Measuring nightmare and bad dream frequency: impact of retrospective and prospective instruments

Dreaming for two: A systematic review of mental sleep activity during pregnancy

Changes in sleep and dreams are often observed during pregnancy. Dreaming may represent privileged access to the inner world of individuals, providing relevant information about their well-being. For this reason, a growing but heterogeneous literature has investigated dream experiences of pregnant women. The present paper aimed to systematically review the available evidence on the relationship between pregnancy and oneric activity, focusing on dream and nightmare frequency, dream contents, and emotional features. Moreover, dream changes between pre-partum and post-partum periods and the impact of previous pregnancy-related adverse events on dreaming have been summarized. Overall, 17 studies have been examined. The reviewed evidence suggests that women tend to have an abundant production of dreams and nightmares during pregnancy, and some results support the view that a high rate of dream recall is associated with poor sleep quality. Most studies have shown a high presence of pregnancy-related dream content, likely reflecting waking experiences and concerns. Additionally, dreaming may promote psychological preparation and activation of functional coping strategies to face life changes after childbirth.

Nightmares share genetic risk factors with sleep and psychiatric traits

Nightmares are vivid, extended, and emotionally negative or negative dreams that awaken the dreamer. While sporadic nightmares and bad dreams are common and generally harmless, frequent nightmares often reflect underlying pathologies of emotional regulation. Indeed, insomnia, depression, anxiety, or alcohol use have been associated with nightmares in epidemiological and clinical studies. However, the connection between nightmares and their comorbidities are poorly understood. Our goal was to examine the genetic risk factors for nightmares and estimate correlation or causality between nightmares and comorbidities. We performed a genome-wide association study (GWAS) in 45,255 individuals using a questionnaire-based assessment on the frequency of nightmares during the past month and genome-wide genotyping data. While the GWAS did not reveal individual risk variants, heritability was estimated at 5%. In addition, the genetic correlation analysis showed a robust correlation (rg > 0.4) of nightmares with anxiety (rg = 0.671, p = 7.507e-06), depressive (rg = 0.562, p = 1.282e-07) and posttraumatic stress disorders (rg = 0.4083, p = 0.0152), and personality trait neuroticism (rg = 0.667, p = 4.516e-07). Furthermore, Mendelian randomization suggested causality from insomnia to nightmares (beta = 0.027, p = 0.0002). Our findings suggest that nightmares share genetic background with psychiatric traits and that insomnia may increase an individual's liability to experience frequent nightmares. Given the significant correlations with psychiatric and psychological traits, it is essential to grow awareness of how nightmares affect health and disease and systematically collect information about nightmares, especially from clinical samples and larger cohorts.

An observatory on changes in dreaming during a pandemic: a living systematic review (part 1)

A 'new' way of dreaming has emerged during the pandemic, enhancing the interest of psychological literature. Indeed, during the years of the spread of coronavirus disease 2019 (COVID-19), many studies have investigated dream-related phenomena and dreaming functions. Considering the constant and rapid emergence of new results on this topic, the main aim of this study was to create an 'observatory' on the short- and long-term consequences of the COVID-19 pandemic on dreaming, by means of a living systematic review. The baseline results are presented, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines, to identify and discuss existing studies about dreams and dreaming during the COVID-19 pandemic published until February 2022. Web of Science, Embase, EBSCO, and PubMed were used for the search strategy, yielding 71 eligible papers included in the review. Our results show: (a) a more intense oneiric activity during lockdown; (b) changes in dreaming components (especially dream-recall and nightmare frequency); (c) a particular dreaming scenario ('pandemic dreams'); (d) an alteration of the dreaming-waking-life continuum and a specific function of dreaming as emotional regulator. Findings suggest that monitoring changes in dreaming provides important information about psychological health and could also contribute to the debate on the difficulties of dreaming, as well as sleeping, in particular during and after a period of 'collective trauma'.

A systematic review of dreams and nightmares recall in patients with rapid eye movement sleep behaviour disorder

Rapid eye movement (REM) sleep behaviour disorder is a REM sleep parasomnia characterised by the loss of the physiological muscle atonia during REM sleep, resulting in dream enactment behaviours that may cause injuries to patients or their bed partners. The nocturnal motor episodes seem to respond to the dream contents, which are often vivid and violent. These behavioural and oneiric features make the REM sleep behaviour disorder a potential model to study dreams. This review aims to unify the literature about dream recall in REM sleep behaviour disorder as a privileged approach to study dreams, systematically reviewing studies that applied retrospective and prospective experimental designs to provide a comprehensive overview of qualitative and quantitative aspects of dream recall in this REM sleep parasomnia. The present work highlights that the study of dreaming in REM sleep behaviour disorder is useful to understand unique aspects of this pathology and to explore neurobiological, electrophysiological, and cognitive mechanisms of REM sleep and dreaming.

The route to recall a dream: theoretical considerations and methodological implications

The goal of this paper is to shed new light on the relation between dream recall and dream experiences by providing a thorough analysis of the process that leads to dream reports. Three crucial steps of this process will be distinguished: dream production (the generation of a conscious experience during sleep), dream encoding (storing a trace of this experience in memory) and dream retrieval (accessing the memory trace upon awakening). The first part of the paper will assess how major theories think about the relationship between dream reports and these distinct steps. The second part will systematise how trait and state factors affecting dream recall-given different theoretical assumptions-might interact with dream production, encoding and retrieval. Understanding how the distinct steps of dream recall can be modulated by different factors is crucial for getting a better grip on how to acquire information about these steps empirically and for drawing methodological conclusions with regard to the tools dream research relies on to collect subjective data about dream experiences. The third part of the paper will analyse how laboratory reports, logs and retrospective scales interact with the different factors that affect the distinct steps leading to dream reports and will argue that prospective methods provide more direct access to data regarding dream production and encoding than retrospective methods, which-due to their inability to provide systematic control over the factors affecting the retrieval stage-screen-off the variability in the production and the encoding of dreams.

Dreaming during the COVID-19 pandemic: A narrative review

According to several influential models, dreams can be affected by state- and trait-like factors, sleep features, and diurnal experiences. The COVID-19 pandemic globally affected daily habits, emotional experiences, and sleep. Previous studies suggested an influence of collective traumatic events on dreaming. Starting from these premises, several studies assessed the effect of the pandemic on dreams. This paper aims to review findings concerning the oneiric activity during the COVID-19 pandemic. We report pandemic-related changes in dreams and nightmares, and we consider the possible factors associated with dreaming. Moreover, we provide results about changes in the oneiric activity in different phases of the pandemic. The reviewed findings suggest a pandemic-related enhancement of dream and nightmare frequency, emotional intensity, and distressing contents, modulated by modifications in restrictive measures and associated with diurnal experiences, emotional status, and sleep pattern. We highlight several methodological issues and a large heterogeneity in the present literature, limiting results’ generalizability. However, we provide possible interpretations of the most consistent findings in light of the main theoretical frameworks about dreaming.

What about dreams? State of the art and open questions

Several studies have tried to identify the neurobiological bases of dream experiences, nevertheless some questions are still at the centre of the debate. Here, we summarise the main open issues concerning the neuroscientific study of dreaming. After overcoming the rapid eye movement (REM) ‐ non‐REM (NREM) sleep dichotomy, investigations have focussed on the specific functional or structural brain features predicting dream experience. On the one hand, some results underlined that specific trait‐like factors are associated with higher dream recall frequency. On the other hand, the electrophysiological milieu preceding dream report upon awakening is a crucial state‐like factor influencing the subsequent recall. Furthermore, dreaming is strictly related to waking experiences. Based on the continuity hypothesis, some findings reveal that dreaming could be modulated through visual, olfactory, or somatosensory stimulations. Also, it should be considered that the indirect access to dreaming remains an intrinsic limitation. Recent findings have revealed a greater concordance between parasomnia‐like events and dream contents. This means that parasomnia episodes might be an expression of the ongoing mental sleep activity and could represent a viable direct access to dream experience. Finally, we provide a picture on nightmares and emphasise the possible role of oneiric activity in psychotherapy. Overall, further efforts in dream science are needed (a) to develop a uniform protocol to study dream experience, (b) to introduce and integrate advanced techniques to better understand whether dreaming can be manipulated, (c) to clarify the relationship between parasomnia events and dreaming, and (d) to determine the clinical valence of dreams.

Adapting to a major crisis: Sleep and mental health during two lockdowns

The present study aimed at investigating the impact of the pandemic on sleep and mental health in healthy individuals (n = 78) as well as in psychiatric outpatients (n = 30) during the first and the second lockdown in Germany, in March and November 2020, respectively. Sleep quality and anxiety were worse in patients compared with controls during both lockdowns. Further, patients but not controls exhibited higher levels of depression and overall psychiatric symptomatology during the second lockdown. No differences were found in the perceived threat evoked by the pandemic. The data suggest that healthy individuals adapt flexibly to the difficult situation over the time course of the pandemic, whereas psychiatric patients seem to get worse, indicating difficulties in adapting to stressful circumstances.

Non-Constructive Ruminations, Insomnia and Nightmares: Trio of Vulnerabilities to Suicide Risk

OBJECTIVE

Nightmare distress, nightmare frequency and anxiety are related to suicidal risk. Ruminations are a factor maximizing the risk of suicide. Research has identified two types of ruminations: constructive ruminations and non-constructive ruminations. As per our knowledge, no study has verified the links between non-constructive ruminations and sleep disorders and their role in the development of suicidal risk. We aimed to highlight the impact of non-constructive ruminations on nightmares, anxiety and insomnia in the development of suicidal risk.

METHODS

A total of 429 French participants responded to an anonymous online survey using the Qualtrics^® software. To assess variables, we used the Mini Cambridge-Exeter Repetitive Thought Scale, the Suicide Behaviors Questionnaire-Revised, the Nightmare Distress Questionnaire, the Beck Anxiety Inventory, and the Sleep Condition Indicator. Nightmare frequency was assessed by subjective evaluation through a question. We tested the possible effects of confounding variables such as age, gender, marital status and depression (Beck Depression Inventory-II).

RESULTS

Nightmare frequency was found to mediate the link between anxiety and suicidal risk (32.9%). Nightmare distress (37%) and non-constructive thoughts (48%) were also seen to mediate this link. Additionally, we found a moderating effect of insomnia on the link between non-constructive ruminations and suicidal risk (Z = 7.42, p < 0.001).

CONCLUSION

Our results showed that the frequency of nightmares, distress and non-constructive ruminations are closely related to suicidal risk. The interoperability between these elements and insomnia has thus been newly explored. The processes related to nightmares and suicidal risk as well as the underlying cognitive processes between sleep disorders and suicidal risk have been shed light upon.

Gender Differences in Childhood Maltreatment: A Comparative Study of Nightmare Sufferers and Non-sufferers

Child maltreatment has been identified as a significant problem, both within India and outside. According to UNICEF, over the last decade, there has been a growing recognition about this, but the problem has remained unresolved largely due to being underreported and undocumented. Previous research in this area has reported inconsistent gender differences across the world. Besides, there are shreds of evidence to suggest that childhood maltreatment would be associated with nightmares later in life, but a handful of studies exist in this context. Moreover, there is a paucity of research concerning the interaction effect of gender and group (nightmare sufferer vs non-sufferer) on childhood maltreatment. Owing to the insufficient research and inconsistent findings, the present study aimed to investigate gender differences in childhood maltreatment among nightmare sufferers as compared to non-sufferers. A total of 120 participants were selected from New Delhi. The results of two-way ANOVA suggest that the nightmares later in life would be associated with the abuse and neglect experienced during childhood as nightmare sufferer group reported having higher rates of child abuse and neglect than non-sufferers. It also suggests that male participants in general experience childhood maltreatment more than females; however, emotional abuse was experienced by males only if they belonged to the nightmare sufferer group.

Treatment of Sleep Comorbidities in Posttraumatic Stress Disorder

Purpose of the review

Sleep disturbances, insomnia and recurrent nightmares in particular, are among the most frequently endorsed symptoms of posttraumatic stress disorder (PTSD). The present review provides a summary of the prevalence estimates and methodological challenges presented by sleep disturbances in PTSD, highlights the recent evidence for empirically supported psychotherapeutic and pharmacological interventions for comorbid sleep disturbances implicated in PTSD, and provides a summary of recent findings on integrated and sequential treatment approaches to ameliorate comorbid sleep disturbances in PTSD.

Recent Findings

Insomnia, recurrent nightmares, and other sleep disorders are commonly endorsed among individuals with PTSD; however, several methodological challenges contribute to the varying prevalence estimates. Targeted sleep-focused therapeutic interventions can improve sleep symptoms and mitigate daytime PTSD symptoms. Recently, attention has focused on the role of integrated and sequential approaches, suggesting that comprehensively treating sleep disturbances in PTSD is likely to require novel treatment modalities.

Summary

Evidence is growing on the development, course, and treatment of comorbid sleep disturbances in PTSD. Further, interventions targeting sleep disturbances in PTSD show promise in reducing symptoms. However, longitudinal investigations and additional rigorous controlled trials with diverse populations are needed to identify key features associated with treatment response in order to alleviate symptoms.

Pandemic dreams: quantitative and qualitative features of the oneiric activity during the lockdown due to COVID-19 in Italy

Objective

The lockdown due to COVID-19 pandemic had a strong impact on daily habits, emotional experience, mental health and sleep. A large body of evidence suggests that dreams are affected by both waking experiences and sleep pattern. In this view, the lockdown should have induced intense modifications in dreaming activity. The aim of the study was to assess dream features during the lockdown in Italy.

Methods

We used an online survey to collect self-reported demographic, clinical, sleep and dream data. Our sample included 1091 participants.

Results

Results point to an increased dream frequency, emotional load, vividness, bizarreness and length during the lockdown, compared to a pre-lockdown period. Higher dream frequency and specific qualitative features were found in females and subjects with poor sleep quality, nocturnal disruptive behaviours and depressive symptoms. Most of the dream features assessed during the lockdown were predicted by age, gender, depressive symptoms, presence/absence of other people at home, and territorial area. A specific focus on sleep features revealed that sleep duration and several sleep quality indexes were the best predictors of dream variables. During the lockdown, dreams were also characterized by increased negative emotions, which were particularly frequent in females, younger adults, and participants with poor sleep quality, nocturnal disruptive behaviours, anxiety and depressive symptoms.

Conclusions

Our results confirm the hypothesis of a strong influence of the pandemic on dreaming, supporting both the hypothesis of continuity between wake and sleep mental processes and the view of a crucial influence of sleep quality and duration on dreaming activity.

Sleep Disturbances and Suicidal Behavior

Sleep disturbances, particularly insomnia, nightmares, and excessive daytime sleepiness (EDS), are significant, proximal, and modifiable risk factors for suicidal ideation and behaviors (SIB) and could be targeted for preventative interventions. In this chapter, we review the evidence supporting the association of insomnia, nightmares, and EDS with SIB. We also describe these sleep disturbances in the general population, as well as their association with psychiatric disorders. A PubMed search was conducted to identify the relevant literature. Insomnia is very frequent across mental disorders, but SIB patients are particularly exposed. Specific interventions focused on insomnia are useful in contending suicidal ideation. Nightmares seem to constitute an independent risk factor for SIB, beyond insomnia, particularly in young people and when experienced frequently. The evidence regarding the association of EDS and SIB is less clear and probably explained by the reduction of health-related quality of life and comorbid depression. The mechanisms underlying the relationship between sleep disturbances and SIB as well as the role of potential confounders and future perspectives in this field are also discussed.

Bad dreams, bedtime anxiety, and trait anxiety in school-aged children

Background and objectives

Occasional nightmares (distressing dreams that awaking the sleeper) and bad dreams (distressing dreams that do not awaking the sleeper) are very common in children and adolescents. About 5% of children experience frequent nightmares (once a week or more often) and the question arises as to what factors contribute to significant nightmare distress which is basic for diagnosing a nightmare disorder.

Materials and methods

A sample of 624 school-aged children (10–16 years; mean age 12.45 ± 1.33 years) completed a dream questionnaire and an anxiety inventory.

Results

About 11% of the participants reported frequent bad dreams; 3.5% reported frequent bedtime anxieties due to bad dreams. Similar to the findings in adults, distress due to bad dreams was not only related to bad dream frequency but also to trait anxiety—controlling for the direct effect of trait anxiety on bad dream frequency, i.e., bad dream frequency and trait anxiety contributed independently to bedtime anxiety due to bad dreams. In the exploratory part, the cultural background of the children’s parents showed only minor effects on bad dreams.

Conclusion

Similar to nightmare studies in adults, bad dream frequency and trait anxiety contributed independently to bad dream distress. Based on the current diagnostic criteria of the nightmare disorder, it would be interesting to have the opportunity to treat children with significant distress due to nightmares or bad dreams and study the long-term benefit—given that many adult nightmare sufferers reported that their nightmares started in childhood.

Nightmares, Chronotype, Urbanicity, and Personality: An Online Study

Chronotype refers to individual differences in sleep timing ("owls" and "larks") and "eveningness" has been associated with nightmares. However, it has not been tested as to whether neuroticism mediates this relationship. Urbanicity refers to being raised in an urban region and/or currently living in an urban region and is associated with heightened risk for developing mental disorders, and thus might be related to nightmare frequency and nightmare distress. Overall, 2492 persons (1437 women, 1055 men) completed an online survey between 23 March 2015 and 8 April 2015. The mean age of the sample was 47.75 ± 14.41 years. The findings indicate that the previously reported relationship between chronotype and nightmare frequency was mediated by neuroticism and "morningness" was related to higher dream recall compared to persons with a late bedtime preference. Urbanicity was not related to nightmare frequency but to lower nightmare distress, raising the interesting question as to whether beliefs about nightmares might be an important variable that contributes to nightmare distress. Based on the few studies so far, there are still many unresolved questions about the interaction between nightmares, chronotype, and urbanicity.

Disturbing Dreams and Psychosocial Maladjustment in Children: A Prospective Study of the Moderating Role of Early Negative Emotionality

Although frequent disturbing dreams, including bad dreams and nightmares, have been repeatedly associated with poor psychological well-being in adults, considerably less information exists on their psychosocial correlates in children. Recent empirical and theoretical contributions suggest that the association between disturbing dream frequency and psychosocial adaptation in children may differ as a function of children's negative emotionality. The current study assessed the moderating effect of very early negative emotionality (17 months of age) in the relation between disturbing dream frequency and psychosocial maladjustment (i.e., externalizing + internalizing behaviors) in a sample of 173 11-year-old children. Mixed-model analyses revealed that disturbing dream frequency was associated with some internalizing behaviors but that the association between disturbing dream frequency and most externalizing behaviors was moderated by early negative emotionality. The latter result indicates that the relation between disturbing dream frequency and externalizing behaviors was significant in 11-year-old children showing moderate negative emotionality early in life, but particularly strong in those children with high early negative emotionality. Whereas, a moderating effect of early negative emotionality was not found between disturbing dream frequency and internalizing behaviors, the findings highlight the more specific role of early emotional negativity as a developmental moderator for the link between disturbing dreams and externalizing behaviors in children. The results are discussed in light of recent models of disturbed dreaming production.

Sleep disturbance in PTSD and other anxiety-related disorders: an updated review of clinical features, physiological characteristics, and psychological and neurobiological mechanisms

The current report provides an updated review of sleep disturbance in posttraumatic stress disorder and anxiety-related disorders. First, this review provides a summary description of the unique and overlapping clinical characteristics and physiological features of sleep disturbance in specific DSM anxiety-related disorders. Second, this review presents evidence of a bidirectional relationship between sleep disturbance and anxiety-related disorders, and provides a model to explain this relationship by integrating research on psychological and neurocognitive processes with a current understanding of neurobiological pathways. A heuristic neurobiological framework for understanding the bidirectional relationship between abnormalities in sleep and anxiety-related brain pathways is presented. Directions for future research are suggested.

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.

Nightmares and Stress: A Longitudinal Study

STUDY OBJECTIVES

In nightmare etiology, trait and state factors play important roles. However, the interaction of state and trait factors has never been studied in a longitudinal design.

METHODS

The current sample included 406 pregnant women who were followed up approximately 6 months after giving birth (n = 375) and 4 years later (n = 302). A nightmare frequency scale and several stress-related questionnaires were presented at three measurement points.

RESULTS

Despite the major life events in this sample, nightmare frequency was very stable over this time period and decreased slightly. In line with previous findings, cross-sectional analyses showed that stressors were associated with current nightmare frequency but longitudinal analyses indicated that previously measured nightmare frequency showed even stronger effects on current nightmare frequency.

CONCLUSIONS

Because the nightmare frequencies were very stable, it would be desirable to carry out intervention studies treating nightmares as early as possible-even in childhood-and study whether nightmare occurrence is lower even years after the intervention.

CITATION

Schredl M, Gilles M, Wolf I, Peus V, Scharnholz B, Sütterlin M, Bardtke S, Send TS, Samaras A, Deuschle M. Nightmares and stress: a longitudinal study. J Clin Sleep Med. 2019;15(9):1209-1215.

Nightmare frequency and nightmare distress: Socio-demographic and personality factors

The diagnosis of a nightmare disorder is based on clinically significant distress caused by the nightmares, e.g., sleep or mood disturbances. In order to understand nightmare etiology better empirical research should focus on studying factors that affect nightmare distress in addition to nightmare frequency. Overall, 2492 persons (1437 woman, 1055 men) completed the online survey. Nightmare frequency, global nightmare distress, and personality traits were measured. The findings indicate that in addition to nightmare frequency heightened emotional reactivity measured as neuroticism contribute to global nightmare distress and, thus, supporting the neurocognitive model of Levin and Nielsen (2007). Moreover, the recurring nightmares that relate to a waking-life event were associated with higher nightmare distress. From a clinical viewpoint, it would be desirable to carry out similar surveys using diagnostic interviews in order to determine the presence of a nightmare disorder and study the variables that are related to that diagnosis.

Exploring Thematic Nightmare Content and Associated Self-Harm Risk

Nightmares have been shown to be robust predictors of self-harm risk, beyond depressive symptoms and hopelessness at times. However, few studies have investigated associations between nightmare content and increased self-harm risk. This study explored associations of thematic nightmare content with history of self-harm, and risk of self-harm phenomena the morning following a nightmare. A mixed-method diary study was performed. Prospective nightmare reports were obtained from 72 participants. A total of 47 nightmare reports met inclusion criteria and were analyzed for themes using inductive thematic analysis. Chi-square and bootstrap Pearson's correlation tests were performed to assess the associations between nightmare themes and self-harm history, and risk of self-harm phenomena following a nightmare. "Powerlessness to Change Behavior" was associated with a history of self-harm engagement, whereas "Financial Hardship" indicated reduced risk. Themes were not significantly associated with increased risk of self-harm phenomena following a nightmare. Content may be of use in detecting lifetime history of self-harm engagement, particularly in populations where disclosure is seen as taboo. However, nightmare symptom severity remains a better indicator of risk. Evidence for the utility of nightmare content in assessing immediate self-harm risk is presently lacking. Replication with increased power is recommended.

Differentiating Single and Multiple Suicide Attempters: What Nightmares Can Tell Us That Other Predictors Cannot

STUDY OBJECTIVES

Although nightmares have been associated with suicidal behavior beyond well-known risk factors, the association between nightmares and multiple suicide attempts remains largely unexplored. This study addressed this gap in the literature by examining whether nightmares differentiated between individuals who reported single versus multiple suicide attempts. The individual contributions of nightmare frequency, distress/severity, and chronicity were also investigated to determine which variable contributed the most variance.

METHODS

Participants (n = 225) were recruited as part of a larger data collection through Amazon Mechanical Turk, an online crowdsourcing venue. Participants reported attempting suicide once (n = 107 individuals), multiple times (n = 118), or never (n = 791). Nightmare frequency, distress, and chronicity were assessed with the Disturbing Dreams and Nightmares Severity Index.

RESULTS

Nightmare frequency differentiated multiple from single suicide attempters, even after controlling for symptoms of depression, posttraumatic stress disorder, insomnia, nightmare severity/distress, nightmare chronicity, and age (P = .019). Comparison participants, those not reporting suicide attempts, reported a significantly lower level of nightmare frequency than those reporting single or multiple suicide attempts.

CONCLUSIONS

Inconsistent with past research, this study showed that nightmare frequency, and not nightmare chronicity or severity/distress, differentiated between single and multiple suicide attempters. This outcome suggests that the number of nightmares experienced may be more pertinent in predicting repeat suicide attempts than their duration or perceived severity. Study limitations include a cross-sectional design, a convenience sampling approach, a lack of control for previous treatment or length of time since last attempt, and a retrospective nightmare measure.

Spotlight on dream recall: the ages of dreams

Brain and sleep maturation covary across different stages of life. At the same time, dream generation and dream recall are intrinsically dependent on the development of neural systems. The aim of this paper is to review the existing studies about dreaming in infancy, adulthood, and the elderly stage of life, assessing whether dream mentation may reflect changes of the underlying cerebral activity and cognitive processes. It should be mentioned that some evidence from childhood investigations, albeit still weak and contrasting, revealed a certain correlation between cognitive skills and specific features of dream reports. In this respect, infantile amnesia, confabulatory reports, dream-reality discerning, and limitation in language production and emotional comprehension should be considered as important confounding factors. Differently, growing evidence in adults suggests that the neurophysiological mechanisms underlying the encoding and retrieval of episodic memories may remain the same across different states of consciousness. More directly, some studies on adults point to shared neural mechanisms between waking cognition and corresponding dream features. A general decline in the dream recall frequency is commonly reported in the elderly, and it is explained in terms of a diminished interest in dreaming and in its emotional salience. Although empirical evidence is not yet available, an alternative hypothesis associates this reduction to an age-related cognitive decline. The state of the art of the existing knowledge is partially due to the variety of methods used to investigate dream experience. Very few studies in elderly and no investigations in childhood have been performed to understand whether dream recall is related to specific electrophysiological pattern at different ages. Most of all, the lack of longitudinal psychophysiological studies seems to be the main issue. As a main message, we suggest that future longitudinal studies should collect dream reports upon awakening from different sleep states and include neurobiological measures with cognitive performances.

Sleep and Dreaming in Posttraumatic Stress Disorder

PURPOSE OF REVIEW

Sleep disturbances are core features of posttraumatic stress disorder (PTSD). This review aims to characterize sleep disturbances, summarize the knowledge regarding the relationships between trauma exposure and sleep difficulties, and highlight empirically supported and/or utilized treatments for trauma-related nightmares and insomnia.

RECENT FINDINGS

Trauma-related nightmares and insomnia, and other sleep disorders, are frequently reported among trauma survivors. The roles of fear of sleep, REM density, and decreased parasympathetic activity are beginning to inform the relationship between trauma exposure and sleep difficulties. Additionally, the potential adaptive role of sleep loss immediately following a traumatic experience is being recognized. Interventions targeting these sleep disturbances show promise in reducing symptoms. Research in understanding the role of sleep on the development, course, and treatment of PTSD is expanding. Longitudinal investigations are needed to further elucidate these relationships and identify treatments most effective in ameliorating symptoms.

Nightmare frequency in last trimester of pregnancy

Background

Pregnancy-related dreams are often found in pregnant women but also the number of negatively toned dreams seems to be increased in this challenging phase of a woman’s life.

Methods

Nightmare frequency and subjectively experienced stress was elicited via questionnaires. The mothers-to-be were approached during their application visit about 4–8 weeks prior to delivery in three obstetric hospitals. The present analysis included 406 women aged 16–40 years in the last trimester of their pregnancy. Women with severe somatic illnesses and/or psychiatric disorders were excluded. The representative sample included 496 women (age range: 14–93 years.).

Results

The findings clearly indicate that pregnant women report nightmares more often compared to a representative sample and that nightmare frequency is closely related to subjectively experienced stress during daytime. Moreover, baby-related dreams were correlated with nightmare frequency but not with day-time stress.

Conclusions

Future studies should investigate the prevalence of nightmare disorders in pregnancy and study whether brief interventions like Imagery Rehearsal Therapy are beneficial for pregnant women suffering from nightmares.

Is dream recall underestimated by retrospective measures and enhanced by keeping a logbook? An empirical investigation

In a recent review, Aspy, Delfabbro, and Proeve (2015) highlighted the tendency for retrospective measures of dream recall to yield substantially lower recall rates than logbook measures, a phenomenon they termed the retrospective-logbook disparity. One explanation for this phenomenon is that retrospective measures underestimate true dream recall. Another explanation is that keeping a logbook tends to enhance dream recall. The present study provides a thorough empirical investigation into the retrospective-logbook disparity using a range of retrospective and logbook measures and three different types of logbook. Retrospective-logbook disparities were correlated with a range of variables theoretically related to the retrospective underestimation effect, and retrospective-logbook disparities were greater among participants that reported improved dream recall during the logbook period. These findings indicate that dream recall is underestimated by retrospective measures and enhanced by keeping a logbook. Recommendations for the use of retrospective and logbook measures of dream recall are provided.

Insomnia, Nightmares, and Chronotype as Markers of Risk for Severe Mental Illness: Results from a Student Population

STUDY OBJECTIVES

To group participants according to markers of risk for severe mental illness based on subsyndromal symptoms reported in early adulthood and evaluate attributes of sleep across these risk categories.

METHODS

An online survey of sleep and psychiatric symptomatology (The Oxford Sleep Survey) was administered to students at one United Kingdom university. 1403 students (undergraduate and postgraduate) completed the survey. The median age was 21 (interquartile range = 20-23) and 55.60% were female. The cross-sectional data were used to cluster participants based on dimensional measures of psychiatric symptoms (hallucinations, paranoia, depression, anxiety, and (hypo)mania). High, medium, and low symptom groups were compared across sleep parameters: insomnia symptoms, nightmares, chronotype, and social jet lag.

RESULTS

Insomnia symptoms, nightmares frequency, and nightmare-related distress increased in a dose-response manner with higher reported subsyndromal psychiatric symptoms (low, medium, and high). The high-risk group exhibited a later chronotype (mid sleep point for free days) than the medium- or low-risk group. The majority of participants (71.7%) in the high-risk group screened positive for insomnia and the median nightmare frequency was two per 14 days (moderately severe pathology).

CONCLUSIONS

Insomnia, nightmares, and circadian phase delay are associated with increased subsyndromal psychiatric symptoms in young people. Each is a treatable sleep disorder and might be a target for early intervention to modify the subsequent progression of psychiatric disorder.

Nightmares in Patients With Psychosis: The Relation With Sleep, Psychotic, Affective, and Cognitive Symptoms

OBJECTIVE

To examine the prevalence of nightmares in people with psychosis and to describe the link between nightmares and sleep quality, psychotic, affective, and cognitive symptoms.

METHODS

Forty participants with psychotic symptoms completed an assessment of nightmares, sleep quality, positive symptoms of psychosis, affect, posttraumatic stress, social functioning, and working memory.

RESULTS

Among the patients, 55% reported weekly distressing nightmares. Experience of more frequent nightmares was related to poorer sleep quality and sleep efficiency. More distressing nightmares were positively associated with greater delusional severity, depression, anxiety, stress, and difficulties with working memory.

CONCLUSIONS

Nightmares might be common in those with psychosis and are associated with increased day- and nighttime impairment. Future research should investigate treatments for nightmares, for people presenting with psychotic symptoms.

Content analysis of 4 to 8 year-old children's dream reports

The role of dreaming in childhood and in adulthood are still equally enigmatic fields yet to be fully explored. However, while there is a consensus at least about the typical content and formal characteristics of adult dream reports, these features are still a matter of debate in the case of young children. Longitudinal developmental laboratory studies concluded that preschoolers' dreams usually depict static images about mostly animals and body states of the dreamer but they basically lack the active representation of the self, human characters, social interactions, dream emotions and motion imagery. Due to methodological arguments these results became the reference points in the literature of developmental dream research, in spite of the significantly different results of numerous recent and relevant studies using extra-laboratory settings. This study aims to establish a methodologically well-controlled and valid way to collect children's dreams for a representative period of time in a familiar home setting to serve as a comparison to the laboratory method. Pre trained parents acted as interviewers in the course of a 6 week-period of dream collection upon morning awakenings. Our results suggest that even preschoolers are likely to represent their own self in an active role (70%) in their mostly kinematic (82%) dream narratives. Their dream reports contain more human, than animal characters (70 and 7% of all dream characters respectively), and social interactions, self-initiated actions, and emotions are usual part of these dreams. These results are rather similar to those of recent extra-laboratory studies, suggesting that methodological issues may strongly interfere with research outcomes especially in the case of preschoolers' dream narratives. We suggest that nighttime awakenings in the laboratory setting could be crucial in understanding the contradictory results of dream studies in case of young children.

Is dream recall underestimated by retrospective measures and enhanced by keeping a logbook? A review

There are two methods commonly used to measure dream recall in the home setting. The retrospective method involves asking participants to estimate their dream recall in response to a single question and the logbook method involves keeping a daily record of one's dream recall. Until recently, the implicit assumption has been that these measures are largely equivalent. However, this is challenged by the tendency for retrospective measures to yield significantly lower dream recall rates than logbooks. A common explanation for this is that retrospective measures underestimate dream recall. Another is that keeping a logbook enhances it. If retrospective measures underestimate dream recall and if logbooks enhance it they are both unlikely to reflect typical dream recall rates and may be confounded with variables associated with the underestimation and enhancement effects. To date, this issue has received insufficient attention. The present review addresses this gap in the literature.

Epidemiological study of self-reported sleep problems in Turkish high school adolescents

BACKGROUND

The aim of the present study was to investigate the frequency and correlates of a variety of sleep problems in adolescents.

METHODS

A representative school-based sample of 3485 8th-12th graders was selected according to the cluster sampling technique. A sleep questionnaire and the Strengths and Difficulties Questionnaire were completed by the students along with their parents. Logistic regression analysis was used to identify the independent variables of insomnia, parasomnia and excessive daytime sleepiness (EDS).

RESULTS

Initiation insomnia, maintenance insomnia, non-restorative sleep (NRS) and EDS were described by 12.4%, 10.7%, 9% and 9.7%, respectively. At least one parasomnia with a frequency above the median was reported by 23.4% (nightmare, 12.8%; sleep terror, 3.6%; sleepwalking, 2.5%; bruxism, 2.5%; and sleep talking, 10.9%). Insomnias and parasomnias were highly associated with each other. Female gender was related to maintenance insomnia, NRS and night terror. Emotional problems correlated with initiation insomnia, maintenance insomnia, NRS, EDS, nightmares and bruxism; hyperactivity/inattention with initiation insomnia, NRS and sleep talking. Conduct problems were associated with NRS, whereas poor school performance was associated with initiation insomnia.

CONCLUSION

Self-reported sleep problems were prevalent and highly associated with each other and behavioral and emotional difficulties in Turkish adolescents.

Quantitative electroencephalography and behavioural correlates of daytime sleepiness in chronic stroke

Sleepiness is common after stroke, but in contrast to its importance for rehabilitation, existing studies focus primarily on the acute state and often use subjective sleepiness measures only. We used quantitative electroencephalography (qEEG) to extract physiological sleepiness, as well as subjective reports, in response to motor-cognitive demand in stroke patients and controls. We hypothesised that (a) slowing of the EEG is chronically sustained after stroke; (b) increased power in lower frequencies and increased sleepiness are associated; and (c) sleepiness is modulated by motor-cognitive demand. QEEGs were recorded in 32 chronic stroke patients and 20 controls using a Karolinska Drowsiness Test protocol administered before and after a motor priming task. Subjective sleepiness was measured using the Karolinska Sleepiness Scale. The findings showed that power density was significantly increased in delta and theta frequency bands over both hemispheres in patients which were not associated with subjective sleepiness ratings. This effect was not observed in controls. The motor priming task induced differential hemispheric effects with greater increase in low-frequency bands and presumably compensatory increases in higher frequency bands. The results indicate sustained slowing in the qEEG in chronic stroke, but in contrast to healthy controls, these changes are not related to perceived sleepiness.

Disturbed dreaming during the third trimester of pregnancy

OBJECTIVE

The majority of women develop sleep impairments during pregnancy, but alterations in dream experiences remain poorly understood. This study aimed to assess prospectively and comparatively the recall of dreaming and of disturbed dreaming in late pregnancy.

METHODS

Fifty-seven nulliparous, third-trimester pregnant women (mean age±SD, 28.7±4.06 years) and 59 non-pregnant controls (mean age±SD, 26.8±4.21 years) completed demographics and psychological questionnaires. A 14-day prospective home log assessed sleep and dream characteristics and the Sleep Disorders Questionnaire measured retrospective dream and disturbed dream recall.

RESULTS

Even though pregnant and non-pregnant women showed similar prospective dream recall (P=0.47), pregnant women reported prospectively more bad dreams (P=0.004). More pregnant women (21%) than non-pregnant women (7%) reported a nightmare incidence exceeding moderately severe pathology (>1/week) (P=0.03). Pregnant women also reported overall lower sleep quality (P=0.007) and more night awakenings (P=0.003). Higher prospective recall of bad dreams (r = -0.40, P=0.002) and nightmares (r = -0.32, P=0.001) both correlated with lower sleep quality in pregnant women.

CONCLUSIONS

Late pregnancy is a period of markedly increased dysphoric dream imagery that may be a major contributor to impaired sleep at this time. Further polysomnographic assessments of pregnant women are needed to clarify relationships between sleep and disturbed dream production in this population.

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.

Bad dream frequency in older adults with generalized anxiety disorder: prevalence, correlates, and effect of cognitive behavioral treatment for anxiety

This study investigated the relation between generalized anxiety disorder (GAD) and frequency of bad dreams in older adults. A secondary analysis from a randomized clinical trial comparing cognitive behavioral therapy (CBT) for anxiety to enhanced usual care (EUC) assessed bad dream frequency at baseline, post treatment (3 months), and at 6, 9, 12, and 15 months. Of 227 participants (mean age = 67.4), 134 met GAD diagnostic criteria (CBT = 70, EUC = 64), with the remaining 93 serving as a comparison group. Patients with GAD had significantly more bad dreams than those without, and bad dream frequency was significantly associated with depression, anxiety, worry, and poor quality of life. CBT for anxiety significantly reduced bad dream frequency at post treatment and throughout follow up compared to EUC.

Nightmare frequency, nightmare distress, and psychopathology in female victims of childhood maltreatment

This study investigated the relationships between a history of childhood maltreatment, the frequency of disturbing dreams, their associated distress, and the presence of psychopathology in 352 female undergraduate volunteers. Participants completed questionnaires assessing dream recall, bad dream and nightmare frequency, nightmare distress, psychological well-being, and history of childhood trauma. Four groups were investigated based on the type and severity of childhood maltreatments experienced. Women reporting more severe forms of maltreatment reported higher frequencies of disturbing dreams, higher levels of nightmare distress, and greater psychopathology. Results showed that nightmare distress explains frequency of disturbed dreaming beyond the effect of psychopathology and childhood trauma. The results highlight the importance of assessing waking distress associated with disturbing dreams independently from their actual incidence.

Is there a negative impact of winter on mental distress and sleeping problems in the subarctic: the Tromsø Study

BACKGROUND

Prior studies have suggested that the darkness of winter impacts the level of mental distress and sleeping problems. Our study investigated whether people living in the sub-arctic had more sleeping problems or mental distress during winter.

METHODS

The cross sectional population Tromsø Study was conducted in Tromsø, North Norway, at 69.4 degrees North and above the Arctic Circle. The study included entire birth cohorts and random samples of the population aged 30 to 87 years. Data was collected continuously from 1 October 2007 to the end of December 2008 except July. 8951 persons completed questionnaires including the HSCL-10 and the MCTQ.

RESULTS

There were no significant differences in the reporting of current mental distress depending on season. Significantly more reported current sleeping problems in winter than in the other seasons, and less sleeping problems was found in spring.

CONCLUSIONS

In this sub-arctic population, insomnia was most prevalent in winter, but there were no significant seasonal differences in mental distress. Although some people in the sub-arctic clearly are mentally negatively affected by the darkness of winter, the negative impact of winter on mental distress for the adult population is not conclusive.

Dream recall frequency: impact of prospective measures and motivational factors

Significant individual differences exist in dream recall frequency (DRF) but some variance is likely attributable to instrument choice in measuring DRF. Three hundred and fifty eight participants estimated their weekly DRF and recorded their dreams in either a narrative log (n = 165) or checklist log (n = 193) for 2-5 weeks. There was an early peak in DRF within the first week of both types of prospective logs after which DRF remained relatively stable. Although the two groups did not differ in their estimated DRF, significantly fewer dreams were reported per week on the narrative logs and only checklist logs yielded significantly higher DRF than participants' questionnaire estimates. The interactions between DRF measures did not vary across groups with low, medium or high baseline levels of DRF. Keeping a dream log does not necessarily increase DRF and narrative logs' time consuming nature can impact subjects' motivation to report all of their dreams over time.

Dream changes following initiation of efavirenz treatment

BACKGROUND AND OBJECTIVE

The objective was to evaluate abnormalities in the quality of dreams after the use of efavirenz.

PATIENTS AND METHOD

Ten HIV patients without neuropsychiatric diseases underwent a polisomnography (PSG) study before and after efavirenz treatment, [after 10.4 (SD 5.4) days]. Patients were awoke after REM phases to record their dreams. All patients had therapeutic efavirenz plasma levels.

RESULTS

Dreams were recalled in 84% before efavirenz and 43% after efavirenz (p=0.024). There were no differences in the mean number of words per dream before and after efavirenz treatment (61.9 versus 47.5, p=0.115). The proportion of dreams with no neutral emotional content (either pleasant or unpleasant) was 37.5% in the first night and 66.7% in the second night (p=0.046).

CONCLUSIONS

There were a higher proportion of dreams with no neutral emotional content after efavirenz treatment in this group of patients. However, no longer dreams and no more dreams with negative emotional content were noted. Dream recall was lower after efavirenz treatment.

Persistent nightmares are associated with repeat suicide attempt: a prospective study

The aim of this prospective study was to determine if sleep disturbances and nightmares are associated with increased risk of repeat suicide attempt. Patients (n=165) aged 18-68 years who were admitted to medical or psychiatric wards after a suicide attempt completed an initial interview; 98 of these took part in a 2-month follow-up interview. The Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and two self-report instruments, the Uppsala Sleep Inventory and the Comprehensive Psychopathological Rating Scale (CPRS) Self-Rating Scale for Affective Syndromes, were administered both at baseline and follow-up. Data concerning repeat suicide attempts within 2 years were obtained from hospital records. Analyses were performed using Student's t-test, chi-square test, and logistic regression. In total 42 patients (26%) made at least one repeat suicide attempt within 2 years. While neither difficulties initiating/maintaining sleep nor early morning awakening at baseline predicted repeat attempt, having frequent nightmares did (OR=3.15). The risk was further heightened when nightmares were reported at both baseline and 2-month follow-up (OR=5.20). These associations remained after adjusting for sex, axis-I DSM-IV diagnoses, and self-reported depression and anxiety symptom intensity. Our findings suggest that nightmares might constitute a marker for increased risk of suicidal behavior.

Correlates and Treatments of Nightmares in Adults

Nightmares, distressing dreams that primarily arise from REM sleep, are prevalent among the general population and even more so among clinical populations. The frequency of nightmares and related nightmare distress are linked to both sleep disturbance and waking psychopathology. Based on the extant evidence, nightmares appear to be particularly relevant to posttraumatic stress disorder, and may even be implicated in its pathophysiology. Significant advances in treatment have occurred in recent years, with effective pharmacological and psychosocial interventions now available. Despite the progress that has been made, however, more consistent assessment methods and more rigorous study designs are needed to fully understand the causes and consequences of nightmares.

The Memory Experiences and Dreams Questionnaire (MED-Q): A Validated Measure of Dream Remembering

Dream recall has been investigated via various means, often relying upon self-report judgments. Such methods, as well as individual differences and cognitive correlates of dream recall, rarely acknowledge models, theory, or empirical work concerning waking memory. Study 1 presents the development and psychometric validation of the Memory Experiences and Dreaming Questionnaire (MED-Q)—a 30-item measure of autobiographical and dream memory sensations incorporating items on dreaming, sensory experiences, and autobiographical remembering behaviors. It produces a single score and can be broken down into its constituent factors: “awareness of dreaming,” “daydreaming,” “dream sensations upon waking,” “déjà-states,” “comprehensibility of dream content,” and “senses.” Study 2 demonstrates the validity of the MED-Q as compared with dream report indices of dream detail. The MED-Q measures the extent to which a person engages with their dream memories through both frequency and subjective characteristic ratings. It is therefore novel in emphasizing the context of autobiographical memory for dreaming.