Acute dissociation after 1 night of sleep loss

Recent research has shown that dissociative symptoms are related to self-reports of deviant sleep experiences. The present study is the 1st to explore whether sleep loss can fuel dissociative symptoms. Twenty-five healthy volunteers were deprived of sleep for 1 night. Sleepiness and dissociative symptoms were assessed every 6 hr. The authors measured both spontaneous dissociative symptoms and dissociative symptoms induced by dot-staring during sensory deprivation. Sleepiness as well as spontaneous and induced dissociative symptoms were stable throughout the day but increased during the night. These findings provide further evidence for a robust relationship between disruptions in sleep patterns and dissociative symptoms.     

Dissociation, psychopathology, and abusive experiences in a nonclinical Latino university student group

A variety of clinical and experimental data suggest that many individuals who report abusive and traumatic experiences also report a wide array of dissociative and other psychopathological symptoms. In this study, 198 Puerto Rican undergraduate students participated in a study to examine the possible relationship between different types of traumatic experiences and the self-report of dissociative experiences, depressive symptoms, and general psychopathology. Another aspect of this study was the examination of the psychometric properties of the Dissociative Experiences Scale (DES) in a Latino sample. Results supported the hypothesis that those individuals who reported frequent and severe traumatic experiences were also the most likely to experience psychological malaise and scored higher on the DES. Of interest was the finding that the psychometric characteristics of the DES are consistent with those reported in the United States and other countries. The authors conclude that individuals with a marked history of trauma and abuse are more likely to use dissociative defenses as a coping response.     

The causal link between self-reported trauma and dissociation: a critical review

The idea that traumatic experiences cause dissociative symptoms is a recurrent theme in clinical literature. The present article summarizes evidence that cast doubts on the commonly voiced view that the connection between self-reported trauma and dissociation is a simple and robust one. It is argued that: (1) the correlations between self-reported traumatic experiences and dissociative symptoms reported in the literature are, at best, modest; (2) other factors may act as a third variable in the relationship between trauma and dissociation; and (3) high scores on the Dissociative Experiences Scale are accompanied by fantasy proneness, heightened suggestibility, and susceptibility to pseudomemories. These correlates of dissociation may promote a positive response bias to retrospective self-report instruments of traumatic experiences. Thus, the possibility that dissociation encourages self-reported traumatic experiences rather than vice versa merits investigation. While attractive, simple models in which trauma directly causes dissociation are unlikely to be true.     

Daily stress interacts with trait dissociation to predict sleep-related experiences in young adults

Building on the previously documented effects of stress and dissociation on sleep and dreaming, we examined their interactive role in general sleep-related experiences (GSEs; e.g., nightmares, falling dreams, hypnagogic hallucinations; see Watson, 2001). Stress, sleep quality, and GSEs were assessed daily for 14 days among young adults. Baseline assessment included life stress, sleep quality, psychopathology, dissociation, and related dimensions. Multilevel analyses indicated that daily stress brings about GSEs among highly dissociative young adults. Additionally, baseline trait dissociation predicted within-subject elevation in GSEs when daily stress was high. Flawed sleep-wake transitions, previously linked to dissociation and sleep-related experiences, might account for this effect.     

Dissociative states and neural complexity

Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of neural disintegration reflecting a number of independent processes by means of neural complexity. In the present study measurement of dissociation, traumatic stress symptoms and neural complexity calculated using nonlinear analysis of EEG [during rest conditions], and electrodermal activity (EDA) [during rest and Stroop task] were performed in 52 university students (mean age 24.1). Neural complexity has been described using pointwise correlation dimension (PD2) calculated from EEG and EDA records. While no significant relationship was found between EEG complexity and dissociative symptoms, statistically significant relationship between EDA complexity and dissociative symptoms during rest, but not during the Stroop task, has been found. These results indicate that electrodermal complexity during rest may reflect a level of dissociative symptoms.     

The relationship between traumatic experiences, dissociation, and borderline personality pathology among male forensic patients and prisoners

In the present study the relationship between traumatic experiences, dissociation, and borderline personality disorder pathology is examined in a group of 39 male forensic patients and 192 male prisoners. Sexual and emotional abuse are significantly more common among forensic patients than among prisoners. Patients also report a broader range of different kinds of traumas. Prisoners report significantly more dissociative symptoms. Analyses of the relationship of type of trauma on the one hand and dissociation and borderline personality pathology on the other show that sexual abuse is significantly associated with borderline personality pathology but not with dissociation among the patients. In the prison sample these associations are found only for familial but not extrafamilial sexual abuse. When the subjects are grouped on account of presence or absence of a borderline personality disorder, highly significant differences on dissociation are found between both groups. The results from this study lend support to the hypothesis that sexual abuse is not related to dissociative symptoms but merely to borderline personality pathology. Because most subjects in this study are not patients, these findings are not likely to be confounded by false memories of traumatic events that are recovered by psychotherapy. Furthermore, dissociative symptoms are found to be related to borderline personality pathology and not to the experience of traumatic events.     

Dissociation in the laboratory: a comparison of strategies

Several methods for inducing dissociation in the laboratory were examined in a sample of 78 undergraduate students. Participants scoring high or low on the Dissociative Experiences Scale participated in three dissociation challenge conditions: (a) dot-staring task, (b) administration of pulsed photic and audio stimulation and (c) stimulus deprivation. Participants recorded their dissociative experiences both before and after each of the three challenge conditions. Across conditions, high DES participants reported significantly more dissociative sensations than low DES participants, even after controlling for pre-challenge dissociation. Moreover, regardless of DES status, pulsed photo and audio stimulation produced the greatest level of dissociative symptoms. The findings suggest that the induction of dissociative symptoms in a nonclinical sample is easily accomplished in the laboratory and that those who report more dissociative symptoms in their day-to-day life exhibit more pronounced dissociative symptoms when undergoing dissociative challenge in the laboratory. Implications for the study and treatment of dissociative symptoms are discussed.     

Personality correlates of dissociative experiences

This study investigated the prevalence of dissociative experiences in a normal British sample. The Dissociation Experiences Scale of Bernstein and Putnam was used to measure these experiences. The relationship between dissociative experiences and personality variables measured by the Eysenck Personality Questionnaire was a major focus of the study. It was found that the degree of dissociative experiences was related to neuroticism, but not to any other variable.     

Dissociative Experiences and Creativity in Fine Arts Students

Studies on creative personality have revealed that the relationship between personality and creativity remains unclear, and various types of creative thinking have been have been associated with various personality traits. To assess the influence of dissociative experiences on creativity in the context of fine arts education, in which the creative process plays a key role, a sample of fine arts students received a test of creative potential and the dissociative experiences test. The results revealed significant differences in creativity (creative imagination and creative experiences) between students scoring high or low in the number of dissociative experiences. High dissociative experiences scores were associated to high scores in creative imagination and creative experiences, and low scores in dissociative experiences were inversely related to creative imagination and creative experiences. Further studies are required to corroborate these findings.     

Traumatic memories of war veterans: not so special after all

Several authors have argued that traumatic experiences are processed and remembered in a qualitatively different way from neutral events. To investigate this issue, we interviewed 121 Croatian war veterans diagnosed with posttraumatic stress disorder (PTSD) about amnesia, intrusions (i.e., flashbacks and nightmares), and the sensory qualities of their most horrific war memories. Additionally, they completed a self-report scale measuring dissociative experiences. In contrast to what one would expect on the basis of theories emphasizing the special status of traumatic memories, amnesia, and high frequency intrusions were not particularly typical for our sample of traumatized individuals. Moreover, traumatic memories were not qualitatively different from neutral memories with respect to their stability and sensory qualities. The severity of PTSD symptoms was not significantly correlated with dissociative experiences. Our findings do not support the existence of special memory mechanisms that are unique to experiencing traumatic events.     

The relationship between different types of dissociation and psychosis-like experiences in a non-clinical sample

This study investigated whether detachment-type dissociation, compartmentalisation-type dissociation or absorption was most strongly associated with psychosis-like experiences in the general population. Healthy participants (N = 215) were tested with the Dissociative Experiences Scale (DES, for detachment-related dissociative experiences); the Harvard Group Scale of Hypnotic Susceptibility (HGSHS: A, for dissociative compartmentalisation); the Tellegen Absorption Scale (TAS, for non-clinical ‘functional’ dissociative experience); and two measures of psychotic-like experiences, the 21-item Peters et al. Delusions Inventory (PDI-21) and the Cardiff Anomalous Perceptions Scale (CAPS). In multiple regression analyses, DES and TAS but not HGSHS: A scores were found to be significantly associated with PDI-21 and CAPS overall scores. A post hoc hierarchical cluster analysis checking for cluster overlap between DES and CAPS items, and the TAS and CAPS items showed no overlap between items on the DES and CAPS and minimal overlap between TAS and CAPS items, suggesting the scales measure statistically distinct phenomena. These results show that detachment-type dissociation and absorption, but not compartmentalisation-type dissociation are significantly associated with psychosis-like experiences in a non-clinical population.     

What Triggers Abnormal Eating in Bulimic and Nonbulimic Women?

Dissociative experiences and abnormal eating were examined in 92 non-eating-disordered women and 61 age-matched bulimic women. In the non-clinical sample of women, dissociative experiences were associated with abnormal eating attitudes and behavior, even after controlling for other forms of psychopathology; furthermore, dissociation mediated the relationships between abnormal eating and sexual abuse, abnormal eating and emotional distress, and abnormal eating and impulsivity. Analyses using both bulimic women and occasional binge eaters among the controls showed that a combination of reported negative affect and dissociative experiences preceding a binge was associated with the highest levels of abnormal eating. Finally, in both bulimic women and occasional binge eaters, feelings of panic appeared to decrease as a binge episode progressed, whereas, in bulimic women only, dissociative experiences appeared to increase during binge eating. The implications for the role of dissociation in combination with emotional distress in triggering and reinforcing abnormal eating in women are discussed.     

Dissociative alterations in body image among individuals reporting out-of-body experiences: a conceptual replication

A conceptual replication of the link between self-reported dissociative alterations in body-image under experimental conditions and the reporting of prior out-of-body experiences in a recent data set was undertaken. Also examined was whether this relationship would hold for experiences reported during the experimental context and whether it is independent of self-reported New Age belief. Data from mostly undergraduates (N= 40; M age = 33.5, SD = 12.5; 27 women) in a mirror-gazing study were retrospectively analyzed. The 9 individuals who reported prior out-of-body experiences, relative to those 31 who did not, exhibited significantly greater self-reported dissociative alterations in body-image during the mirror-gazing task, even when the influence of scores on New Age belief was controlled for statistically. The same differential relationship was not found between 6 individuals who did and 34 who did not report out-of-body experiences during the task.     

Dissociative disorders in Vietnam combat veterans

A group of Vietnam combat veterans were surveyed to determine the quantity and quality of their dissociative symptoms. The results suggest that the symptoms of post-traumatic stress disorder (PTSD) and dissociative disorders in this group of patients may be much more closely intertwined than we have heretofore considered. Those who suffer from PTSD have a continuum of severity of dissociative symptoms ranging from the frequent experience of a partially forgotten traumatic experience to the rare occurrence of a full blown case of multiple personality disorder (MPD). Most cases of MPD are related to trauma during childhood in environments fraught with extreme ambivalence and victimization, in association with abandonment and betrayal. However, the high frequency of dissociative symptoms and even occasional occurrences of MPD in Vietnam veterans suggests a similarity in the environmental factors associated with the Vietnam war.     

Delayed Bedtimes Are Associated With More Severe Obsessive-Compulsive Symptoms in Intensive Residential Treatment

Delays in behavioral and biological circadian rhythms (e.g., sleep timing, melatonin secretion) are found more frequently in individuals with severe and treatment-resistant obsessive-compulsive disorder (OCD). In recent years, it has been documented that these delays in behavioral and biological circadian rhythms are associated with more severe OCD symptoms and poorer response to some OCD treatments. This study examined self-reported sleep behaviors in individuals taking part in an intensive treatment for OCD and the relations between these and OCD symptoms (both at admission to and discharge from the treatment program). Replicating previous findings in less severe populations, delayed sleep phases were relatively common in this group and later bedtimes were associated with more severe OCD symptoms at admission. Sleep onset latency and sleep duration were not associated with OCD symptom severity at admission. Later bedtimes were not associated with self-reported depression or worry symptom severity. There was no evidence of sleep behaviors affecting change in OCD symptoms from admission to discharge from treatment—however, later bedtimes at admission were associated with more severe OCD symptoms at admission and discharge from treatment. There was no evidence of sleep onset latency or sleep duration having a similar predictive effect. More severe OCD symptoms at admission were also associated with later bedtimes at admission and discharge from treatment. These bidirectional predictive relations between late bedtimes and OCD symptoms were of small effect size but support the potential value of evaluating sleep timing in individuals with severe and/or treatment-resistant OCD.     

Symptom overreporting and dissociative experiences: A qualitative review

We discuss a phenomenon that has received little attention to date in research on dissociative phenomena, namely that self-reports of these phenomena overlap with the tendency to overendorse eccentric items. We review the literature documenting the dissociation-overreporting link and then briefly discuss various interpretations of this link: (1) overreporting is an artifact of measuring dissociative symptoms; (2) dissociative psychopathology engenders overreporting of eccentric symptoms through fantasy proneness or impairments in internal monitoring; (3) an overreporting response style as is evident in malingerers, for example, promotes reports of dissociative symptoms. These three interpretations are not mutually exclusive. Also, the dissociation-overreporting link may have different origins among different samples. Because overreporting may introduce noise in datasets, we need more research specifically aimed at disentangling the dissociation-overreporting link. We suggest various avenues to accomplish this goal.     

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

In recent years, a labile sleep-wake cycle has been implicated as a cause for dissociative experiences, and studies show that dissociation is elevated following sleep deprivation. Dissociative individuals may find it harder to regulate sleepiness in the face of sleep disruption. Although there is significant variability in reactions to sleep deprivation, research on trait predictors is scarce. The present study examined the ability of trait dissociation to prospectively predict sleepiness following sleep loss and recovery sleep. Two high-functioning samples, namely, Remotely Piloted Aircraft officers (N = 29) and Air Force jet pilots (N = 57) completed state and trait questionnaires assessing sleep and dissociation before and after full or partial sleep loss. Dissociative absorption was a consistent predictor of an increase in sleepiness following sleep loss and following recovery sleep, controlling for baseline sleepiness levels. We discuss the findings in light of a difficulty to regulate and monitor consciousness states.     

Self-destructive behavior in patients with dissociative disorders

Highrates of self-injury have been reported in patients with dissociative disorders, yet no prior study has directly compared these patients with other psychiatric patients. The present study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. These patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not dissociate. Results have important implications for understanding the relationship between dissociation, childhood trauma, and self-injury and for assessment and treatment of patients with dissociative disorders.     

Repetitive Thought and Self-Reported Sleep Disturbance

Repetitive thought has been focused upon as a transdiagnostic risk factor for depression, anxiety, and poor physical health. Among the forms of repetitive thought, rumination and worry are considered to play important roles in the onset and maintenance of insomnia. However, there have been few attempts to clarify the similarities, differences, and interaction between the functions of rumination and worry in sleep problems. Furthermore, no study has investigated the prospective relationships between these two forms of repetitive thought and sleep disturbance. In the present study, we examined the prospective associations between repetitive thought and subjective sleep quality, measured by a self-report questionnaire. A total of 208 undergraduates participated in a 2-wave longitudinal survey with an interval of 3 weeks between assessments. Hierarchical multiple regression analyses showed that baseline rumination predicted reduction in the follow-up assessment of subjective sleep quality, controlling for levels of depressive and anxious symptoms. This main effect of rumination was qualified by the levels of worry; for individuals with higher levels of worry, rumination was associated with greater reduction in subjective sleep quality. These results suggest that both rumination and worry have unique associations with sleep and that their interaction is especially important in sleep problems.     

Naturalistic Partial Sleep Deprivation Leads to Greater Next-Day Anxiety: The Moderating Role of Baseline Anxiety and Depression

The detrimental effects of insufficient sleep on emotional functioning have been well established. Total sleep deprivation usually leads to increased anxiety and depressive symptoms the following day. However, no study has yet examined the relationships between unmanipulated partial sleep deprivation and next-day symptoms of anxiety and depression in everyday life, which this study sought to characterize. Participants (N = 94) completed daily diary surveys twice per day for 2 weeks without instructions to alter their sleep in any way. Nights of spontaneous, naturally occurring partial sleep deprivation were followed by increased levels of self-reported symptoms of anxious arousal the next day, but were unrelated to next-day symptoms of anhedonic depression or general distress. The relationship between partial sleep deprivation and next-day anxious arousal was found to be moderated by both baseline depressive symptoms and anxiety such that individuals reporting higher levels of depression or anxiety at baseline showed relatively greater increases in symptoms of anxiety following partial sleep deprivation. These results suggest that partial sleep deprivation occurring in everyday life can lead to higher next-day levels of anxious arousal, a relationship that is particularly deleterious for individuals with higher overall levels of anxiety or depressive symptoms.