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

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.

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.

A novel ego dissolution scale: A construct validation study

Ego dissolution (i.e., ego loss, ego disintegration, ego death, or self-loss) is a conscious state marked by a loss or diminution of one's sense of self and a lack of first-person experience. We developed a novel, valid, and internally consistent ego dissolution scale to both (a) assess trait-like aspects of ego dissolution, which have received scant attention to date, and (b) facilitate future research in a variety of contexts (e.g., personality, psychopathology, substance use/psychedelics, contemplative practices). We determined that the 10-item Ego Dissolution Scale (EDS; Cronbach's α = 0.80) and its identified subfactors of Ego-Loss (Cronbach's α = 0.84) and Unity (Cronbach's α = 0.75) were internally consistent, possessed strong convergent (e.g., depersonalization/derealization, mysticism, unusual experiences) and discriminant validity (e.g., neuroticism, social desirability). We found ego dissolution and dissociation to be empirically related yet discriminable on a statistical basis.

The hypnagogic state: A brief update

The hypnagogic state refers to a transitional stage between wakefulness and sleep, in which sensory perceptions can be experienced. In this review, we compile and discuss the recent scientific literature on hypnagogia research regarding the future directions proposed by Schacter (1976; Psychological Bulletin, 83, 452). After a short introduction discussing the terminology used in hypnagogia research and the differentiation of hypnagogic states with other related phenomena, we review the reported prevalence of hypnagogic states. Then, we evaluate the six future directions suggested by Schacter and we propose three further future directions. First, a better understanding of the emotional quality of hypnagogic states is needed. Second, a better understanding of why hypnagogic states occur so frequently in the visual and kinaesthetic modalities is needed. Lastly, a better understanding of the purpose of hypnagogic states is needed. In conclusion, research has made great progress in recent years, and we are one step closer to demystifying the hypnagogic state.

Nightmare distress is related to traumatic childhood experiences, critical life events and emotional appraisal of a dream rather than to its content

Nightmares are a substantial burden for sleep quality. Previous studies have shown that traumatic experiences can increase the probability of nightmares, and also waking-life distress can enhance this effect. There is evidence that the intensity of negative dream emotions is more responsible for rating a dream as a nightmare than threatening dream contents. However, there is still a lack of research concerning effects on nightmare distress. We hypothesise that traumatic childhood experiences (such as emotional abuse, obtained by the Childhood Trauma Questionnaire), critical life events (obtained by the Social Readjustment Rating Scale) and threatening dream contents are associated with nightmare distress. A sample of N = 103 participants kept a dream diary over 28 consecutive days. About 60% of the sample were frequent nightmare dreamers. The participants recorded their violent dream contents and dream emotions in their diary. To predict nightmare distress, regression models were constructed; nightmare distress was measured with the Nightmare Distress Questionnaire. Results showed that emotional abuse in childhood and critical life events predicted nightmare distress. Moreover, violent dream contents were associated with nightmare distress but, after we controlled for nightmare frequency and the intensity of negative dream emotions, the significant impact of violent dream contents decreased. The results suggest that the emotional appraisal of a dream has a substantial influence on nightmares in addition to traumatic childhood experiences and critical life events.

Schizotypy unfolding into the night? Schizotypal traits and daytime psychotic-like experiences predict negative and salient dreams

Symptoms of insomnia and frequent nightmares are prevalent in psychotic disorders, and are associated with psychotic-like experiences (PLEs) in the non-clinical population. Whereas the role of impaired sleep in psychosis was extensively examined by longitudinal and interventional approaches, studies on the association between psychosis and dream quality are scarce, and mainly cross-sectional. We conducted a three-week long prospective study in a group of healthy adults (N = 55), assessed schizotypal traits, daily PLEs, and the emotional quality of dreams recalled in the morning (N = 490). We extracted the latent factors of schizotypal traits and dream emotions, and examined the predictive value of trait-and state-like variables on day-to-day reports of PLEs and dream quality. PLEs reported in the evening predicted emotionally more negative and salient dream reports the following morning. On the other hand, the quality of dreams were not predictive of PLEs reported later during the day. Schizotypal personality traits were differentially associated with dream quality: Introvertive Anhedonia, Cognitive Disorganization, and General-Disorganized schizotypy were linked to more negative dream valence, whereas Unusual Experiences were associated with more salient dreams. Our findings highlight the relevance of the multidimensional nature of schizotypal traits, the role of different facets of schizotypy in daytime and nocturnal mental experiences, and the day-to-day associations between PLEs and dream affect. GENERAL SCIENTIFIC SUMMARIES (GSS): The aim of the study was to examine the temporal associations between psychotic-like experiences and dream emotions, taking into account the trait factors of schizotypy. Psychotic-like experiences during the evening hours predicted reporting more negative and salient dreams the following morning, and schizotypal personality traits were differentially associated with the dimensions of dream emotions.

The Role of Stress and Cognitive Absorption in Predicting Social Network Addiction

Nowadays, the use of social networks (SNs) is pervasive and ubiquitous. Among other things, SNs have become a key resource for establishing and maintaining personal relationships, as further demonstrated by the emergence of the pandemic. However, easy access to SNs may be a source of addictive behaviour, especially among the younger population. The literature highlights various psychological and physiological factors as possible predictors of vulnerability to SN addiction. This paper explores the joint effects of stress level and cognitive absorption, in the form of temporal dissociation while on SNs, on the addiction of university students to SNs. Here, 312 participants were involved in an online survey. About 14% of the sample presented a risk for SN addiction. Moreover, it was found that stress level predicted SN addiction both directly and indirectly through the effect of individual temporal dissociation, as experienced during SN usage. These results suggest a significant role of perceived stress level on addiction risk, while also pointing out additional vulnerability to SN addiction for cognitive profiles that are relatively more prone to temporal dissociation while online.

What goes around comes around: Nightmares and daily stress are bidirectionally associated in nurses

Nurses may experience frequent nightmares due to stressful work environments. Nightmares may also exacerbate stress among nurses, although this has yet to be tested empirically. We examined daily bidirectional associations between stress severity and nightmares, and moderation by post-traumatic stress disorder (PTSD) symptoms. 392 nurses (92% female; 78% White) completed 14 days of sleep diaries to assess previous-day stress severity and nightmare occurrence and severity. PTSD symptoms were assessed at baseline. Multilevel models were used to examine bidirectional, within-person associations between daily stress and nightmares, and cross-level moderation by baseline PTSD symptoms. 47.2% of nurses reported at least one nightmare across the two weeks. Days with greater stress were associated with higher odds of experiencing a nightmare (OR = 1.22, p = 0.001), as well as greater nightmare severity (b = 0.09, p = 0.033). Nightmare occurrence was associated with greater next-day stress severity (b = 0.15, p < 0.001). Daily stress and nightmare associations were similar for those with and without PTSD symptoms. Nightmares and stress may occur in a bidirectional fashion. Nurses face intense occupational demands and frequent exposure to potentially traumatic events. Studies should explore whether targeting nightmares and stress may improve nurses' health and well-being.

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.

The Effects of Sleep Quality on Dream and Waking Emotions

Despite the increasing interest in sleep and dream-related processes of emotion regulation, their reflection into waking and dream emotional experience remains unclear. We have previously described a discontinuity between wakefulness and dreaming, with a prevalence of positive emotions in wakefulness and negative emotions during sleep. Here we aim to investigate whether this profile may be affected by poor sleep quality. Twenty-three ‘Good Sleepers’ (GS) and 27 ‘Poor Sleepers’ (PS), identified through the Pittsburgh Sleep Quality Index (PSQI) cut-off score, completed three forms of the modified Differential Emotions Scale, assessing, respectively, the frequency of 22 emotions over the past 2 weeks, their intensity during dreaming and during the previous day. The ANOVA revealed a different pattern of emotionality between groups: GS showed high positive emotionality in wakefulness (both past 2 weeks and 24 h) with a significant shift to negative emotionality in dreams, while PS showed evenly distributed emotional valence across all three conditions. No significant regression model emerged between waking and dream affect. In the frame of recent hypotheses on the role of dreaming in emotion regulation, our findings suggest that the different day/night expression of emotions between groups depends on a relative impairment of sleep-related processes of affect regulation in poor sleepers. Moreover, these results highlight the importance of including sleep quality assessments in future dream studies.

Relationships between Dream and Previous Wake Emotions Assessed through the Italian Modified Differential Emotions Scale

Despite the increasing interest in sleep and dream-related processes of emotion regulation, their reflection into wake and dream emotional experience remains unclear. Here, we aimed to assess dream emotions and their relationships with wake emotions through the modified Differential Emotions Scale (Fredrickson, 2003), which includes a broad array of both positive and negative emotions. The scale has been first validated on 212 healthy Italian participants, in two versions: a WAKE-2wks form, assessing the frequency of 22 emotions over the past 2 weeks, and a WAKE-24hr form, assessing their intensity over the past 24 h. Fifty volunteers from the wider sample completed the WAKE-24hr mDES for several days until a dream was recalled, and dream emotions were self-reported using the same scale. A bifactorial structure was confirmed for both mDES forms, which also showed good validity and reliability. Though Positive and Negative Affect (average intensity of positive and negative items, PA, and NA, respectively) were balanced in dreams, specific negative emotions prevailed; rmANOVA showed a different pattern (prevalence of PA and positive emotions) in wake (both WAKE-2wks and WAKE-24hr), with a decrease of PA and an increase of NA in the dream compared to previous wake. No significant regression model emerged between waking and dream affect, and exploratory analyses revealed a stable proportion of PA and NA (with prevailing PA) over the 3 days preceding the dream. Our findings highlight a discontinuity between wake and dream affect and suggest that positive and negative emotions experienced during wake may undertake distinct sleep-related regulation pathways.

Predicting the affective tone of everyday dreams: A prospective study of state and trait variables

Although emotions are reported in a large majority of dreams, little is known about the factors that account for night-to-night and person-to-person variations in people’s experience of dream affect. We investigated the relationship between waking trait and state variables and dream affect by testing multilevel models intended to predict the affective valence of people’s everyday dreams. Participants from the general population completed measures of personality and trauma history followed by a three-week daily journal in which they noted dream recall, valence of dreamed emotions and level of perceived stress for the day as well as prior to sleep onset. Within-subject effects accounted for most of the explained variance in the reported valence of dream affect. Trait anxiety was the only variable that significantly predicted dream emotional valence at the between-subjects level. In addition to highlighting the need for more fine-grained measures in this area of research, our results point to methodological limitations and biases associated with retrospective estimates of general dream affect and bring into focus state variables that may best explain observed within-subject variance in emotions experienced in everyday dreams.

Examining the relationship between higher educational attainment, trauma symptoms, and internalizing behaviors in child sexual abuse survivors

The trauma symptoms of child sexual abuse (CSA) survivors don't end with the abuse, or even with the advent of adulthood. Instead, these symptoms can persist into all the realms of a survivor's life, including education, which sets the foundation for career advancement. This retrospective study of adult survivors of childhood sexual abuse (n=260) examined the relationships between trauma symptoms, dissociation, dissociative amnesia, anxiety, depression, sleep problems and higher education attainment. The purpose of this study was to determine if these factors are associated with higher education completion for childhood sexual abuse (CSA) survivors. Linear regressions and ANOVAs suggest that many of these variables are significantly associated with survivors' educational trajectory, and multiple linear regressions show that trauma symptoms (as measured by the Trauma Symptom Checklist-40), caregivers' education levels, and age at onset of abuse are significant predictors of decreased education levels. This information can provide insight into additional risk and protective factors for CSA survivors in order to enhance acute and long-term management of trauma symptoms to increase levels ofattainment of higher education.

Lucid Dreaming: Intensity, But Not Frequency, Is Inversely Related to Psychopathology

Lucid dreaming (LD) is awareness that one is dreaming, during the dream state. However, some define and assess LD relying also on controlling dream events, although control is present only in a subset of lucid dreams. LD has been claimed to represent well-being, and has even been used as a therapeutic agent. Conversely, LD is associated with mixed sleep-wake states, which are related to bizarre cognitions, stress, and psychopathology, and have been construed as arousal permeating and disrupting sleep. We propose that previous conflicting findings regarding relations between LD and both psychopathology and well-being, stem from the non-differentiated assessment of frequency and control. The present study aimed to develop an expansive measure of several LD characteristics (the Frequency and Intensity Lucid Dream questionnaire; FILD), and explore their relations with symptomatology. Undergraduate students (N = 187) self-reported trait LD, psychopathology (depression, anxiety, obsessive-compulsive symptoms, dissociation, and schizotypy), stress, and sleep problems; 2 months later, a subsample (n = 78) reported psychopathology again, and also completed a dream diary each morning for 14 days. Preliminary evidence supports the reliability and validity of the FILD. Items converged into four domains: frequency, intensity (e.g., control, activity, certainty of dreaming), emotional valence, and the use of induction techniques. We report an optimal frequency cutoff score to identify those likely to experience LD within a 2-week period. Whereas LD frequency was unrelated to psychopathology, LD intensity, and positive LD emotions, were inversely associated with several psychopathological symptoms. Use of deliberate induction techniques was positively associated with psychopathology and sleep problems. Additionally, we demonstrated directionality by employing a prospective-longitudinal design, showing that deliberate LD induction predicted an increase in dissociation and schizotypy symptoms across 2 months. We conclude that lucidity should not be considered as necessarily suggestive of well-being; LD may be positive or negative, depending on lucidity characteristics. Additionally, deliberate LD induction may harbor negative long-term risk.

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.

The Association between Sleep and Theory of Mind in School Aged Children with ADHD

Theory of Mind (ToM) is defined as the ability to infer a range of internal mental states of others, including beliefs, intentions, desires, and emotions. These abilities are associated with children’s ability to socialize effectively with peers. ToM impairments are associated with peer rejection and psychiatric disorders such as Attention-Deficit/Hyperactivity Disorder (ADHD). Previous studies have found poor sleep negatively impacts executive functioning (EF) and emotional information processing, which are essential for the effective use of ToM. Youth with ADHD have EF deficits and sleep problems. However, the relationship between sleep, executive functioning, and ToM in children with ADHD has not been studied. In this review, we propose that the poor social and interpersonal skills characterizing individuals with ADHD could be explained by the impact of poor sleep on the emotional and cognitive mechanisms underlying ToM.

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.

School start times for adolescents

The American Academy of Pediatrics recognizes insufficient sleep in adolescents as an important public health issue that significantly affects the health and safety, as well as the academic success, of our nation's middle and high school students. Although a number of factors, including biological changes in sleep associated with puberty, lifestyle choices, and academic demands, negatively affect middle and high school students' ability to obtain sufficient sleep, the evidence strongly implicates earlier school start times (ie, before 8:30 am) as a key modifiable contributor to insufficient sleep, as well as circadian rhythm disruption, in this population. Furthermore, a substantial body of research has now demonstrated that delaying school start times is an effective countermeasure to chronic sleep loss and has a wide range of potential benefits to students with regard to physical and mental health, safety, and academic achievement. The American Academy of Pediatrics strongly supports the efforts of school districts to optimize sleep in students and urges high schools and middle schools to aim for start times that allow students the opportunity to achieve optimal levels of sleep (8.5-9.5 hours) and to improve physical (eg, reduced obesity risk) and mental (eg, lower rates of depression) health, safety (eg, drowsy driving crashes), academic performance, and quality of life.

Night-time experiences and daytime dissociation: a path analysis modeling study

Dissociative symptoms may be the by-products of a labile sleep-wake cycle (Koffel and Watson, 2009a). This may help to explain why dissociation overlaps with fantasy proneness and cognitive failures. Using path analysis, we tested to what extent data gathered in a nonclinical, predominantly female sample (N=139) supported two conceptual models. The first model assumes that unusual sleep experiences increase fantasy proneness and cognitive failures, which in turn encourage trait dissociation and reports of trauma. The second model assumes that trauma leads to dissociative experiences both directly and through its influence on sleep. In this cross-sectional design, the data were reasonably well described by both models. Importantly, in both models, unusual sleep experiences serve as antecedents of trait dissociation. Our analysis underlines the importance of unusual sleep experiences and may inspire treatment intervention focusing on sleep normalization.

Thematic and content analysis of idiopathic nightmares and bad dreams

STUDY OBJECTIVES

To conduct a comprehensive and comparative study of prospectively collected bad dream and nightmare reports using a broad range of dream content variables.

DESIGN

Correlational and descriptive.

SETTING

Participants' homes.

PARTICIPANTS

Three hundred thirty-one adult volunteers (55 men, 275 women, 1 not specified; mean age = 32.4 ± 14.8 y).

INTERVENTIONS

N/A.

MEASUREMENT AND RESULTS

Five hundred seventy-two participants kept a written record of all of their remembered dreams in a log for 2 to 5 consecutive weeks. A total of 9,796 dream reports were collected and the content of 253 nightmares and 431 bad dreams reported by 331 participants was investigated. Physical aggression was the most frequently reported theme in nightmares, whereas interpersonal conflicts predominated in bad dreams. Nightmares were rated by participants as being substantially more emotionally intense than were bad dreams. Thirty-five percent of nightmares and 55% of bad dreams contained primary emotions other than fear. When compared to bad dreams, nightmares were more bizarre and contained substantially more aggressions, failures, and unfortunate endings.

CONCLUSIONS

The results have important implications on how nightmares are conceptualized and defined and support the view that when compared to bad dreams, nightmares represent a somewhat rarer-and more severe-expression of the same basic phenomenon.

The effects of poor sleep on cognitive, affective, and physiological responses to a laboratory stressor

BACKGROUND

Recent research suggests that poor sleep may be associated with altered stress regulation.

PURPOSE

This study aims to examine the associations between prior-night and prior-month sleep measures and affective, cognitive, and physiological responses to a laboratory stressor.

METHODS

Ninety-eight (50 % female) young adults completed measures of sleep quality in the context of a laboratory stress study. Measures included positive (PA) and negative affects (NA) and blood pressure (BP) reactivity, as well as change in pre-sleep arousal.

RESULTS

Prior-month poor sleep quality and sleep disturbances predicted dampened BP reactivity. Both prior-night and prior-month sleep quality predicted greater decrease in PA. Sleep-associated monitoring predicted NA reactivity and prolonged cognitive and affective activation. Prior-month sleep continuity predicted greater cognitive pre-sleep arousal change, and prior-month sleep quality, daytime dysfunction, and disturbances predicted prolonged cognitive and affective activation.

CONCLUSION

Findings suggest that inadequate sleep confers vulnerability to poor cognitive, affective, and physiological responses to stress.

Dissociative symptoms and sleep parameters--an all-night polysomnography study in patients with insomnia

BACKGROUND

Dissociative disorders encompass a range of symptoms varying from severe absent-mindedness and memory problems to confusion about one's own identity. Recent studies suggest that these symptoms may be the by-products of a labile sleep-wake cycle.

METHODS

In the current study, we explored this issue in patients suffering from insomnia (N=46). We investigated whether these patients have raised levels of dissociative symptoms and whether these are related to objective sleep parameters. Patients stayed for at least one night in a specialized sleep clinic, while sleep EEG data were obtained. In addition, they completed self-report measures on dissociative symptoms, psychological problems, and sleep characteristics.

RESULTS

Dissociative symptom levels were elevated in patients suffering from insomnia, and were correlated with unusual sleep experiences and poor sleep quality. Longer REM sleep periods and less time spent awake during the night were predictive of dissociation.

CONCLUSIONS

This is the first study to show that insomnia patients have raised dissociative symptom levels and that their dissociative symptoms are related to objective EEG parameters. These findings are important because they may inspire sleep-related treatment methods for dissociative disorders.

Fragmented Sleep, Fragmented Mind

In psychopathology, dissociation typically refers to a disturbance in the normal integration of thoughts, feelings, and experiences into consciousness and memory. In this article, we review the literature on how sleep disturbances relate to dissociative symptoms and memory failure. We contend that this body of research offers a fresh perspective on dissociation. Specifically, we argue that dissociative symptoms are associated with a labile sleep–wake cycle, in which dreamlike mentation invades the waking state, produces memory failures, and fuels dissociative experiences. The research domain of sleep and dissociation can accommodate the dominant idea in the clinical literature that trauma is the distal cause of dissociation, and it holds substantial promise to inspire new treatments for dissociative symptoms (e.g., interventions that focus on normalization of the sleep-wake cycle). We conclude with worthwhile paths for further investigations and suggest that the sleep–dissociation approach may help reconcile competing interpretations of dissociative symptoms.