Sleep physiology and pathology: pertinence to psychiatry

The impact of a mobile app-based corporate sleep health improvement program on productivity: Validation through a randomized controlled trial

Based on a randomized controlled trial applied to employees of a manufacturing company, this study examines the extent to which a corporate sleep program improves workers' sleep health and productivity. In the three-month sleep improvement program, applicants were randomly divided into a treatment group and a control group, and the treatment group was provided with a noncontact sensing device to visualize their sleep. A smartphone app linked to the device notified them of their sleep data every morning and presented them with advice on behavioral changes to improve their sleep on a weekly basis. The results of the analysis revealed the following. First, even after controlling for factors that may cause sleep disturbances and nocturnal awakenings, such as increased workload and the number of days spent working from home during the measurement period, the treatment group showed improved sleep after the program compared to the control group. Second, the treatment group showed statistically significant improvement in presenteeism (productivity). The effect size on presenteeism through sleep improvement was similar regardless of the estimation method used (i.e., ANCOVA estimator of ATT and two 2SLS methods were performed). In particular, we confirmed that productivity was restored through sleep improvement for the participants who diligently engaged in the program. These results suggest that promoting sleep health using information technology can improve sleep deficiency and restore productivity.

The association between sleep quality and telomere length: A systematic literature review

Several sleep parameters present an elevated risk for processes that contribute to cellular aging. Short sleep duration, sleep apnoea, and insomnia are significantly associated with shorter telomeres, a biological marker of cellular aging. However, there has been no review or analysis of studies that have examined the association between the psychological construct of sleep quality and telomere length. The present study aimed to provide a systematic review of the association between sleep quality and telomere length. A systematic review of English articles was conducted using MEDLINE/PubMed, PsycINFO, Google Scholar, and Web of Science electronic databases, with the final search conducted on 3rd September 2021. Search terms included sleep quality, poor sleep, insomnia, sleep difficulties, sleep issue*, non-restorative sleep, telomere*, cellular aging, and immune cell telomere length. Study eligibility criteria included human participants aged 18 years or older and a reproducible methodology. Study appraisal and synthesis were completed using a systematic search in line with a PICOS approach (P = Patient, problem, or population; I = Intervention, prognostic factor, exposure; C = Comparison, control, or comparator; O = Outcomes; S = Study designs). Twenty-two studies met review inclusion criteria. Qualitative synthesis of the literature indicated insufficient evidence overall to support a significant association between sleep quality and telomere length. Limitations across studies were addressed, such as the assessment of examined constructs. Findings highlight important targets for future research, including the standardised operationalisation of the sleep quality construct and experimental study designs. Research in this area has clinical significance by identifying possible mechanisms that increase the risk for age-related disease and mortality. PROSPERO Registration No.: CRD 42021233139.

Premature Aging Among Trauma Survivors-The Longitudinal Implications of Sleep Disruptions on Telomere Length and Cognitive Performance

OBJECTIVES

Sleep is necessary for brain function as well as physical and cognitive processes. Sleep disruptions, common with aging, intensify among trauma survivors. Moreover, former prisoners-of-war (ex-POWs) often experience premature aging. This study investigates the longitudinal effects of sleep disruptions for ex-POWs in relation to cognitive performance and telomere length as well as between cognition and telomeres.

METHOD

This study included Israeli veterans from the 1973 Yom Kippur War who participated in four assessments (1991, 2003, 2008, 2015): (a) ex-POWs (n = 99), and (b) veterans who not were captured (controls) (n = 101). Among both groups, sleep disruptions were assessed using a self-report item in all four assessments. Cognitive performance was assessed using the Montreal Cognitive Assessment (MOCA) and telomere length was assessed via total white blood cells (leukocytes) from whole blood samples using Southern blot, both were measured only among ex-POWs in 2015. We conducted descriptive statistics, repeated measures, correlations, and path analyses.

RESULTS

Sleep disruptions were related to lower cognitive performance but not to shorter telomeres. Moreover, cognitive performance and telomere length were found to be related when sleep disruptions were taken into consideration.

CONCLUSION

Interpersonal trauma was shown to be a unique experience resulting in sleep disruptions over time, leading to cognitive impairment. These findings highlight the importance of viewing trauma survivors at high-risk for sleep disruptions. Therefore, it is imperative to inquire about sleep and diagnose cognitive disorders to help identify and treat premature aging.

Reliability, Validity, and Factor Structure of Pittsburgh Sleep Quality Index in Community-Based Centenarians

BACKGROUND

The Pittsburgh Sleep Quality Index (PSQI) is a widely used self-report questionnaire that measures general sleep quality in general populations. However, its psychometric properties have yet to be thoroughly examined in longevous persons.

OBJECTIVES

This study aimed to explore the reliability, validity and factor structure of the Chinese-language version of the PSQI in community-dwelling centenarians.

METHODS

A total of 958 centenarians (mean age = 102.8 years; 81.8% females) recruited from 18 regions in Hainan, China, completed the PSQI scale. Cronbach's alpha coefficient was used to measure the internal consistency. Exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were performed to explore the validity and factor structure of the PSQI in this sample. Correlations between the global PSQI score and physical function, depression symptoms, self-reported health status and subjective well-being were used to assess divergent validity.

RESULTS

The Cronbach's α coefficient of the PSQI was 0.68, and it increased to 0.78 after two components (medication use and daytime dysfunction) were removed. The Spearman correlation coefficients of the PSQI score with each component were statistically significant (P<0.01). EFA yielded a two-factor structure model of the original PSQI-7 and a one-factor structure model of the simplified PSQI-5. The one-factor model with five components (χ2/df =1.59, CFI=0.99, RMSEA=0.03) fit the data well and had good configural invariance across demographic characteristics (0.53<Δχ2<5.58, P>0.05).

CONCLUSIONS

The original PSQI showed acceptable applicability in Chinese community-dwelling centenarians, and its psychometric characteristics moderately improved after sleeping medication and daytime dysfunction were removed. Further validation studies on PSQI are needed among centenarians from varied backgrounds.

Anxiety and depressive symptoms among COVID-19 patients in Jianghan Fangcang Shelter Hospital in Wuhan, China

Fangcang shelter hospitals were established in China during the coronavirus disease 2019 (COVID-19) pandemic as a countermeasure to stop the spread of the disease. To our knowledge, no research has been conducted on mental health problems among patients in Fangcang shelter hospitals. This study aimed to determine the prevalence and major influencing factors of anxiety and depressive symptoms among COVID-19 patients admitted to Fangcang shelter hospitals. From February 23, 2020, to February 26, 2020, we obtained sociodemographic and clinical characteristics information of COVID-19 patients in Jianghan Fangcang Shelter Hospital (Wuhan, China) and assessed their mental health status and sleep quality. Data were obtained with an online questionnaire. The questionnaire consisted of a set of items on demographic characteristics, a set of items on clinical characteristics, the Self-Rating Anxiety Scale, Self-Rating Depression Scale, and Pittsburgh Sleep Quality Index. Three hundred seven COVID-19 patients who were admitted to Jianghan Fangcang Shelter Hospital participated in this study. The prevalence of anxiety and depressive symptoms were 18.6% and 13.4%, respectively. Poor sleep quality and having ≥ two current physical symptoms were independent risk factors for anxiety symptoms. Female sex, having a family member with confirmed COVID-19, and having ≥ two current physical symptoms were independent risk factors for depressive symptoms. Anxiety and depressive symptoms were found to be common among COVID-19 patients in Fangcang Shelter Hospital, with some patients being at high risk.

CPAP and Health-Related Quality of Life in Adults With Coronary Artery Disease and Nonsleepy Obstructive Sleep Apnea in the RICCADSA Trial

STUDY OBJECTIVES

To determine the effect of continuous positive airway pressure (CPAP) treatment on health-related quality of life (HRQoL) in adults with coronary artery disease (CAD) and nonsleepy obstructive sleep apnea (OSA).

METHODS

This was a secondary outcome analysis of the RICCADSA trial, conducted in Sweden between 2005 and 2013. Adults with CAD, nonsleepy OSA (apnea-hypopnea index [AHI] ≥ 15 events/h; Epworth Sleepiness Scale [ESS] score < 10) and complete Short-Form (SF)-36 questionnaires at baseline and after 12 months were included. Patients were randomized to CPAP (n = 102) or no CPAP (n = 104). The primary outcome was the between-group difference in absolute change in the SF-36 components. Within-group changes as well as variables associated with absolute change in the domains in the entire population were also tested.

RESULTS

Mean SF-36 scores were similar at baseline, ranging from 44.9 ± 9.6 to 92.2 ± 15.8 in various domains, and between-group changes from baseline were not statistically significant at 1 year. There was a significant increase in Role physical, Vitality, Role emotional, Mental health and Mental Component Summary (MCS), and a decrease in Bodily pain and General health scores in the CPAP group. The change in Physical Component Summary (PCS) was determined by female sex (beta coefficient -0.19, 95% confidence interval [CI] -7.25 to -0.98, P = .010), baseline AHI (beta coefficient -0.19, 95% CI -0.21 to -0.03, P = .009), CPAP use (h/night) (beta coefficient -0.16, 95% CI -0.93 to -0.06, P = .028), and acute myocardial infarction at baseline (beta coefficient 0.18, 95% CI 0.59 to 5.19, P = .014). Determinants of the change in MCS from baseline were change in the ESS score (beta coefficient -0.14, 95% CI -0.87 to -0.01, P = .054) and change in the Zung Self-rated Depression Scale scores (beta coefficient -0.33, 95% CI -0.58 to -0.24, P < .001).

CONCLUSIONS

Assignment to CPAP treatment compared to no CPAP had no significant effect on HRQoL as measured by the SF-36 in adults with CAD and nonsleepy OSA. Although several components of the SF-36 scores were improved within the CPAP group, CPAP use was associated with a decrease in PCS. The improvement in MCS was determined by the improvement in daytime sleepiness and depressive mood.

CLINICAL TRIAL REGISTRATION

Registry: ClinicalTrials.gov; Identifier: NCT00519597.

CITATION

Wallström S, Balcan B, Thunström E, Wolf A, Peker Y. CPAP and health-related quality of life in adults with coronary artery disease and nonsleepy obstructive sleep apnea in the RICCADSA trial. J Clin Sleep Med. 2019;15(9):1311-1320.

The Prevalence of Depression among Untreated Obstructive Sleep Apnea Patients Using a Standardized Psychiatric Interview

STUDY OBJECTIVES

The aims of this study were: (1) to use a standardized psychiatric interview, conducted by a trained psychologist to assess the prevalence of depression among patients with untreated OSA, and (2) to identify if OSA severity or other comorbid disorders (insomnia, hypertension, and diabetes) are related to depression among patients with untreated OSA.

METHODS

Participants were newly diagnosed patients with OSA (n = 284) waiting to start positive airway pressure (PAP) treatment. The Mini International Neuropsychiatric Interview (MINI) was used to assess depression.

RESULTS

Overall, 15.5% of the sample met the diagnosis for dysthymia. Women had a significantly higher prevalence (29.5% versus 11.7% among men, p < 0.001). The prevalence of major depression was 6% in the overall sample and there was no difference in the prevalence among sexes (5.8% among men versus 6.6 % among women). Obesity, daytime sleepiness, low physical activity, initial and late insomnia, low quality of life, and sleep medication and antidepressant use were all related to depression, whereas OSA severity, as measured by apnea-hypopnea index or oxygen desaturation index, was not. Daytime sleepiness, initial insomnia, and sleep medication use were the strongest predictors of depression in multivariable analyses.

CONCLUSIONS

Sleep medication use, daytime sleepiness, and symptoms of initial insomnia were independently related to depression but OSA severity was not. Increased awareness of the relationship between depression and OSA and the appropriate use of assessment tools might substantially improve diagnostic accuracy as well as treatment outcome for both disorders.

Sleep disruption increases seizure susceptibility: Behavioral and EEG evaluation of an experimental model of sleep apnea

Sleep disruption accompanies sleep apnea as one of its major symptoms. Obstructive sleep apnea is particularly common in patients with refractory epilepsy, but causing factors underlying this are far from being resolved. Therefore, translational studies regarding this issue are important. Our aim was to investigate the effects of sleep disruption on seizure susceptibility of rats using experimental model of lindane-induced refractory seizures. Sleep disruption in male Wistar rats with implanted EEG electrodes was achieved by treadmill method (belt speed set on 0.02 m/s for working and 0.00 m/s for stop mode, respectively). Animals were assigned to experimental conditions lasting 6h: 1) sleep disruption (sleep interrupted, SI; 30s working and 90 s stop mode every 2 min; 180 cycles in total); 2) activity control (AC, 10 min working and 30 min stop mode, 9 cycles in total); 3) treadmill chamber control (TC, only stop mode). Afterwards, the animals were intraperitoneally treated with lindane (L, 4 mg/kg, SI+L, AC+L and TC+L groups) or dimethylsulfoxide (DMSO, SIc, ACc and TCc groups). Convulsive behavior was assessed by seizure incidence, latency time to first seizure, and its severity during 30 min after drug administration. Number and duration of ictal periods were determined in recorded EEGs. Incidence and severity of lindane-induced seizures were significantly increased, latency time significantly decreased in animals undergoing sleep disruption (SI+L group) compared with the animals from TC+L. Seizure latency was also significantly decreased in SI+L compared to AC+L groups. Number of ictal periods were increased and duration of it presented tendency to increase in SI+L comparing to AC+L. No convulsive signs were observed in TCc, ACc and SIc groups, as well as no ictal periods in EEG. These results indicate sleep disruption facilitates induction of epileptic activity in rodent model of lindane-epilepsy enabling translational research of this phenomenon.

Quality of life among untreated sleep apnea patients compared with the general population and changes after treatment with positive airway pressure

Obstructive sleep apnea leads to recurrent arousals from sleep, oxygen desaturations, daytime sleepiness and fatigue. This can have an adverse impact on quality of life. The aims of this study were to compare: (i) quality of life between the general population and untreated patients with obstructive sleep apnea; and (ii) changes of quality of life among patients with obstructive sleep apnea after 2 years of positive airway pressure treatment between adherent patients and non-users. Propensity score methodologies were used in order to minimize selection bias and strengthen causal inferences. The enrolled obstructive sleep apnea subjects (n = 822) were newly diagnosed with moderate to severe obstructive sleep apnea who were starting positive airway pressure treatment, and the general population subjects (n = 742) were randomly selected Icelanders. The Short Form 12 was used to measure quality of life. Untreated patients with obstructive sleep apnea had a worse quality of life when compared with the general population. This effect remained significant after using propensity scores to select samples, balanced with regard to age, body mass index, gender, smoking, diabetes, hypertension and cardiovascular disease. We did not find significant overall differences between full and non-users of positive airway pressure in improvement of quality of life from baseline to follow-up. However, there was a trend towards more improvement in physical quality of life for positive airway pressure-adherent patients, and the most obese subjects improved their physical quality of life more. The results suggest that co-morbidities of obstructive sleep apnea, such as obesity, insomnia and daytime sleepiness, have a great effect on life qualities and need to be taken into account and addressed with additional interventions.

Circadian sleep-wake cycles, well-being, and light therapy in borderline personality disorder

Individuals with borderline personality disorder (BPD) frequently suffer from sleep disturbances. The authors investigated circadian rhythms, sleep, and well-being in women with BPD in their habitual life conditions during 3 weeks with morning light therapy (LT) and 3 weeks without LT (oLT). Sleep-wake cycles were measured using wrist actimetry, proximal skin temperature as an indirect index of relaxation, as well as weekly salivary melatonin to document the internal circadian rhythm phase. Questionnaires assessed clinical state throughout the 6-week protocol. Ten matched healthy women followed the same 6-week protocol without light treatment. Women with BPD had significantly worse subjective sleep quality and reduced daytime alertness compared to controls. Sleep-wake cycles in BPD ranged from highly disturbed to extremely regular patterns. Melatonin and proximal skin temperature profiles revealed appropriate synchronization of the circadian system with the sleep-wake cycle in most BPD women and in all controls. Morning LT significantly phase-advanced activity in BPD compared to oLT, shortened sleep duration, decreased movement time, and increased skin temperature during sleep (a marker of relaxation). Although general depression scores and borderline symptoms did not change, daytime alertness improved with morning LT, and atypical depression scores were attenuated. Morning LT is a potential adjunct treatment for BPD.

Prolonged sleep fragmentation of mice exacerbates febrile responses to lipopolysaccharide

BACKGROUND

Sleep disruption is a frequent occurrence in modern society. Whereas many studies have focused on the consequences of total sleep deprivation, few have investigated the condition of sleep disruption.

NEW METHOD

We disrupted sleep of mice during the light period for 9 consecutive days using an intermittently rotating disc.

RESULTS

Electroencephalogram (EEG) data demonstrated that non-rapid eye movement (NREM) sleep was severely fragmented and REM sleep was essentially abolished during the 12h light period. During the dark period, when sleep was not disrupted, neither NREM sleep nor REM sleep times differed from control values. Analysis of the EEG revealed a trend for increased power in the peak frequency of the NREM EEG spectra during the dark period. The fragmentation protocol was not overly stressful as body weights and water consumption remained unchanged, and plasma corticosterone did not differ between mice subjected to 3 or 9 days of sleep disruption and home cage controls. However, mice subjected to 9 days of sleep disruption by this method responded to lipopolysaccharide with an exacerbated febrile response.

COMPARISON WITH EXISTING METHODS

Existing methods to disrupt sleep of laboratory rodents often subject the animal to excessive locomotion, vibration, or sudden movements. This method does not suffer from any of these confounds.

CONCLUSIONS

This study demonstrates that prolonged sleep disruption of mice exacerbates febrile responses to lipopolysaccharide. This device provides a method to determine mechanisms by which chronic insufficient sleep contributes to the etiology of many pathologies, particularly those with an inflammatory component.

The neuropsychiatry of multiple sclerosis: focus on disorders of mood, affect and behaviour

Neuropsychiatric symptoms are common in multiple sclerosis (MS). They include two broad categories of disturbances: abnormalities in cognition, and abnormalities of mood, affect and behaviour. The present review deals with the epidemiology, clinical features, etiology and treatment of disturbances included in the second category, i.e., major depression, fatigue and sleep disorders, bipolar disorder, euphoria, pathological laughing and crying, anxiety, psychosis and personality changes. Major depression is one of the most common neuropsychiatric disorders in MS with an approximate 50% lifetime prevalence rate. Early recognition and management of depression in MS is of major importance because it is a key predictor of morbidity, mortality, quality of life, possibly physical outcome and disease exacerbations, adherence to immunomodulatory treatments and suicide risk in MS patients, as well as of the caregiver's distress and quality of life. The etiopathogenesis of neuropsychiatric disorders in MS has been incompletely investigated. It is postulated that a complex interplay of biological, disease-related, behavioural and psychosocial factors contribute to the pathophysiology of most of them. Management of neuropsychiatric symptoms in MS is often effective, although commonly based on evidence provided by case studies and uncontrolled trials. A comprehensive biopsychosocial neuropsychiatric approach is essential for the optimal care of patients with MS.

Longitudinal study on poor sleep and life dissatisfaction in a nationwide cohort of twins

Life satisfaction and quality of sleep are important, related components of subjective well-being and general health. However, no earlier investigation is known to have tested the direction of the temporal relation between poor sleep and diminished life satisfaction, including simultaneous examination of shared genetic influences. These features were examined in the present study of a nationwide cohort of 18,631 same-sex Finnish twins with repeated measurements of life satisfaction, sleep quality, and several potential confounders within an interval of 6 years (1975 and 1981). Most individuals (59%) with new-onset life dissatisfaction had experienced suboptimal sleep at baseline. Poor sleep predicted a consistent pattern of life dissatisfaction (odds ratio = 2.1, 95% confidence interval: 1.7, 2.7 from logistic regression on individuals; odds ratio = 3.0, 95% confidence interval: 1.7, 5.3 from conditional logistic regression on twin pairs discordant for life dissatisfaction), whereas life dissatisfaction did not consistently predict poor sleep. There was substantial heritability for both traits, but their shared genetic component was relatively weak, as indicated by genetic correlations of 0.21 for men and 0.27 for women in a multivariate genetic model. This finding is consistent with the hypothesis that poor sleep may have direct effects on the brain, emotions, and mood.

Sleep fragmentation elevates behavioral, electrographic and neurochemical measures of sleepiness

Sleep fragmentation, a feature of sleep apnea as well as other sleep and medical/psychiatric disorders, is thought to lead to excessive daytime sleepiness. A rodent model of sleep fragmentation was developed (termed sleep interruption, SI), where rats were awakened every 2 min by the movement of an automated treadmill for either 6 or 24 h of exposure. The sleep pattern of rats exposed to 24 h of SI resembled sleep of the apneic patient in the following ways: sleep was fragmented (up to 30 awakening/h), total rapid eye movement (REM) sleep time was greatly reduced, non-rapid eye movement (NREM) sleep episode duration was reduced (from 2 min, 5 s baseline to 58 s during SI), whereas the total amount of NREM sleep time per 24 h approached basal levels. Both 6 and 24 h of SI made rats more sleepy, as indicated by a reduced latency to fall asleep upon SI termination. Electrographic measures in the recovery sleep period following either 6 or 24 h of SI also indicated an elevation of homeostatic sleep drive; specifically, the average NREM episode duration increased (e.g. for 24 h SI, from 2 min, 5 s baseline to 3 min, 19 s following SI), as did the NREM delta power during recovery sleep. Basal forebrain (BF) levels of extracellular adenosine (AD) were also measured with microdialysis sample collection and high performance liquid chromatography detection, as previous work suggests that increasing concentrations of BF AD are related to sleepiness. BF AD levels were significantly elevated during SI, peaking at 220% of baseline during 30 h of SI exposure. These combined findings imply an elevation of the homeostatic sleep drive following either 6 or 24 h of SI, and BF AD levels appear to correlate more with sleepiness than with the cumulative amount of prior wakefulness, since total NREM sleep time declined only slightly. SI may be partially responsible for the symptom of daytime sleepiness observed in a number of clinical disorders, and this may be mediated by mechanisms involving BF AD.

Walking back to health: a qualitative investigation into service users' experiences of a walking project

The relationship between physical activity and mental health is well documented and has led to the inclusion of physical activity into the treatment of people with mental health problems within heath care. However, little research has been conducted on the outcomes these programmes have for the people who participate in them. This study investigated the perceived health outcomes of people with mental health problems who had successfully participated in a walking project. The research is a descriptive qualitative study that used individual interviews and the constant comparative method of analysis. Findings conclude that physical activity programmes have a significant part to play in the quality of life of people with mental health problems and have the potential to be an integral part of their health care.

Genetics of the sleep-wake cycle and its disorders

The sleep-wake cycle is under the control of the circadian clock. Recent advances in rhythm biology have identified molecular clocks and their key regulating genes. Circadian clock genes (Clock, Per) were first isolated in Drosophila, and their homologous counterparts have been found in mammals. Some of the circadian master genes have been shown to influence sleeping behavior. For instance, a point mutation in a human clock gene (Per2) was shown to produce the rare advanced sleep phase syndrome, whereas a functional polymorphism in Per3 is associated with the more frequent delayed sleep phase syndrome. Furthermore, a study examining the association between Clock gene polymorphisms and insomnia revealed a higher recurrence of initial, middle, and terminal insomnia in patients homozygous for the Clock genotype. Other genes have been shown to contribute to sleep pathologies. A point mutation in the prion protein gene appears to be the cause of fatal familial insomnia. A missense mutation has been found in the gene encoding the GABA-A beta 3 subunit in a patient with chronic insomnia. In both animal models and humans, a deficiency in the hypocretin/orexin system was proposed to be responsible for narcolepsy. Selective destruction of hypocretin neurons is the most probable culprit in humans. These findings suggest that the genetic contribution to sleep disorders and wake determinants is more important than originally thought. Beyond sleep, light/dark cycles and sleep deprivation appear also to be associated with eating habits, and epidemics of obesity have to be evaluated in the context of shortened sleep duration.

The dual origins of affect in nightmares: The roles of physiological homeostasis and memory

Strong negative affect is a key and distressing ingredient of nightmares. Affect in nightmares arises either from the new generation of affective states due to physiological imbalances that occur during sleep or from the reactivation of affect-laden memories. The disruption of physiological balance produces a negative hedonic state, restoration of this balance produces a positive hedonic state, and when balance is attained, a neutral hedonic state results. As a result, hedonic states provoke behaviors in defense of homeostasis, then guide and terminate them. When, due to inadvertent behavior, a pronounced disruption of homeostasis occurs after sleep onset, the resultant strong negative hedonic state is likely to precipitate a nightmare and may lead to awakening. During normal wakefulness, associations of the interplay between stimuli and behaviors that disrupt homeostasis, those that restore homeostasis, and the affective states generated in the process, are committed to memory as affecto-cognitive ensembles. Sleep serves to build or rebuild neural architecture to effect development or to compensate for use- or disease-related wear (e.g. repair oxidative damage). Dreaming serves to synchronize or resynchronize such modified neural circuits with each other and those not modified. Hence, during dreaming, affecto-cognitive ensembles may get reactivated as part of the synchronization process. Where such an ensemble contains strong negative affect (i.e., due to strong affect generated during the original experience), a nightmare may be precipitated. Although both can occur throughout life, the latter type of nightmare is more likely in adults and the former in young children. For the latter memory-based behavioral therapy and for the former education and care are expected to be useful. For both types of nightmare, because strong negative affect is deemed dependent on noradrenergic outflow from the locus coeruleus, the administration of alpha-adrenergic antagonists will provide relief subject to certain caveats.