Disturbed dreaming and sleep quality: altered sleep architecture in subjects with frequent nightmares

Brief Psychoeducational and Cognitive Therapy for Nightmare Disorder (BPCT-ND)

In adults, nightmare disorder is related to sleep deprivation, drug consumption or abuse, or other comorbid sleep disorders such as insomnia or insufficient sleep syndrome. Behavioral treatment has solid scientific evidence in disorders such as insomnia and, more recently, parasomnias. The aim of the present study was to investigate the clinical effectiveness of a Brief Behavioral Telemedicine Therapy in Nightmare Disorder in a 23-year-old female patient. The procedure consisted of the case study, with pre and posttreatment measures as well as follow-up after 1 month; and the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, Paris Arousal Disorders Severity Scale, and a sleep diary were applied. In parallel with changes recorded in the sleep diary, a decrease in nightmares, sleepiness, and insomnia symptoms was observed when the intervention was finished. The behavioral intervention was clinically effective; therefore, the present case report provides information on behavioral treatments for nightmare disorder.

Nocturnal exposure to a preferred ambient scent does not affect dream emotionality or post-sleep core affect valence in young adults

Emotions experienced within sleep mentation (dreaming) affect mental functioning in waking life. There have been attempts at enhancing dream emotions using olfactory stimulation. Odors readily acquire affective value, but to profoundly influence emotional processing, they should bear personal significance for the perceiver rather than be generally pleasant. The main objective of the present sleep laboratory study was to examine whether prolonged nocturnal exposure to self-selected, preferred ambient room odor while asleep influences emotional aspects of sleep mentation and valence of post-sleep core affect. We asked twenty healthy participants (12 males, mean age 25 ± 4 years) to pick a commercially available scented room diffuser cartridge that most readily evoked positively valenced mental associations. In weekly intervals, the participants attended three sessions. After the adaptation visit, they were administered the odor exposure and odorless control condition in a balanced order. Participants were awakened five minutes into the first rapid eye movement (REM) stage that took place after 2:30 a.m. and, if they had been dreaming, they were asked to rate their mental sleep experience for pleasantness, emotional charge, and magnitude of positive and negative emotions and also to evaluate their post-sleep core affect valence. With rs < 0.20, no practically or statistically significant differences existed between exposure and control in any outcome measures. We conclude that in young, healthy participants, the practical value of olfactory stimulation with self-selected preferred scents for enhancement of dream emotions and post-sleep core affect valence is very limited.

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.

Short-term stability and night-to-night variability of sleep parameters in nightmares comorbid with chronic insomnia Disorder across multiple nights of polysomnography

STUDY OBJECTIVES

The purpose of this study was to examine the degree of short-term stability of polysomnographic (PSG) measured sleep parameters and the overall differences between individuals with comorbid nightmares and insomnia compared to those with chronic insomnia disorder alone or good sleeping controls across four nights in the sleep lab.

METHODS

A total of 142 good sleeping controls, 126 chronic insomnia alone, and 24 comorbid insomnia/nightmare participants underwent four consecutive nights of 8-hour PSG recordings. Outcomes included sleep continuity, architecture, and REM-related parameters across nights one through four. Intraclass correlation coefficients with mixed-effect variances and repeated-measure analysis of covariance were used, respectively, to determine short-term stability as well as between-participants and time-by-group interaction effects.

RESULTS

Wake after sleep onset and stage 1 showed "poor stability" in the comorbid insomnia/nightmare group compared to "moderate stability" in the good sleeping controls and chronic insomnia alone group. Significant between-group effects (all ps < .05) showed that the comorbid insomnia/nightmare group took longer to fall asleep and had a greater first-night-effect in stage 1 compared to good sleeping controls and chronic insomnia alone group; in addition, the comorbid insomnia/nightmare and insomnia alone groups slept shorter, with fewer awakenings and REM periods, compared to the good sleeping controls.

CONCLUSIONS

Nightmares are associated with abnormal sleep above and beyond REM disruption, as sleep continuity was the primary aspect in which poor stability and group differences emerged. The greater inability to fall asleep and instability of sleep fragmentation in those with comorbid insomnia/nightmares compared to chronic insomnia alone may be attributed to the impact of presleep anticipatory anxiety and nightmare-related distress itself.

CLINICAL TRIAL INFORMATION

The data analyzed in this study does not come from any current or previous clinical trials. Therefore, there is no clinical trial information to report.

Cortical hyperarousal in individuals with frequent nightmares

Nightmares are common among the general population and psychiatric patients and have been associated with signs of nocturnal arousal such as increased heart rate or increased high-frequency electroencephalographic (EEG) activity. However, it is still unclear, whether these characteristics are more of a trait occurring in people with frequent nightmares or rather indicators of the nightmare state. We compared participants with frequent nightmares (NM group; n = 30) and healthy controls (controls; n = 27) who spent 4 nights in the sleep laboratory over the course of 8 weeks. The NM group received six sessions of imagery rehearsal therapy (IRT), the 'gold standard' of cognitive-behavioural therapy for nightmares, between the second and the third night. Sleep architecture and spectral power were compared between groups, and between nights of nightmare occurrence and nights without nightmare occurrence in the NM group. Additionally, changes before and after therapy were recorded. The NM group showed increased beta (16.25-31 Hz) and low gamma (31.25-35 Hz) power during the entire night compared to the controls, but not when comparing nights of nightmare occurrence to those without. Moreover, low gamma activity in rapid eye movement sleep was reduced after therapy in the NM group. Our findings indicate, cortical hyperarousal is more of a trait in people with frequent nightmares within a network of other symptoms, but also malleable by therapy. This is not only a new finding for IRT but could also lead to improved treatment options in the future that directly target high-frequency EEG activity.

Clinical neurophysiology of REM parasomnias: Diagnostic aspects and insights into pathophysiology

Parasomnias are due to a transient unstable state dissociation during entry into sleep, within sleep, or during arousal from sleep, and manifest with abnormal sleep related behaviors, perceptions, emotions, dreams, and autonomic nervous system activity. Rapid eye movement (REM) parasomnias include REM sleep behavior disorder (RBD), isolated recurrent sleep paralysis and nightmare disorder. Neurophysiology is key for diagnosing these disorders and provides insights into their pathophysiology. RBD is very well characterized from a neurophysiological point of view, also thank to the fact that polysomnography is needed for the diagnosis. Diagnostic criteria are provided by the American Academy of Sleep Medicine and video-polysomnography guidelines for the diagnosis by the International REM Sleep Behavior Disorder Study Group. Differences between the two sets of criteria are presented and discussed. Availability of polysomnography in RBD provides data on sleep electroencephalography (EEG), electrooculography (EOG) and electromyography (EMG). Sleep EEG in RBD shows e.g. changes in delta and theta power, in sleep spindles and K complexes. EMG during REM sleep is essential for RBD diagnosis and is an important neurodegeneration biomarker. RBD patients present alterations also in wake EEG, autonomic function, evoked potentials, and transcranial magnetic stimulation. Clinical neurophysiological data on recurrent isolated sleep paralysis and nightmare disorder are scant. The few available data provide insights into the pathophysiology of these disorders, demonstrating a state dissociation in recurrent isolated sleep paralysis and suggesting alterations in sleep macro- and microstructure as well as autonomic changes in nightmare disorder.

Sleep tight! Adolescent sleep quality across three distinct sleep ecologies

Background and objectives

Good sleep quality, associated with few arousals, no daytime sleepiness and self-satisfaction with one's sleep, is pivotal for adolescent growth, maturation, cognition and overall health. This article aims to identify what ecological factors impact adolescent sleep quality across three distinct sleep ecologies representing a gradient of dense urbanity to small, rural environments with scarce artificial lighting and no Internet.

Methodology

We analyze variation of sleep efficiency, a quantitative measure of sleep quality-defined as the ratio of total time spent asleep to total time dedicated to sleep-in two agricultural indigenous populations and one post-industrial group in Mexico (Campeche = 44, Puebla = 51, Mexico City = 50, respectively). Data collection included actigraphy, sleep diaries, questionnaires, interviews and ethnographic observations. We fit linear models to examine sleep efficiency variation within and between groups.

Results

We found that sleep efficiency varied significantly across sites, being highest in Mexico City (88%) and lowest in Campeche (75%). We found that variation in sleep efficiency was significantly associated with nightly exposure to light and social sleep practices.

Conclusions and implications

Our findings point toward contextual cost-benefits of sleep disruption in adolescence. We highlight the need to prioritize research on adolescent sleep quality across distinct developmental ecologies and its impact on health to improve adolescent wellbeing through evidence-based health practices.

Nightmares: an independent risk factor for cardiovascular disease?

STUDY OBJECTIVES

Prior work has established associations between post-traumatic stress disorder (PTSD), disrupted sleep, and cardiovascular disease (CVD), but few studies have examined health correlates of nightmares beyond risks conferred by PTSD. This study examined associations between nightmares and CVD in military veterans.

METHODS

Participants were veterans (N = 3468; 77% male) serving since September 11, 2001, aged 38 years (SD = 10.4); approximately 30% were diagnosed with PTSD. Nightmare frequency and severity were assessed using the Davidson Trauma Scale (DTS). Self-reported medical issues were assessed using the National Vietnam Veterans Readjustment Study Self-report Medical Questionnaire. Mental health disorders were established using the Structured Clinical Interview for DSM-IV. The sample was stratified by the presence or absence of PTSD. Within-group associations between nightmare frequency and severity and self-reported CVD conditions, adjusting for age, sex, race, current smoking, depression, and sleep duration.

RESULTS

Frequent and severe nightmares during the past week were endorsed by 32% and 35% of participants, respectively. Those endorsing nightmares that were frequent, severe, and the combination thereof were more likely to also evidence high blood pressure (ORs 1.42, OR 1.56, and OR 1.47, respectively) and heart problems (OR 1.43, OR 1.48, and OR 1.59, respectively) after adjusting for PTSD diagnosis and other covariates.

CONCLUSIONS

Nightmare frequency and severity among veterans are associated with cardiovascular conditions, even after controlling for PTSD diagnosis. Study findings suggest that nightmares may be an independent risk factor for CVD. Additional research is needed to validate these findings using confirmed diagnoses and explore potential mechanisms.

Autonomic activity, posttraumatic and nontraumatic nightmares, and PTSD after trauma exposure

BACKGROUND

Nightmares are a hallmark symptom of posttraumatic stress disorder (PTSD). This strong association may reflect a shared pathophysiology in the form of altered autonomic activity and increased reactivity. Using an acoustic startle paradigm, we investigated the interrelationships of psychophysiological measures during wakefulness and PTSD diagnosis, posttraumatic nightmares, and nontraumatic nightmares.

METHODS

A community sample of 122 trauma survivors were presented with a series of brief loud tones, while heart rate (HRR), skin conductance (SCR), and orbicularis oculi electromyogram (EMGR) responses were measured. Prior to the tone presentations, resting heart rate variability (HRV) was assessed. Nightmares were measured using nightmare logs. Three dichotomous groupings of participants were compared: (1) current PTSD diagnosis (n = 59), no PTSD diagnosis (n = 63), (2) those with (n = 26) or without (n = 96) frequent posttraumatic nightmares, and (3) those with (n = 22) or without (n = 100) frequent nontraumatic nightmares.

RESULTS

PTSD diagnosis was associated with posttraumatic but not with nontraumatic nightmares. Both PTSD and posttraumatic nightmares were associated with a larger mean HRR to loud tones, whereas nontraumatic nightmare frequency was associated with a larger SCR. EMGR and resting HRV were not associated with PTSD diagnosis or nightmares.

CONCLUSIONS

Our findings suggest a shared pathophysiology between PTSD and posttraumatic nightmares in the form of increased HR reactivity to startling tones, which might reflect reduced parasympathetic tone. This shared pathophysiology could explain why PTSD is more strongly related to posttraumatic than nontraumatic nightmares, which could have important clinical implications.

Enhancing imagery rehearsal therapy for nightmares with targeted memory reactivation

Nightmare disorder (ND) is characterized by dreams with strong negative emotions occurring during rapid eye movement (REM) sleep. ND is mainly treated by imagery rehearsal therapy (IRT), where the patients are asked to change the negative story line of their nightmare to a more positive one. We here used targeted memory reactivation (TMR) during REM sleep to strengthen IRT-related memories and accelerate remission of ND. Thirty-six patients with ND were asked to perform an initial IRT session and, while they generated a positive outcome of their nightmare, half of the patients were exposed to a sound (TMR group), while no such pairing took place for the other half (control group). During the next 2 weeks, all patients performed IRT every evening at home and were exposed to the sound during REM sleep with a wireless headband, which automatically detected sleep stages. The frequency of nightmares per week at 2 weeks was used as the primary outcome measure. We found that the TMR group had less frequent nightmares and more positive dream emotions than the control group after 2 weeks of IRT and a sustained decrease of nightmares after 3 months. By demonstrating the effectiveness of TMR during sleep to potentiate therapy, these results have clinical implications for the management of ND, with relevance to other psychiatric disorders too. Additionally, these findings show that TMR applied during REM sleep can modulate emotions in dreams.

The Nightmare Quality of Life Questionnaire

RATIONALE

Patient-centered outcomes are increasingly sought to evaluate social interactions and healthcare interventions in patients with sleep disorders. Yet, measures to assess quality of life (QoL) are lacking for those who experience nightmares.

OBJECTIVE

The aim of the study is to describe the development and validation of a new health-related quality of life (HRQoL) instrument for patients with nightmares.

METHODS

Attributes obtained from a focus group of patients (n = 113) with established nightmares were analyzed using exploratory factor analysis to elicit salient QoL themes for the new instrument. A validation cohort (n = 34) was used to determine the psychometric performance of the 16-item questionnaire including item-scaling, concurrent validity, and test-retest reliability tested four weeks apart.

RESULTS

Four factors (sleep health, emotional and psychological well-being, social interaction, and motivation) explained 53.9% of the total variance. The Nightmare Quality of Life (NQoL) showed good internal consistency (Cronbach's alpha 0.85) and test-retest reliability (ICC = 0.89). Concurrent validity was evidenced by a strong correlation with the Nightmare Distress Questionnaire (r = 0.87; p < .001) and more modest associations with the Nightmare Frequency Questionnaire (r = , 0.69; p < .001), SF-36 (r = -0.68; p < .001), and PSQI (r = 0.45; p = .007).

CONCLUSIONS

The NQoL has demonstrable construct validity and reliability and represents a promising multi-dimensional instrument to assess outcome measures for quality of life in patients with nightmares.

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.

The heartbeat evoked potential is a questionable biomarker in nightmare disorder: A replication study

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Perogamvros et al. (2013) examined heart beat evoked potential (HEP) in nightmare sufferers.

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Increased HEP was proposed to be a robust biomarker in nightmare disorder.

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We aimed to replicate the original study in two separate and larger databases.

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We did not confirm the original finding showing differential HEP in REM sleep.

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Our data cast doubts on the utility of HEP as a biomarker in nightmare disorder.

Frequent nightmares are highly prevalent and constitute a risk factor for a wide range of psychopathological conditions. Despite its prevalence and clinical relevance however, the pathophysiological mechanisms of nightmares are poorly understood. A recent study (Perogamvros et, al 2019) examined the heart beat evoked potential (HEP) in a small group of nightmare sufferers (N = 11) and matched healthy controls (N = 11) and observed markedly different (Hedges’ g = 1.42 [0.62–2.22]) HEP response across the groups during Rapid Eye Movement (REM) sleep. Moreover, the HEP correlated with depression scores in the nightmare group only. The authors concluded that the HEP in REM sleep could be used as a trait-like biomarker reflecting pathological emotional-and sleep regulation in nightmare disorder. To replicate the above study, we performed the same analyses of HEPs in two separate, and larger databases comprising the polysomnographic recordings of nightmare sufferers and matched controls (N_{Study 1} = 39 ; N_{Study 2} = 41). In contrast to the original findings, we did not observe significant differences in HEP across the two groups in either of the two databases. Moreover, we found no associations between depression scores and HEP amplitudes in the relevant spatiotemporal cluster. Our data cast doubts on the utility of HEP as a biomarker in the diagnostic and treatment procedures of nightmare disorder and suggests that the interpretation of HEP as a marker of impaired arousal and emotional processing during REM sleep is premature and requires further validation.

Nightmares in Children with Foetal Alcohol Spectrum Disorders, Autism Spectrum Disorders, and Their Typically Developing Peers

Children with Foetal Alcohol Spectrum Disorders (FASD) and Autism Spectrum Disorders (ASD) experience significantly higher rates of sleep disturbances than their typically developing (TD) peers. Pre-sleep anxiety and waking emotional content is known to affect the content and frequency of nightmares, which can be distressing to children and caregivers. This is the first study to analyse nightmare frequency and content in FASD, and to assess its association with psychometric outcomes. Using online caregiver questionnaires, we assessed reports from 277 caregivers of children with ASD (n = 61), FASD (n = 112), and TD children (n = 104) using the Children's Sleep Habits Questionnaire (CSHQ), the Child Behaviour Checklist (CBCL), the Spence Children's Anxiety Scale (SCAS), and the Behaviour Rating Inventory for Executive Functioning (BRIEF). Within the ASD group, 40.3% of caregivers reported their children had nightmares. Within the FASD group, 73.62% of caregivers reported their children had nightmares, and within the TD group, 21.36% of caregivers reported their children had nightmares. Correlation analysis revealed significant associations between anxiety and nightmares, maladaptive behaviour and nightmares, and executive functioning and nightmares in the TD and FASD groups, but not ASD group. This paper adds to the emerging body of work supporting the need for sleep interventions as part of clinical practice with regard to children with ASD and FASD. As a relatively niche but important area of study, this warrants much needed further research.

Cortical monitoring of cardiac activity during rapid eye movement sleep: the heartbeat evoked potential in phasic and tonic rapid-eye-movement microstates

Sleep is a fundamental physiological state that facilitates neural recovery during periods of attenuated sensory processing. On the other hand, mammalian sleep is also characterized by the interplay between periods of increased sleep depth and environmental alertness. Whereas the heterogeneity of microstates during non-rapid-eye-movement (NREM) sleep was extensively studied in the last decades, transient microstates during rapid-eye-movement (REM) sleep received less attention. REM sleep features two distinct microstates: phasic and tonic. Previous studies indicate that sensory processing is largely diminished during phasic REM periods, whereas environmental alertness is partially reinstated when the brain switches into tonic REM sleep. Here, we investigated interoceptive processing as quantified by the heartbeat evoked potential (HEP) during REM microstates. We contrasted the HEPs of phasic and tonic REM periods using two separate databases that included the nighttime polysomnographic recordings of healthy young individuals (N = 20 and N = 19). We find a differential HEP modulation of a late HEP component (after 500 ms post-R-peak) between tonic and phasic REM. Moreover, the late tonic HEP component resembled the HEP found in resting wakefulness. Our results indicate that interoception with respect to cardiac signals is not uniform across REM microstates, and suggest that interoceptive processing is partially reinstated during tonic REM periods. The analyses of the HEP during REM sleep may shed new light on the organization and putative function of REM microstates.

Local Neuronal Synchronization in Frequent Nightmare Recallers and Healthy Controls: A Resting-State Functional Magnetic Resonance Imaging Study

Nightmares are highly dysphoric dreams that are well-remembered upon awakening. Frequent nightmares have been associated with psychopathology and emotional dysregulation, yet their neural mechanisms remain largely unknown. Our neurocognitive model posits that nightmares reflect dysfunction in a limbic-prefrontal circuit comprising medial prefrontal and anterior cingulate cortices, hippocampus, and amygdala. However, there is a paucity of studies that used brain imaging to directly test the neural correlates of nightmares. One such study compared the regional homogeneity (ReHo) of resting-state functional magnetic resonance imaging blood-oxygen level-dependent signals between frequent nightmare recallers and controls. The main results were greater regional homogeneity in the left anterior cingulate cortex and right inferior parietal lobule for the nightmare recallers than for the controls. In the present study, we aimed to document the ReHo correlates of frequent nightmares using several nightmare severity measures. We acquired resting-state functional magnetic resonance imaging data from 18 frequent nightmare recallers aged 18-35 (3 males and 15 females) and 18 age- and sex-matched controls, as well as retrospective and prospective disturbed dreaming frequency estimates and scores on the Nightmare Distress Questionnaire. While there were inconsistent results for our different analyses (group comparisons, correlational analyses for frequency estimates/Nightmare Distress scores), our results suggest that nightmares are associated with altered ReHo in frontal (medial prefrontal and inferior frontal), parietal, temporal and occipital regions, as well as some subcortical regions (thalamus). We also found a positive correlation between retrospective disturbed dreaming frequency estimates and ReHo values in the hippocampus. These findings are mostly in line with a recent SPECT study from our laboratory. Our results point to the possibility that a variety of regions, including but not limited to the limbic-prefrontal circuit of our neurocognitive model, contribute to nightmare formation.

Prevalence and Characteristics of Posttraumatic Nightmares in War- and Conflict-Affected Students

INTRODUCTION

Recurrent nightmares, frequently associated with traumatic experiences, may impair quality of life and daily functioning. However, there have been few studies of posttraumatic nightmares occurring among children and youth, in particular for trauma-exposed populations in conflict zones.

METHODS

Using two quantitative data sets, this study investigates the prevalence and characteristics of recurrent nightmares among conflict-exposed young people in the Gaza Strip (N = 300) and examines the characteristics of posttraumatic nightmares and their association with academic functioning among treatment-seeking students in Gaza (N = 1093).

RESULTS

Among 300 students (10-12 years old) who lived in the ongoing conflict area in Gaza, nightmares were often mentioned, with 56% reporting recurrent nightmares with an average weekly frequency of 4.20 nights in the past week (SD = 1.94) and a mean duration of 2.48 years (SD = 2.01). Similarly, the large sample of 1093 students (6-17 years of age) who sought help for nightmares and sleep disturbance reported recurrent traumatic nightmares on average 4.57 nights per week, with an average duration of 2.82 years. Their self-reported academic functioning was negatively affected by whether they experienced nightmares but was not associated with nightmare frequency or intensity.

DISCUSSION

Given the high prevalence of nightmares and the relation between nightmares and academic functioning, students in conflict-affected areas appear to be a particularly vulnerable group. This study proposes screening and treating conflict-affected students for recurrent posttraumatic nightmares.

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 all-night exposure to ambient odour on dreams and affective state upon waking

Previous laboratory research has shown that exposure to odours of contrasting pleasantness during sleep differentially affects the emotional tone of dreams. In the present study, we sought to investigate how a generally pleasant (vanillin) and unpleasant (thioglycolic acid [TGA]) smell influenced various dream characteristics, dream emotions, and post-sleep core affect during all-night exposure, controlling for appraisal of the olfactory environment during the assessments and sleep stage from which the participants woke up. We expected that exposure to vanillin would result in more pleasant dreams, more positive and less negative dream emotions, and a more positive post-sleep core affect compared to the control condition, whereas exposure to TGA would have the opposite effect. Sixty healthy volunteers (36 males, mean age 24 ± 4 years) were invited to visit the sleep laboratory three times in weekly intervals. The first visit served to adapt the participants to the laboratory environment. On the second visit, half the participants were exposed to an odour (vanillin or TGA, 1:1) and the other half to the odourless control condition. On the third visit, they received control or exposure in a balanced order. On each visit, the participants woke up twice, first from the rapid eye movement (REM) sleep stage and then in the morning, usually from a non-REM sleep stage. Repeated measures were taken upon each awakening. Dream pleasantness, emotional charge of the dream, positive and negative emotions experienced in the dream, and four dimensions of post-sleep core affect (valence, activation, pleasant activation - unpleasant deactivation, and unpleasant activation - pleasant deactivation) were assessed. We found a small effect of condition (exposure vs. control) in interaction with appraisal of the ambient olfactory environment on dream pleasantness. Specifically, false alarms (i.e., perceiving odour in the absence of the target stimulus) were associated with lower dream pleasantness than correct rejections. Although exposure had a statistically significant positive influence on post-sleep core affect (namely, valence, activation, and pleasant activation - unpleasant deactivation), the size of the effect was small and lacked practical significance. The hypothesised differential effects of vanillin and TGA were only modelled for dream ratings because they decreased the fit of the other models. Neither dream pleasantness nor emotionality differed according to the odour used for stimulation. The results of the present study suggest that all-night exposure to odours is unlikely to produce practically significant positive effects on dreams and post-sleep core affect.

Treatment of comorbid sleep disorders and posttraumatic stress disorder in active duty military: Design and methodology of a randomized clinical trial

Many individuals with posttraumatic stress disorder (PTSD) also suffer from insomnia and nightmares, which may be symptoms of PTSD or constitute partially independent comorbid disorders. Sleep disturbances are resistant to current treatments for PTSD, and those suffering from PTSD, insomnia, and nightmares have worse PTSD treatment outcomes. In addition, insomnia and nightmares are risk factors for depression, substance abuse, anxiety, and suicide. Cognitive-Behavioral Therapy for Insomnia and Nightmares (CBT-I&N) and Cognitive Processing Therapy (CPT) for PTSD are first line treatments of these conditions. CPT does not typically address insomnia or nightmares, and CBT-I&N does not typically address other symptoms of PTSD. There are limited scientific data on how best to provide these therapies to individuals suffering with all three disorders. This project aims to inform the most effective way to treat individuals suffering from PTSD, insomnia, and nightmares, potentially changing the standard of care. U.S. military personnel and recently discharged Veterans who served in support of combat operations following 9/11 aged 18-65 with PTSD, insomnia, and nightmares (N = 222) will be randomly assigned to one of the following 18-session individual treatment conditions delivered over 12-weeks: (1) 6 sessions of CBT-I&N followed by 12 sessions of CPT; (2) 12 sessions of CPT followed by 6 sessions of CBT-I&N; or (3) 12 sessions of CPT followed by an additional 6 sessions of CPT. All participants will be assessed at baseline, during treatment, and at 1-week, 1-month, 3-months, and 6-months posttreatment. The primary outcome will be PTSD symptom severity.

Nightmare experience and personality disorder functioning styles in healthy volunteers and nightmare disorder patients

Nightmares are prevalent in psychiatric disorders, and personality disorder features might be associated with nightmare experience, especially in nightmare disorder patients. The authors invited 219 healthy volunteers and 118 nightmare disorder patients to undergo tests of the Nightmare Experience Questionnaire (NEQ), the Parker Personality Measure (PERM), and the Plutchik-van Praag Depression Inventory. Compared to healthy volunteers, nightmare disorder patients scored significantly higher on annual nightmare frequency and NEQ Physical Effect, Negative Emotion, Meaning Interpretation, and Horrible Stimulation, and higher on PERM Paranoid, Schizotypal, Borderline, Histrionic, Narcissistic, Avoidant, and Dependent styles. Borderline, Schizotypal, and Passive-Aggressive styles in healthy volunteers and Dependent, Avoidant, Histrionic, and Paranoid in patients were significant predictors of some NEQ scales. Higher annual nightmare frequency, higher scale scores of nightmare experience and personality disorder styles, and more associations between the two were found in nightmare disorder patients, implying the need for personality-adjustment therapy for nightmare disorder.

Sleep problems in active duty military personnel seeking treatment for posttraumatic stress disorder: presence, change, and impact on outcomes

Study Objectives

To examine sleep disorder symptom reports at baseline and posttreatment in a sample of active duty U.S. Army Soldiers receiving treatment for posttraumatic stress disorder (PTSD). Explore sleep-related predictors of outcomes.

Methods

Sleep was evaluated in 128 participants in a parent randomized clinical trial comparing Spaced formats of Prolonged Exposure (PE) or Present Centered Therapy and a Massed format of PE. In the current study, Spaced formats were combined and evaluated separately from Massed.

Results

At baseline, the average sleep duration was &lt; 5 h per night on weekdays/workdays and &lt; 6 h per night on weekends/off days. The majority of participants reported clinically significant insomnia, clinically significant nightmares, and probable sleep apnea and approximately half reported excessive daytime sleepiness at baseline. Insomnia and nightmares improved significantly from baseline to posttreatment in all groups, but many patients reported clinically significant insomnia (&gt;70%) and nightmares (&gt;38%) posttreatment. Excessive daytime sleepiness significantly improved only in the Massed group, but 40% continued to report clinically significant levels at posttreatment. Short sleep (Spaced only), clinically significant insomnia and nightmares, excessive daytime sleepiness, and probable sleep apnea (Massed only) at baseline predicted higher PTSD symptoms across treatment course. Short weekends/off days sleep predicted lower PTSD symptom improvement in the Spaced treatments.

Conclusions

Various sleep disorder symptoms were high at baseline, were largely unchanged with PTSD treatment, and were related to worse PTSD treatment outcomes. Studies are needed with objective sleep assessments and targeted sleep disorders treatments in PTSD patients.

Clinical Trial Registration

NCT01049516.

Hyperarousal captured in increased number of arousal events during pre-REM periods in individuals with frequent nightmares

The aim of this study was to investigate hyperarousal in individuals with frequent nightmares (NM participants) by calculating arousal events during nocturnal sleep. We hypothesized an increased number of arousals in NM participants compared with controls, especially during those periods where the probability of spontaneous arousal occurrence is already high, such as non-rapid eye movement to rapid eye movement transitions (pre-rapid eye movement periods). Twenty-two NM participants and 23 control participants spent two consecutive nights in our sleep laboratory, monitored by polysomnography. Arousal number and arousal length were calculated only for the second night, for 10 min before rapid eye movement (pre-rapid eye movement) and 10 min after rapid eye movement (post-rapid eye movement) periods, as well as non-rapid eye movement and rapid eye movement phases separately. Repeated-measures ANOVA model testing revealed significant Group (NM participants, controls) × Phase (pre-rapid eye movement, post-rapid eye movement) interaction in case of the number of arousals. Furthermore, post hoc analysis showed a significantly increased number of arousals during pre-rapid eye movement periods in NM participants, compared with controls, a difference that disappeared in post-rapid eye movement periods. We propose that focusing the analyses of arousals specifically on state transitory periods offers a unique perspective into the fragile balance between the sleep-promoting and arousal systems. This outlook revealed an increased number of arousals in NM participants, reflecting hyperarousal during pre-rapid eye movement periods.

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.

Sleep problems in advanced disease

Sleep problems are relatively common in patients with advanced disease, and are associated with significant morbidity in these groups of patients. The focus of this article is sleep problems in patients with advanced cancer, and specifically insomnia, 'vivid' dreams and nightmares. However, other sleep problems are also relatively common in this group of patients, including sleep-related breathing disorders and circadian rhythm sleep-wake disorders. Healthcare professionals should screen all patients with advanced diseases for sleep problems and, equally, initiate appropriate (evidence-based) interventions when they are discovered.

Factors involved in sleep efficiency: a population-based study of community-dwelling elderly persons

STUDY OBJECTIVES

Research indicates that sleep efficiency below 80% substantially increases mortality risk in elderly persons. The aim of this study was to identify factors that would best predict poor sleep efficiency in the elderly, and to determine whether associations between these factors and sleep efficiency were similar for men and women and for younger and older elderly persons.

METHODS

A total of 2468 individuals aged 65-96 years (40.7% men) participated. They were recruited via random generation of telephone numbers according to a geographic sampling strategy. The participants agreed to have health professionals visit their home and to answer structured interview questions. Sleep efficiency was calculated based on interview responses. Descriptive statistics and logistic regressions were conducted.

RESULTS

The factors most strongly associated with sleep efficiency below 80% were pain, nocturia, sleep medication use, and awakening from bad dreams. Some factors varied by sex: women aged 75 years and older or who had an anxiety disorder were more likely to have sleep efficiency below 80%, whereas being single or having painful illness raised the likelihood for men only. Except for sex, all the factors that showed associations with sleep efficiency affected younger and older elderly persons similarly.

CONCLUSIONS

Poor sleep efficiency is prevalent among elderly persons. The results shed new light on factors associated with poor sleep efficiency, highlighting the presence of sex differences and that certain factors make no significant contribution, such as typically proscribed sleep hygiene behaviors, mood disorders, and illness in general.

Increased heartbeat-evoked potential during REM sleep in nightmare disorder

Nightmares are characterized by the experience of strong negative emotions occurring mainly during REM sleep. Some people suffer from nightmare disorder, which is defined by the repeated occurrence of nightmares and by significant distress in wakefulness. Yet, whether frequent nightmares relate to a general increase in emotional reactivity or arousal during sleep remains unclear. To address this question, we recorded heartbeat-evoked potentials (HEPs) during wakefulness, NREM and REM sleep in patients with nightmare disorder and healthy participants. The HEP represents a cortical (EEG) response to the heartbeat and indexes brain-body interactions, such as interoceptive processing and intrinsic levels of arousal. HEP amplitude is typically increased during states of high emotional arousal and motivation, and is decreased in depression. Here we compared the amplitude of HEPs between nightmare patients and healthy controls separately during AWAKE, NREM, REM periods, and found higher HEP amplitude in nightmare patients compared to healthy controls over a cluster of frontal regions only during REM sleep. This effect was not paralleled by any group difference in cardiac control measures (e.g. heart rate variability, interbeat interval). These findings corroborate the notion that nightmares are essentially a REM pathology and suggest that increased emotional arousal during REM sleep, as measured by HEP, is a physiological condition responsible for frequent nightmares. This result also supports that HEP may be used as a biomarker of increased emotional and sensory processing during REM sleep in these patients.

What Do You Think About Your Dreams? The Construction of a Belief About Dreams Questionnaire

BACKGROUND AND PURPOSE

Nightmare distress (ND) is associated with a broad spectrum of psychopathological conditions such as anxiety, depression and bipolar disorder. Some studies have indicated that dream beliefs play an important role in the occurrence and treatment of nightmare distress. However, existing instruments used to assess dream beliefs either fail to satisfy the requirements of the psychometrics or fail to capture the essence of dream beliefs. This research pursued two objectives: (1) to develop a questionnaire, called the Beliefs About Dreams Questionnaire (BADQ), to measure beliefs people hold about their dreams and (2) to describe the dream beliefs of Chinese college students.

METHODS

The structure and items on the BADQ were based on the previous literature and were the result of an open questionnaire. Some items were deleted through expert review and the result of predict test. To evaluate its validity and reliability, a sample of 1408 Chinese college students from two universities answered the BADQ, the Chinese version of Van Dream Anxiety Scale (CVDAS), the Dream Survey Questionnaire (DSQ), the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7(GAD-7) Questionnaire. After two weeks, 95 of them answered the BADQ again. Exploratory factor analysis (n=704) and confirmatory factor analysis (n=704) were conducted to explore and verify the structure of BADQ. The correlation between the CVDAS and the BADQ was calculated to evaluate the divergent validity.

RESULTS

The BADQ contains 26 items. Exploratory factor analysis indicated a five-factor structure: Dream omen and health, Dream superstitions, Dream meaninglessness, Dream reality, and Dream attitude. The result of the confirmatory factor analysis also supported the five-factors structure. Acceptable internal consistency (Cronbach's α of all subscales exceeded 0.80) and ordinary to moderate test-retest reliability (the intraclass correlation coefficient of all subscales ranged from 0.467 to 0.713) of the BADQ were presented. Low degree correlation between the CVDAS and the BADQ (ranged from to -0.052 to 0.219) showed that they were two different variables, indicating a good divergent validity.

CONCLUSION

The present investigation revealed moderate to high construct validity and reliability of the BADQ.

Frequent nightmares in Chinese patients undergoing methadone maintenance therapy: prevalence, correlates, and their association with functional impairment

PURPOSE

Nightmares are associated with many negative health outcomes; however, little is known about the characteristics of nightmares in heroin-dependent patients (HDPs). This study examined the prevalence and correlates of frequent nightmares (FNs) and their association with functional impairment in Chinese patients undergoing methadone maintenance therapy (MMT).

PATIENTS AND METHODS

In total, 603 Chinese HDPs from three MMT clinics in Wuhan, China, completed this survey. FNs were defined as reporting nightmares at least once a week. The Sheehan Disability Scale (ShDS) was used to assess the severity of functional impairment of patients. A standardized questionnaire was used to collect data on socio-demographics, drug use characteristics, physical health, mental health, and insomnia.

RESULTS

The prevalence of FNs in Chinese HDPs receiving MMT was 25.9%. Factors significantly associated with nightmares among MMT HDPs included an educational attainment of senior high school and above (OR=2.73, P<0.001), unemployment (OR=3.16, P<0.001), a history of re-education through forced labor (OR=3.14, P<0.001), injecting heroin before MMT (OR=3.62, P=0.002), a high dose of methadone (>70 mg/day) (OR=2.03, P=0.006), use of hypnotics (OR=1.91, P=0.044), the presence of hepatitis B virus core antibody (OR=4.63, P<0.001), pain (OR=3.20, P<0.001), anxiety (OR=2.06, P=0.039), and insomnia (OR=5.75, P<0.001). After controlling for potential confounders, nightmares were still significantly associated with a higher ShDS score (β=2.718, P=0.006).

CONCLUSION

FNs are prevalent among Chinese HDPs receiving MMT and significantly associated with functional impairment. Nightmares are a clinically relevant phenomenon in Chinese MMT clinics, which deserves more clinical and research attention.

Management of nightmares in patients with posttraumatic stress disorder: current perspectives

Nightmares are considered the hallmark of posttraumatic stress disorder (PTSD). Although the characteristics of these distressing dreams may vary with the type of traumatic event, the pathophysiology exposes central dysfunction of brain structures at the level of the hippocampus, amygdala, and locus coeruleus, modulated by neurochemical imbalance in nor-adrenergic, dopaminergic, and serotonin pathways. Underlying comorbid conditions, including other sleep disorders, may contribute to worsening symptoms. Addressing sleep disruption can alleviate the severity of these nocturnal events and augment the effectiveness of other PTSD treatments. The expansion of behavioral treatment modalities for PTSD-related nightmares has been encouraging, but the core of these interventions is heavily structured around memory manipulation and imagery rescripting. A lack of a standardized delivery and a high dropout rate continue to pose significant challenges in achieving successful outcomes. The efficacy of existing pharmacological studies, such as α-adrenergic blocking agents, antidepressants, and atypical antipsychotics, has been undermined by methodological limitations and absence of large randomized controlled trials. This review is aimed at reviewing the available treatment strategies for alleviating nightmares in subjects with PTSD. Given the intricate relationship between PTSD and nightmares, future clinical trials have to adopt a more pragmatic approach focused not only on efficacy of novel interventions but also on adjunctive iteration of existing therapies tailored to individual socio-cultural background.

Decreased serum potassium may disturb sleep homeostasis in essential hypertensives

The aim is to investigate the association between alterations in the serum potassium (K+) concentration and sleep architecture parameters in essential hypertensives. Two hundred ninety-two hypertensives undergoing polysomnography and providing blood samples were recruited. The sleep architecture was composed of sleep stages 1 (N1), 2 (N2), 3 (N3), 4 (N4) and REM. The light sleep stage (LST) was composed of N1 + N2, and the deep sleep stage (DST) was composed of N3 + N4. The potentialrelationships between electrolytes and sleep parameters were determined via univariate and multivariate analyses. The subjects were divided into two groups via the serum K⁺ median (3.86 mmol/L). The K⁺ < 3.86 mmol/L group showed significantly decreased N1 (7.10 ± 4.55% vs 8.61 ± 5.23%, p = 0.002), LST (71.48 ± 11.33% vs 75.92 ± 17.08%, p = 0.013), and periodic leg movement during sleep related to microarousals (MA) /arousal (PLMS-A) [4 (1~10) vs 8 (3~15)/night, p < 0.001] and increased REM (17.38 ± 6.43% vs 15.37 ± 6.18%, p = 0.007) compared to the K⁺ ≥ 3.86 mmol/L group. A subdivided analysis by gender showed that these changes were more statistically significant in men than in women. Significant positive correlations were identified between K⁺ and N1 (r = 0.169, p = 0^.004), as well as PLMS-A (r = 0.222, p < 0.001) in subjects. Compared to women, a significantly strong correlation was identified between K+ and REM sleep in men (r = 0.158, p = 0.028 vs. r = 0.078, p = 0.442). Multiple linear regression analysis indicated that K+ is significantly associated with N1 in all subjects (p = 0.03) and with REM in men (p = 0.008), even after adjusting for confounders. Decreased K+ may disturb the homeostasis of the sleep architecture, and gender may interfere with their links in the hypertensive population.

Adverse drug reactions of montelukast in children and adults

Montelukast, a selective leukotriene receptor antagonist, is recommended in guidelines for the treatment of asthma in both children and adults. However, its effectiveness is debated, and recent studies have reported several adverse events such as neuropsychiatric disorders and allergic granulomatous angiitis. This study aims to obtain more insight into the safety profile of montelukast and to provide prescribing physicians with an overview of relevant adverse drug reactions in both children and adults. We retrospectively studied all adverse drug reactions on montelukast in children and adults reported to the Netherlands Pharmacovigilance Center Lareb and the WHO Global database, VigiBase^® until 2016. Depression was reported most frequently in the whole population to the global database VigiBase^® (reporting odds ratio (ROR) 6.93; 95% CI: 6.5–7.4). In the VigiBase^®, aggression was reported the most in children (ROR, 29.77; 95% CI: 27.5–32.2). Headaches were reported the most frequently to the Dutch database (ROR, 2.26; 95% CI: 1.61–3.19). Furthermore, nightmares are often reported for both children and adults to the Dutch and the global database. Eight patients with allergic granulomatous angiitis were reported to the Dutch database and 563 patients in the VigiBase^®. These data demonstrate that montelukast is associated with neuropsychiatric adverse drug reactions such as depression and aggression. Especially in children nightmares are reported frequently. Allergic granulomatous angiitis is also reported, a causal relationship has not been established.

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.

REM Sleep Theta Changes in Frequent Nightmare Recallers

Study Objectives

To replicate and expand upon past research by evaluating sleep and wake electroencephalographic spectral activity in samples of frequent nightmare (NM) recallers and healthy controls.

Methods

Computation of spectral activity for sleep (non-REM and REM) and wake electroencephalogram recordings from 18 frequent NM recallers and 15 control participants.

Results

There was higher "slow-theta" (2-5 Hz) for NM recallers than for controls during wake, non-REM sleep and REM sleep. Differences were clearest for frontal and central derivations and for REM sleep cycles 2-4. There was also higher beta activity during NREM sleep for NM recallers. Findings partially replicate past research by demonstrating higher relative "slow-theta" (3-4Hz) for NM recallers than for controls.

Conclusions

Findings are consistent with a neurocognitive model of nightmares that stipulates cross-state anomalies in emotion processing in NM-prone individuals.

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.

Waking-hour cerebral activations in nightmare disorder: A resting-state functional magnetic resonance imaging study

AIM

The purpose of the current study was to explore the cerebral areas involved in nightmare disorder.

METHODS

Fifteen nightmare disorder patients and 15 healthy volunteers were invited to undergo resting-state functional magnetic resonance imaging and to complete the Nightmare Experience Questionnaire.

RESULTS

The nightmare disorder patients scored higher on the Physical Effect and Horrible Stimulation scales, had higher values of regional homogeneity in clusters within the left anterior cingulate cortex and right inferior parietal lobule, and lower regional homogeneity values within the left superior and inferior frontal gyri and bilateral middle occipital gyri. Physical Effect was negatively correlated with regional homogeneity values in anterior cingulate cortex and inferior parietal lobule in the nightmare disorder group, and was positively correlated with regional homogeneity value in the inferior frontal gyrus in the healthy control group.

CONCLUSION

To our best knowledge, this is the first neuroimaging study on nightmare disorder, and we have characterized the cerebral activities underlying altered hyperarousal and emotion regulation in nightmare disorder at resting-state.

Things that Go Bump in the Night: Frequency and Predictors of Nightmares in Anxious and Nonanxious Children

Frequency and predictors of nightmares among children 7-11 years old with generalized anxiety disorder (GAD; n = 42) and no diagnosis (n = 44) were examined using both prospective and retrospective child and parent reports. Both children with GAD and their parents reported significantly more nightmares than controls based on retrospective reports, but the groups did not differ when nightmares were assessed daily across a one-week prospective period. Females reported more nightmares than males according to prospective assessment only. Controlling for sex and group, child sleep anxiety and presleep somatic arousal predicted parent but not child report of nightmares. Results suggest both clinically anxious youth and their parents overestimate the occurrence of nightmares, yet factors influencing retrospective accounts appear to differ across informants.

Ayurvedic doshas as predictors of sleep quality

Background

The 3 Ayurvedic constitutional types or Doshas – vata, pitta, and kapha – are responsible for homeostasis and health. The doshas determine various functions, including sleep. According to the Ayurvedic texts, sleep is caused by increased kapha and insomnia by increased vata or pitta, which may follow physical or mental exertion, or disease. The present study was carried out to determine whether this relationship could be found using contemporary standardized questionnaires.

Material/Methods

In this cross-sectional single-group study, 995 persons participated (646 males; group average age ±S.D., 49.1±15.2 years). Participants were attending a 1-week residential yoga program in northern India. Participants were assessed for dosha scores using a Tridosha questionnaire and the quality of sleep in the preceding week was self-rated using a sleep rating questionnaire.

Results

Multiple linear regression analyses were used to determine if each dosha acted as a predictor of quality and quantity of sleep. Vata scores significantly predicted the time taken to fall asleep [p<0.01], and the feeling of being rested in the morning [p<0.001]; with higher vata scores being associated with a longer time to fall asleep and a lesser feeling of being rested in the morning. Kapha scores significantly predicted day-time somnolence [p<0.05] and the duration of day-time naps in minutes [p<0.05], with higher kapha scores being associated with longer day-time naps.

Conclusions

The results suggest that the doshas can influence the quality and quantity of sleep.

Relationship between drug dreams, affect, and craving during treatment for substance dependence

OBJECTIVES

To explore the relationship between occurrence of drug dreams (DDs) and daytime negative affect and drug craving during the course of a 5-week treatment program for substance dependence.

METHODS

Using the dream journal methodology, 86 participants reported occurrence of dreams, dream content, and ratings of affect and drug craving. The relationships between the experience of DD, dream content ("active" vs "passive"), and affect and craving were analyzed using mixed model methods.

RESULTS

The experience of DD was associated with higher levels of negative affect (P < 0.001) and craving (P < 0.001). The occurrence of DD did not decrease significantly over the 5 weeks of the study. Cocaine/crack users reported a higher occurrence of DD (P < 0.05) than the other drug groups (opiates and alcohol), and DD involving "active" drug use was associated with larger (P < 0.05) changes in negative affect.

CONCLUSIONS

These results are consistent with the hypothesis that DD can act as drug-conditioned stimuli to elevate negative affect and craving in abstaining individuals. Although correlational, such findings support the implementation of psychological and pharmacological interventions aimed at minimizing the impact of DD on individuals in recovery from drug addiction.