Sleep debt elicits negative emotional reaction through diminished amygdala-anterior cingulate functional connectivity

Too little or too much: nonlinear relationship between sleep duration and daily affective well-being in depressed adults

BACKGROUND

In addition to having higher negative affect and lower positive affect overall, depressed individuals exhibit heightened affective reactivity to external stimuli than non-depressed individuals. Sleep may contribute to day-to-day fluctuations in depressed individuals, given that sleep disturbance is a common symptom of depression. Yet, little is known about changes in daily affect as a function of nightly sleep duration in depressed adults and non-depressed adults. The current study examined whether and how naturally-occurring sleep duration is associated with negative and positive affect, and how these associations differ between depressed vs. non-depressed adults.

METHODS

Data were drawn from the second wave of the National Study of Daily Experiences (NSDE), a daily diary project of the Midlife in the United States (MIDUS) study. The sample of 2,012 adults (Mage=56.5; 57% female; 84% white) completed eight-day diary interviews via telephone on their daily experiences including nightly sleep duration and negative and positive affect. They also completed assessments of the Composite International Diagnostic Interview-Short form, and depressed status was determined based on DSM-III. Multilevel regression models with linear, quadratic, and cubic terms of sleep duration examined the nonlinear relationship between nightly sleep duration and daily affect. Interaction terms with depression status were added to examine differences between depressed and non-depressed adults.

RESULTS

Depressed adults exhibited significant and greater fluctuations in daily affect as a function of nightly sleep duration than non-depressed adults. Specifically, the degree of decrease in positive affect and increase in negative affect was greater when depressed adults slept 2 or more hours less or longer than their usual sleep hours. Non-depressed adults exhibited relatively stable daily affect regardless of their nightly sleep hours.

CONCLUSIONS

Sleep duration is nonlinearly associated with affect in daily lives of depressed adults, highlighting that both having too little sleep and excessive sleep are associated with adverse daily affective well-being. Implementing sleep interventions to promote an appropriate sleep duration may help improve daily affect among depressed adults.

Postoperative cognitive dysfunction: spotlight on light, circadian rhythms, and sleep

Postoperative cognitive dysfunction (POCD) is a neurological disorder characterized by the emergence of cognitive impairment after surgery. A growing body of literature suggests that the onset of POCD is closely tied to circadian rhythm disruption (CRD). Circadian rhythms are patterns of behavioral and physiological change that repeat themselves at approximately, but not exactly, every 24 h. They are entrained to the 24 h day by the daily light-dark cycle. Postoperative CRD affects cognitive function likely by disrupting sleep architecture, which in turn provokes a host of pathological processes including neuroinflammation, blood-brain barrier disturbances, and glymphatic pathway dysfunction. Therefore, to address the pathogenesis of POCD it is first necessary to correct the dysregulated circadian rhythms that often occur in surgical patients. This narrative review summarizes the evidence for CRD as a key contributor to POCD and concludes with a brief discussion of how circadian-effective hospital lighting can be employed to re-entrain stable and robust circadian rhythms in surgical patients.

Overnight neuronal plasticity and adaptation to emotional distress

Expressions such as 'sleep on it' refer to the resolution of distressing experiences across a night of sound sleep. Sleep is an active state during which the brain reorganizes the synaptic connections that form memories. This Perspective proposes a model of how sleep modifies emotional memory traces. Sleep-dependent reorganization occurs through neurophysiological events in neurochemical contexts that determine the fates of synapses to grow, to survive or to be pruned. We discuss how low levels of acetylcholine during non-rapid eye movement sleep and low levels of noradrenaline during rapid eye movement sleep provide a unique window of opportunity for plasticity in neuronal representations of emotional memories that resolves the associated distress. We integrate sleep-facilitated adaptation over three levels: experience and behaviour, neuronal circuits, and synaptic events. The model generates testable hypotheses for how failed sleep-dependent adaptation to emotional distress is key to mental disorders, notably disorders of anxiety, depression and post-traumatic stress with the common aetiology of insomnia.

Relationship between bedtime, nighttime sleep duration, and anxiety symptoms in preschoolers in China

Background

Sleep problems in preschoolers are becoming increasingly prominent, and the association between sleep status and anxiety symptoms has attracted growing attention. However, studies investigating the relationship between bedtime and nighttime sleep duration in preschoolers and their anxiety symptoms remain scant. We used the large sample data from the Longhua Cohort Study of Children in Shenzhen, China (LCCS) to analyze the association between bedtime and sleep in preschoolers and their anxiety symptoms.

Methods

A cross-sectional study of 69,138 preschoolers in Longhua District, Shenzhen, China was conducted in 2022. Data on sociodemographic characteristics of families, bedtime, nighttime sleep duration of preschoolers, and their anxiety symptoms (measured by the Spence Preschool Children Anxiety Scale) were collected through a structured questionnaire completed by the parents. Using binary logistic regression models, the relationship between bedtime, nighttime sleep duration, and childhood anxiety symptoms was examined.

Results

The bedtimes of preschoolers were concentrated between 21:01-22:00 (52.41%). Among the preschoolers, 38.70% had bedtimes later than 22:00, and 75.49% had insufficient nighttime sleep duration. The positive screening rate for anxiety symptoms among preschoolers was 3.50%. After adjusting for confounding factors using binary logistic regression models, compared with preschoolers with bedtime ≤21:00, The OR (95%CI) values of anxiety in preschoolers with bedtime ≥23:01, 22:01-23:00 and 21:01-22:00 were 2.86 (2.21-3.69), 1.51 (1.27-1.79) and 1.48 (1.26-1.76), respectively. Compared with those with sufficient nighttime sleep duration, the OR (95%CI) of children with nighttime sleep duration less than 9 h was 1.36 (1.23-1.51).

Conclusion

An association exists between bedtime and nighttime sleep duration in preschoolers and their anxiety symptoms. Preschoolers with 21:00 for bedtime and a nighttime sleep duration of 10 h may have lower anxiety symptoms. These findings support the importance of adequate sleep for preventing anxiety symptoms in children.

Longitudinal Associations Between Mild Behavioral Impairment, Sleep Disturbance, and Progression to Dementia

Background

Clinical guidelines recommend incorporating non-cognitive markers like mild behavioral impairment (MBI) and sleep disturbance (SD) into dementia screening to improve detection.

Objective

We investigated the longitudinal associations between MBI, SD, and incident dementia.

Methods

Participant data were from the National Alzheimer's Coordinating Center in the United States. MBI was derived from the Neuropsychiatric Inventory Questionnaire (NPI-Q) using a published algorithm. SD was determined using the NPI-Q nighttime behaviors item. Cox proportional hazard regressions with time-dependant variables for MBI, SD, and cognitive diagnosis were used to model associations between baseline 1) MBI and incident SD (n = 11,277); 2) SD and incident MBI (n = 10,535); 3) MBI with concurrent SD and incident dementia (n = 13,544); and 4) MBI without concurrent SD and incident dementia (n = 11,921). Models were adjusted for first-visit age, sex, education, cognitive diagnosis, race, and for multiple comparisons using the Benjamini-Hochberg method.

Results

The rate of developing SD was 3.1-fold higher in older adults with MBI at baseline compared to those without MBI (95% CI: 2.8-3.3). The rate of developing MBI was 1.5-fold higher in older adults with baseline SD than those without SD (95% CI: 1.3-1.8). The rate of developing dementia was 2.2-fold greater in older adults with both MBI and SD, as opposed to SD alone (95% CI:1.9-2.6).

Conclusions

There is a bidirectional relationship between MBI and SD. Older adults with SD develop dementia at higher rates when co-occurring with MBI. Future studies should explore the mechanisms underlying these relationships, and dementia screening may be improved by assessing for both MBI and SD.

Examining the longitudinal direct and indirect relationships between early sleep (quality and duration) and later cyberbullying perpetration in emerging adults

OBJECTIVES

Researchers have recently posited the importance of sleep as a predictor of cyberbullying perpetration. We aimed to fill several theoretical gaps in the literature. First, most of the research focuses on sleep quality and not duration. Second, most of the studies are correlational, limiting causal claims. Third, few studies have tested the theoretical mediators (anger, hostility, and self-control) in the relationship between sleep (quality and duration) and cyberbullying.

METHODS

We employed short-term three-wave longitudinal study with US emerging adults (N = 182). At each wave participants completed measures of cyberbullying perpetration, anger, hostility, self-control, sleep quality, and sleep duration.

RESULTS

Findings from our longitudinal path model showed that Wave 2 anger was the only significant mediator between Wave 1 sleep duration (not quality) and Wave 3 cyberbullying.

CONCLUSIONS

We supported past research focused on the mediating role of anger in the relationship between sleep and cyberbullying, and theory that explicates the importance of mediators. Moreover, we contributed to this literature by employing a longitudinal design, assessing mediators, focusing on sleep duration and quality, and using an emerging adult population.

Opposing brain signatures of sleep in task-based and resting-state conditions

Sleep and depression have a complex, bidirectional relationship, with sleep-associated alterations in brain dynamics and structure impacting a range of symptoms and cognitive abilities. Previous work describing these relationships has provided an incomplete picture by investigating only one or two types of sleep measures, depression, or neuroimaging modalities in parallel. We analyze the correlations between brainwide neural signatures of sleep, cognition, and depression in task and resting-state data from over 30,000 individuals from the UK Biobank and Human Connectome Project. Neural signatures of insomnia and depression are negatively correlated with those of sleep duration measured by accelerometer in the task condition but positively correlated in the resting-state condition. Our results show that resting-state neural signatures of insomnia and depression resemble that of rested wakefulness. This is further supported by our finding of hypoconnectivity in task but hyperconnectivity in resting-state data in association with insomnia and depression. These observations dispute conventional assumptions about the neurofunctional manifestations of hyper- and hypo-somnia, and may explain inconsistent findings in the literature.

Insomnia and distress as mediators on the relationship from cyber-victimization to self-reported psychotic experiences: a binational study from Tunisia and Lebanon

BACKGROUND

While expansive research has accumulated concerning the association between traditional, face-to-face peer victimization and psychosis, a paucity of empirical research has been undertaken so far to investigate these associations with experiences of new and evolving ways of victimization through the digital world. Exploring these associations is highly relevant and timely, given that emerging adults are heavy users of digital technologies, highly exposed to online risks, and are at the peak age of onset of psychosis. This study aimed to test the hypothesis that psychological distress and insomnia symptoms have a significant indirect mediating effect on the association between cyber-victimization and self-reported positive psychotic experiences (SRPEs) in a binational sample of Tunisian and Lebanese community adults.

METHOD

The total sample was composed of 3766 participants; 3103 were from Lebanon (Mean age: 21.73 ± 3.80 years, 63.6% females) and 663 from Tunisia (Mean age: 26.32 ± 4.86 years, 59.9% females). Online anonymous self-report questionnaires were administered to all participants.

RESULTS

Higher SRPEs were found in Lebanese participants compared to Tunisians, in single participants compared to married ones, in those with a university level of education compared to secondary or less, in those who live in rural areas compared to urban, in those who do not smoke, do not drink alcohol and do not use marijuana or any other illegal drug. Furthermore, more cyber-victimization, a higher insomnia severity and psychological distress were significantly associated with higher SRPEs. After adjusting for potential confounders, mediation analysis demonstrated that higher cyber-victimization was significantly associated with more insomnia severity/psychological distress; which were, in turn, significantly associated with greater SRPEs. Finally, more cyber-victimization was significantly and directly associated with more positive dimension.

CONCLUSION

Identifying insomnia and distress as mediators could provide novel insight for psychosis prevention efforts and intervention targets for cyber-victimized individuals prone to experience subclinical psychotic symptoms.

Enhanced amygdala-cingulate connectivity associates with better mood in both healthy and depressive individuals after sleep deprivation

Sleep loss robustly disrupts mood and emotion regulation in healthy individuals but can have a transient antidepressant effect in a subset of patients with depression. The neural mechanisms underlying this paradoxical effect remain unclear. Previous studies suggest that the amygdala and dorsal nexus (DN) play key roles in depressive mood regulation. Here, we used functional MRI to examine associations between amygdala- and DN-related resting-state connectivity alterations and mood changes after one night of total sleep deprivation (TSD) in both healthy adults and patients with major depressive disorder using strictly controlled in-laboratory studies. Behavioral data showed that TSD increased negative mood in healthy participants but reduced depressive symptoms in 43% of patients. Imaging data showed that TSD enhanced both amygdala- and DN-related connectivity in healthy participants. Moreover, enhanced amygdala connectivity to the anterior cingulate cortex (ACC) after TSD associated with better mood in healthy participants and antidepressant effects in depressed patients. These findings support the key role of the amygdala-cingulate circuit in mood regulation in both healthy and depressed populations and suggest that rapid antidepressant treatment may target the enhancement of amygdala-ACC connectivity.

Assessing the Impact of Technology Use, Social Engagement, Emotional Regulation, and Sleep Quality Among Undergraduate Students in Jordan: Examining the Mediating Effect of Perceived and Academic Stress

The quality of sleep is affected by several psychological factors. University students experience different types of stress and develop various strategies to cope with it. This study assesses the impact of technology use, social engagement, emotional regulation, and sleep quality among undergraduate students in Jordan, while examining the mediating effect of perceived and academic stress. A convenience sample of 308 undergraduate students was selected from the University of Jordan. The results indicated that the study model was fit, with significant direct negative impacts of social engagement, time management, and emotional regulation on perceived stress. Additionally, there was a significant direct negative relationship between technology use, time management, and emotional regulation on academic stress. The results show indirect significant standardized effects of social engagement, time management, and emotional regulation on the quality of sleep through the mediation of perceived stress.

Insomnia and impacts on facial expression recognition accuracy, intensity and speed: A meta-analysis

Facial expressions provide nonverbal cues that are important for delivering and interpreting human emotions. Previous studies have shown that the ability to interpret facial emotions correctly could be partially impaired in sleep-deprived people. People with insomnia might also suffer from sleep loss, so we assumed that facial expression recognition ability might also be impaired in people with insomnia. Despite a growing body of research exploring insomnia's potential impacts on facial expression recognition, conflicting results have been reported, and no systematic review of this research body has been conducted. In this study, after screening 1100 records identified through database searches, six articles examining insomnia and facial expression recognition ability were included in a quantitative synthesis. The main outcomes were classification accuracy (ACC), reaction time (RT), and intensity rating-the three most studied facial expression processing variables. Subgroup analysis was performed to identify altered perceptions according to the facial expressions of four emotions-happiness, sadness, fear, and anger-used to examine insomnia and emotion recognition. The pooled standard mean differences (SMDs) and corresponding 95% confidence intervals (CIs) demonstrated that facial expression recognition among people with insomnia was less accurate (SMD = -0.30; 95% CI: -0.46, -0.14) and slower (SMD = 0.67; 95% CI: 0.18, -1.15) compared to good sleepers. The classification ACC of fearful expression was lower in the insomnia group (SMD = -0.66; 95% CI: -1.02, -0.30). This meta-analysis was registered using PROSPERO.

Is decision-making influenced by interactions between extended wakefulness and weak emotional stressors? An experimental study

In this study, we aimed to determine whether 21-hour continuous wakefulness decreases performance in the Iowa Gambling Task and examine the effect of the interaction between a weak emotional stressor and prolonged continuous wakefulness on the decision-making process, as measured by the Iowa Gambling Task. Approximately half of 38 healthy college students were in the sleep deprivation condition (they performed the task at 4:30 a.m.); the remainder were in the daytime condition (they performed the task during the day). The participants in each sleep condition were further divided into non-exposed and exposed to an emotional stressor via a social exclusion procedure before the task, with the Iowa Gambling Task score as the dependent variable. In the sleep deprivation condition, performance in the final block of the task was significantly worse in the group with an emotional stressor than the group without. There was no main effect of sleep conditions or emotional stressors on the task performance in either block. The results of this study suggest that even 21 hours of continuous wakefulness, which can occur in daily work life, may prevent appropriate learning in people exposed to an emotional stressor, even if the stress caused due to it is low.

Sleep deprivation altered encoding of basolateral amygdala on fear acquisition

Sleep deprivation (SD) may lead to the development of fear- and anxiety-related emotional disorders. However, the neural mechanisms underlying the effects of SD on fear acquisition are unclear. Here, we tested whether and how SD influences the behavioral and neural manifestations of fear acquisition. We found that subjective fear ratings and objective fear indices (skin conductance response [SCR]) in the SD group were greater than those in the control group during fear acquisition, suggesting that SD facilitated fear acquisition (nSD = 18 and ncontrol = 23 for self-reported rating analysis; nSD = 10 and ncontrol = 10 for SCR analysis). Neuroimaging data showed that the SD group exhibited stronger activity in the left basolateral amygdala (BLA) and left superficial amygdala (SFA). Moreover, the left BLA activity, which positively correlated with the objective fear indices, significantly mediated the effect of SD on fear acquisition. Together, the present findings indicate that SD facilitates fear acquisition by augmenting threat-specific encoding in the BLA, which may be a potential biomarker of the risk of developing fear-related disorders under traumatic and distressing situations.

Operation early-bird: Investigating altered light exposure in military barracks on sleep and performance-a placebo-controlled study

The manipulation of light exposure in the evening has been shown to modulate sleep, and may be beneficial in a military setting where sleep is reported to be problematic. This study investigated the efficacy of low-temperature lighting on objective sleep measures and physical performance in military trainees. Sixty-four officer-trainees (52 male/12 female, mean ± SD age: 25 ± 5 years) wore wrist-actigraphs for 6 weeks during military training to quantify sleep metrics. Trainee 2.4-km run time and upper-body muscular-endurance were assessed before and after the training course. Participants were randomly assigned to either: low-temperature lighting (LOW, n = 19), standard-temperature lighting with a placebo "sleep-enhancing" device (PLA, n = 17), or standard-temperature lighting (CON, n = 28) groups in their military barracks for the duration of the course. Repeated-measures ANOVAs were run to identify significant differences with post hoc analyses and effect size calculations performed where indicated. No significant interaction effect was observed for the sleep metrics; however, there was a significant effect of time for average sleep duration, and small benefits of LOW when compared with CON (d = 0.41-0.44). A significant interaction was observed for the 2.4-km run, with the improvement in LOW (Δ92.3 s) associated with a large improvement when compared with CON (Δ35.9 s; p = 0.003; d = 0.95 ± 0.60), but not PLA (Δ68.6 s). Similarly, curl-up improvement resulted in a moderate effect in favour of LOW (Δ14 repetitions) compared with CON (Δ6; p = 0.063; d = 0.68 ± 0.72). Chronic exposure to low-temperature lighting was associated with benefits to aerobic fitness across a 6-week training period, with minimal effects on sleep measures.

Probing different paradigms of morphine withdrawal on sleep behavior in male and female C57BL/6J mice

Opioid misuse has dramatically increased over the last few decades resulting in many people suffering from opioid use disorder (OUD). The prevalence of opioid overdose has been driven by the development of new synthetic opioids, increased availability of prescription opioids, and more recently, the COVID-19 pandemic. Coinciding with increases in exposure to opioids, the United States has also observed increases in multiple Narcan (naloxone) administrations as life-saving measures for respiratory depression, and, thus, consequently, naloxone-precipitated withdrawal. Sleep dysregulation is a main symptom of OUD and opioid withdrawal syndrome, and therefore, should be a key facet of animal models of OUD. Here we examine the effect of precipitated and spontaneous morphine withdrawal on sleep behaviors in C57BL/6J mice. We find that morphine administration and withdrawal dysregulate sleep, but not equally across morphine exposure paradigms. Furthermore, many environmental triggers promote relapse to drug-seeking/taking behavior, and the stress of disrupted sleep may fall into that category. We find that sleep deprivation dysregulates sleep in mice that had previous opioid withdrawal experience. Our data suggest that the 3-day precipitated withdrawal paradigm has the most profound effects on opioid-induced sleep dysregulation and further validates the construct of this model for opioid dependence and OUD.

Highlights

Morphine withdrawal differentially dysregulates the sleep of male and female mice3-day precipitated withdrawal results in larger changes than spontaneous withdrawalOpioid withdrawal affects responses to future sleep deprivation differently between sexes.

Co-occurring insomnia and anxiety: a randomized controlled trial of internet cognitive behavioral therapy for insomnia versus internet cognitive behavioral therapy for anxiety

STUDY OBJECTIVES

Insomnia and anxiety are highly prevalent and frequently co-occur. Given limited therapeutic resources and time constraints, the aim of this study was to compare which treatment-internet cognitive behavioral therapy (CBT) for insomnia or internet CBT for anxiety-leads to the best outcomes in individuals with comorbid insomnia and anxiety.

METHODS

120 participants with comorbid insomnia and clinical anxiety (as defined by scores above the clinical cutoff on the insomnia severity index (ISI) and the generalized anxiety disorder 7-item scale (GAD-7)) were randomized to receive internet-based cognitive behavioral therapy (iCBT) for insomnia or iCBT for anxiety. The primary outcome measures were the ISI and the generalized anxiety disorder 7-item scale. Primary outcome measures were assessed before treatment, at mid-treatment, at post-treatment, and 3 months after treatment. Secondary outcome measures assessed depression symptoms, distress, and sleep diary parameters.

RESULTS

Participants in both groups experienced large reductions in symptoms of insomnia, anxiety, depression, and distress, as well as improvements in sleep efficiency and total sleep time. Improvements were maintained at follow-up. Crucially, at the end of treatment, the insomnia treatment was more effective in reducing symptoms of insomnia than the anxiety treatment, and equally effective in reducing symptoms of anxiety. Treatment gains were maintained at 3-month follow-up, however, there were no differences between groups at that time point.

CONCLUSIONS

These results suggest that in the common case of a patient presenting with comorbid insomnia and anxiety, treatment for insomnia may be the most efficient treatment strategy.

TRIAL REGISTRATION

The trial was registered with the Australian and New Zealand Clinical Trials Registry, https://anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12618001141235. Trial ID: ACTRN12618001141235. Trial name: a comparison of internet-based CBT for insomnia versus internet-based CBT for anxiety in a comorbid sample.

Pre-sleep affect predicts subsequent REM frontal theta in nonlinear fashion

Pre-sleep affect is thought to influence sleep, but associations with both sleep architecture and the electroencephalographic (EEG) power spectrum are mixed. In this pre-registered study, we assessed negative valence and arousal 1 h pre-sleep in 52 adults drawn from the community, then recorded one night of polysomnography (PSG) in participants' own homes. Pre-sleep affect was not associated with nonrapid eye movement (NREM) or rapid eye movement (REM) sleep architecture parameters, but we did observe inverted U-shaped relationships between both negative valence and arousal and REM frontal theta power, such that theta power was highest at moderate negative valence and arousal, and lowest at either affective extreme. When entered into a model together, both valence and arousal accounted for independent variance. Secondary analyses revealed a similar quadratic association with pre-sleep positive valence, suggesting a nonspecific effect of pre-sleep valence on REM frontal theta. Robustness checks confirmed that effects were not explained by homeostatic sleep pressure or sleep timing. Our results suggest that mixed findings in the literature may reflect different ends of a quadratic function, underscoring the importance of assessing how different components of pre-sleep affect relate to sleep.

Nocturnal hypoxemia is related to morning negative affectivity in untreated patients with severe obstructive sleep apnea

The relationship between sleep apnea and morning affectivity remains unclear. We aimed to clarify how sleep disturbance in patients with obstructive sleep apnea (OSA) influences their affectivity. The enrolled participants underwent the Positive and Negative Affect Schedule on their beds immediately before and after overnight polysomnography. Thirty patients with OSA were divided into two groups according to the apnea-hypopnea index (AHI): mild to moderate OSA (5 ≤ AHI < 30/h) and severe OSA (AHI ≥ 30/h) groups. Additionally, 11 healthy participants (AHI < 5/h) were included as the control group. No independent association was found between affectivity and OSA severity markers in the whole population; however, the severe OSA group had a significantly higher cumulative percentage of sleep time at saturations < 90% (CT90) and worsened morning negative affectivity. Multiple regression analysis showed that CT90 was an independent factor for increasing negative affectivity in the severe OSA group (p = 0.0422). In patients with OSA, the receiver operating characteristic curve analysis showed that the best cutoff value for CT90 for predicting no decrease in negative affectivity after sleep was 1.0% (sensitivity = 0.56, specificity = 0.86); the corresponding area under the curve was 0.71. Worsening of negative affectivity in the morning was influenced by nocturnal hypoxemia in patients with severe OSA.

Daily Associations of Sleep Quality and Sleep Duration with Anxiety in Young Adults: The Moderating Effect of Alexithymia

OBJECTIVES

The present study examined the daily, within-individual associations of anxiety with sleep quality and sleep duration and the moderating effects of alexithymia on these associations in community-dwelling young adults. It was hypothesized that daily anxiety and sleep parameters would be bidirectionally related and alexithymia would moderate these relationships.

METHOD

Participants completed morning and evening diaries assessing daily anxiety and sleep parameters for 30 consecutive days. They also completed questionnaires assessing baseline sleep parameters, anxiety, and alexithymia. Multilevel modeling was used to evaluate the within-individual associations between daily anxiety and sleep parameters and whether between-individual differences in alexithymia moderated these associations.

RESULTS

Higher anxiety relative to personal averages across the study period was associated with shorter sleep duration at night. Poorer sleep quality and shorter sleep duration relative to personal averages were associated with higher next-day anxiety. A significantly stronger association between poorer sleep quality and higher next-day anxiety was observed in individuals with higher levels of alexithymia.

CONCLUSION

Daily anxiety and sleep quantity are bidirectionally associated within individuals in community-dwelling young adults. Poorer sleep quality was associated with higher next-day anxiety but not vice versa. Individuals with higher levels of alexithymia might be more vulnerable to the effects of poor sleep on next-day anxiety.

The moderating effect of prefrontal response to sleep-related stimuli on the association between depression and sleep disturbance in insomnia disorder

We investigated differences in brain activity in response to sleep-related pictures between chronic insomnia disorder (CID) patients and good sleepers (GS), and examined whether brain activity moderated the relationship between depressive symptoms and sleep disturbance in CID patients and GS. This study included 43 patients diagnosed with CID, based on the International Classification of Sleep Disorders-3, and 42 GS. The participants kept a sleep diary, underwent nocturnal polysomnography to measure sleep parameters, and completed self-report questionnaires to assess sleep and psychiatric symptoms. They underwent functional magnetic resonance imaging (fMRI) to examine differences in brain activity in response to sleep-related pictures compared to neutral pictures. A moderated moderation analysis was performed to investigate the moderating role of brain responses to sleep-related pictures in the association between depressive symptoms and sleep disturbance. Compared to GS, the brain responses to sleep-related stimuli were significantly lower in CID patients in the right lateral prefrontal cortex (LPFC) and dorsomedial prefrontal cortex (DMPFC). More severe depressive symptoms were significantly associated with longer sleep latency only when LPFC activity was low in CID patients, but not in GS. LPFC hypoactivity in response to sleep-related stimuli in CID patients could moderate the relationship between depression and sleep disturbance.

Heritability of REM sleep neurophysiology in adolescence

Alterations of rapid eye movement (REM) sleep have long been observed in patients with psychiatric disorders and proposed as an endophenotype-a link between behavior and genes. Recent experimental work has shown that REM sleep plays an important role in the emotional processing of memories, emotion regulation, and is altered in the presence of stress, suggesting a mechanism by which REM sleep may impact psychiatric illness. REM sleep shows a developmental progression and increases during adolescence-a period of rapid maturation of the emotional centers of the brain. This study uses a behavioral genetics approach to understand the relative contribution of genes, shared environmental and unique environmental factors to REM sleep neurophysiology in adolescents. Eighteen monozygotic (MZ; n = 36; 18 females) and 12 dizygotic (DZ; n = 24; 12 females) same-sex twin pairs (mean age = 12.46; SD = 1.36) underwent whole-night high-density sleep EEG recordings. We find a significant genetic contribution to REM sleep EEG power across frequency bands, explaining, on average, between 75 to 88% of the variance in power, dependent on the frequency band. In the lower frequency bands between delta and sigma, however, we find an additional impact of shared environmental factors over prescribed regions. We hypothesize that these regions may reflect the contribution of familial and environmental stress shared amongst the twins. The observed strong genetic contribution to REM sleep EEG power in early adolescence establish REM sleep neurophysiology as a potentially strong endophenotype, even in adolescence-a period marked by significant brain maturation.

Sleep Characteristics and Socio-Emotional Functioning of Gifted Children

OBJECTIVES/BACKGROUND

Intellectual giftedness is characterized by an intellectual development superior to peers, while emotional and relational developments correspond to the age norms. Few empirical researches have investigated sleep profile of gifted children (GC) and its association with their well-being, all of which used IQ as the sole definition criteria for GC. This study aimed to investigate the interaction between giftedness and sleep on socio-emotional functioning.

PARTICIPANTS

The sample consisted of 32 GC (25 boys; mean age = 9.62, SD = 1.81) and 17 typically-developing children (TD: 13 boys; mean age = 10.23 years, SD = 1.95). Giftedness was identified using Renzulli's three-factor definition of giftedness.

METHODS

Children's sleep and socio-emotional functioning were respectively assessed with the Children's Sleep Habits Questionnaire and the Child Behavior Checklist, both completed by parents.

RESULTS

Being in the GC group increased by 4.67 times the risk of having sleep problems and 14.12 times the risk of having maladaptive behaviors. Two-way ANOVA tests showed that sleep problems tended to moderate the relation between giftedness and adjustment difficulties so that the combination of giftedness and sleep problems appeared to be prejudicial to socio-emotional functioning.

CONCLUSION

Giftedness could be a risk factor for sleep disorders as well as adjustment difficulties. The present results support the importance of addressing sleep in the GC assessment to improve their well-being and eventually limit the negative impacts of sleep difficulties on emotional and behavioral functioning.

Investigating the effects of sleep and sleep loss on the different stages of episodic emotional memory: A narrative review and guide to the future

For two decades, sleep has been touted as one of the primary drivers for the encoding, consolidation, retention, and retrieval of episodic emotional memory. Recently, however, sleep’s role in emotional memory processing has received renewed scrutiny as meta-analyses and reviews have indicated that sleep may only contribute a small effect that hinges on the content or context of the learning and retrieval episodes. On the one hand, the strong perception of sleep’s importance in maintaining memory for emotional events may have been exacerbated by publication bias phenomena, such as the “winner’s curse” and “file drawer problem.” On the other hand, it is plausible that there are sets of circumstances that lead to consistent and reliable effects of sleep on emotional memory; these circumstances may depend on factors such as the placement and quality of sleep relative to the emotional experience, the content and context of the emotional experience, and the probes and strategies used to assess memory at retrieval. Here, we review the literature on how sleep (and sleep loss) influences each stage of emotional episodic memory. Specifically, we have separated previous work based on the placement of sleep and sleep loss in relation to the different stages of emotional memory processing: (1) prior to encoding, (2) immediately following encoding during early consolidation, (3) during extended consolidation, separated from initial learning, (4) just prior to retrieval, and (5) post-retrieval as memories may be restructured and reconsolidated. The goals of this review are three-fold: (1) examine phases of emotional memory that sleep may influence to a greater or lesser degree, (2) explicitly identify problematic overlaps in traditional sleep–wake study designs that are preventing the ability to better disentangle the potential role of sleep in the different stages of emotional memory processing, and (3) highlight areas for future research by identifying the stages of emotional memory processing in which the effect of sleep and sleep loss remains under-investigated. Here, we begin the task of better understanding the contexts and factors that influence the relationship between sleep and emotional memory processing and aim to be a valuable resource to facilitate hypothesis generation and promote important future research.

Sleep deprivation and fatigue in early postpartum and their association with postpartum depression in primiparas intending to establish breastfeeding

Objective: To examine the association of objective sleep and fatigue in the early postpartum period with postpartum depression in Japanese primiparas intending to establish breastfeeding.

Materials and Methods: The participants were 34 primiparas who were in the postnatal ward after vaginal delivery and responsively breastfeeding their rooming-in baby. Actigraphy data for objective sleep were collected for three consecutive days starting from the first day postpartum. Fatigue and postpartum depression were assessed using the Postpartum Fatigue Scale and Edinburgh Postnatal Depression Scale, respectively, on numerous days between the first day postpartum and the one-month checkup. Breastfeeding and rooming-in data were also collected.

Results: The mean total sleep time was 252.0 ± 73.1 min/day. Mean breastfeeding frequency was 12.4 ± 3.2 times/day and mean total breastfeeding time was 247.4 ± 101.8 min/day. Among the participants, 67.6% were exclusively breastfeeding on the discharge day. Fatigue scores were significantly higher during the hospital stay, compared with one month postpartum. Multiple regression analysis showed that sleep frequency on the third day postpartum and mean total breastfeeding time and fatigue on the fifth day postpartum were factors affecting the Edinburgh Postnatal Depression Scale score.

Conclusion: The association between postpartum depression among breastfeeding primiparas in the early postpartum period and objective sleep, fatigue, and total breastfeeding time per day was suggested. An environment wherein breastfeeding mothers can rest and sleep without hesitation will be beneficial. Moreover, the importance of sleep during pregnancy and the early postpartum period must be highlighted. Midwifery and/or nursing care starting while the mother is in a postnatal hospital stay can play a key role in preventing postpartum depression.

Sleep and violence perpetration: A review of biological and environmental substrates

Violence is a worldwide societal burden that negatively impacts individual health, wellbeing and economic development. Evidence suggests a bidirectional relationship between sleep changes and violence. This review details, evaluates and discusses the biological and demographic substrates linking sleep and violence perpetration, and summarizes the overlap of brain areas, functional neuronal systems and genetic features involved, not including violent behaviours during sleep. Knowledge on the biological variables that affect the individual's susceptibility to violent behaviour may have implications for criminology, management of detentions and rehabilitation strategies.

Sleep disturbance has the largest impact on children's behavior and emotions

OBJECTIVE

Children's behavior and emotions are affected by sleep disturbances, the parent-child relationship, media viewing time, and the social status of parents and caregivers. We conducted a questionnaire survey to identify the factors that have the greatest impact on children's behavior and emotions and how these factors relate to each other.

METHODS

A parental questionnaire survey was performed at a public elementary school. The questionnaire comprised questions on the family environment (e.g., family structure, media and game exposure, after-school lessons, and caregiver's work schedule) and physical information, the Strengths and Difficulties Questionnaire (SDQ), the Children's Sleep Habits Questionnaire (CSHQ), and the Pittsburgh Sleep Quality Index (PSQI) for parents' sleep condition. A path diagram was drawn to hypothesize the complex interrelationships among factors, and structural equation modeling was used to estimate the path coefficients.

RESULT

We identified several factors that significantly affected the SDQ score. The CSHQ total score had the largest impact, followed by after-school lessons, single-mother families, and children's sex. In addition, several indirect pathways that led to the CSHQ score (i.e., a pathway from time spent watching television to CSHQ score via children's bedtime and a pathway from single-mother family to CSHQ score via PSQI total score) significantly affected the SDQ score.

CONCLUSION

Children's sleep habits that were influenced by several environmental factors had the greatest impact on children's behavior and emotions, which suggested that children's behavioral problems can be improved by interventions focused on sleep habits, such as sleep hygiene instructions.

The effect of sleep deprivation on empathy for pain: An ERP study

Empathy for pain has a strong adaptive function. It plays a protective role in survival and exerts a vital impact on successful social interaction. Sleep loss, however, is commonplace in current society, and people are increasingly plagued by it. Previous studies have investigated whether sleep loss affects empathy for pain, yet the results were undecided. We aimed to determine whether this effect is existed and further explore the temporal and frequency dynamics of neural activities involved in this effect by recording the electroencephalogram (EEG) signals. We recruited 25 healthy adults (11 females) who were required to perform a pain judgement and unpleasantness rating about the presented nociceptive and neutral pictures after nocturnal sleep (NS) and sleep deprivation (SD), and their neuronal activities were recorded by event-related potentials (ERPs). Results showed a significantly decreased amplitude in the early components (N2, N340) of vicarious pain processing after SD. In further time-frequency (TF) analysis, a reduced energy occurred in theta2 (5-7 Hz) band under SD condition. Moreover, the decreased theta2 was positively correlated with the subjective ratings of both other's pain and self-unpleasantness only under SD condition. Our results indicated that SD impairs affective sharing of empathy for pain.

REM Sleep: An Unknown Indicator of Sleep Quality

Standard polysomnographic analysis of sleep has not provided evidence of an objective measure of sleep quality; however, factors such as sleep duration and sleep efficiency are those more consistently associated with the subjective perception of sleep quality. Sleep reduction as currently occurs in our 24/7 society has had a profound impact on sleep quality; the habitual sleep period should fit within what is a limited nighttime window and may not be sufficient to satisfy the whole sleep process; moreover, the use of artificial light during the evening and early night hours can delay and disturb the circadian rhythms, especially affecting REM sleep. The correct phase relationship of the sleep period with the circadian pacemaker is an important factor to guarantee adequate restorative sleep duration and sleep continuity, thus providing the necessary background for a good night's sleep. Due to the fact that REM sleep is controlled by the circadian clock, it can provide a window-like mechanism that defines the termination of the sleep period when there is still the necessity to complete the sleep process (not only wake-related homeostasis) and to meet the circadian end of sleep timing. An adequate amount of REM sleep appears necessary to guarantee sleep continuity, while periodically activating the brain and preparing it for the return to consciousness.

The effect of sleep deprivation and restriction on mood, emotion, and emotion regulation: three meta-analyses in one

STUDY OBJECTIVES

New theory and measurement approaches have facilitated nuanced investigation of how sleep loss impacts dimensions of affective functioning. To provide a quantitative summary of this literature, three conceptually related meta-analyses examined the effect of sleep restriction and sleep deprivation on mood, emotion, and emotion regulation across the lifespan (i.e. from early childhood to late adulthood).

METHODS

A total of 241 effect sizes from 64 studies were selected for inclusion, and multilevel meta-analytic techniques were used when applicable.

RESULTS

There was a moderate, positive effect of sleep loss on negative mood (g = 0.45), which was stronger for studies with younger samples, as well as a large, negative effect of sleep loss on positive mood (g = -0.94). For negative mood only, studies that used total sleep deprivation had larger effect sizes than studies that restricted sleep. After correcting for publication bias, a modest but significant negative effect for sleep loss on emotion (g = -0.11) was found; the valence of emotional stimuli did not change the direction of this effect, and type of sleep manipulation was also not a significant moderator. Finally, sleep restriction had a small, negative effect on adaptive emotion regulation (g = -0.32), but no significant impact on maladaptive emotion regulation (g = 0.14); all studies on adaptive emotion regulation were conducted with youth samples.

CONCLUSIONS

Sleep loss compromises optimal affective functioning, though the magnitude of effects varies across components. Findings underscore the importance of sleep for healthy affective outcomes.

Inconsistent effects of sleep deprivation on memory function

In this review article, we aimed to discuss the role of sleep deprivation (SD) in learning and memory processing in basic and clinical studies. There are numerous studies investigating the effect of SD on memory, while most of these studies have shown the impairment effect of SD. However, some of these studies have reported conflicting results, indicating that SD does not impair memory performance or even improves it. So far, no study has discussed or compared the conflicting results of SD on learning and memory. Thus, this important issue in the neuroscience of sleep remains unknown. The main goal of this review article is to compare the similar mechanisms between the impairment and the improvement effects of SD on learning and memory, probably leading to a scientific solution that justifies these conflicting results. We focused on the inconsistent effects of SD on some mechanisms involved in learning and memory, and tried to discuss the inconsistent effects of SD on learning and memory.

Decreased activity in the reward network of chronic insomnia patients

In modern society, many people have insomnia. Chronic insomnia has been noted as a risk factor for depression. However, there are few functional imaging studies of the brain on affective functions in chronic insomnia. This study aimed to investigate brain activities induced by emotional stimuli in chronic insomnia patients. Fifteen patients with primary insomnia and 30 age and gender matched healthy controls participated in this study. Both groups were presented images of fearful, happy, and neutral expressions consciously and non-consciously while undergoing MRI to compare the activity in regions of the brain responsible for emotions. Conscious presentation of the Happy-Neutral contrast showed significantly lower activation in the right orbitofrontal cortex of patients compared to healthy controls. The Happy-Neutral contrast presented in a non-conscious manner resulted in significantly lower activation of the ventral striatum, right insula, putamen, orbitofrontal cortex and ventral tegmental area in patients compared to healthy controls. Our findings revealed that responsiveness to positive emotional stimuli were decreased in insomniac patients. Specifically, brain networks associated with rewards and processing positive emotions showed decreased responsiveness to happy emotions especially for non-conscious image. The magnitude of activity in these areas also correlated with severity of insomnia, even after controlling for depression scale scores. These findings suggest that insomnia induces an affective functional disorder through an underlying mechanism of decreased sensitivity in the regions of the brain responsible for emotions and rewards to positive emotional stimuli.

The Moderating Effect of Physical Activity on the Relationship between Sleep and Emotional Distress and the Difference between Blacks and Whites: A Secondary Data Analysis Using the National Health Interview Survey from 2005-2015

(1) Background: Unhealthy sleep durations (short and long sleep) are associated with emotional distress (ED). Minority populations, specifically Blacks, are more burdened with unhealthy sleep durations and ED. The ameliorative effect of physical activity (PA) on ED and sleep duration may provide insight into how to reduce the burden among Blacks and other minorities. However, it is unclear whether PA attenuates the relationship between sleep and ED, and whether this relationship differs by race. (2) Methods: We analyzed data from the nationally representative 2005–2015 National Health Interview Survey (NHIS) dataset. ED, physical activity, and sleep duration were collected through self-reports. Regression analyses investigated the moderating effect of PA on the relationship between sleep and ED (adjusting for age, sex, BMI, and employment status) and stratified by race. (3) Results: We found that sleep duration was independently associated with ED. Physical activity moderated the relationship between sleep and ED, the full population, and Whites, but not Blacks. (4) Conclusion: PA moderated the relationship between short, average, or long sleep and ED, but in stratified analyses, this was only evident for Whites, suggesting Blacks received differing protective effects from physical activity. Further research should be performed to understand the connection of physical activity to sleep and mental health.

Natural sleep loss is associated with lower mPFC activity during negative distracter processing

Previous research has demonstrated that loss of sleep has a negative impact on both emotional and cognitive functioning. We examined whether subjectively reported natural sleep loss is associated with the interplay between emotion and cognition, as was probed by brain activity in response to emotional distraction during a working memory task. Forty-six healthy male adults reported their typical weekly sleep pattern using the Munich Chronotype Questionnaire (MCTQ), while recent sleep loss was enquired using a sleep diary in the 7 days preceding scanning. Participants performed a delayed match-to-sample task with negative and neutral distracters during the delay period inside the MRI scanner. Activity differences between negative and neutral distracters were associated to both sleep loss measures across participants. The amount of typically encountered sleep loss indicated by the MCTQ, but not sleep diary, was negatively associated with activity in the rostral anterior cingulate cortex and dorsomedial prefrontal cortex during emotionally negative compared to neutral distraction (p < 0.025, whole brain corrected). Participants showed less distracter-related activity in the ACC and dorsomedial PFC with increasing sleep loss, which, in the long run, might contribute to less adaptive emotional processing, and therefore a greater vulnerability to develop affective disorders.

Sickness and sleep health predict frustration and affective responses to a frustrating trigger

Fluctuations in health and sleep are common, but we know surprisingly little about how these daily life stressors affect one's level of frustration and sensitivity to becoming frustrated. In this pre-registered study, 517 participants (M_age = 30.4, SD = 10.4) reported their current sickness symptoms, health status, sleepiness, and sleep duration and quality the previous night. They also rated their general frustration and mood before and after a mild frustration-eliciting task. In the task, participants were instructed to copy geometric shapes onto a piece of paper, without lifting the pen from the paper. Participants were given three minutes to copy the eight shapes, but in order to induce frustration half of them were unsolvable. The study was subsequently repeated in an independent sample (N = 113). Frustration increased in response to the task; however, those with the worst sickness symptoms or sleep health reduced or did not change their frustration levels. Instead, across both studies, frustration was already high at baseline for these individuals. These findings indicate that being sick or having poor sleep is related to high general frustration, but resilience to further frustration due to mild frustrating situations.

The Effects of Sleep Quality on Dream and Waking Emotions

Despite the increasing interest in sleep and dream-related processes of emotion regulation, their reflection into waking and dream emotional experience remains unclear. We have previously described a discontinuity between wakefulness and dreaming, with a prevalence of positive emotions in wakefulness and negative emotions during sleep. Here we aim to investigate whether this profile may be affected by poor sleep quality. Twenty-three ‘Good Sleepers’ (GS) and 27 ‘Poor Sleepers’ (PS), identified through the Pittsburgh Sleep Quality Index (PSQI) cut-off score, completed three forms of the modified Differential Emotions Scale, assessing, respectively, the frequency of 22 emotions over the past 2 weeks, their intensity during dreaming and during the previous day. The ANOVA revealed a different pattern of emotionality between groups: GS showed high positive emotionality in wakefulness (both past 2 weeks and 24 h) with a significant shift to negative emotionality in dreams, while PS showed evenly distributed emotional valence across all three conditions. No significant regression model emerged between waking and dream affect. In the frame of recent hypotheses on the role of dreaming in emotion regulation, our findings suggest that the different day/night expression of emotions between groups depends on a relative impairment of sleep-related processes of affect regulation in poor sleepers. Moreover, these results highlight the importance of including sleep quality assessments in future dream studies.

Assessment of Physician Sleep and Wellness, Burnout, and Clinically Significant Medical Errors

IMPORTANCE

Sleep-related impairment in physicians is an occupational hazard associated with long and sometimes unpredictable work hours and may contribute to burnout and self-reported clinically significant medical error.

OBJECTIVE

To assess the associations between sleep-related impairment and occupational wellness indicators in physicians practicing at academic-affiliated medical centers and the association of sleep-related impairment with self-reported clinically significant medical errors, before and after adjusting for burnout.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study used physician wellness survey data collected from 11 academic-affiliated medical centers between November 2016 and October 2018. Analysis was completed in January 2020. A total of 19 384 attending physicians and 7257 house staff physicians at participating institutions were invited to complete a wellness survey. The sample of responders was used for this study.

EXPOSURES

Sleep-related impairment.

MAIN OUTCOMES AND MEASURES

Association between sleep-related impairment and occupational wellness indicators (ie, work exhaustion, interpersonal disengagement, overall burnout, and professional fulfillment) was hypothesized before data collection. Assessment of the associations of sleep-related impairment and burnout with self-reported clinically significant medical errors (ie, error within the last year resulting in patient harm) was planned after data collection.

RESULTS

Of all physicians invited to participate in the survey, 7700 of 19 384 attending physicians (40%) and 3695 of 7257 house staff physicians (51%) completed sleep-related impairment items, including 5279 women (46%), 5187 men (46%), and 929 (8%) who self-identified as other gender or elected not to answer. Because of institutional variation in survey domain inclusion, self-reported medical error responses from 7538 physicians were available for analyses. Spearman correlations of sleep-related impairment with interpersonal disengagement (r = 0.51; P < .001), work exhaustion (r = 0.58; P < .001), and overall burnout (r = 0.59; P < .001) were large. Sleep-related impairment correlation with professional fulfillment (r = -0.40; P < .001) was moderate. In a multivariate model adjusted for gender, training status, medical specialty, and burnout level, compared with low sleep-related impairment levels, moderate, high, and very high levels were associated with increased odds of self-reported clinically significant medical error, by 53% (odds ratio, 1.53; 95% CI, 1.12-2.09), 96% (odds ratio, 1.96; 95% CI, 1.46-2.63), and 97% (odds ratio, 1.97; 95% CI, 1.45-2.69), respectively.

CONCLUSIONS AND RELEVANCE

In this study, sleep-related impairment was associated with increased burnout, decreased professional fulfillment, and increased self-reported clinically significant medical error. Interventions to mitigate sleep-related impairment in physicians are warranted.

Selective suppression of rapid eye movement sleep increases next-day negative affect and amygdala responses to social exclusion

Healthy sleep, positive general affect, and the ability to regulate emotional experiences are fundamental for well-being. In contrast, various mental disorders are associated with altered rapid eye movement (REM) sleep, negative affect, and diminished emotion regulation abilities. However, the neural processes mediating the relationship between these different phenomena are still not fully understood. In the present study of 42 healthy volunteers, we investigated the effects of selective REM sleep suppression (REMS) on general affect, as well as on feelings of social exclusion, cognitive reappraisal (CRA) of emotions, and their neural underpinnings. Using functional magnetic resonance imaging we show that, on the morning following sleep suppression, REMS increases general negative affect, enhances amygdala responses and alters its functional connectivity with anterior cingulate cortex during passively experienced experimental social exclusion. However, we did not find effects of REMS on subjective emotional ratings in response to social exclusion, their regulation using CRA, nor on functional amygdala connectivity while participants employed CRA. Our study supports the notion that REM sleep is important for affective processes, but emphasizes the need for future research to systematically investigate how REMS impacts different domains of affective experience and their neural correlates, in both healthy and (sub-)clinical populations.

The relationship between insomnia and trait anger and anger expression among adolescents

PROBLEM

Sleeplessness and inadequate sleep may cause an adolescent to experience reduced self-control and behavioral problems that include anger and an inclination toward crime. This study aimed to examine the relationship between insomnia and trait anger and anger expression among adolescents.

METHODS

The study was conducted with 749 students from 27 high schools who were selected by using the stratified cluster sampling method. The data were collected with an Individual Characteristics Form, the Trait Anger/Anger Expression Inventory, and the Insomnia Severity Index.

FINDINGS

The insomnia scores of 14.0% of the participants were over the clinical insomnia threshold of 15 points. A positive relationship was found between insomnia and trait anger, anger-in, anger-out scores but a negative relationship with anger control scores. It was observed that the determinants of the severity of insomnia were trait anger and anger-in, dozing off in class, feeling anger after a sleepless night, sleeping <6 h a night during the week and over the weekend.

CONCLUSION

It was found that 14.0% of the participants experienced insomnia and there was a two-way correlation between insomnia and anger among adolescents.

Characterizing psychiatric symptoms and neurocognitive functioning among substance-naïve early adolescents: Associations with sleep problems

AIM

Evidence consistently links psychiatric symptoms, reduced neurocognitive functioning (NCF) and sleep problems to the initiation of a wide range of risk behaviours. Less is known, however, about the associations between sleep problems with psychiatric symptoms and NCF among early adolescents yet to engage in substance use.

METHODS

The present study examined baseline data from an ongoing prospective study of 529 youth aged 10-12 years who completed a battery of instruments measuring symptom counts for four psychiatric disorders, performance on six tests of NCF and five types of sleep behaviour on week days. We used latent class analysis to classify the 473 substance-naïve youth into subtypes characterized by probabilistic patterns of psychiatric symptoms and poorer NCF.

RESULTS

Four subtypes emerged: normative (24% of the sample); nonspecific mental health symptoms (27%); lower neurocognitive function (24%) and comorbid psychiatric symptoms and lower neurocognitive function (25%). In a multivariable latent regression model, three or more sleep arousals per night, sleep phase of two or more hours and sleep latency of 20 minutes or more were significantly associated with the two classes having higher symptom counts. Lack of family support was significantly associated with the two classes having lower neurocognitive function and comorbid psychiatric symptoms.

CONCLUSIONS

The youth subtypes in this study provide an important baseline characterization to subsequently understand how these neuropsychiatric relationships may change when substance use and other risk behaviours develop during adolescence. Implications for preventing and treating sleep problems associated with psychiatric comorbidity and neurocognitive dysfunctions are discussed.

Adaptive light: a lighting control method aligned with dark adaptation of human vision

Light exposure before sleep causes a reduction in the quality and duration of sleep. In order to reduce these detrimental effects of light exposure, it is important to dim the light. However, dimming the light often causes inconvenience and can lower the quality of life (QOL). We therefore aimed to develop a lighting control method for use before going to bed, in which the illuminance of lights can be ramped down with less of a subjective feeling of changes in illuminance. We performed seven experiments in a double-blind, randomized crossover design. In each experiment, we compared two lighting conditions. We examined constant illuminance, linear dimming, and three monophasic and three biphasic exponential dimming, to explore the fast and slow increases in visibility that reflect the dark adaptation of cone and rod photoreceptors in the retina, respectively. Finally, we developed a biphasic exponential dimming method termed Adaptive Light 1.0. Adaptive Light 1.0 significantly prevented the misidentification seen in constant light and effectively suppressed perceptions of the illuminance change. This novel lighting method will help to develop new intelligent lighting instruments that reduce the negative effect of light on sleep and also lower energy consumption.

Facial Emotion Recognition and Executive Functions in Insomnia Disorder: An Exploratory Study

BACKGROUND

Clinical and experimental findings suggest that insomnia is associated with changes in emotional processing and impairments in cognitive functioning. In the present study, we investigate the relationship between facial emotion recognition and executive functioning among individuals with insomnia as well as healthy controls.

METHOD

A total of 11 individuals (mean age 31.3 ± 9.4) diagnosed with insomnia disorder and 15 control participants (mean age 24.8 ± 4.6) took part in the study. Participants responded to a facial emotion recognition task which presented them with static and dynamic stimuli, and were evaluated with regard to cognition, sleep, and mood.

RESULTS

Compared to controls, we found that participants with insomnia performed worse in the recognition of the facial emotion of fear (p = 0.001; η p 2 = 0.549; β = 0.999) and had lower scores in tests of verbal comprehension and perceptual organization (104.00 vs. 115.00, U = 135.5; p = 0.004; Cohen's, 2013 d = 1.281). We also found a relationship between facial emotion recognition and performance in cognitive tests, such as those related to perceptual organization, cognitive flexibility, and working memory.

CONCLUSION

Results suggest that participants with insomnia may present some impairment in executive functions as well as in the recognition of facial emotions with negative valences (fear and sadness).

The impact of five nights of sleep restriction on emotional reactivity

An inadequate amount of sleep can negatively affect emotional processing, causing behavioural and neurofunctional changes. However, unlike the condition of total sleep deprivation, which has been extensively studied, the effects of prolonged sleep restriction have received less attention. In this study, we evaluated, for the first time, the effects of five nights of sleep restriction (5 hr a night) on emotional reactivity in healthy subjects. Forty-two subjects were selected to participate, over two consecutive weeks, in two experimental conditions in counterbalanced order. The subjects were tested the morning after five nights of regular sleep and after five consecutive nights of sleep restriction. During the test, participants evaluated valence and arousal of 90 images selected from the International Affective Picture System. The subjects perceived pleasant and neutral pictures in a more negative way in the sleep-restriction condition compared to the sleep condition. This effect survived after removing the contribution of mood changes. In contrast, there was no significant difference between conditions for ratings of unpleasant pictures. These results provide the first evidence that an inadequate amount of sleep for five consecutive nights determines an alteration of the evaluation of pleasant and neutral stimuli, imposing a negative emotional bias. Considering the pervasiveness of insufficient sleep in modern society, our results have potential implications for daily life, as well as in clinical settings.

Examining the Causal Effects of Sleep Deprivation on Emotion Regulation and Its Neural Mechanisms

Cognitive reappraisal (CR) is a strategy used to regulate emotions that is thought to be effective but effortful, relying on higher-order cognitive control systems to engage in active regulation. Sleep deprivation is believed to impair the functioning of these control systems, suggesting that it may impede the ability to implement CR effectively. This study tested the causal effects of sleep deprivation on emotional reactivity and the neurobiological systems underlying CR. We employed a within-subject crossover design in which participants underwent fMRI scanning twice, once when fully rested and once after a night of total sleep deprivation. During scans, participants passively viewed or used CR to down-regulate their emotional response to negative and neutral images. Contrary to hypotheses, both self-reported negative affect ratings and neural responses to the images indicated no difference in the way participants implemented CR when sleep deprived and when fully rested. Meanwhile, neural regions that showed distinct reactivity responses to negative relative to neutral images lost this specificity under deprived conditions. Negative affect ratings and heart rate deceleration, a physiological response typically evoked by aversive pictures, exhibited a similar blunting. Together, these results suggest that, although sleep deprivation may reduce the discrimination between emotional reactivity responses to negative and neutral stimuli, it does not impact CR the way it is presently studied.

Integrating sleep, neuroimaging, and computational approaches for precision psychiatry

In advancing precision psychiatry, we focus on what imaging technology and computational approaches offer for the future of diagnostic subtyping and personalized tailoring of interventions for sleep impairment in mood and anxiety disorders. Current diagnostic criteria for mood and anxiety tend to lump different forms of sleep disturbance together. Parsing the biological features of sleep impairment and brain circuit dysfunction is one approach to identifying subtypes within these disorders that are mechanistically coherent and offer targets for intervention. We focus on two large-scale neural circuits implicated in sleep impairment and in mood and anxiety disorders: the default mode network and negative affective network. Through a synthesis of existing knowledge about these networks, we pose a testable framework for understanding how hyper- versus hypo-engagement of these networks may underlie distinct features of mood and sleep impairment. Within this framework we consider whether poor sleep quality may have an explanatory role in previously observed associations between network dysfunction and mood symptoms. We expand this framework to future directions including the potential for connecting circuit-defined subtypes to more distal features derived from digital phenotyping and wearable technologies, and how new discovery may be advanced through machine learning approaches.