Sleep deprivation amplifies reactivity of brain reward networks, biasing the appraisal of positive emotional experiences

Sleep, event appraisal, and affect: An ecological momentary assessment study

BACKGROUND

Appraisal theory posits that emotions result from cognitive appraisals of events and situations. Experimental work suggests that sleep influences cognitive processes and event appraisal, which the present study examines in real life. Poor sleep influences brain regions involved in the appraisal-to-emotion process, and tired participants showed more conservative appraisal and reported less positive and more negative affect. In the present study, we tested whether sleep duration and/or quality predicted more pleasant event appraisal and whether sleep moderated the association between event appraisal and affect.

METHODS

Participants (N = 892) from the general Dutch population reported thrice daily on event appraisal and various emotions for 30 days and once daily on sleep duration and quality. We constructed multilevel models to account for the nested structure of our data (observations within participants).

RESULTS

Multilevel regression analyses showed that on days when participants reported having slept longer and better than their average, their event appraisal was more positive. Subjective sleep duration and quality did not influence the relationship between event appraisal and affect. Hence, poor sleep predicted changes in cognitive functioning, as people appraised situations as more unpleasant.

LIMITATIONS

We measured subjective sleep duration and quality with two single items and focused on only pleasantness dimension of event appraisal.

CONCLUSIONS

Results match perspectives on emotions as multicomponent systems involving appraisal processes. Understanding the elements of event appraisal may help unravel the detrimental effects of poor sleep on mental health and well-being.

From trenches to technology: a narrative review of sleep medicine in the military

Diagnoses of military-relevant sleep disorders have increased substantially since the terrorist attacks of September 11, 2001. The cause of this increase appears to be complicated and multifactorial, with military and civilian populations clearly differing with respect to both the nature and distribution of sleep disorders diagnoses. In part, these differences may be attributable to the fact that a majority of service members are chronically sleep-restricted-an unavoidable consequence of continuous and sustained military operations that "set the stage" for development of specific sleep disorders. The purpose of this narrative review is to describe the military relevance of several common sleep disorders, assess the extent to which these disorders currently constitute a burden on the military health care system, and suggest strategies to alleviate that burden. The military health care system does not have enough sleep medicine providers to address the immediate and long-term consequences of sleep disorders in military personnel. Digital technologies and education packages can be leveraged to improve access to care.

CITATION

Thomas CL, Carr K, Yang F, et al. From trenches to technology: a narrative review of sleep medicine in the military. J Clin Sleep Med. 2024;20(6):973-981.

Association between a composite measure of sleep health and depressive symptoms in patients with obstructive sleep apnea treated with CPAP therapy: Real-world data

OBJECTIVE

Sleep health is known to be multidimensional, and there is increasing clinical interest in composite sleep health scores that capture the number of adverse sleep characteristics. We investigated whether a composite sleep health score was associated with depressive symptoms in patients with obstructive sleep apnea (OSA) treated with continuous positive airway pressure (CPAP).

METHODS

Participants were OSA patients using CPAP (n = 1768, (92.1 % men, age 52.7 ± 10.7 years) attending sleep clinics in Japan. A cross-sectional survey conducted in 2020 assessed self-reported sleep and depressive symptoms. Sleep health was categorized as "good' or "poor' on five dimensions: satisfaction, daytime sleepiness, mid-sleep time, efficiency, and duration. A composite sleep health score was calculated by summing the "poor' dimensions. Depressive symptoms were assessed using two items from the Patient Health Questionnaire (PHQ-2). Associations between sleep health and depressive symptoms were assessed using multivariable logistic regression analysis.

RESULTS

Individual sleep health symptoms of poor satisfaction and efficiency were significantly associated with depressed mood; poor satisfaction, daytime sleepiness, and duration were significantly associated with loss of interest; and poor satisfaction, efficiency, and duration were significantly associated with depressive symptoms. Composite sleep health scores were associated with greater odds of depressive symptoms in a graded manner.

CONCLUSIONS

Individual and composite sleep health scores were associated with depressive symptoms. Measures of multidimensional sleep health may provide a better understanding of the association between poor sleep and depressive symptoms among patients with OSA using CPAP, accounting for CPAP adherence, leading to improved intervention strategies.

Insufficient Sleep and Behavioral Health in the Military: A 5-Country Perspective

PURPOSE OF REVIEW

The goal of this paper was to highlight the degree to which sleep, behavioral health, and leader involvement were interrelated using data from militaries in five English-speaking countries: Australia, Canada, New Zealand, the UK, and the United States.

RECENT FINDINGS

Many service members reported sleeping fewer than the recommended 7 h/night: 34.9%, 67.2%, and 77.2% of respondents from New Zealand, Canada, and the United States, respectively. Countries reporting shorter sleep duration also reported fewer insomnia-related difficulties, likely reflecting higher sleep pressure from chronic sleep loss. Across all countries, sleep problems were positively correlated with behavioral health symptoms. Importantly, leader promotion of healthy sleep was positively correlated with more sleep and negatively correlated with sleep problems and behavioral health symptoms. Insufficient sleep in the military is ubiquitous, with serious implications for the behavioral health and functioning of service members. Leaders should attend to these risks and examine ways to promote healthy sleep in service members.

Daily sleepiness magnifies the relation between same-day passive and active suicide ideation

Disrupted sleep has been linked to suicidal thoughts and behavior. Less is known, however, about the underlying mechanisms of this relationship. A more nuanced understanding of the link between sleep and suicide may help inform treatment decisions and the development of prevention and intervention strategies. The present study examined daily average sleepiness as a moderator to the relation between same-day passive and active suicide ideation (SI). Fifty-nine young adults (mean age = 21.04; SD = 2.22) endorsing SI at least twice in the two weeks prior to baseline completed 3-5 daily surveys of sleepiness and SI over 2 weeks as part of a broader study. Across several indicators of sleepiness (desire to stay awake, desire to fall asleep), passive SI (desire to die, desire to live), and active SI (occurrence, intensity, duration, and controllability), the overall findings demonstrated that daily average sleepiness magnified the relation between same-day passive SI and active SI severity. These findings indicate that being sleepier than usual may increase the likelihood that passive SI transitions to active SI. Future research is needed to test the causal influence of sleepiness on this transition.

What can we learn about stress and sleep from COVID-19 pandemic-perspective from the theory of preventive stress management

Background

The COVID-19 pandemic has presented unique challenges to individuals worldwide, with a significant focus on the impact on sleep. However, the precise mechanisms through which emotional and cognitive variables mediate this relationship remain unclear. To expand our comprehensive understanding of variables, the present study utilizes the Preventive Stress Management theory, to test the relationship between perceived social support and sleep quality, as well as the effect of perceived COVID-19 stress, hope, negative emotions and coping styles.

Methods

Data were collected in March 2022 from 1,034 college students in two universities located in Liaoning Province, China, using an online survey platform regarding perceived social support, perceived COVID-19 stress, sleep quality, hope, negative emotions and coping styles. The moderated mediation model were conducted using Process macro program (Model 6) and the syntax in SPSS.

Results

The results revealed perceived COVID-19 stress and negative emotions sequentially mediated the negative relationship between perceived social support and sleep quality. Furthermore, hope and coping styles were found to moderate the sequential mediating effect.

Conclusion

The present study sheds light on the pathways that affect sleep quality among college students during the COVID-19 pandemic. Findings highlight the protective roles played by positive social and personal resources, such as perceived social support, hope, and effective coping styles, against sleep problems. These insights have important implications for the development of targeted interventions to improve sleep outcomes during this challenging time.

Interaction of sleep and emotion across the menstrual cycle

Menstruating individuals experience an increased risk for sleep and affective disorders, attributed in part to monthly oscillations in sex hormones. Emotional functioning and sleep continuity worsens during the perimenstrual phase of the menstrual cycle. This study examined the interactive effects of sleep, menstrual phase, and emotion in healthy women. Participants (N = 51, 43% Caucasian) aged 18-35 (m = 24 years) completed actigraphy and daily sleep/emotion diaries over two menstrual cycles (m days = 51.29). Diary and actigraphic total wake time at night (TWT) and daily ratings of positive and negative affect were compared across four phases of the menstrual cycle: perimenstrual, mid-follicular, periovulatory, and mid-luteal. Relationships between phase, sleep, and emotion were estimated using multistep hierarchical linear modelling. Mean menstrual cycle length was 28.61 ± 2.69 days. Perimenstrual phase positively predicted anger (p < 0.001) but no other emotions. Additionally, the perimenstrual phase predicted higher rates of TWT, such that diary TWT was 8-16 min longer during the perimenstrual (m = 67.54, SE = 3.37) compared to other phases (p < 0.001). Actigraphic TWT was also increased by 4-7 min (m = 61.54, SE = 3.37) in the perimenstrual phase (p < 0.001). Positive emotions were 0.05-0.10 points lower (p = 0.006-0.02) when TWT was greater in the perimenstrual phase. Greater rates of anger and sleep disruption were seen during the perimenstrual phase compared with other phases. When poor sleep occurred during the perimenstrual phase individuals reported reduced positive emotions. Reducing perimenstrual sleep disruptions may be an important intervention target for those at risk for affective disorders.

Sleep-Related Predictors of Risk for Alcohol Use and Related Problems in Adolescents and Young Adults

PURPOSE

Growing evidence supports sleep and circadian rhythms as influencing alcohol use and the course of alcohol use disorder (AUD). Studying sleep/circadian-alcohol associations during adolescence and young adulthood may be valuable for identifying sleep/circadian-related approaches to preventing and/or treating AUD. This paper reviews current evidence for prospective associations between sleep/circadian factors and alcohol involvement during adolescence and young adulthood with an emphasis on the effects of sleep/circadian factors on alcohol use.

SEARCH METHODS

The authors conducted a literature search in PsycInfo, PubMed, and Web of Science using the search terms "sleep" and "alcohol" paired with "adolescent" or "adolescence" or "young adult" or "emerging adult," focusing on the title/abstract fields, and restricting to English-language articles. Next, the search was narrowed to articles with a prospective/longitudinal or experimental design, a sleep-related measure as a predictor, an alcohol-related measure as an outcome, and confirming a primarily adolescent and/or young adult sample. This step was completed by a joint review of candidate article abstracts by two of the authors.

SEARCH RESULTS

The initial search resulted in 720 articles. After review of the abstracts, the list was narrowed to 27 articles reporting on observational longitudinal studies and three articles reporting on intervention trials. Noted for potential inclusion were 35 additional articles that reported on studies with alcohol-related predictors and sleep-related outcomes, and/or reported on candidate moderators or mediators of sleep-alcohol associations. Additional articles were identified via review of relevant article reference lists and prior exposure based on the authors' previous work in this area.

DISCUSSION AND CONCLUSIONS

Overall, the review supports a range of sleep/circadian characteristics during adolescence and young adulthood predicting the development of alcohol use and/or alcohol-related problems. Although sleep treatment studies in adolescents and young adults engaging in regular and/or heavy drinking show that sleep can be improved in those individuals, as well as potentially reducing alcohol craving and alcohol-related consequences, no studies in any age group have yet demonstrated that improving sleep reduces drinking behavior. Notable limitations include relatively few longitudinal studies and only two experimental studies, insufficient consideration of different assessment timescales (e.g., day-to-day vs. years), insufficient consideration of the multidimensional nature of sleep, a paucity of objective measures of sleep and circadian rhythms, and insufficient consideration of how demographic variables may influence sleep/circadian-alcohol associations. Examining such moderators, particularly those related to minoritized identities, as well as further investigation of putative mechanistic pathways linking sleep/circadian characteristics to alcohol outcomes, are important next steps.

Middle childhood and adolescence sleep duration and behavior problems in adolescence

We examined the associations of middle childhood and adolescence nighttime sleep duration with adolescence internalizing and externalizing behavior problems per the Youth Self-Report (YSR) and the Child Behavior Checklist (CBCL) questionnaires, in a cohort of 889 Colombian schoolchildren. We estimated adjusted differences with 95% confidence intervals (CI) in mean behavior problem t-scores in standardized units between recommended sleep duration categories and as a continuous exposure using multiple linear regression and restricted cubic spline models, respectively. Compared with sleep duration within recommendations, middle childhood sleep above recommendations was related to 4.6 (95% CI: 1.6, 7.6; p = .004) and 5.4 (95% CI: 1.2, 9.7; p = .01) adjusted units higher YSR and CBCL externalizing problem scores, respectively. In continuous exposure analyses, this association seemed restricted to children aged ≥11 years. Longer sleep, both in categories and as a continuous exposure, was also associated with increased CBCL internalizing problems. Results did not differ by sex or weekend/weekday sleep. Sleeping under recommendations in middle childhood was not significantly related to behavior problems; nevertheless, shorter sleep in adolescence, in both categorical and continuous scales, was significantly related to behavior problems. In conclusion, behavior problems in adolescence are associated with longer sleep in middle childhood and shorter sleep in adolescence.

Mental health disturbance in preclinical medical students and its association with screen time, sleep quality, and depression during the COVID-19 pandemic

BACKGROUND

Affected by various hurdles during COVID-19, preclinical medical students are at an elevated risk for mental health disturbances. However, the effects of modern mental health problems on preclinical medical students have not been adequately researched. Thus, this study was aimed to identify the proportions and implications of current mental health problems for depression, sleep quality and screen time among Indonesian medical preclinical students during the COVID-19 pandemic.

METHODS

This cross-sectional study was conducted using crowdsourcing between October 2020 and June 2021. During the study period, 1,335 subjects were recruited, and 1,023 datasets were identified as valid. General Health Questionnaire-12 (GHQ-12) was used to measure current mental health disturbances (categorized as without current mental health disturbances, psychological distress, social dysfunction, or both). The Patient Health Questionnaire-9 (PHQ-9) was used to assess depression, the Pittsburgh Sleep Quality Index (PSQI) was employed to assess sleep quality, and a questionnaire devised for this study was used to assess screen time length per day. Multivariate data analysis was conducted using SPSS version 24 for Mac.

RESULTS

According to the findings, 49.1% of the 1,023 participants had current mental health disturbances: 12.8% had psychological distress, 15.9% had social dysfunction, and the rest (20.4%) had both psychological distress and social dysfunction. The statistical analysis provided strong evidence of a difference (p < 0.001) between the medians of depression and sleep quality with at least one pair of current mental health disturbance groups, but the difference for screen time was not significant (p = 0.151). Dunn's post-hoc analysis showed that groups without current mental health problems had significantly lower mean ranks of depression and sleep quality compared to groups that had current mental health problems (p < 0.001).

CONCLUSION

Current mental health disturbances during the COVID-19 pandemic were significantly associated with preclinical medical students' depression and sleep quality in preclinical medical students. Thus, mental health programs for this specific population should be tailored to integrate mindfulness therapy, support groups, stress management, and skills training to promote mental wellbeing.

The role of the brainstem in sleep disturbances and chronic pain of Gulf War and Iraq/Afghanistan veterans

Introduction

Gulf War Illness is a type of chronic multisymptom illness, that affects about 30% of veterans deployed to the 1990-91 Persian Gulf War. Veterans deployed to Iraq/Afghanistan after 2000 are reported to have a similar prevalence of chronic multisymptom illness. More than 30 years after the Persian Gulf War, Gulf War Illness still has an unexplained symptom complex, unknown etiology and lacks definitive diagnostic criteria and effective treatments. Our recent studies have found that substantially smaller brainstem volumes and lower fiber integrity are associated with increased sleep difficulty and pain intensity in 1990-91 Persian Gulf War veterans. This study was conducted to investigate whether veterans deployed to Iraq/Afghanistan present similar brainstem damage, and whether such brainstem structural differences are associated with major symptoms as in Gulf War Illness.

Methods

Here, we used structural magnetic resonance imaging and diffusion tensor imaging to measure the volumes of subcortices, brainstem subregions and white matter integrity of brainstem fiber tracts in 188 veterans including 98 Persian Gulf War veterans and 90 Iraq/Afghanistan veterans.

Results

We found that compared to healthy controls, veterans of both campaigns presented with substantially smaller volumes in brainstem subregions, accompanied by greater periaqueductal gray matter volumes. We also found that all veterans had reduced integrity in the brainstem-spinal cord tracts and the brainstem-subcortical tracts. In veterans deployed during the 1990-91 Persian Gulf War, we found that brainstem structural deficits significantly correlated with increased sleep difficulties and pain intensities, but in veterans deployed to Iraq/Afghanistan, no such effect was observed.

Discussion

These structural differences in the brainstem neurons and tracts may reflect autonomic dysregulation corresponding to the symptom constellation, which is characteristic of Gulf War Illness. Understanding these neuroimaging and neuropathological relationships in Gulf War and Iraq/Afghanistan veterans may improve clinical management and treatment strategies for modern war related chronic multisymptom illness.

Subjective and neural reactivity during savoring and rumination

Repetitive thinking about negative emotions or events is strongly associated with worse mental health, whereas repetitive positive thought is generally believed to be beneficial. This observation is at odds with the idea that all forms of repetitive thinking share underlying neural mechanisms. To resolve this apparent discrepancy, the present study examined relationships between subjective affect and neural mechanisms during periods of sustained processing of positive (savoring) and negative (rumination) emotion. We also examined potential common moderators of savoring and rumination including memory specificity and sleep quality. Results indicated that individuals who experience high positive affect during savoring also are likely to experience more intense negative affect during rumination. fMRI-derived brain activity revealed common mechanisms of rumination and savoring. Memory specificity had common effects on neural correlates of rumination and savoring; sleep quality was not associated with mechanisms of savoring or rumination. These results suggest that repetitive engagement with positive and negative affect is similar both subjectively and mechanistically. Clinical interventions for rumination may benefit from capitalizing on preserved capacity for savoring.

Phase-amplitude coupling of Go/Nogo task-related neuronal oscillation decreases for humans with insufficient sleep

Phase-amplitude coupling (PAC) across frequency might be associated with the long-range synchronization of brain networks, facilitating the spatiotemporal integration of multiple cell assemblies for information transmission during inhibitory control. However, sleep problems may affect these cortical information transmissions based on cross-frequency PAC, especially when humans work in environments of social isolation. This study aimed to evaluate changes in the theta-beta/gamma PAC of task-related electroencephalography (EEG) for humans with insufficient sleep. Here, we monitored the EEG signals of 60 healthy volunteers and 18 soldiers in the normal environment, performing a Go/Nogo task. Soldiers also participated in the same test in isolated cabins. These measures demonstrated theta-beta PACs between the frontal and central-parietal, and robust theta-gamma PACs between the frontal and occipital cortex. Unfortunately, these PACs significantly decreased when humans experienced insufficient sleep, which was positively correlated with the behavioral performance of inhibitory control. The evaluation of theta-beta/gamma PAC of Go/Nogo task-related EEG is necessary to help understand the different influences of sleep problems in humans.

Bidirectional mechanism of comorbidity of depression and insomnia based on synaptic plasticity

Insomnia is one of the most common accompanying symptoms of depression, with both sharing highly overlapping molecular pathways. The same pathological changes can trigger comorbidity of insomnia and depression, which further forms a vicious cycle with the involvement of more mechanisms and disease progression. Thus, understanding the potential interaction mechanisms between insomnia and depression is critical for clinical diagnosis and treatment. Comorbidity genetic factors, the hypothalamic-pituitary-adrenal axis, along with circadian rhythms of cortisol and the brain reward mechanism, are important ways in contributing to the comorbidity occurrence and development. However, owing to lack of pertinent investigational data, intricate molecular mechanisms necessitate further elaboration. Synaptic plasticity is a solid foundation for neural homeostasis. Pathological alterations of depression and insomnia may perturb the production and release of neurotransmitter, dendritic spine remodeling and elimination, which converges and reflects in aberrant synaptic dynamics. Hence, the introduction of synaptic plasticity research route and the construction of a comprehensive model of depression and insomnia comorbidity can provide new ideas for clinical depression insomnia comorbidity treatment plans.

Assessing impulse control behaviors in early Parkinson's disease: a longitudinal study

Objective

Impulse control behaviors (ICBs) frequently coexist with Parkinson's disease (PD). However, the predictors of ICBs in PD remain unclear, and there is limited data on the biological correlates of ICBs in PD. In this study, we examined clinical, imaging, and biological variables to identify factors associated with longitudinal changes in ICBs in early-stage PD.

Methods

The data for this study were obtained from the Parkinson's Progression Markers Initiative, an international prospective cohort study that evaluates markers of disease progression in PD. We examined clinical, imaging, and biological variables to determine their associations with ICBs over a period of up to 5 years. Cox regression models were employed to investigate the predictors of ICBs in early-stage, untreated PD.

Results

The study enrolled 401 individuals with PD and 185 healthy controls (HC). At baseline, 83 PD subjects (20.7%) and 36 HC (19.5%) exhibited ICBs. Over the course of 5 years, the prevalence of ICBs increased in PD (from 20.7% to 27.3%, p < 0.001), while it decreased in HC (from 19.5% to 15.2%, p < 0.001). Longitudinally, the presence of ICBs in PD was associated with depression, anxiety, autonomic dysfunction, and excessive daytime sleepiness (EDS). However, there was no significant association observed with cognitive dysfunction or motor severity. Treatment with dopamine agonists was linked to ICBs at years 3 and 4. Conversely, there was no association found between ICBs and presynaptic dopaminergic dysfunction. Additionally, biofluid markers in baseline and the first year did not show a significant association with ICBs. A predictive index for ICBs was generated, incorporating three baseline characteristics: anxiety, rapid eye movement sleep behavior disorder (RBD), and p-tau levels in cerebrospinal fluid (CSF).

Conclusion

During the early stages of PD, there is a notable increase in ICBs over time. These ICBs are associated with depression, anxiety, autonomic dysfunction, EDS, and the use of dopaminergic medications, particularly dopamine agonists. Anxiety, RBD, and p-tau levels in CSF are identified as predictors for the incident development of ICBs in early PD. Further longitudinal analyses will provide a more comprehensive understanding of the associations between ICBs and imaging findings, as well as biomarkers. These analyses will help to better characterize the relationships and implications of these factors in the context of ICBs in early PD.

Enhanced functional connectivity in the reward circuitry in healthy adults with weekend catch-up sleep

We aimed to identify structural and functional changes in healthy adults with catch-up sleep (CUS), we applied seed-based functional connectivity (FC) analysis using resting-state functional magnetic resonance imaging (MRI). We hypothesized that deficits in reward processing could be a fundamental mechanism underlying the motivation of taking CUS. Then, 55 healthy adults voluntarily (34 with CUS and 21 without CUS) participated in this study. Voxel-based morphometry was performed to explore region of gray matter volume (GMV) difference between CUS and non-CUS groups. Between-group comparison of FC was then carried out using resting-state functional MRI analysis seeding at the region of volume difference. Moreover, the region of volume difference and the strength of FC were correlated with scores of questionnaires for reward-seeking behavior and clinical variables. CUS group had a higher reward-seeking tendency, and increased GMV in the bilateral nucleus accumbens and right superior frontal gyrus relative to non-CUS group. FC analysis seeding at the bilateral accumbens revealed increases of FC in the bilateral medial prefrontal cortex in CUS group compared to non-CUS group. The questionnaire scores reflecting the reward-seeking tendency were correlated with the FC strength between bilateral accumbens and medial prefrontal cortex. Our results indicate that CUS is associated with reward-seeking tendency and increased GMV and FC in regions responsible for reward network. Our findings suggest that enhanced reward network could be the crucial mechanism underlying taking CUS and might be implicated in the detrimental effects of circadian misalignment.

Day-to-day directional relationships between sleep duration and negative affect

OBJECTIVE

There is a strong association between sleep disturbance and negative affect. However, the day-to-day directional connections between sleep and negative affect remain unclear. We examined day-to-day relationships between sleep duration and negative affect in community adults.

METHODS

Participants were two subsamples of the Midlife in the United States Study (Sample 1: n = 2,022; Sample 2: n = 782). Daily negative affect and previous night sleep duration were assessed via end-of-day telephone interviews for eight days. Random intercept cross-lagged panel models tested sleep duration as a predictor of next-day negative affect and vice versa, controlling for age, gender, and race.

RESULTS

In both samples, shorter sleep duration predicted higher next-day negative affect, but daily negative affect was not a significant predictor of upcoming-night sleep duration. Follow-up analyses indicated that the relationship between sleep duration and negative affect was nonlinear. Sleeping fewer than 7.5 hours or more than 10.5 hours was associated with greater next-day negative affect than sleeping between 7.5 and 10.5 hours.

CONCLUSIONS

In two large samples of community adults, sleep duration unidirectionally predicted higher next-day negative affect, and this relationship was nonlinear. Sleeping at least 7.5 hours and no more than 10.5 hours appeared to be an optimal range associated with lowest next-day negative affect.

The role of baseline insomnia in moderating the hypnotic properties of quetiapine

INTRODUCTION

The primary aim of this study was to investigate the effect of quetiapine on insomnia and alcohol craving (craving) in subjects with co-occurring insomnia and AUD.

METHODS

Insomnia was assessed with the Insomnia Severity Index (ISI) and craving with the Penn Alcohol Craving Scale (PACS, primary) and Obsessive-Compulsive Drinking Scale (OCDS, secondary). A multivariable model adjusted for covariates (N = 123) evaluated the relationship between craving (PACS and OCDS total scores) and insomnia (ISI total score). To simultaneously assess the effects of treatment arm allocation and insomnia status, subjects (N = 115) were stratified into 4 groups, quetiapine-insomnia(N = 38), quetiapine-No insomnia(N = 19), placebo-insomnia(N = 38), and placebo-No insomnia(N = 20). Linear mixed-effects regression models adjusted for covariates compared the trajectories of ISI, PACS, and OCDS total scores across 12 weeks of treatment and at post-treatment follow-up at week 24, between the four groups.

RESULTS

The ISI total score was positively associated with the PACS (p = 0.006) and OCDS (p = 0.001) total scores in the multivariable models. In the longitudinal analysis, when compared to the three other groups, subjects with insomnia treated with quetiapine showed a marked reduction in their insomnia scores with a return of insomnia after stopping treatment. There was no significant difference between the groups for the PACS and OCDS total score trajectories.

DISCUSSION

Although craving is associated with insomnia, treatment with quetiapine may improve insomnia but not craving in patients with co-occurring AUD and insomnia.

Bidirectional Relationship Between Sleep and Depression

Patients with depression almost inevitably exhibit abnormalities in sleep, such as shortened latency to enter rapid eye movement (REM) sleep and decrease in electroencephalogram delta power during non-REM sleep. Insufficient sleep can be stressful, and the accumulation of stress leads to the deterioration of mental health and contributes to the development of psychiatric disorders. Thus, it is likely that depression and sleep are bidirectionally related, i.e. development of depression contributes to sleep disturbances and vice versa. However, the relation between depression and sleep seems complicated. For example, acute sleep deprivation can paradoxically improve depressive symptoms. Thus, it is difficult to conclude whether sleep has beneficial or harmful effects in patients with depression. How antidepressants affect sleep in patients with depression might provide clues to understanding the effects of sleep, but caution is required considering that antidepressants have diverse effects other than sleep. Recent animal studies support the bidirectional relation between depression and sleep, and animal models of depression are expected to be beneficial for the identification of neuronal circuits that connect stress, sleep, and depression. This review provides a comprehensive overview regarding the current knowledge of the relationship between depression and sleep.

Associations between resting state brain activity and A1 adenosine receptor availability in the healthy brain: Effects of acute sleep deprivation

Introduction

Previous resting-state fMRI (Rs-fMRI) and positron emission tomography (PET) studies have shown that sleep deprivation (SD) affects both spontaneous brain activity and A1 adenosine receptor (A1AR) availability. Nevertheless, the hypothesis that the neuromodulatory adenosinergic system acts as regulator of the individual neuronal activity remains unexplored.

Methods

Therefore, fourteen young men underwent Rs-fMRI, A1AR PET scans, and neuropsychological tests after 52 h of SD and after 14 h of recovery sleep.

Results

Our findings suggested higher oscillations or regional homogeneity in multiple temporal and visual cortices, whereas decreased oscillations in cerebellum after sleep loss. At the same time, we found that connectivity strengths increased in sensorimotor areas and decreased in subcortical areas and cerebellum.

Discussion

Moreover, negative correlations between A1AR availability and rs-fMRI metrics of BOLD activity in the left superior/middle temporal gyrus and left postcentral gyrus of the human brain provide new insights into the molecular basis of neuronal responses induced by high homeostatic sleep pressure.

Intertemporal Decision-making and Risk Decision-making Among Habitual Nappers Under Nap Sleep Restriction: A Study from ERP and Time-frequency

Sleep restriction affects people's decision-making behavior. Nap restriction is a vital subtopic within sleep restriction research. In this study, we used EEG to investigate the impact of nap sleep restriction on intertemporal decision-making (Study 1) and decision-making across risky outcomes (Study 2) from ERP and time-frequency perspectives. Study 1 found that habitual nappers restricting their naps felt more inclined to choose immediate, small rewards over delayed, large rewards in an intertemporal decision-making task. P200s, P300s, and LPP in our nap-restriction group were significantly higher than those in the normal nap group. Time-frequency results showed that the delta band (1 ~ 4 Hz) power of the restricted nap group was significantly higher than that of the normal nap group. In Study 2, the nap-restriction group was more likely to choose risky options. P200s, N2s, and P300s in the nap deprivation group were significantly higher than in the normal nap group. Time-frequency results also found that the beta band (11 ~ 15 Hz) power of the restricted nap group was significantly lower than that of the normal nap group. The habitual nappers became more impulsive after nap restriction and evinced altered perceptions of time. The time cost of the LL (larger-later) option was perceived to be too high when making intertemporal decisions, and their expectation of reward heightened when making risky decisions-believing that they had a higher probability of receiving a reward. This study provided electrophysiological evidence for the dynamic processing of intertemporal decision-making, risky decision-making, and the characteristics of nerve concussions for habitual nappers.

Decreased Functional Connectivity of Brain Networks in the Alpha Band after Sleep Deprivation Is Associated with Decreased Inhibitory Control in Young Male Adults

Sleep deprivation leads to reduced inhibitory control in individuals. However, the underlying neural mechanisms are poorly understood. Accordingly, this study aimed to investigate the effects of total sleep deprivation (TSD) on inhibitory control and their neuroelectrophysiological mechanisms from the perspective of the time course of cognitive processing and brain network connectivity, using event-related potential (ERP) and resting-state functional connectivity techniques. Twenty-five healthy male participants underwent 36 h of TSD (36-h TSD), completing Go/NoGo tasks and resting-state data acquisition before and after TSD; their behavioral and electroencephalogram data were recorded. Compared to baseline, participants' false alarms for NoGo stimuli increased significantly (t = -4.187, p < 0.001) after 36-h TSD. ERP results indicated that NoGo-N2 negative amplitude increased and latency was prolonged (t = 4.850, p < 0.001; t = -3.178, p < 0.01), and NoGo-P3 amplitude significantly decreased and latency was prolonged (t = 5.104, p < 0.001; t = -2.382, p < 0.05) after 36-h TSD. Functional connectivity analysis showed that the connectivity of the default mode and visual networks in the high alpha band was significantly reduced after TSD (t = 2.500, p = 0.030). Overall, the results suggest that the negative amplitude increase in N2 after 36-h TSD may reveal that more attention and cognitive resources are invested after TSD; the significant decrease in P3 amplitude may indicate the impairment of advanced cognitive processing. Further functional connectivity analysis indicated impairment of the brain's default mode network and visual information processing after TSD.

The Role of Emotion Dysregulation in the Relationship Between Sleep Disturbances and PTSD Symptom Severity

ABSTRACT

Emotion dysregulation is implicated in the development, maintenance, and treatment of sleep disturbances and posttraumatic stress disorder (PTSD) separately. However, few studies have assessed interactions among these variables. To address this gap, this study examined whether the associations of sleep quality and sleep quantity with PTSD severity were stronger at higher levels of negative and positive emotion dysregulation in a community sample of 199 trauma-exposed individuals. This study found that both poorer sleep quality and lower sleep quantity were associated with greater PTSD severity at low to average (but not high) levels of negative emotion dysregulation. Positive emotion dysregulation did not moderate the relationships between sleep quality or quantity and PTSD severity. Exploratory additive multiple moderation analyses showed significant associations between poorer sleep quality and lower sleep quantity with greater PTSD severity at low to average levels of negative emotion dysregulation, coupled with any level of positive emotion dysregulation. Findings inform theoretical perspectives on the sleep-PTSD relationship and clinical applications of targeting emotion dysregulation in the treatment of sleep disturbances and PTSD symptoms for trauma-exposed individuals.

[Research Progress in the Effect of Sleep Deprivation on Working Memory and Its Mechanisms]

The incidence of sleep deprivation is increasing year by year and people are also paying more attention to the effects of sleep deprivation on the human body and on cognition. In addition, working memory is the foundation of many advanced cognitive functions. Therefore, we reviewed, herein, the relevant research literature on the influence of sleep deprivation on working memory, the relevant influencing factors, and possible mechanisms of action, intending to acquire a more thorough understanding of the effects of sleep deprivation on working memory and to provide evidence for scientific and sound strategies of sleep.

The Effects of Acute Sleep Curtailment on Salt Taste Measures and Relationships with Energy-Corrected Sodium Intake: A Randomized Cross-Over Trial with Methodology Validation

(1) Background: Sleep may be a factor that influences the taste-dietary intake relationship. The effect of sleep on salt taste measures has not been adequately studied, and no standardized methodology has been developed for measuring salt taste preference. (2) Methods: A sweet taste forced-choice paired-comparison test was adapted and validated to determine salt taste preference. In a randomized cross-over trial, participants slept a curtailed night (33% reduction in sleep duration) and a habitual night, confirmed by a single-channel electroencephalograph. Salt taste tests were conducted the day after each sleep condition using five aqueous NaCl solutions. One 24-h dietary recall was obtained after each taste test. (3) Results: The adapted forced-choice paired-comparison tracking test reliably determined salt taste preference. No changes in salt taste function (intensity slopes: p = 0.844) or hedonic measures (liking slopes: p = 0.074; preferred NaCl concentrations: p = 0.092) were observed after the curtailed sleep condition compared to habitual sleep. However, sleep curtailment disrupted the association between liking slope and energy-corrected Na intake (p < 0.001). (4) Conclusions: The present study serves as the first step toward more standardized taste assessments to facilitate comparison between studies and suggests accounting for sleep when exploring taste-diet relationships.

Evaluation of Correlation between Sleep and Psychiatric Disorders in a Population of Night Shift Workers: A Pilot Study

BACKGROUND

Insomnia is the perception of inadequate, insufficient or non-restorative sleep. Of all sleep-related disorders, insomnia is the most common. It is important to remember that the sleep-wake cycle also plays a central role in the genesis of anxiety and depression. The aim of our study is to evaluate the association between sleep disturbances and anxiety and depression in a group of workers of both sexes who perform night shift work.

METHODS

Information on sleep disorders was collected by administering the Insomnia Severity Index (ISI) questionnaire. Statistical analysis was conducted using the Chi-square test to assess whether there were any differences between sex for those who were healthy or who were diagnosed with psychiatric disorders.

RESULTS

The results showed that there was a good percentage of subjects with insomnia problems, impairing normal daily activities and promoting the onset of fatigue, daytime sleepiness, cognitive performance deficits and mood disorders.

CONCLUSION

We highlighted how anxious and depressive anxiety disorders are more pronounced in people who suffer from altered sleep-wake rhythms. Further research in this direction could prove to be fundamental for understanding the genesis of the onset of other disorders as well.

A Narrative Review on REM Sleep Deprivation: A Promising Non-Pharmaceutical Alternative for Treating Endogenous Depression

Endogenous depression represents a severe mental health condition projected to become one of the worldwide leading causes of years lived with disability. The currently available clinical and non-clinical interventions designed to alleviate endogenous depression-associated symptoms encounter a series of inconveniences, from the lack of intervention effectiveness and medication adherence to unpleasant side effects. In addition, depressive individuals tend to be more frequent users of primary care units, which markedly affects the overall treatment costs. In parallel with the growing incidence of endogenous depression, researchers in sleep science have discovered multiple links between rapid eye movement (REM) sleep patterns and endogenous depression. Recent findings suggest that prolonged periods of REM sleep are associated with different psychiatric disorders, including endogenous depression. In addition, a growing body of experimental work confidently describes REM sleep deprivation (REM-D) as the underlying mechanism of most pharmaceutical antidepressants, proving its utility as either an independent or adjuvant approach to alleviating the symptoms of endogenous depression. In this regard, REM-D is currently being explored for its potential value as a sleep intervention-based method for improving the clinical management of endogenous depression. Therefore, this narrative review represents a comprehensive inventory of the currently available evidence supporting the potential use of REM-D as a reliable, non-pharmaceutical approach for treating endogenous depression, or as an adjuvant practice that could improve the effectiveness of currently used medication.

The relationship between sleep and appetitive conditioning: A systematic review and meta-analysis

This systematic review and meta-analysis (PROSPERO registration animal/human studies: CRD42021234793/CRD42021234790) examined the relationship between sleep and appetitive conditioning. Inclusion criteria included: a) appetitive conditioning paradigm; b) measure of conditioning; c) sleep measurement and/or sleep loss; d) human and/etor non-human animal samples; and e) written in English. Searches of seven databases returned 3777 publications. The final sample consisted of 42 studies using primarily animal samples and involving food- and drug-related conditioning tasks. We found sleep loss disrupted appetitive conditioning of food rewards (p < 0.001) but potentiated appetitive conditioning of drug rewards (p < 0.001). Furthermore, sleep loss negatively impacted extinction learning irrespective of the reward type. Post-learning sleep was associated with increases in REM sleep (p = 0.02). Findings suggest sleep loss potentiates the impact of psychoactive substances in a manner likely to produce an increased risk of problematic substance use. In obese/overweight populations, sleep loss may be associated with deficits in the conditioning and extinction of reward-related behaviours. Further research should assess the relationship between sleep and appetitive conditioning in humans.

Sleep-mediated regulation of reward circuits: implications in substance use disorders

Our modern society suffers from both pervasive sleep loss and substance abuse-what may be the indications for sleep on substance use disorders (SUDs), and could sleep contribute to the individual variations in SUDs? Decades of research in sleep as well as in motivated behaviors have laid the foundation for us to begin to answer these questions. This review is intended to critically summarize the circuit, cellular, and molecular mechanisms by which sleep influences reward function, and to reveal critical challenges for future studies. The review also suggests that improving sleep quality may serve as complementary therapeutics for treating SUDs, and that formulating sleep metrics may be useful for predicting individual susceptibility to SUDs and other reward-associated psychiatric diseases.

More time awake after sleep onset is linked to reduced ventral striatum response to rewards in youth with anxiety

BACKGROUND

Poor sleep and anxiety disorders are highly comorbid in youth, and each predicts altered ventral striatum (VS) response to rewards, which may impact mental health risk. Contrasting evidence suggests previously reported negative associations between sleep health and VS response may be stronger or weaker in youth with anxiety, indicating sensitivity to win/loss information or blunted reward processing, respectively. We cross-sectionally examined the role of sleep in VS response to rewards among youth with anxiety versus a no-psychiatric-diagnosis comparison (ND) group. We expected a group*sleep interaction on VS response to rewards but did not hypothesize directionality.

METHODS

As part of the pretreatment battery for a randomized clinical trial, 74 youth with anxiety and 31 ND youth (ages 9-14 years; n = 55 female) completed a monetary reward task during fMRI. During the same pretreatment window, actigraphy and diary-estimated sleep were collected over 5 days, and participants and their parents each reported participants' total sleep problems. We examined group*sleep interactions on VS response to monetary rewards versus losses via three mixed linear models corresponding to actigraphy, diary, and questionnaires, respectively.

RESULTS

Each model indicated group*sleep interactions on VS response to rewards. Actigraphy and diary-estimated time awake after sleep onset predicted reduced VS response in youth with anxiety but not ND youth. Parent-reported sleep problems similarly interacted with group, but simple slopes were nonsignificant.

CONCLUSIONS

Wake after sleep onset was associated with blunted reward response in youth with anxiety. These data suggest a potential pathway through which sleep could contribute to perturbed reward function and reward-related psychopathology (e.g., depression) in youth with anxiety.

Sleep and Daily Positive Emotions – Is Heart Rate Variability a Mediator?

Abstract. Sleep quality is considered a basic dimension of emotional health. The psychophysiological mechanisms underlying the associations between sleep quality and positive emotions are still largely unknown, yet autonomic regulation may play a role. This study employed a two-day ecological momentary assessment methodology in a sample of young adults to investigate whether subjective sleep quality reported in the morning was associated with daily positive emotional experience and whether this association was mediated by heart rate variability (HRV), a measure of cardiac vagal tone. Sleep quality was assessed using an electronic sleep diary upon awakening, while resting HRV and positive emotions were inspected at random times throughout the day using photoplethysmography and an electronic diary, respectively. Relevant confounding variables such as smoking, alcohol intake, and physical exercise between each measurement were also assessed. The sample included 121 participants (64.8% females, Mage = 25.97 ± 5.32 years). After controlling for relevant confounders including health behaviors and psychiatric comorbidities, mediation analysis revealed that greater sleep quality positively predicted daily HRV (β = .289, p < .001) which, in turn, had a direct influence on positive emotions (β = .244, p = .006). Also, sleep quality directly predicted positive emotional experience (β = .272, p = .001). Lastly, the model showed an indirect effect between sleep quality and positive emotions via HRV (β = .071, 95% BCI [.011, .146]). Results support the view of HRV as a process variable linking sleep to positive emotions. Experimental data is needed to consolidate the present findings.

Sleepiness Moderates the Associations between Personality and Financial Risk Tolerance and Spending Habits among College Students

OBJECTIVES

Personality and sleep characteristics are related to financial attitudes and behaviors. However, to our knowledge no study has examined how personality and sleep may be conjointly associated with these financial outcomes. The present study examined sleepiness as a moderator of the associations between college students' personality traits and financial risk tolerance and spending habits.

METHODS

Undergraduates (N = 177, 77% women, 78% White) self-reported their personality traits and sleepiness using well-established questionnaires. Financial attitudes and behaviors were assessed via students' self-reported responses to a set of scenarios assessing risk tolerance as well as their spending habits over the prior two weeks.

RESULTS

Multiple regression analyses were run. Across five significant two-way interactions, high levels of sleepiness exacerbated risk for greater financial risk tolerance and higher spending among those characterized by high open-mindedness and low neuroticism, whereas low sleepiness increased protection for lower risk tolerance and less spending among those high in agreeableness and conscientiousness.

CONCLUSIONS

Sleepiness may act as both a vulnerability and protective factor in relations between personality and financial attitudes and behaviors. Improvements in sleepiness, which is modifiable via intervention, may have significant implications for individuals' financial well-being.

An experimental test of the effects of acute sleep deprivation on affect and avoidance

BACKGROUND AND OBJECTIVES

Avoidance and sleep have been identified as mechanisms involved in the development and maintenance of many mental health disorders. However, there has been little research into the relation between sleep and avoidance.

METHODS

To address this, a randomized controlled experiment using behavioral and self-report measures of affect and avoidance was conducted. Compared to a control group, we hypothesized that sleep-deprived individuals would demonstrate increased negative, and decreased positive, affectivity, more avoidance behavior toward a negatively valenced stimulus, as well as increased self-reported avoidance. Fifty-two healthy individuals ages 18-30 years old were randomly assigned to a full night of sleep deprivation or normal sleep. They completed a baseline and post-manipulation behavioral avoidance task (BAT) using a disgusting stimulus and self-reports of avoidance and state affect.

RESULTS

Repeated measures ANOVAs demonstrated negative affectivity and self-reported avoidance increased, and positive affectivity decreased, from pre-to post-manipulation in the sleep loss condition as expected. However, there were no effects of sleep deprivation on avoidance behaviors.

LIMITATIONS

This study emphasized internal validity over generalizability. Additionally, the at-home sleep deprivation limited researcher control over the overnight activities of participants.

CONCLUSIONS

Results replicate prior work on the affective consequences of sleep deprivation and highlight a discrepancy between the effect of sleep deprivation on behavioral avoidance toward a specific stimulus compared to self-reported cognitive and social avoidance behaviors.

Anxiety and depression in dry eye patients during the COVID-19 pandemic: Mental state investigation and influencing factor analysis

Objective

Investigate the anxiety and depression states among dry eye (DE) patients during the COVID-19 outbreak and analyze their influence factors.

Methods

The study was conducted in a tertiary eye hospital in Tianjin, China from March–April 2021. Four hundred twenty-eight DE patients were tested with the Ocular Surface Disease Index, Short Healthy Anxiety Inventory, Hospital Anxiety and Depression Scale, and Pittsburgh Sleep Quality Index. Descriptive statistics was used to assess the difference between DE with depression or anxiety among different groups. And multiple linear regression was used to explore factors that influence anxiety and depression in DE patients.

Results

The incidence rates of anxiety and depression among DE patients during COVID-19 were 27.34 and 26.87%, respectively. The proportion with comorbid anxiety and depression was 24.30%. Patients' education level (t = −3.001, P < 0.05; t = −3.631, P < 0.05), course of disease (t = 2.341, P < 0.05; t = 2.444, P < 0.05), health anxiety (t = 3.015, P < 0.05; t = 2.731, P < 0.05), and subjective sleep quality (t = 3.610, P < 0.05; t = 4.203, P < 0.05) had certain influences on anxiety and depression.

Conclusion

The results showed that subjective symptoms of DE patients were related to depression and anxiety. Higher education, shorter disease duration, lower health anxiety levels, and better subjective sleep quality were associated with the reduced depressive and anxiety symptoms in DE patients. These findings could be deemed beneficial to the treatment and prevention of DE during the COVID-19 epidemic.

The Common Effects of Sleep Deprivation on Human Long-Term Memory and Cognitive Control Processes

Sleep deprivation is known to have adverse effects on various cognitive abilities. In particular, a lack of sleep has been reported to disrupt memory consolidation and cognitive control functions. Here, focusing on long-term memory and cognitive control processes, we review the consistency and reliability of the results of previous studies of sleep deprivation effects on behavioral performance with variations in the types of stimuli and tasks. Moreover, we examine neural response changes related to these behavioral changes induced by sleep deprivation based on human fMRI studies to determine the brain regions in which neural responses increase or decrease as a consequence of sleep deprivation. Additionally, we discuss about the possibility that light as an environmentally influential factor affects our sleep cycles and related cognitive processes.

Neural effects of sleep deprivation on inhibitory control and emotion processing

Sleep deprivation is commonplace and impairs memory, inhibition, cognitive flexibility and attention. However, little is known about the neurophysiological impact of sleep deprivation in the context of go/no-go (GNG) task performance and emotion processing. To address this knowledge gap, 12 females performed two computerized GNG tasks (shapes; emotional facial expressions) and an object hit and avoid (OHA) task after a night of typical sleep and 24hours without sleep. Electroencephalographic (EEG) recordings were taken during a 3-minute eyes-open resting period as well as during GNG task performance. Resting EEG power in the theta band was 33% higher for the sleep-deprived than control condition (p < 0.05), whereas alpha activity was unchanged. When sleep deprived, participants had ~6% slower response times (go trials) and made ~7% more total errors during GNG tasks (p < 0.05). Reaction time and overall accuracy were ~25% and ~9% worse for the emotional compared to shape GNG task (p < 0.05), respectively, which suggests interference of emotion processing on task performance. Smaller differences in amplitude between go and no-go trials for the N2 and both the N2 and P3 event-related potential components were found during sleep deprivation for the emotional and shape GNG tasks, respectively (p < 0.05). No changes to the N170 component were found. Lastly, participants hit more distractors during the OHA when sleep deprived (p < 0.05). Altogether, these results indicate sleep deprivation slows neural processing and impairs inhibitory task performance, possibly due to a more bottom-up, stimulus-driven approach to inhibiting motor responses.

Association of physical activity and positive thinking with global sleep quality

This study examined the association of different intensity levels of physical activity and positive thinking with a global sleep quality among college students. The research question was: to what degree were the different intensity levels of physical activity and positive thinking significantly associated with the global sleep quality among college students? We recruited students, who enrolled in regular physical education classes during a fall semester at a major public university. 553 students signed the consent form and indicated their voluntary participation in this study. The final data set for analysis consisted of 403 college students with the mean age of 19.01 years ± 1.559 years (217 males vs. 186 females) based on the results of data screening. They completed three questionnaires: International Physical Activity Questionnaire (IPAQ), Pittsburgh Sleep Quality Index (PSQI), and Positive Thinking Scale (PTS) during a regular physical education class. The multiple regression model revealed that vigorous-intensity physical activity, positive thinking, and negative thinking were collectively and individually associated with the Global PSQI sleep quality (F = 19.389, p = .000), explaining 12.8% of the total variance in the Global PSQI sleep quality for the total sample. College students' engaging in vigorous intensity level of physical activity, and having a good level of positive thinking and a low level of negative thinking were both collectively and individually linked to the Global PSQI sleep quality.

The Mind After Midnight: Nocturnal Wakefulness, Behavioral Dysregulation, and Psychopathology

Sufficient sleep with minimal interruption during the circadian/biological night supports daytime cognition and emotional regulation. Conversely, disrupted sleep involving significant nocturnal wakefulness leads to cognitive and behavioral dysregulation. Most studies to-date have examined how fragmented or insufficient sleep affects next-day functioning, but recent work highlights changes in cognition and behavior that occur when someone is awake during the night. This review summarizes the evidence for day-night alterations in maladaptive behaviors, including suicide, violent crime, and substance use, and examines how mood, reward processing, and executive function differ during nocturnal wakefulness. Based on this evidence, we propose the Mind after Midnight hypothesis in which attentional biases, negative affect, altered reward processing, and prefrontal disinhibition interact to promote behavioral dysregulation and psychiatric disorders.

How sleep disturbances affect internet gaming disorder: The mediating effect of hippocampal functional connectivity

BACKGROUND

Studies have revealed that sleep disturbances lead to an increased risk of Internet gaming disorder (IGD). However, the neural underpinnings of this feature remain unknown. Exploring this issue would be valuable in understanding the relationship between sleep and psychiatric disorders.

METHODS

Given the impact of sleep on reward circuitry, we examined nucleus accumbens (NAcc) and hippocampal resting-state functional connectivity (rsFC) differences between 41 IGD subjects and 59 healthy controls. Significant connections were determined and used to examine correlations with clinical variables. Finally, we explored the relationship between neuroimaging findings, IGD severity and sleep disturbances through a mediation model.

RESULTS

We observed the connection deviation between the hippocampus and a wide range of cerebral cortexes in IGD subjects, including the prefrontal, parietal and temporal lobes. More importantly, the right posterior hippocampus (pHIP)-left caudate rsFC was positively correlated with both the Pittsburgh Sleep Quality Index (PSQI) and Internet Addiction Test scores and mediated the relationship between the two. For the NAcc, a difference between groups was only observed in the rsFC between the shell partition of the NAcc and the inferior orbitofrontal cortex, but this connectivity was not related to the PSQI score.

CONCLUSIONS

IGD subjects showed a wide range of abnormal connections in the hippocampus, involving memory, reward motivation, and cognitive control. Here we emphasized the potential of the hippocampus in studying sleep disturbances in IGD, especially the coupling between the pHIP and caudate nucleus, which could provide novel insight into how sleep interacts with motivational systems in IGD subjects.

Rapid-acting antidepressants and the circadian clock

A growing number of epidemiological and experimental studies has established that circadian disruption is strongly associated with psychiatric disorders, including major depressive disorder (MDD). This association is becoming increasingly relevant considering that modern lifestyles, social zeitgebers (time cues) and genetic variants contribute to disrupting circadian rhythms that may lead to psychiatric disorders. Circadian abnormalities associated with MDD include dysregulated rhythms of sleep, temperature, hormonal secretions, and mood which are modulated by the molecular clock. Rapid-acting antidepressants such as subanesthetic ketamine and sleep deprivation therapy can improve symptoms within 24 h in a subset of depressed patients, in striking contrast to conventional treatments, which generally require weeks for a full clinical response. Importantly, animal data show that sleep deprivation and ketamine have overlapping effects on clock gene expression. Furthermore, emerging data implicate the circadian system as a critical component involved in rapid antidepressant responses via several intracellular signaling pathways such as GSK3β, mTOR, MAPK, and NOTCH to initiate synaptic plasticity. Future research on the relationship between depression and the circadian clock may contribute to the development of novel therapeutic strategies for depression-like symptoms. In this review we summarize recent evidence describing: (1) how the circadian clock is implicated in depression, (2) how clock genes may contribute to fast-acting antidepressants, and (3) the mechanistic links between the clock genes driving circadian rhythms and neuroplasticity.

Daily fluctuations in young children's persistence

Children's behavior changes from day to day, but the factors that contribute to its variability are understudied. We developed a novel repeated measures paradigm to study children's persistence by capitalizing on a task that children complete every day: toothbrushing (N = 81; 48% female; 36-47 months; 80% white, 14% Multiracial, 10% Hispanic, 2% Asian, 1% Black; 1195 observations collected between January 2019 and March 2020). Children brushed longer on days when their parents used more praise (d = .23) and less instruction (d = -.22). Sensitivity to mood, sleep, and parent stress varied across children, suggesting that identifying the factors that shape an individual child's persistence could lead to personalized interventions.

Chronic Sleep Deprivation Blocks Voluntary Morphine Consumption but Not Conditioned Place Preference in Mice

The opioid epidemic remains a significant healthcare problem and is attributable to over 100,000 deaths per year. Poor sleep increases sensitivity to pain, impulsivity, inattention, and negative affect, all of which might perpetuate drug use. Opioid users have disrupted sleep during drug use and withdrawal and report poor sleep as a reason for relapse. However, preclinical studies investigating the relationship between sleep loss and substance use and the associated underlying neurobiological mechanisms of potential interactions are lacking. One of the most common forms of sleep loss in modern society is chronic short sleep (CSS) (<7 h/nightly for adults). Here, we used an established model of CSS to investigate the influence of disrupted sleep on opioid reward in male mice. The CSS paradigm did not increase corticosterone levels or depressive-like behavior after a single sleep deprivation session but did increase expression of Iba1, which typically reflects microglial activation, in the hypothalamus after 4 weeks of CSS. Rested control mice developed a morphine preference in a 2-bottle choice test, while mice exposed to CSS did not develop a morphine preference. Both groups demonstrated morphine conditioned place preference (mCPP), but there were no differences in conditioned preference between rested and CSS mice. Taken together, our results show that recovery sleep after chronic sleep disruption lessens voluntary opioid intake, without impacting conditioned reward associated with morphine.

Preliminary Evidence That Circadian Alignment Predicts Neural Response to Monetary Reward in Late Adolescent Drinkers

Background

Robust evidence links sleep and circadian rhythm disturbances to alcohol use and alcohol-related problems, with a growing literature implicating reward-related mechanisms. However, the extant literature has been limited by cross-sectional designs, self-report or behavioral proxies for circadian timing, and samples without substantive alcohol use. Here, we employed objective measures of sleep and circadian rhythms, and an intensive prospective design, to assess whether circadian alignment predicts the neural response to reward in a sample of late adolescents reporting regular alcohol use.

Methods

Participants included 31 late adolescents (18–22 y/o; 19 female participants) reporting weekly alcohol use. Participants completed a 14-day protocol including pre- and post-weekend (Thursday and Sunday) circadian phase assessments via the dim light melatonin onset (DLMO), in counterbalanced order. Sleep-wake timing was assessed via actigraphy. Circadian alignment was operationalized as the DLMO-midsleep interval; secondary analyses considered social jet lag based on weekday-weekend differences in midsleep or DLMO. Neural response to reward (anticipation and outcome) was assessed via a monetary reward fMRI task (Friday and Monday scans). Alcohol use was assessed at baseline and via ecological momentary assessment. Mean BOLD signal was extracted from two regions-of-interest (striatum and medial prefrontal cortex, mPFC) for analyses in regression models, accounting for age, sex, racial identity, and scan order.

Results

In primary analyses, shorter DLMO-midsleep intervals (i.e., greater misalignment) on Thursday predicted lower striatal and mPFC responses to anticipated reward, but not reward outcome, on Friday. Lower neural (striatum and mPFC) responses to anticipated reward on Friday correlated with more binge-drinking episodes at baseline, but were not associated with alcohol use in the post-scan weekend. In secondary analyses, greater social jet lag (particularly larger weekend delays in midsleep or DLMO) was associated with lower neural responses to reward anticipation on Monday.

Conclusion

Findings provide preliminary evidence of proximal associations between objectively determined circadian alignment and the neural response to anticipated monetary reward, which is linked in turn to patterns of problematic drinking. Replication in a larger sample and experimental designs will be important next steps to determining the extent to which circadian misalignment influences risk for alcohol involvement via alterations in reward function.

Associations between coping strategies and insomnia: a longitudinal study of Japanese workers

STUDY OBJECTIVES

Coping with stress is important because stress disturbs sleep. However, only a few longitudinal studies have investigated the association between coping and insomnia. We examined whether individuals with insomnia symptoms used more maladaptive coping strategies than individuals without insomnia symptoms, and evaluated the association between insomnia symptoms and coping strategies.

METHODS

In this prospective cohort study, Japanese workers were enrolled and observed over a 2-year period. During both years, self-administered questionnaires on coping and insomnia symptoms were administered. Coping was assessed using the Brief-Coping Orientation to Problems Experienced, and insomnia symptoms were examined using the Athens Insomnia Scale. Generalized estimating equation modeling identified the effects of coping strategies on insomnia severity.

RESULTS

In total, 1358 of 1855 workers at baseline were followed up. Individuals with insomnia symptoms showed a higher use of maladaptive coping strategies and less use of humor and instrumental support than individuals without insomnia symptoms. Active coping, humor, emotional support, and instrumental support were negatively associated with insomnia severity. In contrast, venting, substance use, behavioral disengagement, and self-blame were positively associated with insomnia severity.

CONCLUSIONS

This study showed that individuals with insomnia symptoms use both adaptive and maladaptive coping strategies and are more likely to use maladaptive strategies than individuals without insomnia symptoms. In the future, interventions focused on educating people about adaptive coping strategies should be conducted to determine whether coping strategies may prevent insomnia symptoms.

Interactions between Sleep and Emotions in Humans and Animal Models

Recently, increased interest and efforts were observed in describing the possible interaction between sleep and emotions. Human and animal model studies addressed the implication of both sleep patterns and emotional processing in neurophysiology and neuropathology in suggesting a bidirectional interaction intimately modulated by complex mechanisms and factors. In this context, we aimed to discuss recent evidence and possible mechanisms implicated in this interaction, as provided by both human and animal models in studies. In addition, considering the affective component of brain physiological patterns, we aimed to find reasonable evidence in describing the two-way association between comorbid sleep impairments and psychiatric disorders. The main scientific literature databases (PubMed/Medline, Web of Science) were screened with keyword combinations for relevant content taking into consideration only English written papers and the inclusion and exclusion criteria, according to PRISMA guidelines. We found that a strong modulatory interaction between sleep processes and emotional states resides on the activity of several key brain structures, such as the amygdala, prefrontal cortex, hippocampus, and brainstem nuclei. In addition, evidence suggested that physiologically and behaviorally related mechanisms of sleep are intimately interacting with emotional perception and processing which could advise the key role of sleep in the unconscious character of emotional processes. However, further studies are needed to explain and correlate the functional analysis with causative and protective factors of sleep impairments and negative emotional modulation on neurophysiologic processing, mental health, and clinical contexts.

How Sleep-Deprived People See and Evaluate Others' Faces: An Experimental Study

BACKGROUND

Acute sleep loss increases the brain's reactivity toward positive and negative affective stimuli. Thus, despite well-known reduced attention due to acute sleep loss, we hypothesized that humans would gaze longer on happy, angry, and fearful faces than neutral faces when sleep-deprived. We also examined if facial expressions are differently perceived after acute sleep loss.

METHODS

In the present, within-subjects study, 45 young adults participated in one night of total sleep deprivation and one night with an 8-hour sleep opportunity. On the morning after each night, an eye tracker was used to measure participants' time spent fixating images of happy, angry, fearful, and neutral faces. Participants also evaluated faces' attractiveness, trustworthiness, and healthiness on a 100-mm visual analog scale.

RESULTS

Following sleep loss, participants struggled more fixating the faces than after sleep. The decrease in total fixation duration ranged from 6.3% to 10.6% after sleep loss (P<0.001). Contrary to our hypothesis, the reduction in total fixation duration occurred irrespective of the displayed emotion (P=0.235 for sleep*emotion interaction) and was also present for the upper (P<0.001) but not the lower part of the faces (except for the lower part of angry faces). Overall, faces were evaluated as less trustworthy (-2.6 mm) and attractive (-3.6 mm) after sleep loss (p<0.05).

DISCUSSION

Facial expressions are crucial for social interactions. Thus, spending less time fixating on faces after acute sleep loss may come along with several problems for social interactions, eg, inaccurate and delayed judgment of the emotional state of others. In addition, more negative social impressions of others may lead to social withdrawal in sleep-deprived humans.

A Scoping Review and Conceptual Framework Examining the Role of Sleep Disturbance in Financial Exploitation in Older Adults

Sleep disturbances and financial exploitation have both been linked to impaired cognitive ability, loneliness, and depressed mood in older adults, suggesting a potential role of sleep disturbances in increasing vulnerability to financial exploitation. We sought to identify evidence linking sleep disturbances to financial exploitation. We conducted a systematic search of MEDLINE, PubMed Central, and National Center for Biotechnology Information Bookshelf for relevant published articles on sleep and financial exploitation. Three studies examining both sleep and financial exploitation were identified. None of the studies explored sleep disturbances as a cause of financial exploitation. More work needs to be done to examine the role of sleep disturbances in financial exploitation. We propose a conceptual framework for identifying possible associations among sleep disturbance, biopsychosocial, and decision-related situational factors to guide further exploration of relationships between sleep and financial exploitation.

Sleep and anxiety: From mechanisms to interventions

Anxiety is the most common mental health problem worldwide. Epidemiological studies show that sleep disturbances, particularly insomnia, affect ∼50% of individuals with anxiety, and that insufficient sleep can instigate or further exacerbate it. This review outlines brain mechanisms underlying sleep and anxiety, by addressing recent human functional/structural imaging studies on brain networks underlying the anxiogenic impact of sleep loss, and the beneficial effect of sleep on these brain networks. We discuss recent developments from human molecular imaging studies that highlight the role of specific brain neurotransmitter mechanisms, such as the adenosinergic receptor system, on anxiety, arousal, and sleep. This review further discusses frontline sleep interventions aimed at enhancing sleep in individuals experiencing anxiety, such as nonbenzodiazepines/antidepressants, lifestyle and sleep interventions and cognitive behavioral therapy for insomnia. Notwithstanding therapeutic success, up to ∼30% of individuals with anxiety can be nonresponsive to frontline treatments. Thus, we address novel non-invasive brain stimulation techniques that can enhance electroencephalographic slow waves, and might help alleviate sleep and anxiety symptoms. Collectively, these findings contribute to an emerging biological framework that elucidates the interrelationship between sleep and anxiety, and highlight the prospect of slow wave sleep as a potential therapeutic target for reducing anxiety.

Improving sleep quality leads to better mental health: A meta-analysis of randomised controlled trials

The extent to which sleep is causally related to mental health is unclear. One way to test the causal link is to evaluate the extent to which interventions that improve sleep quality also improve mental health. We conducted a meta-analysis of randomised controlled trials that reported the effects of an intervention that improved sleep on composite mental health, as well as on seven specific mental health difficulties. 65 trials comprising 72 interventions and N = 8608 participants were included. Improving sleep led to a significant medium-sized effect on composite mental health (g+ = -0.53), depression (g+ = -0.63), anxiety (g+ = -0.51), and rumination (g+ = -0.49), as well as significant small-to-medium sized effects on stress (g+ = -0.42), and finally small significant effects on positive psychosis symptoms (g+ = -0.26). We also found a dose response relationship, in that greater improvements in sleep quality led to greater improvements in mental health. Our findings suggest that sleep is causally related to the experience of mental health difficulties. Future research might consider how interventions that improve sleep could be incorporated into mental health services, as well as the mechanisms of action that explain how sleep exerts an effect on mental health.

Neural mechanisms that promote food consumption following sleep loss and social stress: An fMRI study in adolescent girls with overweight/obesity

STUDY OBJECTIVES

Insufficient sleep and social stress are associated with weight gain and obesity development in adolescent girls. Functional magnetic resonance imaging (fMRI) research suggests that altered engagement of emotion-related neural networks may explain overeating when under stress. The purpose of this study is to explore the effects of acute sleep restriction on female adolescents' neural responding during social evaluative stress and their subsequent eating behavior.

METHODS

Forty-two adolescent females (ages 15-18 years) with overweight or obesity completed a social stress induction task in which they were told they would be rated by peers based on their photograph and profile. Participants were randomly assigned to one night of sleep deprivation or 9 hours of sleep the night before undergoing fMRI while receiving positive and negative evaluations from their peers. After which, subjects participated in an ad libitum buffet.

RESULTS

Sleep deprived, relative to non-deprived girls had distinct patterns of neural engagement to positive and negative evaluation in anterior, mid, and posterior aspects of midline brain structures. Moreover, a sleep deprivation-by-evaluation valence-by-caloric intake interaction emerged in bilateral dorsal anterior cingulate. Among sleep deprived girls, greater engagement during negative, but not positive, feedback was associated with lower caloric intake. This was not observed for non-sleep deprived girls.

CONCLUSIONS

Results suggest an interaction between acute sleep loss and social evaluation that predicts emotion-related neural activation and caloric intake in adolescents. This research helps to elucidate the relationship between sleep loss, social stress, and weight status using a novel health neuroscience model.