers, were more likely to have been bullied, and expressed a higher level of depressed mood, which led to a lower level of perceived happiness. Adolescents that spent more than five hours online during school days, compared to those that spent less than an hour online, were more likely to have been bullied, which effected their level of happiness, showing that they may be a group of higher concern. Therefore, spending more than five hours per day online maybe a clinical prevention indicator for problematic internet use.

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.

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.

Who wrote that? Automaticity and reduced sense of agency in individuals prone to dissociative absorption

Dissociative absorption (DA) is a tendency to become completely immersed in a stimulus while neglecting to attend to one's surroundings. Theoretically, DA implies automatic functioning in areas that are outside the focus of attention. This study examined whether high absorbers indeed act more automatically, i.e., with decreased meta-consciousness for, and therefore poor memory of, their own actions, along with reduced sense of agency (SoA). High and low absorbers (N = 63) performed three DA-promoting tasks: choice-reaction time (CRT), Tetris, and free writing. Participants were tested on memory of task details and self-reported their state SoA. As hypothesized, trait DA was correlated with impaired autobiographical memory for self-generated writing. However, DA was not related to episodic memory disruptions in externally-generated content tasks (Tetris, CRT). In most tasks, DA was associated with decreased SoA. Absorbers' specific difficulty in identifying self-generated content suggests that their memory failures stem from reduced accessibility to self-actions and intentions.

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.