Do nightmares and generalized anxiety disorder in childhood and adolescence have a common genetic origin?

Nightmare experiences and perceived ethnic discrimination amongst female university students in the United Arab Emirates: a cross-sectional study

Perceived ethnic discrimination is known to be associated with anxiety and depression, and in turn, anxiety and depression are known to be associated with nightmare frequency and distress. This elicits a question: is perceived ethnic discrimination associated with nightmare frequency and distress? In this study, 179 female university students from the United Arab Emirates were assessed to answer that question. Results showed that while anxiety and depression were related to nightmare experiences, perceived ethnic discrimination was a stronger predictor of nightmare experiences. We posit two explanations for this finding: one based on psychoanalytical insights, and the other based on the Disposition-Stress model with neurobiological correlates. No significant differences were found across ethnicity when it comes to nightmare experiences or perceived ethnic discrimination. This is an encouraging sign of optimal societal integration in the United Arab Emirates.

The Genetics of Sleep Disorders in Children: A Narrative Review

Sleep is a universal, highly preserved process, essential for human and animal life, whose complete functions are yet to be unravelled. Familial recurrence is acknowledged for some sleep disorders, but definite data are lacking for many of them. Genetic studies on sleep disorders have progressed from twin and family studies to candidate gene approaches to culminate in genome-wide association studies (GWAS). Several works disclosed that sleep-wake characteristics, in addition to electroencephalographic (EEG) sleep patterns, have a certain degree of heritability. Notwithstanding, it is rare for sleep disorders to be attributed to single gene defects because of the complexity of the brain network/pathways involved. Besides, the advancing insights in epigenetic gene-environment interactions add further complexity to understanding the genetic control of sleep and its disorders. This narrative review explores the current genetic knowledge in sleep disorders in children, following the International Classification of Sleep Disorders-Third Edition (ICSD-3) categorisation.

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.

Sleep spindles are altered in early- but not late-onset nightmare recallers

Nightmares are a common sleep disorder, defined as highly disturbing mentation which usually awakens the individual from rapid eye movement (REM) sleep. While nightmares are mainly a REM sleep phenomenon, Picard-Deland et al., (2017) recently showed an association between nightmare recall and sleep spindles, which are a non-rapid eye movement (NREM) oscillatory feature. Their results pointed to fewer slow spindles and a higher oscillatory frequency for fast spindles among frequent nightmare recallers compared with controls. To test the suggestion that nightmares stem from changes to emotional neural circuits arising in early childhood (Nielsen, 2017), including early changes in sleep spindles (Scholle et al., 2007), we investigated if the spindle features of early-onset nightmare recallers (ie, recalling nightmares since childhood) (N = 22), differed from those of late-onset nightmare recallers (ie, since adolescence or adulthood) (N = 11), or from those of controls (N = 23). A retrospective analysis of the sleep spindles of 56 participants who had undergone a polysomnographically-recorded morning nap revealed that Early starters uniquely exhibited lower slow spindle densities in five of six derivations (all p < 0.045) and higher fast spindle frequencies in all six derivations (all p < 0.015). These results add precision to previously reported findings for Nightmare recallers: spindle differences are shown to hold only for Early starters. The lifelong occurrence of nightmares may be closely tied to disruptions in the normal development of spindle generation processes occurring early in development.

The Stress Acceleration Hypothesis of Nightmares

Adverse childhood experiences can deleteriously affect future physical and mental health, increasing risk for many illnesses, including psychiatric problems, sleep disorders, and, according to the present hypothesis, idiopathic nightmares. Much like post-traumatic nightmares, which are triggered by trauma and lead to recurrent emotional dreaming about the trauma, idiopathic nightmares are hypothesized to originate in early adverse experiences that lead in later life to the expression of early memories and emotions in dream content. Accordingly, the objectives of this paper are to (1) review existing literature on sleep, dreaming and nightmares in relation to early adverse experiences, drawing upon both empirical studies of dreaming and nightmares and books and chapters by recognized nightmare experts and (2) propose a new approach to explaining nightmares that is based upon the Stress Acceleration Hypothesis of mental illness. The latter stipulates that susceptibility to mental illness is increased by adversity occurring during a developmentally sensitive window for emotional maturation—the infantile amnesia period—that ends around age 3½. Early adversity accelerates the neural and behavioral maturation of emotional systems governing the expression, learning, and extinction of fear memories and may afford short-term adaptive value. But it also engenders long-term dysfunctional consequences including an increased risk for nightmares. Two mechanisms are proposed: (1) disruption of infantile amnesia allows normally forgotten early childhood memories to influence later emotions, cognitions and behavior, including the common expression of threats in nightmares; (2) alterations of normal emotion regulation processes of both waking and sleep lead to increased fear sensitivity and less effective fear extinction. These changes influence an affect network previously hypothesized to regulate fear extinction during REM sleep, disruption of which leads to nightmares. This network consists of a fear circuit that includes amygdala, hippocampus, and medial prefrontal cortex and whose substantial overlap with the stress acceleration findings allows the latter to be incorporated into a wider, more developmentally coherent framework.

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.

Bullying and parasomnias: a longitudinal cohort study

BACKGROUND AND OBJECTIVES

Environmental factors such as serious trauma or abuse and related stress can lead to nightmares or night terrors. Being bullied can be very distressing for children, and victims display long-term social, psychological, and health consequences. Unknown is whether being bullied by peers may increase the risk for experiencing parasomnias such as nightmares, night terrors, or sleepwalking.

METHODS

A total of 6796 children of the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort were interviewed at elementary school age (8 and 10 years) about bullying experiences with a previously validated bullying interview and at secondary school age (12.9 years) about parasomnias such as nightmares, night terrors and sleepwalking by trained postgraduate psychologists.

RESULTS

Even after adjusting for pre-existing factors related to bullying and parasomnias, being bullied predicted having nightmares (8 years odds ratio [OR], 1.23; 95% confidence interval [CI], 1.05-1.44; 10 years OR, 1.62; 95% CI, 1.35-1.94) or night terrors (8 years OR, 1.39; 95% CI, 1.10-1.75; 10 years OR, 1.53; 95% CI, 1.18-1.98) at age 12 to 13 years. Especially being a chronic victim was associated with both nightmares (OR, 1.82; 95% CI, 1.46-2.27) and night terrors (OR, 2.01; 95% CI, 1.48-2.74). Being a bully/victim also increased the risk for any parasomnia at ages 8 or 10 years (8 years OR, 1.42; 95% CI, 1.08-1.88; 10 years OR, 1.75; 95% CI, 1.30-2.36). In contrast, bullies had no increased risk for any parasomnias.

CONCLUSIONS

Being bullied increases the risk for having parasomnias. Hence, parents, teachers, school counselors, and clinicians may consider asking about bullying experiences if a child is having parasomnias.

Retrospective assessment of premorbid psychopathology and cognitive impairments in bipolar disorder

The present study investigated whether premorbid psychopathological and cognitive impairment symptoms could be retrospectively identified during the childhood and adolescence of those later diagnosed with bipolar disorder (BPD). The present sample consisted of 30 adults diagnosed with BPD, 30 of their significant-others, a group-matched control group of 30 adults (without any reported psychological or cognitive disorders), and 30 of their significant-others. The adults diagnosed with BPD and the control group completed a self-report form of the retrospective version of the Coolidge Personality and Neuropsychological Inventory (CPNI-R) as they were before the age of 16 years. The significant-others reported on the adults diagnosed with BPD or upon their controls. Initial two-factor analyses of variance revealed that on a comprehensive measure of psychopathology and of cognitive impairment, those diagnosed with BPD scored significantly higher than the control group on the self-report and the significant-other forms, with large effects sizes. Overall, the overarching research hypothesis was confirmed: adults diagnosed with BPD and their significant-others could report salient prodromes during their childhood or adolescence.

Nightmares in the bedroom of science: mapping of a neglected sleep disorder

Nightmares are intense and unpleasant dream experiences that characterize approximately 4 percent of the adult population at least on a weekly basis. Nightmare frequency is often co-morbid with other mental complaints; however, recent results indicate that nightmare disorder is independent from waking mental dysfunctions. Nightmare disorder is intimately related to poor subjective sleep quality, and according to polysomnographic studies nightmare subjects’ sleep is characterized by increased sleep fragmentation and hyper-arousal. These findings suggest that instead of the psychopathological perspective nightmare disorder should be viewed as a specific sleep disorder that requires targeted treatment. Nevertheless, in order to choose the adequate treatment procedure clinicians should examine the co-morbid mental disorders as well taking into consideration the severity of nightmare distress, the latter supposed to be the mediator between nightmare frequency and waking mental dysfunctions. Orv. Hetil., 2013, 154, 497–502.

Disturbed dreaming and the instability of sleep: altered nonrapid eye movement sleep microstructure in individuals with frequent nightmares as revealed by the cyclic alternating pattern

STUDY OBJECTIVES

Nightmares are disturbing mental experiences during sleep that usually result in abrupt awakenings. Frequent nightmares are associated with poor subjective sleep quality, and recent polysomnographic data suggest that nightmare sufferers exhibit impaired sleep continuity during nonrapid eye movement (NREM) sleep. Because disrupted sleep might be related to abnormal arousal processes, the goal of this study was to examine polysomnographic arousal-related activities in a group of nightmare sufferers and a healthy control group.

DESIGN

Sleep microstructure analysis was carried out by scoring the cyclic alternating pattern (CAP) in NREM sleep and the arousal index in rapid eye movement (REM) sleep on the second night of the polysomnographic examination.

SETTING

Hospital-based sleep research laboratory.

PARTICIPANTS

There were 17 in the nightmare (NMs) group and 23 in the healthy control (CTLs) group.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

The NMs group exhibited reduced amounts of CAP A1 subtype and increased CAP A2 and A3 subtypes, as well as longer duration of CAP A phases in comparison with CTLs. Moreover, these differences remained significant after controlling for the confounding factors of anxious and depressive symptoms. The absolute number and frequency of REM arousals did not differ significantly between the two groups.

CONCLUSIONS

The results of our study indicate that NREM sleep microstructure is altered during nonsymptomatic nights of nightmares. Disrupted sleep in the NMs group seems to be related to abnormal arousal processes, specifically an imbalance in sleep-promoting and arousing mechanisms during sleep.

CITATION

Simor P; Bódizs R; Horváth K; Ferri R. Disturbed dreaming and the instability of sleep: altered nonrapid eye movement sleep microstructure in individuals with frequent nightmares as revealed by the cyclic alternating pattern. SLEEP 2013;36(3):413-419.

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

Nightmares are intense, emotionally negative mental experiences that usually occur during late-night sleep and result in abrupt awakenings. Questionnaire-based studies have shown that nightmares are related to impaired sleep quality; however, the polysomnographic profile of nightmare subjects has been only scarcely investigated. We investigated the sleep architecture of 17 individuals with frequent nightmares and 23 control subjects based on polysomnographic recordings of a second night spent in the laboratory after an adaptation night. Nightmare subjects in comparison with control subjects were characterized by impaired sleep architecture, as reflected by reduced sleep efficiency, increased wakefulness, a reduced amount of slow wave sleep, and increased nocturnal awakenings, especially from Stage 2 sleep. While these differences were independent of the effects of waking psychopathology, nightmare subjects also exhibited longer durations of REM sleep that was mediated by heightened negative affect. Our results support that nightmares are related to altered sleep architecture, showing impaired sleep continuity and emotion-related increase in REM propensity.

Frequent nightmares in children: familial aggregation and associations with parent-reported behavioral and mood problems

STUDY OBJECTIVES

To conduct a systematic investigation on the prevalence, correlates, and familial aggregation of frequent nightmares in children, and to scrutinize the associations between frequent nightmares and parent-reported behavioral and mood problems in children.

DESIGN

A cross-sectional study was conducted by collecting the data on sociodemographic, sleep, behavioral, and family-related information from a total of 6359 children (age: mean [SD]=9.2 [1.8] years; girls: 49.9%) and their reported biological parents.

SETTING

Community.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Prevalence of frequent nightmares with a criterion of at least once per week was 5.2%. Multinomial regression analysis indicated that monthly family income, paternal and maternal nightmares, insomnia symptoms, parasomniac symptoms, and daytime consequences were significantly associated with nightmares in children. Frequent nightmares in children were significantly associated with hyper-activity (odds ratio [OR]=1.68, 95% CI 1.16-2.44), frequent temper outbursts/mood disturbance (OR=1.76, 95%CI 1.27-2.44), and poor academic performance (OR=1.62, 95% CI 1.11-2.36), after controlling for potential confounding factors. Approximately 20% of children with frequent nightmares experienced comorbid frequent insomnia. Comorbid nightmares and insomnia were associated with increased odds of hyperactivity (OR=4.13, 95% CI 2.13-8.00) and frequent temper outbursts/mood disturbance (OR=2.41, 95%CI 1.27-4.60).

CONCLUSIONS

Frequent nightmares in children are associated with a constellation of child-, sleep-, and family-related factors, including comorbid sleep problems, such as insomnia and parasomnia, family economic status, and parental predisposition. Frequent nightmares are independently associated with emotional and behavioral problems in children.

Preliminary psychometric properties of a measure of Karen Horney's Tridimensional theory in children and adolescents

This study established the psychometric properties of a child and adolescent version of the Horney-Coolidge Tridimensional Inventory (HCTI), which assesses psychoanalyst Karen Horney's theory of neurotic types. Parents of 302 children (ages 5 to 17 years; median age = 12.0 years) completed the new 45-item version of the HCTI and the Coolidge Personality and Neuropsychological Inventory (CPNI) about their children. The three main scales (Compliance, Aggression, and Detachment) had good internal scale reliability and excellent test-retest reliability. Principal components analysis supported Horney's three dimensions and a six-component substructure. There was also sufficient construct validity with personality disorder scales from the CPNI with the three HCTI dimensions and their six components. The implications of the findings are discussed for Horneyan theory.