Nightmare frequency and nightmare topics in a representative German sample

Nightmare frequency and nightmare distress in psychiatric inpatients

Previous research indicated that the prevalence of frequent nightmares and/or the presence of a nightmare disorder is quite high in patients with mental disorders. In the present study, 75 randomly selected psychiatric inpatients were interviewed and completed questionnaires regarding nightmares, sleep, and psychopathology. The percentage of patients with nightmares once per week or more often was 61.54% in the group with PTSD diagnosis (N = 13) and 40.32% in the patients without PTSD diagnosis (N = 62). Moreover, depression scores and having PTSD were related to heightened nightmare distress. Based on the high prevalence rates of frequent nightmares, future research should aim at understanding better the interplay between psychopathology and nightmares and test whether nightmare interventions like Imagery Rehearsal Therapy might be beneficial for patients with mental disorders.

Neuroticism affects nightmare distress through rumination

BACKGROUND/AIMS

The role of neuroticism in predicting nightmare distress have been highlighted, and negative coping style may contribute to this relationship, but how these variables interact is limited. The present study aimed to explore how neuroticism and ruminative response contribute to producing nightmare distress, and to explore whether sex influences this relationship.

METHODS

We recruited 758 university students, aged an average of 19.07. A moderated mediation model was built to examine the relationships among neuroticism, rumination, and nightmare distress (measured by dream anxiety scale), and explore whether sex could affect this relationship, using the SPSS PROCESS 3.5 macro.

RESULTS

The moderated mediation analyses results showed that ruminative response-depression related can significantly partially mediate the relationship between neuroticism and dream anxiety (β = 0.32), dream anxiety-sleep-related disturbances (β = 0.11) and dream anxiety-daytime dysfunctions (β = 0.21). However, the moderating effects of sex were not significant in all path from neuroticism to dream anxiety.

CONCLUSION

The study provides a novel architecture on the underlying psychological mechanisms of neuroticism and nightmare distress. This interplay is assumed to be facilitated by ruminations, suggesting that interventions for individuals who suffer from nightmares may focus on their repetitive negative response strategies, especially in people with high neuroticism, irrespective of sex differences.

Interpersonal Loneliness Predicts the Frequency and Intensity of Nightmares: An Examination of Theoretic Mechanisms

The evolutionary theory of loneliness (ETL) argues that human belongingness is essential to survival and failing to meet belongingness needs constitutes a threat to viability. In two separate studies (total N = 1,609), links between loneliness and nightmares were examined as a test of ETL postulates. As hypothesized, loneliness predicted nightmare frequency (both studies) and nightmare intensity (Study Two only). Although stress mediated the relationship between loneliness and nightmare frequency in Study One, stress was not a significant mediator of this relationship in Study Two. As predicted, in Study Two both hyperarousal and rumination mediated the relationships between loneliness and nightmare frequency and between loneliness and nightmare intensity. Theoretical implications include support for both the aversive signaling and implicit vigilance postulates of ETL.

A prospective study of nightmare disorder among Chinese adults in Hong Kong: Persistence and mental health outcomes

OBJECTIVES

Previous studies showed that nightmares are prevalent and are associated with negative health outcomes. However, no empirical data is available demonstrating the extent to which nightmare disorder persists over time. Current literature provides a limited understanding of the trajectory and wider mental health outcomes of nightmare disorder. This longitudinal study examined the persistence and mental health outcomes of nightmare disorder.

METHODS

A total of 230 Hong Kong Chinese adults completed standardized assessments twice with an interval of about 6 months.

RESULTS

Over half (66.7%) of the participants with probable nightmare disorder at baseline remained to meet the DSM-5 criteria for the disorder at follow-up. Participants with probable nightmare disorder at baseline were significantly more likely to screen positive for PTSD (82.1% vs 18.3%) (p < .001) (p < .001), and they reported higher rates of mental health service usage at both timepoints (p = .001 to .003). Baseline nightmare disorder severity was negatively associated with subsequent self-rated mental health (β = -.151, p = .010) and self-esteem (β = -.141, p = .009) and it also predicted subsequent PTSD symptoms (β = .122, p = .012).

CONCLUSIONS

This study provides first empirical data showing that nightmare disorder could be persistent over time. Nightmare disorder symptoms are associated not only with PTSD symptoms but also with a broader range of mental health issues. This study points to the public health importance of identifying and managing nightmare disorder symptoms in the community. Additionally, the presence of nightmare disorder symptoms may be a helpful indicator for identifying post-traumatic stress.

Nightmares in Swiss elite athletes: Associated factors

Nightmares, defined as extremely dysphoric dreams, can cause significant distress in everyday life if they occur frequently. Their aetiology is based on a disposition-stress model. As elite athletes often experience high stress levels, the present study investigated factors that might be associated with nightmare frequency in a large cohort of 2297 Swiss elite athletes (1066 women, 1231 men) with a mean age of 22.05 ± 7.53 years. In total, about 6% of the athletes reported frequent nightmares (once a week or more often). We found that well-established factors like female gender and general stress levels were related to nightmare frequency. To a smaller extent, the number of training hours, lost training days due to illness, and having early training sessions were also associated with nightmare frequency. Sport discipline was not related to nightmare frequency. An unexpected finding was the association between late alcohol intake 4 hr prior to bedtime and nightmare frequency. Our findings support the idea that stress related to practicing sports might affect nightmare frequency. Future research should study whether inventions designed for athletes suffering from frequent nightmares are beneficial for them and might even improve their athletic performance.

Seeking help for nightmares: Associated personality factors

Research indicated that patients suffering from nightmares are often undertreated. One reason for this gap is that nightmare sufferers themselves often have not sought professional help for their nightmares, and-if they did-it was not very helpful. The current study aimed at studying trait factors (personality, harm avoidance) in relation to the persons considering seeking professional help. In a population-sample of 1108 persons (712 women, 396 men) with a mean age of 50.55 ± 14.22 years, it was also found that only some of the persons who have problems with nightmares even considered seeking professional help as an option. As expected and after controlling for effects of nightmare frequency, persons with high harm avoidance and high introversion were more likely not seeking help for their problems with nightmares. The associations with low education, low agreeableness and low conscientiousness with considering seeking professional help might point to the fear of stigmatisation in nightmare sufferers. Interestingly, the association between harm avoidance and "Considering seeking professional help" was even stronger in the subsample of frequent nightmare sufferers (once a week or more often). Future efforts should aim at findings new ways to offer adequate help for nightmares and increase the knowledge about nightmare treatment in healthcare professionals.

Association of nightmares with cardio-cerebrovascular disease, hypertension and hyperlipidemia in older adults: A population-based cross-sectional study

OBJECTIVE

This cross-sectional study investigated the relationship of nightmares with cardio-cerebrovascular disease (CVD), hypertension and hyperlipidemia which are major preceding diseases of CVD in older adults.

METHODS

Participants (n = 2824; mean age 63.6 ± 6.6 years, females 49.3%) completed the Disturbing Dream and Nightmare Severity Index (DDNSI), which was used to divide the sample into either the Nightmare or Non-Nightmare group (cut-off score ≥ 10). Demographic information, history of CVD (cerebrovascular disease, myocardial infarction, congestive heart failure, coronary artery disease, and arrhythmia), hypertension, hyperlipidemia, and self-report questionnaires about stress (Perceived Stress Scale), depression (Beck Depression Inventory), sleep quality (Pittsburgh Sleep Quality Index), and insomnia symptoms were also collected.

RESULTS

Among the sample, 379 participants (13.4%) reported experiencing nightmares more than once a year, and 73 participants (2.6%) were classified as having nightmare disorder based on DDNSI scores (≥10). 11.3% of participants (n = 319) reported having more than one CVD. Approximately half of the participants reported a history of hypertension (52.1%, n = 1471) and hyperlipidemia (47.7%, n = 1346). Logistic regression analysis indicated the Nightmare group was 2.04 times at higher risk for hyperlipidemia (OR = 2.04, 95% CI 1.22-3.40, p = .006) after controlling for covariates compared to the Non-Nightmare group. Although non-significant, there was a trend toward a higher risk of hypertension in the Nightmare group (OR = 1.67, 95% CI 0.99-2.84, p = .056).

CONCLUSIONS

Results of this study indicate frequent nightmares in older adults may be associated with hyperlipidemia, which are risk factors for CVD. Further studies are needed to explore nightmares' directionality and health consequences in an aging population.

Social media-related nightmare - a potential explanation for poor sleep quality and low affective well-being in the social media era?

Research has posited that social media use during the day may be reflected in nighttime dreams. Nevertheless, no prior studies have explored frightening, unpleasant dreams arising from social media use. This study introduces the construct of the social media-related nightmare by (a) developing and validating a scale capturing negative-valenced dreams with themes of helplessness, loss of control, inhibition, victimization, and making mistakes in social media, and (b) examining relationships between social media use, social media-related nightmares, sleep quality, and affective well-being. A convenience sample of 595 Iranian adult social media users (Mage = 27.45, SDage = 11.42) reported on social media-related nightmare, social media use integration, anxiety, peace of mind, sleep quality, and nightmare distress. The Social Media-Related Nightmare Scale (SMNS) demonstrated a unidimensional structure with sound psychometric properties. The most common nightmares involved the inability to log in to social media and the disruption of relationships with other users. Social media use intensity predicted frequency of social media-related nightmares. These nightmares were correlated with increased anxiety, lower peace of mind, poor sleep quality, and nightmare distress. Importantly, social media-related nightmares mediated the relationship between social media use intensity and low affective well-being (i.e., anxiety and peace of mind), poor sleeping, and nightmare distress. The findings suggest that social media-related nightmares could be a potential pathway through which social media engagement may lead to affective distress and sleep difficulties.

The Effects of Pharmacological Treatment of Nightmares: A Systematic Literature Review and Meta-Analysis of Placebo-Controlled, Randomized Clinical Trials

Nightmares are highly prevalent and distressing for the sufferer, which underlines the need for well-documented treatments. A comprehensive literature review and meta-analysis of the effects of different pharmacological placebo-controlled randomized clinical trials, covering the period up to 1 December 2022, was performed. Searches were conducted in PubMed, Embase, Web of Science, PsychInfo, Cinahl, and Google Scholar, resulting in the identification of 1762 articles, of which 14 met the inclusion criteria: pharmacological intervention of nightmares, based on a placebo-controlled randomized trial published in a European language, reporting outcomes either/or in terms of nightmare frequency, nightmare distress, or nightmare intensity, and reporting sufficient information enabling calculation of effect sizes. Most studies involved the effect of the α1-adrenergic antagonist prazosin in samples of veterans or soldiers suffering from posttraumatic stress disorder. Other medications used were hydroxyzine, clonazepam, cyproheptadine, nabilone, and doxazosin. The vast majority of studies were conducted in the USA. The studies comprised a total of 830 participants. The Clinician-Administered PTSD Scale was the most frequently used outcome measure. The results showed an overall effect size of Hedges' g = 0.50 (0.42 after adjustment for publication bias). The synthetic cannabinoid nabilone (one study) showed the highest effect size (g = 1.86), followed by the histamine H1-antagonist hydroxyzine (one study), and prazosin (10 studies), with effect sizes of g = 1.17 and g = 0.54, respectively. Findings and limitations are discussed, and recommendations for future studies are provided.

COVID-19 nightmare response and stress: A new Mexico sample based survey

Studies conducted during the COVID-19 Pandemic have reported increased rates of mental illnesses including depression, anxiety, and post-traumatic stress disorder (PTSD) [1]. A common symptom of mental illness is change in Rapid Eye Movement (REM) sleep, the phase of sleep associated with dreaming and nightmares. The COVID-19 pandemic offers a unique opportunity to evaluate the effects of systemic stress on nightmares.

In this study, we investigate whether the COVID-19 pandemic affects nightmare frequency and content using a web-based survey within the state of New Mexico. The survey returned 197 responses showing an increase in the quantity of both bad dreams and nightmares. Furthermore, significant changes in nightmare themes were reported compared to relative rates prior to the pandemic (RR 1,42, p < 0.01; RR 5, p < 0.001). This novel data supports that increased stress from the COVID-19 pandemic has altered dream and nightmare content and frequency.

The role of mindful acceptance and lucid dreaming in nightmare frequency and distress

A theoretical and empirical association between lucid dreaming and mindfulness, as well as lucid dreaming and nightmares has previously been observed; however, the relationship between nightmares and mindfulness has received surprisingly little attention. Here, we present the findings of two studies exploring the relation of nightmare frequency and distress with two components of mindfulness, termed presence and acceptance, as well as lucid dreaming. Study 1 (N = 338) consisted of a low percentage of frequent lucid dreamers whereas Study 2 (N = 187) consisted primarily of frequent lucid dreamers that used lucid dream induction training techniques and meditation. Across studies, nightmare-related variables showed a more robust association with mindful acceptance as opposed to mindful presence. Moreover, individuals with high levels of meditation expertise and practice of lucid dreaming induction techniques reported lower nightmare frequency. Finally, in Study 2, which consisted of frequent lucid dreamers, a positive correlation between lucid dreaming frequency and mindfulness was apparent. The present findings support the notion that wakeful mindfulness is associated with the quality of dreams and extend previous research by suggesting a disentangled role of the two facets of mindfulness in dream variation. This association remains open for experimental manipulation, the result of which could have clinical implications.

Nightmares' Pattern and Predictors among a Saudi University Students during COVID-19 Pandemic

Purpose: During the coronavirus disease 2019 (COVID-19) pandemic quarantine, university students were under various types of stressors, including the exams period, which might have affected their quality and quantity of sleep, and consequently, their quality of life. This study aimed to investigate the pattern and predictors of nightmares among university students and coinvestigate the presence of other types of sleep disturbances, mental disorders, and quarantine-related stressors. Methods: This cross-sectional study included 368 university students who answered a self-completed questionnaire covering their sociodemographic features, nightmare indicators, and associated quarantine stressors. Additionally, sleep disturbances were measured using the Generalized Sleep Disturbance Scale (GSDS), anxiety using the Generalized Anxiety Disorder 2 scale, and depression using the Patient Health Questionnaire-2. Results: The participants’ mean age was 20.4 ± 1.6 years, and male participants represented 35.9% of the sample. Nightmares were experienced by 117 (31.8%) of the participants, of whom 44.4% had new-onset nightmares. The mean GSDS was 45.0 ± 14.9 (min. = 12, max. = 130). This value is associated with elevated odds of the following outcomes: the presence of nightmares (odds ratio [OR] = 1.8; confidence interval [CI] 95% = 1.1–3.0); new-onset nightmares at the time of pandemic (OR = 2.6; CI 95% = 1.3–5.5); and anxiety (OR = 1.74; CI 95% = 1.0–2.9). The presence of nightmares elevated the score of GSDS by 11.3 points (S.E. = 1.6, p < 0.001), elevated the odds of anxiety by 4.1 (CI 95% = 2.5–6.8), and depression by 2.1 (CI 95% = 1.3–3.4). Conclusions: Stressors resulting from both the exams period and the fact that it was conducted during COVID-19 quarantine increased the rate and affected the pattern of nightmares. These stressors also led to other sleep disturbances and mental disorders that were significantly more prevalent among females.

Dissociated Effects of Age and Recent Troubling Experiences on Nightmares, Threats and Negative Emotions in Dreams

Several studies have highlighted associations between adverse life events and the dysphoric character of dream experiences. This degree of continuity between waking-life and dream content seems partly attributed to the emotional and personal attachment linked to the incorporated waking experiences. Numerous changes in the processing of emotion-related stimuli are also reported across different human developmental stages. Therefore, we were interested in testing whether age would modulate the impact of recent troubling experiences on dream characteristics. Two hundred sixty participants, evenly distributed in five developmental stages, matched for gender and their exposure to a troubling experience, were selected from a large sample collected for a previous normative study of dreams of Canadians. Participants completed a dream questionnaire from which independent judges subsequently scored the dreams. We observed no interactions between the experience of troubling events and age. However, individuals who experienced a recent troubling event reported a higher frequency of nightmares and their dreams were more emotionally negative. Participants who experienced a moderately severe troubling event were also more likely to experience a dream whose maximal threat severity was of moderate intensity. Adolescents and young adults had dreams with a higher level of oneiric threats compared to older adults (>40 years old). Young adults also reported a higher frequency of nightmares compared to older adults. Our findings have implications for modern dream theories. They also suggest that dysphoric dreams might serve as potential proxies of mental health status and developmental stages. Future studies are now needed to explore the implications of these findings for psychological adaptation.

Can You Sleep? - Effect of Retrospective Recall of Child Maltreatment on Sleep Parameters and the Mediating Role of Psychological Distress Among Students of Two German Universities

PURPOSE

Child maltreatment may be linked with long-term sleeping disorders and limited coping with stress. Yet, the potential relationships are only marginally studied.

PATIENTS AND METHODS

Based on a sample of young adults (n = 312) this study aims at exploring the effects of child maltreatment and the experience of threat to personal safety and life in childhood on sleep disturbances in early adulthood. Data were collected at the two study sites, Ulm University and Bielefeld University, by an online survey. For both risk factors, child maltreatment and the experience of threat to personal safety and life in childhood, a direct impact on sleep disturbances and an indirect path via psychological distress were tested using Structural Equation Modelling (SEM).

RESULTS

In these models, the direct path to sleep disturbances turned out to be significant for the experience of threat to personal safety and life (Path C: b = 0.18, p = 0.013), but not for child maltreatment (Path C: b = 0.05, p = 0.491). However, the current level of psychological distress was found to have a mediating effect on sleep disturbances for both risk factors, thereby confirming indirect significant effects.

CONCLUSION

Considering that the etiological pathway of child maltreatment on sleeping disturbances is mediated via psychological distress, this provides a venue to test in future research whether stress reduction interventions can reduce the negative consequences of child maltreatment on sleep disorders.

Clocks in Dreams: Analysis of a Long Dream Series

Many dream content analytic studies focus on dream characters, animals, social interactions and so on, but they rarely analyze the frequency of everyday objects in dreams. In the present paper, the frequency and phenomenology of clock dreams in a dream series of 12,476 dreams of a single male dreamer was analyzed. The clock dreams (0.74% of all dreams) show a variety of contexts not only related to the time management of the dreamer within the dream. Interestingly, clocks that belong to the dreamer in waking life occurred very rarely in his dreams. Given that keeping time schedules and appointments in waking life is of importance to almost everyone, the low frequency of clock dreams might be explained by novelty, that is, waking-life experiences that repeat themselves regularly do not show up in dreams that often. Thus, studying everyday objects such as clocks in dreams might help refine the current models describing the continuity between waking and dreaming.

Conquering nightmares on the phone: one-session counseling using imagery rehearsal therapy

Background

Since people with nightmares rarely seek help, low-threshold interventions and self-help methods are needed. Among different treatment approaches for nightmares, imagery rehearsal therapy (IRT) is the method of choice.

Objective

In the current study, the authors tested whether IRT is also effective when applied in a short version, within the scope of a single session of telephone counseling.

Methods

The nightmare frequency and nightmare distress of 28 participants was investigated before and 8 weeks after one session of telephone counseling. The 30-minute session included information on nightmare etiology as well as a short version of IRT. The session was followed by an 8‑week period of self-practice. Participants were either part of a student group or part of a group of patients from a sleep laboratory. Within-group and between-group differences were assessed. There was no control group.

Results

The intervention significantly reduced nightmare frequency and nightmare distress in the total sample and in both samples individually analyzed. Effect sizes were very high compared to those of waiting-list control groups of similar studies.

Conclusion

We were able to show that a one-session intervention can be enough to achieve significant relief from nightmares. As nightmares are underdiagnosed and undertreated, this approach might help to provide a low-threshold intervention for nightmare sufferers.

Frequent nightmares and its associations with psychological and sleep disturbances in hospitalized patients with cardiovascular diseases

AIMS

Frequent nightmares can pose a serious clinical problem, especially in association with sleep and psychological disturbances, in the general population. However, this association has not been investigated in inpatients with cardiovascular (CV) diseases. Furthermore, whether CV medications could induce iatrogenic nightmares remains unknown. In a cross-sectional designed study, we evaluated the prevalence and determinants of frequent nightmares and its association with sleep and psychological disturbances among hospitalized CV patients.

METHODS AND RESULTS

A total of 1233 patients (mean age, 64 ± 15 years; 25.1% female) hospitalized for various CV diseases in a single university hospital were enrolled. We assessed nightmares and sleep characteristics using the Pittsburgh Sleep Quality Index (PSQI), sleep-disordered breathing (SDB) using nocturnal pulse oximetry, and psychological disturbances using Hospital Anxiety and Depression Scale (HADS). Overall, 14.8% and 3.6% of the patients had at least one nightmare per month and per week (frequent nightmares), respectively. In this cohort, 45.9% had insomnia (modified PSQI > 5), 28.0% had SDB (3% oxygen desaturation index > 15), 18.5% had depression (HADS-depression ≥ 8), and 16.9% had anxiety (HADS-anxiety ≥ 8). Frequent nightmares were not associated with CV medications and SDB but were associated with depression [odds ratio (OR) = 4.61, 95% confidence interval (CI) = 2.03-10.48], anxiety (OR = 5.32, 95% CI = 2.36-12.01), and insomnia (OR = 7.15, 95% CI = 2.41-21.22).

CONCLUSIONS

Frequent nightmares were not uncommon in patients hospitalized for CV diseases. Although the cause-effect relationship is unclear, frequent nightmares were associated with psychological disturbances and insomnia, but not iatrogenic factors, among hospitalized CV patients. Cardiologists should be more conscientious to nightmare complaints with respect to screening for psychological disturbances and insomnia.

The Nightmare Disorder Index: development and initial validation in a sample of nurses

STUDY OBJECTIVES

Nurses are a group at high risk for nightmares, yet little is known about the rate of nightmare disorder and associated psychosocial factors in this group in part attributable to the lack of a self-report questionnaire to assess DSM-5 criteria for nightmare disorder. Aims of the current study were to (1) report on development and initial validity of a self-report measure of DSM-5 nightmare disorder, and (2) examine the rate and associated factors of nightmare disorder among nurses.

METHODS

Nurses (N = 460) completed baseline measures online including Nightmare Disorder Index (NDI), psychosocial and demographic questionnaires. A subset (n = 400) completed 14 days of sleep diaries and actigraphy.

RESULTS

NDI demonstrated satisfactory psychometric characteristics as indicated by good internal consistency (α = 0.80), medium inter-item correlations (r = 0.50), medium to large item-total (r = 0.55-0.85) and convergent correlations (0.32-0.45), and small to medium discriminant correlations (-0.12-0.33). Per NDI, 48.7% of nurses reported no nightmares in the past month, 43.9% met partial/subthreshold criteria and 7.4% met full criteria for probable nightmare disorder. Nurses with nightmare disorder demonstrated significantly poorer psychosocial functioning (i.e. posttraumatic stress, depression, anxiety, stress) than those with subthreshold nightmare symptoms, who had poorer functioning than those with no nightmares.

CONCLUSIONS

NDI is an efficient and valid self-report assessment of nightmare disorder. Nurses have high rates of nightmares and nightmare disorder which are associated with poorer psychosocial functioning. We recommend increased nightmare screening particularly for high-risk populations such as healthcare workers.

Psychometric properties of the Disturbing Dream and Nightmare Severity Index-Korean version

STUDY OBJECTIVES

This study aimed to examine psychometric properties of the Disturbing Dream and Nightmare Severity Index (DDNSI) in individuals aged between 18 and 39.

METHODS

All participants (n = 674) were asked to complete the DDNSI, including the modified Nightmare Effects Survey. Additionally, 109 participants were tested for test-retest reliability after 3 months. Among our sample, 229 (33.9%) reported having at least 1 nightmare per month.

RESULTS

Internal consistency was evaluated for the total sample (Cronbach's α = .920) and separately for individuals reporting more than once per month (Cronbach's α = .755). Test-retest reliability after 3 months was .705. Convergent validity of the DDNSI with Nightmare Effects Survey was also satisfactory (r = .638, P < .001). Finally, exploratory factor analysis was conducted to explore the construct of the DDNSI, and results indicated that it consisted of 2 factors, nightmare frequency and nightmare distress [χ²(df) = 2.241(1) ∆χ² (∆df) = 155.575(4), Tucker-Lewis incremental fit index = .980, root mean square error of approximation (90% confidence interval) = .074 (0, .208), standardized root-mean-square residual = .011].

CONCLUSIONS

The DDNSI is a reliable measure of nightmare severity that can be used in various settings.

Reduced Sleep Duration and Sleep Efficiency Were Independently Associated With Frequent Nightmares in Chinese Frontline Medical Workers During the Coronavirus Disease 2019 Outbreak

Objectives

Nightmares were related to emotion and behavioral problems and also emerged as one of the core features of post-traumatic stress disorder (PTSD). Our study aimed to investigate the associations of frequent nightmares with sleep duration and sleep efficiency among frontline medical workers in Wuhan during the coronavirus disease 2019 (COVID-19) outbreak.

Methods

A total of 528 health-care workers from the province of Fujian providing medical aid in Wuhan completed the online questionnaires. There were 114 doctors and 414 nurses. The age, sex, marital status, and work situation were recorded. A battery of scales including the Pittsburgh Sleep Quality Index (PSQI) and the 12-item General Health Questionnaire (GHQ-12) were used to evaluate subjects’ sleep and general mental health. Frequent nightmares were defined as the response of at least once a week in the item of “nightmare” of PSQI.

Results

Frequent nightmares were found in 27.3% of subjects. The frequent nightmare group had a higher score of PSQI-sleep duration and PSQI-habitual sleep efficiency (frequent nightmares vs. non-frequent nightmares: PSQI-sleep duration, 1.08 ± 0.97 vs. 0.74 ± 0.85, P < 0.001; PSQI-habitual sleep efficiency, 1.08 ± 1.10 vs. 0.62 ± 0.88, P < 0.001). Reduced sleep duration and reduced sleep efficiency were independently associated with frequent nightmares after adjustment for age, sex, poor mental health, and regular sleeping medication use (reduced sleep duration: OR = 1.96, 95% CI = 1.07–3.58, P = 0.029; reduced sleep efficiency: OR = 2.17, 95% CI = 1.09–4.32, P = 0.027). Subjects with both reduced sleep duration and sleep efficiency were also associated with frequent nightmares (OR = 2.70, 95% CI = 1.57–4.65, P < 0.001).

Conclusion

The present study found that sleep duration and sleep efficiency were both independently associated with frequent nightmares among frontline medical workers in Wuhan during the COVID-19 pandemic. We should pay attention to nightmares and even the ensuing PTSD symptoms among subjects with reduced sleep duration or sleep efficiency facing potential traumatic exposure.

Nightmare Distress Questionnaire: associated factors

STUDY OBJECTIVES

The diagnosis of a nightmare disorder is based on clinically significant distress caused by the nightmares, eg, sleep or mood disturbances during the day. The question what factors might be associated with nightmare distress in addition to nightmares frequency is not well studied.

METHODS

Overall, 1,474 persons (893 women, 581 men) completed an online survey. Nightmare distress was measured with the Nightmare Distress Questionnaire.

RESULTS

The findings indicated that nightmare distress, measured by the Nightmare Distress Questionnaire, correlated with a variety of factors in addition to nightmare frequency: neuroticism, female sex, low education, extraversion, low agreeableness, and sensation seeking. Moreover, the percentage of replicative trauma-related nightmares was also associated with higher nightmare distress.

CONCLUSIONS

A large variety of factors are associated with nightmare distress, a finding that is of clinical importance. The construct harm avoidance, however, was not helpful in explaining interindividual differences in nightmare distress. Furthermore, the relationship between nightmare distress and other factors, eg, education or agreeableness, is not yet understood.

Nightmares in Patients with Major Depressive Disorder, Bipolar Disorder, and Psychotic Disorders: A Systematic Review

Chronic nightmares are very common in psychiatric disorders, affecting up to 70% of patients with personality or post-traumatic stress disorders. In other psychiatric disorders, the relationships with nightmares are poorly known. This review aimed to clarify the relationship between nightmares and both mood and psychotic disorders. We performed a systematic literature search using the PubMed, Cochrane Library and PsycINFO databases until December 2019, to identify studies of patients suffering from either a mood disorder or a psychotic disorder associated with nightmares. From the 1145 articles screened, 24 were retained, including 9 studies with patients with mood disorders, 11 studies with patients with psychotic disorders and 4 studies with either psychotic or mood disorders. Nightmares were more frequent in individuals with mood or psychotic disorders than in healthy controls (more than two-fold). Patients with frequent nightmares had higher suicidality scores and had more frequently a history of suicide attempt. The distress associated with nightmares, rather than the frequency of nightmares, was associated with the severity of the psychiatric disorder. Further studies assessing whether nightmare treatment not only improves patient-sleep perception but also improves underlying psychiatric diseases are needed. In conclusion, nightmares are overrepresented in mood and psychotic disorders, with the frequency associated with suicidal behaviors and the distress associated with the psychiatric disorder severity. These findings emphasize major clinical and therapeutic implications.

Differentiating Oneiric Stupor in Agrypnia Excitata From Dreaming Disorders

Oneiric Stupor (OS) in Agrypnia Excitata represents a peculiar condition characterized by the recurrence of stereotyped gestures such as mimicking daily-life activities associated with the reporting of a dream mentation consisting in a single oneiric scene. It arises in the context of a completely disorganized sleep structure lacking any physiological cyclic organization, thus, going beyond the concept of abnormal dream. However, a proper differential diagnosis of OS, in the complex world of the “disorders of dreaming” can become quite challenging. The aim of this review is to provide useful clinical and videopolygraphic data on OS to differentiate it from other dreaming disorders. Each entity will be clinically evaluated among the areas of dream mentation and abnormal sleep behaviors and its polygraphic features will be analyzed and distinguished from OS.

Prevalence of and factors associated with nightmares in the elderly in a population based cohort study

OBJECTIVES

Nightmares are extremely unpleasant and vivid recurring dreams that are accompanied with awakening during sleep. However, earlier studies were mostly conducted with children and adults, with very few studies on nightmares in older adults. This population-based study aims to investigate the prevalence of nightmares and its associated factors nightmares in the elderly.

METHODS

This study utilized a subsample from the Korean Genome and Epidemiology Study (KoGES). Participants (n = 2940; mean age 63.71 ± 6.73) completed the questionnaires on nightmares (Disturbing Dream and Nightmare Severity Index; DDNSI), depression, suicidal ideation, sleep quality and stress.

RESULTS

Among the sample, 2.7% (n = 79) were classified into the nightmare group (NG), which was classified with DDNSI scores. In the age group over 70, prevalence of nightmares was 6.3% (n = 37), which was significantly higher than other age groups. Marital status, employment status and family income were associated with nightmares. Additionally, NG reported significantly more sleep problems, higher suicidal ideation, depression and stress compared to the non-nightmare group (N-NG). Logistic regression analyses results indicated that the NG was 4.35 times at higher risk for depression, and 3.16 higher risks for stress, and 3.45 higher risks for suicidal ideation compared to the N-NG after controlling for covariates.

CONCLUSIONS

Our results indicate that psychological and demographic factors are associated with nightmares in the elderly. Furthermore, this population-based cohort study showed the prevalence of nightmares increased after age 70, which suggests the need for further studies of nightmares in older populations.

Effects of nightmares on the cortisol awakening response: An ambulatory assessment pilot study

Previous studies have reported an association between sleep-related factors such as sleep duration, sleep quality and time of awakening with the cortisol awakening response (CAR). Preliminary evidence suggests that frequent nightmares are associated with a blunted CAR. In the present pilot study we investigated the effect of acute nightmares on the CAR and the cortisol profile of the subsequent day using a within-subject ambulatory assessment study design. Thirty healthy volunteers who reported frequent nightmares enrolled in the study. Over a period of 14 days, salivary samples in addition to sleep-related and state variables were collected at home over the day. Salivary profiles of free cortisol and alpha amylase for up to two days following a nightmare were compared to those following a neutral dream. Overall, mood and health were decreased and the CAR was elevated following nightmares compared to neutral dreams. No differences were found for alpha amylase and for all variables over the remaining part of the day. Results suggest that sleep-related factors such as the occurrence of nightmares account for a certain amount of variance observed in the CAR. This has important methodological implications for CAR studies in general and might have even more relevance for studies in clinical populations suffering from chronic sleep disturbances.

Pandemic Dreams: Network Analysis of Dream Content During the COVID-19 Lockdown

We used crowdsourcing (CS) to examine how COVID-19 lockdown affects the content of dreams and nightmares. The CS took place on the sixth week of the lockdown. Over the course of 1 week, 4,275 respondents (mean age 43, SD = 14 years) assessed their sleep, and 811 reported their dream content. Overall, respondents slept substantially more (54.2%) but reported an average increase of awakenings (28.6%) and nightmares (26%) from the pre-pandemic situation. We transcribed the content of the dreams into word lists and performed unsupervised computational network and cluster analysis of word associations, which suggested 33 dream clusters including 20 bad dream clusters, of which 55% were pandemic-specific (e.g., Disease Management, Disregard of Distancing, Elderly in Trouble). The dream-association networks were more accentuated for those who reported an increase in perceived stress. This CS survey on dream-association networks and pandemic stress introduces novel, collectively shared COVID-19 bad dream contents.

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.

Nightmare distress revisited: Cognitive appraisal of nightmares according to Lazarus' transactional model of stress

Aim of the current research was to newly conceptualize nightmare distress. The special focus was on the appraisal of nightmare distress while applying a theory-driven approach based on Lazarus' transactional model of stress. It was argued that individuals feel the more distressed the more they feel threatened and harmed by their nightmares (primary appraisal according to Lazarus) and the more they lack of adequate coping skills to deal with the stressor (secondary appraisal). Based on these assumptions, the questionnaire of Cognitive Appraisal of Nightmares (CAN) was challenged empirically in two studies of patients who have experienced distressing nightmares using explorative and confirmative factor analyses (N = 504 and N = 402). Items and scales showed good psychometric properties and plausible correlations. The CAN sum score was more distinct from nightmare frequency than the frequently used Nightmare Distress Questionnaire (NDQ), underpinning that frequency and distress are both different approaches to what patients suffer from. The NDQ was particularly associated with acted out behaviors after a nightmare, while the CAN was particularly associated with physiological and emotional consequences of a nightmare. In order to obtain a multifactorial and theory-driven picture about how individuals appraise their nightmares, the CAN may be convenient.

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.

Unaltered EEG spectral power and functional connectivity in REM microstates in frequent nightmare recallers: are nightmares really a REM parasomnia?

BACKGROUND

Frequent nightmares show signs of hyperarousal in NREM sleep. Nevertheless, idiopathic nightmare disorder is considered a REM parasomnia, but the pathophysiology of REM sleep in relation to frequent nightmares is controversial. Cortical oscillatory activity in REM sleep is largely modulated by phasic and tonic REM periods and seems to be linked to different functions and dysfunctions of REM sleep. Here, we examined cortical activity and functional synchronization in frequent nightmare recallers and healthy controls, during phasic and tonic REM.

METHODS

Frequent nightmare recallers (N = 22) and healthy controls (N = 22) matched for high dream recall spent two nights in the laboratory. Phasic and tonic REM periods from the second nights' recordings were selected to examine differences in EEG spectral power and weighted phase lag index (WPLI) across groups and REM states.

RESULTS

Phasic REM showed increased power and synchronization in delta and gamma frequency bands, whereas tonic REM featured increased power and synchronization in the alpha and beta bands. In the theta band, power was higher during tonic, and synchronization was higher during phasic REM sleep. No differences across nightmare and control participants or patterns representing interactions between the groups and REM microstates emerged.

CONCLUSIONS

Our findings do not support the idea that abnormal REM sleep power and synchronization play a role in the pathophysiology of frequent nightmares. Altered REM sleep in nightmare disorder could have been confounded with comorbid pathologies and increased dream recall, or might be linked to more specific state factors (nightmare episodes).

The relationship between nightmares and psychotic experiences in young adults

BACKGROUND

There is indication that frequent nightmares are an early indicator of psychotic disorders in adolescents and young adults. Yet which aspects of nightmares are relevant and how they contribute to psychotic experiences has remained unclear.

METHODS

We conducted a cross-sectional online survey in a community sample of young adults between the ages of 18 and 27 (n = 486) to identify aspects of nightmares (nightmare frequency (NF), nightmare distress (ND), nightmare contents), that are related to specific psychotic experiences (paranoid thoughts, hallucinations, negative symptoms) after controlling for sleep quality, and examined factors that potentially mediate this relationship (stress, depression).

RESULTS

Nightmare frequency and -distress were significantly associated with paranoid thoughts, hallucinations and negative symptoms (NF: r_s = 0.293 - 0.139; ND: r_s = 0.411 - 0.166). Nightmares significantly added to explaining paranoid thoughts and hallucinations, over and above sleep quality, but not to explaining negative symptoms. The relations between nightmare distress and psychotic experiences were partially mediated by stress (percentage mediated for paranoid thoughts: 38.20%; for hallucinations: 11.77%) and depression (percentage mediated for paranoid thoughts: 56.61%; for hallucinations: 28.02%). The most commonly reported nightmare contents revolved around being chased, falling and losing a close relative and specific contents were significantly related to the frequency of hallucinations (eg, threatening surroundings, OR = 1.73) or paranoia (eg, workspace bullying, OR = 2.02).

CONCLUSIONS

Thorough assessments of nightmares and sleep disturbances in young individuals could facilitate early detection of those at risk and help to target preventive treatments. However, longitudinal studies are needed to test for a causal relationship between nightmares and the development of psychotic symptoms.

Interest in telephone nightmare counselling in patients with sleep-related breathing disorders

Background and objective

Nightmares are typically underdiagnosed and undertreated, even though frequent nightmares are quite common in patients with sleep-related breathing disorders. Based on a previous study, we investigated whether patients would respond if they were specifically asked whether they would be interested in telephone counselling about nightmares and nightmare treatment.

Materials and methods

The present study included 537 patients with sleep-related breathing disorders who completed a nightmare questionnaire and—if interested—provided their contact data for a telephone counselling session.

Results

Of the total patients, 5.40% were interested in the telephone counselling. Most of these patients had never sought help for their nightmare condition before. This percentage is much lower than in a previous study, possibly due to the higher time expenditure related to the new consent procedure.

Conclusion

The findings indicate that patients with nightmare problems can be reached with this approach even though they have never sought professional help before. In order to minimize the threshold, it would be desirable to have clinical in-house nightmare counselling, which would not require a detailed study information brochure and informed consent.

Telephone-guided imagery rehearsal therapy for nightmares: Efficacy and mediator of change

The currently best‐supported psychological treatment for nightmares is imagery rehearsal therapy. The problem, however, is that not enough trained practitioners are available to offer this treatment. A possible solution is to conduct imagery rehearsal therapy in a guided self‐help format. In the current study, 70 participants with nightmares according to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders were randomized to either telephone‐guided imagery rehearsal therapy (n = 36) or a wait‐list condition (n = 34). Participants in the imagery rehearsal therapy condition received three sessions over the course of 5 weeks. Every treatment session was followed by telephone support delivered by postgraduate students. Participants who received imagery rehearsal therapy showed larger improvements on nightmare frequency (d = 1.03; p < .05), nightmare distress (d = 0.75; p < .05) and insomnia severity (d = 1.12; p < .001) compared with the participants in the wait‐list condition. The effects were sustained at 3‐ and 6‐month follow‐up. No significant effects were observed on the number of nights with nightmares per week, anxiety and depression. In line with earlier reports, the treatment effect was mediated by the increase of mastery at mid‐treatment, underlining the mechanistic value of mastery in imagery rehearsal therapy. The present study demonstrates that it is possible to deliver imagery rehearsal therapy in a self‐help format supported by unexperienced therapists and with relatively little time investment. This opens possibilities in terms of cost‐effectiveness, scalability and dissemination of imagery rehearsal therapy in the treatment of nightmares.

Stability of nightmare frequency and its relation to neuroticism: A longitudinal study

Models of nightmare aetiology postulate an interaction between trait and state factors. However, most of the studies that support these models have been cross-sectional and longitudinal studies are scarce. The present data were obtained from N = 888 participants completing two online dream studies carried out independently with the same online panel 2 years apart. Nightmare frequency declined over the 2-year period and these changes were related to changes in neuroticism. The effect of current psychopathology (state aspect) on nightmare frequency was significant but much smaller compared to the effect of previously measured nightmare frequency (trait aspect) and, thus, the study provided empirical evidence for diathesis-stress models. Future longitudinal studies should take a closer look at life events and other factors that increase and/or decrease nightmare frequencies.

Influence of Sleeping Patterns in Health and Academic Performance Among University Students

Sleep problems in university students are important and have implications for health, quality of life, and academic performance. Using an ex post facto design, a total sample of 855 students (55.7% women) participated in the study. Sleep assessment was conducted using the Pittsburgh Sleep Quality Index, the Nightmare Frequency Scale, the Nightmare Proneness Scale, and the Composite Morningness Scale. Women show a higher risk [OR = 2.61] of presenting poor sleep quality (> 5 points on the PSQI) compared with men (p < 0.001). Similarly, women reported a greater frequency of nightmares (p < 0.001, d = 0.60), greater propensity for nightmares (p < 0.001, d = 0.70) and a higher score on Item-5h of the PSQI regarding nightmares (p < 0.001, d = 0.59). Women, compared with men, show higher risk [OR = 2.84] for a sleep disorder related to nightmares (p = 0.012). Women need more time to reach a state of alertness after getting up (p = 0.022), and there was an interaction between sex and the alertness factor when evaluating the subjective quality of sleep (p = 0.030). Women show worse sleep quality and a higher frequency and propensity for suffering nightmares. When considering the relationship between sleep quality and academic performance, it is observed that students with poor sleep quality obtain lower academic scores (M = 7.21, SD = 0.805) than those with good sleep quality (M = 7.32, SD = 0.685), an effect that reaches significance (t = 2.116, p = 0.035). Regarding the relationship between the categorized chronotype and academic performance, students with a morning chronotype achieve better academic results (M = 7.41, SD = 0.89) than their evening counterparts (M = 7.15, SD = 0.76), although these differences have a small effect size (d = 0.31).

Mental Sleep Activity and Disturbing Dreams in the Lifespan

Sleep significantly changes across the lifespan, and several studies underline its crucial role in cognitive functioning. Similarly, mental activity during sleep tends to covary with age. This review aims to analyze the characteristics of dreaming and disturbing dreams at different age brackets. On the one hand, dreams may be considered an expression of brain maturation and cognitive development, showing relations with memory and visuo-spatial abilities. Some investigations reveal that specific electrophysiological patterns, such as frontal theta oscillations, underlie dreams during sleep, as well as episodic memories in the waking state, both in young and older adults. On the other hand, considering the role of dreaming in emotional processing and regulation, the available literature suggests that mental sleep activity could have a beneficial role when stressful events occur at different age ranges. We highlight that nightmares and bad dreams might represent an attempt to cope the adverse events, and the degrees of cognitive-brain maturation could impact on these mechanisms across the lifespan. Future investigations are necessary to clarify these relations. Clinical protocols could be designed to improve cognitive functioning and emotional regulation by modifying the dream contents or the ability to recall/non-recall them.

Cortical hyperarousal in NREM sleep normalizes from pre- to post- REM periods in individuals with frequent nightmares

Study Objectives

Frequent nightmares have a high prevalence and constitute a risk factor for psychiatric conditions, but their pathophysiology is poorly understood. Our aim was to examine sleep architecture and electroencephalographic markers—with a specific focus on state transitions—related to sleep regulation and hyperarousal in participants with frequent nightmares (NM participants) versus healthy controls.

Methods

Healthy controls and NM participants spent two consecutive nights in the sleep laboratory. Second night spectral power during NREM to REM sleep (pre-REM) and REM to NREM (post-REM) transitions as well as during NREM and REM periods were evaluated for 22 NM participants compared to 22 healthy controls with a similar distribution of age, gender, and dream recall frequency.

Results

We found significant differences between the groups in the pre-REM to post-REM changes in low- and high-frequency domains. NM participants experienced a lower amount of slow-wave sleep and showed increased beta and gamma power during NREM and pre-REM periods. No difference was present during REM and post-REM phases. Furthermore, while increased pre-REM high-frequency power seems to be mainly driven by post-traumatic stress disorder (PTSD) symptom intensity, decreased low-frequency activity occurred regardless of PTSD symptom severity.

Conclusion

Our findings indicate that NM participants had increased high-frequency spectral power during NREM and pre-REM periods, as well as relatively reduced slow frequency and increased fast frequency spectral power across pre-and post-REM periods. This combination of reduced sleep-protective activity and increased hyperarousal suggests an imbalance between sleep regulatory and wake-promoting systems in NM participants.

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.

Mediators of Change in Imagery Rescripting and Imaginal Exposure for Nightmares: Evidence From a Randomized Wait-List Controlled Trial

Imagery rescripting (IR) and imaginal exposure (IE) are two efficacious treatments for nightmare disorder, but their discrete underlying mechanism(s) remain largely unknown. We therefore examined mediators of the treatment effects of IR and IE in a randomized wait-list controlled trial (N = 104). Therapeutic outcomes were assessed at pre- and post-assessment, and mediator assessment took place in between treatment sessions to establish a temporal relationship between mediators and nightmare symptoms (i.e., frequency and distress). In line with the hypothesis, enhanced mastery (or self-efficacy) of the nightmare content mediated the therapeutic efficacy of IR. Furthermore, the treatment effects of IE were mediated by increased tolerability of the negative emotions elicited by nightmares. Even though IR and IE for nightmares seem to produce similar therapeutic effects, the results of this study suggest that IR and IE tap into different underlying processes.

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.

Psychometric evaluation of the Hamburg Nightmare Questionnaire (HNQ)

Background: Nightmares are a widespread phenomenon. In comparison to the general population, they occur in mentally ill and especially in traumatized individuals with an increased frequency. Despite the high prevalence, there is no short questionnaire in the German language that is able to characterize nightmares, to differentiate between different nightmare types and to assess their impact on daytime functioning. Objective: The Hamburg Nightmare Questionnaire (HNQ) has been developed as a short self-rating instrument to fill this gap. Method: Psychometric characteristics of the HNQ were evaluated in a sample of 707 German soldiers passing through the standard diagnostics of the Center for Mental Health at the German Armed Forces Hospital Hamburg. Results: The results of this study show satisfactory psychometric characteristics as a sound factorial structure and adequate internal consistency for the HNQ as well as initial indications of the construct validity of its subscales. Conclusions: The HNQ is a reliable and economic tool for the assessment of posttraumatic nightmares in clinical as well as research settings.

Aetiology and treatment of nightmare disorder: State of the art and future perspectives

This consensus paper provides an overview of the state of the art in research on the aetiology and treatment of nightmare disorder and outlines further perspectives on these issues. It presents a definition of nightmares and nightmare disorder followed by epidemiological findings, and then explains existing models of nightmare aetiology in traumatized and non‐traumatized individuals. Chronic nightmares develop through the interaction of elevated hyperarousal and impaired fear extinction. This interplay is assumed to be facilitated by trait affect distress elicited by traumatic experiences, early childhood adversity and trait susceptibility, as well as by elevated thought suppression and potentially sleep‐disordered breathing. Accordingly, different treatment options for nightmares focus on their meaning, on the chronic repetition of the nightmare or on maladaptive beliefs. Clinically, knowledge of healthcare providers about nightmare disorder and the delivery of evidence‐based interventions in the healthcare system is discussed. Based on these findings, we highlight some future perspectives and potential further developments of nightmare treatments and research into nightmare aetiology.

The factor structure, reliability and validity of the Chinese version of the Van Dream Anxiety Scale

BACKGROUND/PURPOSE

Dream emotions and contents are associated with psychological well-being. Dream disturbances, such as frequent nightmares and dream anxiety, are associated with a variety of psychopathological conditions. Therefore, it is important to consider nightmares and the resulting dream anxiety. To address this issue, the Van Dream Anxiety Scale (VDAS) was designed especially for measuring nightmare frequency and dream anxiety caused by frightening dreams. As a Chinese version of VDAS may be helpful in promoting study of nightmare and dream anxiety among Chinese population, in the current study, we sought to develop a Chinese version of the VDAS (CVDAS).

METHODS

We translated the VDAS into Chinese. To evaluate its validity and reliability, a sample of 1,081 Chinese college students from two universities answered the CVDAS, GAD-7, PHQ-9 and EPQ-R-N. Ninety of them answered the CVDAS twice. We also conducted exploratory factor analysis (EFA) to explore the structure of CVDAS.

RESULTS

Excellent internal consistency (Cronbach's alpha coefficient was 0.926), split-half reliability (equal-length Spearman-Brown coefficient was 0.938) and good test-retest reliability (the intraclass correlation coefficient was 0.942 and t=-1.478, P=0.143) of the CVDAS was presented. Exploratory factor analyses indicated a two-factor structure: sleep-related disturbances caused by nightmares and dysfunction caused by nightmares. Convergent and divergent validities were acceptable.

CONCLUSION

The CVDAS shows promise for the measurement of nightmare frequency and specific dream anxiety in Chinese population. Future study should confirm the reliability and validity in the clinical population and further improve this scale.

Validating Psychometric Questionnaires Using Experience-Sampling Data: The Case of Nightmare Distress

Nightmares are a comparatively frequent phenomenon. They are often accompanied by emotional distress and gain clinical relevance when recurrent. To assess how much distress nightmares cause the individual, the Nightmare Distress Questionnaire (NDQ, Belicki, 1992) is probably the most often used measure. However, its validity is still disputed. To analyze the validity of the proposed three NDQ subscales in more detail, we conducted an experience sampling study, gathering data either in real-time or short retrospective timeframes over the course of 22 days twice per day (N = 92 participants). The measurements were implemented via a mobile app using participants’ own smartphones. Besides the dream quality, we assessed concepts on a daily basis that past research found to be related to dreams. These included critical life events, alcohol consumption, eating behavior, and well-being. We found that only the subscales “general nightmare distress” and “impact on sleep” showed convergent as well as divergent validity. The validity of the subscale “impact on daily reality perception” is unclear. If at all, this subscale is rather indirectly associated with nightmare distress. Furthermore, all of the NDQ items did not differentiate between a bad dream and a nightmare, which suggests that the NDQ might rather be a measure of negative dreams in general and not nightmares in particular. Based on the present experience sampling design, we propose to advance the validation process by further possibilities, such as an item-level, person-level, and multi-level approach. This approach seems to be especially fruitful for concepts which are not very salient (e.g., laughter), can hardly be remembered retrospectively (e.g., dream content), or are potentially threatened by recall biases (e.g., alcohol consumption).

The Effects of an Internet-Based Imagery Rehearsal Intervention: A Randomized Controlled Trial

BACKGROUND

Nightmares are extremely dysphoric dreams, which are prevalent and associated with psychological strain. This study investigated (a) the efficacy of an internet-based imagery rehearsal therapy (IRT), (b) the role of imagery rescription, and (c) the role of guidance during internet-based IRT.

METHODS

A total of 127 patients suffering from mainly idiopathic nightmares were randomly assigned to 1 of 2 IRT internet-based groups (guided IRT; unguided IRT) or to 1 of 2 active control groups (frequency control group; narrative control group).

RESULTS

IRT was more effective than a nightmare frequency control condition with respect to nightmare frequency and nightmare distress. Compared to the narrative control group, IRT was only superior in improving nightmare distress but not in nightmare frequency because the narrative control group also improved regarding nightmare frequency. Guidance by a nightmare coach did not affect efficacy, compliance, or dropout.

CONCLUSION

Internet-based IRT seems to be an effective treatment even when offered with minimal guidance by a nightmare coach. Describing the nightmare narrative in detail already decreased nightmare frequency. However, with regard to inducing decreases in nightmare frequency and nightmare distress, IRT was superior to the narrative control group. The results are discussed with reference to the mastery hypothesis.

Nightmare Themes: An Online Study of Most Recent Nightmares and Childhood Nightmares

STUDY OBJECTIVES

Even though the common diagnostic criteria (ICSD-3, DSM-5) acknowledge that nightmares do not only contain anxiety/fear (definition of the ICD-10) but also other emotions such as grief, disgust, and anger, the definition of a nightmare still focuses on threats to survival, security, or physical integrity. However, empirical studies on nightmare content in larger samples are scarce.

METHODS

The current study elicited 1,216 of the most recent nightmares including childhood nightmares of a population-based sample.

RESULTS

The findings show that nightmares encompass a diversity of different topics, being chased, physical aggression, including death/injury of close persons. Infrequent themes like being the aggressor and suicide are of special interest as they might be related to waking-life psychopathology.

CONCLUSIONS

The variety of nightmare topics clearly indicate that current definitions of nightmare content are too narrow. Future studies should look into nightmare content of persons in whom nightmare disorder has been diagnosed.

Nightmares in United States Military Personnel With Sleep Disturbances

STUDY OBJECTIVES

Sleep disturbances are common in United States military personnel. Despite their exposure to combat and trauma, little is known about nightmares in this population. The purpose of this study was to describe the prevalence and associated clinical and polysomnographic characteristics of nightmares in United States military personnel with sleep disturbances.

METHODS

Retrospective review of 500 active duty United States military personnel who underwent a sleep medicine evaluation and polysomnography at our sleep center. The Pittsburgh Sleep Quality Index and the Pittsburgh Sleep Quality Index-Addendum were used to characterize clinically significant nightmares. Subjective and objective sleep attributes were compared between groups.

RESULTS

At least weekly nightmares were present in 31.2%; yet, only 3.9% reported nightmares as a reason for evaluation. Trauma-related nightmares occurred in 60% of those patients with nightmares. Patients with nightmares had increased sleep onset latency (SOL) and rapid eye movement (REM) sleep latency (mean SOL/REM sleep latency 16.6/145 minutes, P = .02 and P = .01 respectively) compared to those without (mean SOL/REM sleep latency 12.5/126 minutes). The comorbid disorders of depression (P ≤ .01, relative risk [RR] 3.55 [95% CI, 2.52-4.98]), anxiety (P ≤ .01, RR 2.57 [95% CI, 1.93-3.44]), posttraumatic stress disorder (P ≤ .01, RR 5.11 [95% CI, 3.43-7.62]), and insomnia (P ≤ .01, RR 1.59 [95% CI, 1.42-1.79]) were all associated with nightmares.

CONCLUSIONS

Clinically significant nightmares are highly prevalent in United States military personnel with sleep disturbances. Nightmares are associated with both subjective and objective sleep disturbances and are frequently comorbid with other sleep and mental health disorders.

COMMENTARY

A commentary on this article appears in this issue on page 303.