Effects of state and trait anxiety on sleep structure: A polysomnographic study in 1083 subjects

Polysomnographic features of insomnia occurring in major depressive disorder, generalized anxiety disorder and bipolar mania: Comparison with primary insomnia and association with metabolic indicators

BACKGROUND

Insomnia is very common in psychiatric disorders, but the polysomnographic (PSG) characteristics of insomnia in various psychiatric disorders are still not agreed upon. This study aimed to investigate the characteristics of PSG and its relationship with metabolic indicators in insomnia patients with affective disorders and primary insomnia (PI) patients.

METHODS

A total of 38 patients with PI, 44 major depressive disorder patients with insomnia (DI), 49 generalized anxiety disorder patients with insomnia (GI), and 19 bipolar mania patients with insomnia (BI) were included. PSG was used to detect sleep problems in subjects, and biochemical indicators were also collected.

RESULTS

The results of this study found that subjects with BI were lower on REM sleep latency (RL), awakenings number (AN), number of microarousals (NM), and apnea-hypopnea index (AHI) than those with DI and GI, and lower on RL and AN than those with PI. Subjects with PI had lower NM and AHI than those with DI and GI. Patients with DI had a higher RL than those with GI. All results passed Bonferroni correction (p < 0.00078). No differences in biochemical indices were found among the four groups of subjects. Also, AHI was found to be positively correlated with free triiodothyronine (FT3) and fasting blood glucose in subjects.

CONCLUSION

This study suggests that various psychiatric disorders may have their characteristics in terms of PSG parameters, which prompted us to focus on the PSG characteristics of these disorders when assessing them, as well as to focus on their biochemical indicators.

Relationship of Sleep Disorder with Neurodegenerative and Psychiatric Diseases: An Updated Review

Sleep disorders affect many people worldwide and can accompany neurodegenerative and psychiatric diseases. Sleep may be altered before the clinical manifestations of some of these diseases appear. Moreover, some sleep disorders affect the physiological organization and function of the brain by influencing gene expression, accelerating the accumulation of abnormal proteins, interfering with the clearance of abnormal proteins, or altering the levels of related hormones and neurotransmitters, which can cause or may be associated with the development of neurodegenerative and psychiatric diseases. However, the detailed mechanisms of these effects are unclear. This review mainly focuses on the relationship between and mechanisms of action of sleep in Alzheimer's disease, depression, and anxiety, as well as the relationships between sleep and Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. This summary of current research hotspots may provide researchers with better clues and ideas to develop treatment solutions for neurodegenerative and psychiatric diseases associated with sleep disorders.

Sleep Quality, Nutrient Intake, and Social Development Index Predict Metabolic Syndrome in the Tlalpan 2020 Cohort: A Machine Learning and Synthetic Data Study

This study investigated the relationship between Metabolic Syndrome (MetS), sleep disorders, the consumption of some nutrients, and social development factors, focusing on gender differences in an unbalanced dataset from a Mexico City cohort. We used data balancing techniques like SMOTE and ADASYN after employing machine learning models like random forest and RPART to predict MetS. Random forest excelled, achieving significant, balanced accuracy, indicating its robustness in predicting MetS and achieving a balanced accuracy of approximately 87%. Key predictors for men included body mass index and family history of gout, while waist circumference and glucose levels were most significant for women. In relation to diet, sleep quality, and social development, metabolic syndrome in men was associated with high lactose and carbohydrate intake, educational lag, living with a partner without marrying, and lack of durable goods, whereas in women, best predictors in these dimensions include protein, fructose, and cholesterol intake, copper metabolites, snoring, sobbing, drowsiness, sanitary adequacy, and anxiety. These findings underscore the need for personalized approaches in managing MetS and point to a promising direction for future research into the interplay between social factors, sleep disorders, and metabolic health, which mainly depend on nutrient consumption by region.

Causal associations between modifiable risk factors and isolated REM sleep behavior disorder: a mendelian randomization study

Objectives

This Mendelian randomization (MR) study identified modifiable risk factors for isolated rapid eye movement sleep behavior disorder (iRBD).

Methods

Genome-wide association study (GWAS) datasets for 29 modifiable risk factors for iRBD in discovery and replication stages were used. GWAS data for iRBD cases were obtained from the International RBD Study Group. The inverse variance weighted (IVW) method was primarily employed to explore causality, with supplementary analyses used to verify the robustness of IVW findings. Co-localization analysis further substantiated causal associations identified via MR. Genetic correlations between mental illness and iRBD were identified using trait covariance, linkage disequilibrium score regression, and co-localization analyses.

Results

Our study revealed causal associations between sun exposure-related factors and iRBD. Utilizing sun protection (odds ratio [OR] = 0.31 [0.14, 0.69], p = 0.004), ease of sunburn (OR = 0.70 [0.57, 0.87], p = 0.001), childhood sunburn occasions (OR = 0.58 [0.39, 0.87], p = 0.008), and phototoxic dermatitis (OR = 0.78 [0.66, 0.92], p = 0.003) decreased iRBD risk. Conversely, a deep skin color increased risk (OR = 1.42 [1.04, 1.93], p = 0.026). Smoking, alcohol consumption, low education levels, and mental illness were not risk factors for iRBD. Anxiety disorders and iRBD were genetically correlated.

Conclusion

Our study does not corroborate previous findings that identified smoking, alcohol use, low education, and mental illness as risk factors for iRBD. Moreover, we found that excessive sun exposure elevates iRBD risk. These findings offer new insights for screening high-risk populations and devising preventive measures.

Sleep Efficiency and Sleep Onset Latency in One Saskatchewan First Nation

BACKGROUND

Sleep efficiency and sleep onset latency are two measures that can be used to assess sleep quality. Factors that are related to sleep quality include age, sex, sociodemographic factors, and physical and mental health status. This study examines factors related to sleep efficiency and sleep onset latency in one First Nation in Saskatchewan, Canada.

METHODS

A baseline survey of the First Nations Sleep Health project was completed between 2018 and 2019 in collaboration with two Cree First Nations. One-night actigraphy evaluations were completed within one of the two First Nations. Objective actigraphy evaluations included sleep efficiency and sleep onset latency. A total of 167 individuals participated, and of these, 156 observations were available for analysis. Statistical analysis was conducted using logistic and linear regression models.

RESULTS

More females (61%) than males participated in the actigraphy study, with the mean age being higher for females (39.6 years) than males (35.0 years). The mean sleep efficiency was 83.38%, and the mean sleep onset latency was 20.74 (SD = 27.25) minutes. Age, chronic pain, ever having high blood pressure, and smoking inside the house were associated with an increased risk of poor sleep efficiency in the multiple logistic regression model. Age, chronic pain, ever having anxiety, heart-related illness, and smoking inside the house were associated with longer sleep onset latency in the multiple linear regression model.

CONCLUSIONS

Sleep efficiency and sleep onset latency were associated with physical and environmental factors in this First Nation.

Pathways from adolescent close friendship struggles to adult negative affectivity

This 19-year prospective study applied a social development lens to the challenge of identifying long-term predictors of adult negative affectivity. A diverse community sample of 169 individuals was repeatedly assessed from age 13 to age 32 using self-, parent-, and peer-reports. As hypothesized, lack of competence establishing and maintaining close friendships in adolescence had a substantial long-term predictive relation to negative affectivity at ages 27-32, even after accounting for prior depressive, anxious, and externalizing symptoms. Predictions also remained robust after accounting for concurrent levels of depressive symptoms, indicating that findings were not simply an artifact of previously established links between relationship quality and depressive symptoms. Predictions also emerged from poor peer relationships within young adulthood to future relative increases in negative affectivity by ages 27-32. Implications for early identification of risk as well as for potential preventive interventions are discussed.

Sleep patterns before and after competition: A real-world examination of elite athletes

Good sleep before and after competitions is crucial to cognitive, physiological performance and recovery. Yet, elite athletes face a unique set of challenges when acquiring good sleep before and after competitions, and indeed commonly report sleep problems when it matters most. This study examined the sleep of elite athletes before and after competition compared to before and after free days. A total of 1808 unique nights of actigraphy (n = 1495) and sleep diary (n = 1335) data from elite Australian Football League and National Rugby League male athletes (N = 85, M-age = 24.4 ± 3.6) were collected and analysed using multi-level mixed models. On nights before competitions, athletes advanced sleep timings (p < .001, d = 0.63) and increased total sleep time (p < .001, d = 0.65) compared to nights before free days. On nights after competitions, athletes delayed sleep timings (p < .001, d = 1.64), reduced total sleep time (p < .001, d = 1.28), and had significantly worse quality sleep (p < .001, d = 0.71) compared to nights after free days. Sleep was especially worse following night competitions. While elite athletes and organisations may be implementing effective sleep strategies to optimise sleep the night before competitions, strategies to improve sleep after competitions may be lacking. We discuss potential factors contributing to this asymmetry and propose areas for research moving forward.

The Effect of Trait Anxiety on Bedtime Procrastination: the Mediating Role of Self-Control

BACKGROUND

Bedtime procrastination (BP), a special type of health behavior procrastination, is considered to be a failure of self-control. Notably, self-control may mediate the effect of trait anxiety on general procrastination. However, there is no evidence demonstrating the role of self-control in the relationship between trait anxiety and BP. Moreover, the association between BP and trait anxiety has not yet been thoroughly studied. Therefore, the present study aimed to explore the direct relationship between them as well as the mediating role of self-control in this relationship.

METHODS

This cross-sectional survey included 718 college students enrolled in Chinese universities between October 2018 and January 2020. The Chinese versions of the Bedtime Procrastination Scale, the Self-Control Scale, and the Trait Anxiety Inventory were used to evaluate BP, self-control, and trait anxiety, respectively.

RESULTS

Multiple linear regression analysis revealed trait anxiety independently predicted BP while controlling for demographic characteristics. Correlation analyses showed that BP was positively correlated with trait anxiety, but negatively related to self-control. Structural equation modeling further revealed a mediating role of self-control in the relationship between trait anxiety and BP.

CONCLUSIONS

Trait anxiety is a significant independent predictor of BP and may induce BP directly or indirectly through the effect of self-control. These findings provide a deeper understanding of the relationship between trait anxiety and BP and the underlying mechanism by exploring the mediating effect of self-control. As such, trait anxiety and self-control should be included in prevention and intervention strategies to address BP behavior in college students.

More Competition in Mind, Better Sleep at Night? The Mediating Role of Anxiety between Competitive Attitude and Sleep Quality

Previous studies have suggested that individuals with hypercompetitive attitude and interpersonal insecurity would have a high level of anxiety, and anxiety has been found to strongly impact on sleep quality. However, the associations between competitive attitudes and sleep quality have not been studied until now. The present study aimed to examine whether anxiety mediates the relationship between competitive attitudes and interpersonal relationships with sleep quality. This was a cross-sectional study with a total of 713 college students (age = 20.18 ± 2.16 years old; 78.8% female) recruited online to measure hypercompetitive attitude, personal development competitive attitude, interpersonal security, state anxiety and sleep quality. Path analysis models were conducted in this study. The path analysis models showed that both hypercompetitive attitude and interpersonal security had direct and indirect significant effects on poor sleep quality due to the mediating effect of state anxiety (β = 0.023, 95% bootstrapped CI: 0.005 to 0.047; β = -0.051, 95% bootstrapped CI: -0.099 to -0.010, respectively). However, personal development competitive attitude had only an indirect significant effect, but it had a negative role on poor sleep quality via state anxiety (β = -0.021, 95% bootstrapped CI: -0.042 to -0.008). The current study provided evidence that college students' competitive attitudes would impact sleep quality and highlighted the mediating role of state anxiety. The current findings suggested that individuals shifting their hypercompetitive thinking to concentrate on ability development would benefit their mental health.

Progressive muscle relaxation increases slow-wave sleep during a daytime nap

Sleep is critical for health, cognition, and restorative processes, and yet, many experience chronic sleep restriction. Sleep interventions have been designed to enhance overnight sleep quality and physiology. Components of these interventions, like relaxation-based progressive muscle relaxation (PMR), have been studied in isolation and have shown direct effects on sleep architecture, including increasing time in restorative, slow-wave sleep (SWS). These relaxation methods have been understudied in naps, which are effective fatigue countermeasures that reduce deleterious effects of chronic sleep restriction. We hypothesised that PMR should boost SWS in a nap, as compared to an active control. We used a between-subject design in which healthy young adults underwent PMR training or listened to Mozart music (control) prior to a 90-min nap opportunity. We assessed changes in the amount and lateralisation of SWS, as evidence suggests left hemispheric lateralisation may be a proxy for recuperative sleep needs, and changes to state-dependent anxiety and fatigue before and after the nap to assess intervention success. We found PMR participants spent ~10 min more in SWS, equivalent to 125% more time, than the control group, and concomitantly, significantly less time in rapid eye movement sleep. PMR participants also had greater right lateralised slow-wave activity and delta activity compared to the control suggesting a more well-rested brain profile during sleep. Further, pre-sleep anxiety levels predicted nap architecture in the intervention group, suggesting benefits may be impacted by anxiety. The feasibility and accessibility of PMR prior to a nap make this an interesting research avenue to pursue with strong translational application.

Mental Health Disturbance after a Major Earthquake in Northern Peru: A Preliminary, Cross-Sectional Study

Little has been studied in Peru on the mental health repercussions after a major earthquake. We aimed to explore the factors associated with depressive and anxiety symptoms in people who experienced a 6.1 magnitude earthquake in Piura, Peru, on 30 July 2021. A preliminary cross-sectional study was conducted in the general population between August–September 2021. An online questionnaire was provided using PHQ-9, GAD-7, and other relevant measures. Generalized linear models were applied. Of the 177 participants, the median age was 22 years, the majority were female (56%), and many experienced depressive (52%) or anxiety symptoms (52%). Presence of depressive symptoms was associated with a personal history of mental disorder, moderate housing damage, social/material support from politicians, moderate food insecurity, and insomnia. Presence of anxiety symptoms was associated with physical injury caused by the earthquake, mild food insecurity, and insomnia. The development of depressive and anxiety symptoms following the 2021 earthquake experienced in Piura depended on multiple individual and socioeconomic factors. Additional studies should reinforce the factors identified here given the methodological limitations, such as the study design, sampling method, and sample size. This would lead to effective intervention measures to mitigate the impact of earthquakes on mental health.

Trait Anxiety Does Not Predict the Anxiogenic Response to Sleep Deprivation

Sleep deprivation has in several studies been found to increase anxiety. However, the extent to which this anxiogenic effect depends on one’s underlying trait anxiety has not previously been determined. Using two separate sleep-loss experiments, the current research investigated whether trait anxiety (STAI-T) moderates the increase in state anxiety (STAI-S) following one night of total sleep loss (study 1, N = 182, age 25.3 ± 6.5, 103 women) and two nights of partial sleep restriction (study 2, N = 67, age 26.5 ± 7.4, 38 women). Both studies showed the expected anxiogenic effect of sleep loss, and a clear relationship between trait anxiety and state anxiety. However, the anxiogenic effect of sleep loss was not moderated by trait anxiety, as there was an equal impact regardless of trait anxiety level. These findings indicate that, although sleep loss is related to general anxiety as well as anxiety disorders, for a non-clinical sample the anxiogenic effect of short-term sleep loss is not affected by baseline levels of anxiety.

Individual Factors Associated With COVID-19 Infection: A Machine Learning Study

The fast, exponential increase of COVID-19 infections and their catastrophic effects on patients' health have required the development of tools that support health systems in the quick and efficient diagnosis and prognosis of this disease. In this context, the present study aims to identify the potential factors associated with COVID-19 infections, applying machine learning techniques, particularly random forest, chi-squared, xgboost, and rpart for feature selection; ROSE and SMOTE were used as resampling methods due to the existence of class imbalance. Similarly, machine and deep learning algorithms such as support vector machines, C4.5, random forest, rpart, and deep neural networks were explored during the train/test phase to select the best prediction model. The dataset used in this study contains clinical data, anthropometric measurements, and other health parameters related to smoking habits, alcohol consumption, quality of sleep, physical activity, and health status during confinement due to the pandemic associated with COVID-19. The results showed that the XGBoost model got the best features associated with COVID-19 infection, and random forest approximated the best predictive model with a balanced accuracy of 90.41% using SMOTE as a resampling technique. The model with the best performance provides a tool to help prevent contracting SARS-CoV-2 since the variables with the highest risk factor are detected, and some of them are, to a certain extent controllable.

Characteristics of Sleep Paralysis and Its Association with Anxiety Symptoms, Perceived Stress, PTSD, and Other Variables Related to Lifestyle in Selected High Stress Exposed Professions

Sleep paralysis (SP) is a hypnagogic or hypnopompic state associated with the inability to move while conscious. Recurrent isolated sleep paralysis (RISP) is a type of REM parasomnia. Individuals experiencing anxiety disorders, PTSD, exposure to chronic stress, or shift work are at risk of developing this sleep disorder. This study aimed to assess: (1) the prevalence, frequency, and symptomatology of SP, and (2) the impact of the severity of anxiety symptoms, perceived stress, and lifestyle mode variables on the frequency and severity of SP in four professional groups at high risk of SP (n = 844): nurses and midwives (n = 172), policemen (n = 174), teachers (n = 107), and a group of mixed professions—“other professions” (n = 391). The study used a battery of online questionnaires: the Sociodemographic and Health Status Questionnaire, the SP-EPQ, the PCL -5, the STAI-T, the PSWQ and the PSS-10. The prevalence of SP was the lowest among policemen (15.5%) and the highest in the group of “other professions” (39.4%). The association of SP with symptoms of PTSD and anxiety was confirmed in the group of nurses and “other professions”. Among other factors modulating the incidence and severity of SP were: age, BMI, smoking, alcohol consumption, sleep duration, and perceived stress. This study indicates that there exist links between SP and psychological and lifestyle factors, suggesting a complex etiology for this sleep disorder. Due to the high prevalence of SP in the studied groups of occupations, further research is necessary to develop preventive and therapeutic methods for SP.

Arousal-Mediated Sleep Disturbance Persists During Cocaine Abstinence in Male Mice

Acute cocaine disturbs sleep on a dose-dependent basis; however, the consequences of chronic cocaine remain unclear. While the arousal promotion following cocaine has been well-established, effects of cocaine on sleep after termination of chronic cocaine exposure appear variable in human subjects with few studies in non-human subjects. Here, a within-subjects design (outcomes normalized to baseline, undisturbed behavior) and between-subjects design (repeated experimenter-administered cocaine vs. experimenter-administered saline) was used to investigate sleep homeostasis and sleep/waking under repeated cocaine/saline exposure and prolonged forced abstinence conditions in mice. Overall, during the forced abstinence period increases in arousal, as determined by sleep latency and gamma energy, persisted for 2 weeks. However, the sleep response to externally enforced sleep deprivation was unchanged suggesting that sleep disruptions during the forced abstinence period were driven by enhancement of arousal in the absence of changes in sleep homeostatic responses.

Sleep and Mental Health Issues in Current and Former Athletes: A Mini Review

Sleep and mental health are important aspects of human health that work concurrently. However, sleep and mental health disorders are often overlooked and undiagnosed in sport due to the negative stigma associated with them. Evidence suggests that athletes are disproportionately affected by mental health issues and sleep problems. Internal and external pressures contribute to psychological distress. Variable competition times, travel and stress are detrimental to sleep quality. Retirement from sport can deteriorate sleep and psychological wellbeing, particularly for those who retired involuntarily and identify strongly with their athletic role. When untreated, these issues can manifest into a range of clinical disorders. This is concerning, not only for compromised athletic performance, but for general health and wellbeing beyond sport. Previous research has focussed on sleep and health independently among currently competing, or former, athletes. To date, no research has comprehensively assessed and compared sleep complaints and mental health issues between these two cohorts. Moreover, research has failed to obtain data across a variety of different competition levels, sports, and genders, leaving the current scope of the literature narrow. Comorbid conditions (e.g., concussion history, obesity), ex-college athletes, and mental health has been the focus of existing literature post-retirement. Future research would benefit from employing both quantitative and qualitative methodologies to comprehensively assess the prevalence and severity of sleep and mental health disorders across current and retired athletes. Research outcomes would inform education strategies, safeguarding athletes from these issues by reducing negative stigmas associated with help-seeking in sport and ultimately increase self-guided treatment.

Effect of short-term meditation training in central serous chorioretinopathy

Purpose:

Stress and Type A personality are established risk factors for the development of central serous chorioretinopathy (CSC). Meditation is known to have a positive effect on reducing stress levels. This study aimed to assess the effect of short-term meditation training in patients of CSC.

Methods:

A pilot study was conducted where 40 patients diagnosed with acute and non-resolving CSC were randomly assigned to either of two groups – meditation training and routine care (without meditation). The primary outcome measure was time to resolution of CSC based on optical coherence tomography and fluorescein angiography. Secondary outcome measures were changes in anxiety score (State–Trait Anxiety Inventory [STAI] scores) and blood pressure. The patients were followed up for a minimum period of 4 months.

Results:

Twenty cases were included in each group. The demographic pattern, baseline swept-source optical coherence tomography parameters, and STAI scores were similar in both groups. The time to disease resolution was 9.4 ± 4.22 weeks in the meditation group and 19.5 ± 2.79 weeks in the nonmeditation group (P < 0.001). At 4 months, CSC had failed to resolve in 60% of patients with routine care compared with 8% in cases following short-term meditation training. STAI scores showed a reduction in stress levels in the meditation group. Furthermore, statistically significant improvement in systolic and diastolic blood pressures was also observed following meditation training.

Conclusion:

Short-term meditation training may be a useful approach in the management of patients with CSC as it tends to reduce stress and prehypertension, and promotes earlier resolution of the condition. However, patient’s motivation to complete and pursue the meditation training is a significant barrier.

Motive control of unconscious inference: The limbic base of adaptive Bayes

Current computational models of neocortical processing, described as predictive coding theory, are providing new ways of understanding Helmholtz's classical insight that perception cannot proceed in a data-driven fashion, but instead requires unconscious inference based on prior experience. Predictive coding is a Bayesian process, in which the operations at each lower level of the cortical hierarchy are predicted by prior projections of expectancies from a higher level, and are then updated by error-correction with lower level evidence. To generalize the predictive coding model to the human neocortex as a whole requires aligning the Bayesian negotiation of prior expectancies with sensory and motor evidence not only within the connectional architecture of the neocortex (primary sensory/motor, unimodal association areas, and heteromodal association areas) but also with the limbic cortex that forms the base for the adaptive control of the heteromodal areas and thereby the cerebral hemisphere as a whole. By reviewing the current evidence on the anatomy of the human corticolimbic connectivity (now formalized as the Structural Model) we address the problem of how limbic cortex resonates to the homeostatic, personal significance of events to provide Bayesian priors to organize the operations of predictive coding across the multiple levels of the neocortex. By reviewing both classical evidence and current models of control exerted between limbic and neocortical networks, we suggest a neuropsychological theory of human cognition, the adaptive Bayes process model, in which prior expectancies are not simply rationalized propositions, but rather affectively-charged expectancies that bias the interpretation of sensory data and action affordances to support allostasis, the motive control of expectancies for future events.

Influence of Electronic Devices on Sleep and Cognitive Performance During Athlete Training Camps

Jones, MJ, Dawson, B, Eastwood, PR, Halson, SL, Miller, J, Murray, K, Dunican, IC, Landers, GJ, and Peeling, P. Influence of electronic devices on sleep and cognitive performance during athlete training camps. J Strength Cond Res 35(6): 1620-1627, 2021-This study investigated the effects of removing athletes' electronic devices in the evening on sleep and performance during training camps. Water polo athletes (n = 26) attending a 7-night training camp (study 1) and triathletes (n = 23) attending a 4-night training camp (study 2) were randomly allocated to a no-device group (no electronic devices could be used after dinner or overnight; ND) or control group (unrestricted electronic device use; CON). Sleep was monitored through wrist actigraphy. The ND group completed a questionnaire measuring anxiety related to being unable to use electronic devices ("nomophobia"). Triathletes also completed a psychomotor vigilance test (PVT) at the start and end of camp. Water polo ND athletes went to bed earlier and spent longer time in bed than CON on the first night, but not on other nights. In triathletes, sleep quantity was not different between groups on any night. No statistically significant differences were observed for changes in nomophobia from the first to the last night of camp. No differences in PVT performance were observed between ND and CON triathletes. In conclusion, removal of evening electronic devices does not improve sleep quantity or cognitive performance in athletes during short-duration (4-7 nights) training camps.

Polysomnographic Sleep and Attentional Deficits in Traumatized North Korean Refugees

INTRODUCTION

Attentional deficits and sleep problems are common in refugees who have experienced trauma. In the present study, we used polysomnography (PSG) to investigate the relationship between attentional deficits and objective measures of sleep structure in traumatized North Korean refugees.

METHODS

We recruited 32 North Korean refugees (mean age = 33.78 ± 14.33 years) and 39 South Korean participants (mean age = 35.03 ± 11.08 years). Sustained attention and divided attention were assessed using the Computerized Attention Test. We conducted an overnight PSG to objectively assess sleep structure. The participants also completed the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Impact of Event Scale-Revised (IES-R), Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Insomnia Severity Index (ISI).

RESULTS

The North Korean refugees showed more commission errors (CEs, p < 0.05) and a larger standard deviation (SD) of the reaction time (RT) (p < 0.05) in the sustained attention task compared to the South Korean participants. Furthermore, the North Korean refugees showed a shorter period of wake after sleep onset (WASO, p < 0.01), less time spent in N1 (p < 0.05), and more time spent in N2 (p < 0.05). The larger SD of RT in the sustained attention task in the North Korean refugees was positively correlated with WASO (r = 0.62, p < 0.01) and N1 stage (r = 0.47, p < 0.05) after controlling for age, sex, BDI, BAI, and IES-R.

CONCLUSION

The North Korean refugees showed poorer performance on the sustained attention task. Nocturnal PSG revealed shorter WASO and time spent in N1 in this population, which are independently associated with the preservation of attentional capacity. These data suggest that traumatized refugees may compensate for attentional deficits induced by their traumatic experiences via increased sleep continuity.

Subclinical epileptiform activity accelerates the progression of Alzheimer's disease: A long-term EEG study

OBJECTIVE

While many studies suggest that patients with Alzheimer's disease have a higher chance for developing epileptic seizures, only a few studies are available examining independent epileptic discharges. The major aims of our study was to determine the prevalence of subclinical epileptiform activity (SEA) in AD compared to healthy elderly controls with the hypothesis that SEA is more frequent in AD than in cognitively normal individuals. Another aim was to analyze the effect of baseline SEA captured with electroencephalography on the progression of the disease with longitudinal cognitive testing.

METHODS

We investigated 52 Alzheimer patients with no history of epileptic seizures and 20 healthy individuals. All participants underwent a 24-hour electroencephalography, neurology, neuroimaging and neuropsychology examination. Two independent raters analyzed visually the electroencephalograms and both raters were blind to the diagnoses. Thirty-eight Alzheimer patients were enrolled in a 3-year long prospective follow-up study with yearly repeated cognitive evaluation.

RESULTS

Subclinical epileptiform discharges were recorded significantly (p:0.018) more frequently in Alzheimer patients (54%) than in healthy elderly (25%). Epileptiform discharges were associated with lower performance scores in memory. Alzheimer patients with spikes showed 1.5-times faster decline in global cognitive scores than patients without (p < 0.001). The decline in cognitive performance scores showed a significant positive correlation with spike frequency (r:+0.664; p < 0.001).

CONCLUSIONS

Subclinical epileptiform activity occurs in half of Alzheimer patients who have never suffered epileptic seizures. Alzheimer patients with subclinical epileptiform activity showed accelerated cognitive decline with a strong relation to the frequency and spatial distribution (left temporal) of spikes.

SIGNIFICANCE

Our findings suggest the prominent role of epileptiform discharges in the pathomechanism of Alzheimer's disease which might serve as potential therapeutic target.

Validation of the Satisfaction, Alertness, Timing, Efficiency and Duration (SATED) Questionnaire for Sleep Health Measurement

Rationale: Sleep constitutes a fundamental pillar of health in individuals and is an indicator of the health of a population.Objectives: Aiming to develop an easy-to-use tool to measure sleep health, we translated to Spanish, adapted, and validated the Satisfaction, Alertness, Timing, Efficiency and Duration (SATED) questionnaire.Methods: The reliability of the questionnaire was evaluated using a sample of 4,385 participants from the 2015 Catalan Health Survey. Criterion validity, construct validity, and feasibility were assessed in an independent sample of 200 subjects who completed the Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, anxiety scale of the State-Trait Anxiety Inventory, mood scale of the Profile of Mood States, and a 1-week sleep diary.Results: The SATED questionnaire obtained adequate internal consistency (Cronbach's α = 0.77), statistically significant correlations of its five items with the total score (rho = 0.55-0.69), and a suitable goodness of fit in the confirmatory factor analysis (χ² = 30.93; df = 5; P < 0.001; root mean square error of approximation, 0.049; comparative fit index, 0.99; standardized root mean residual, 0.043). The criterion and construct validity were adequate, with correlations in the expected directions. The feasibility of the questionnaire was satisfactory, being easy and intelligible and requiring approximately 1 minute to complete.Conclusions: This questionnaire is reliable and valid for measuring sleep health in the general population. Encouraging the use of SATED is expected to raise awareness that sleep, like diet and physical activity, is a key modifiable factor for promoting health.

Sleep disturbances in obsessive-compulsive disorder: influence of depression symptoms and trait anxiety

BACKGROUND

Sleep disturbances have been reported in obsessive-compulsive disorder (OCD) patients, with heterogeneous results. The aim of our study was to assess sleep function in OCD and to investigate the relationship between sleep and the severity of obsessive-compulsive (OC) symptoms, depressive symptoms and trait anxiety.

METHODS

Sleep quality was measured in 61 OCD patients and 100 healthy controls (HCs) using the Pittsburgh Sleep Quality Index (PSQI). Multiple linear regression was conducted to explore the association between sleep and psychopathological measures; a mediation analysis was also performed.

RESULTS

OCD patients showed poor sleep quality and more sleep disturbances compared to HCs. The severity of depression, trait anxiety and OC symptomatology were correlated with poor sleep quality. Multiple linear regression analyses controlling for potential confounders revealed that the severity of depression and trait anxiety were independently related to poor sleep quality in OCD. A mediation analysis showed that both the severity of trait anxiety and depression mediate the relationship between the severity of OC symptoms and poor sleep quality among patients with OCD.

CONCLUSIONS

Our findings support the existence of sleep disturbances in OCD. Trait anxiety and depression play a key role in sleep quality among OCD patients.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

Perceived stress and sleep quality among the non-diseased general public in China during the 2019 coronavirus disease: a moderated mediation model

BACKGROUND

The 2019 coronavirus disease (COVID-19) has spread worldwide, and its associated stressors have resulted in decreased sleep quality among front-line workers. However, in China, the general public displayed more psychological problems than the front-line workers during the pandemic. Therefore, we investigated the influence of perceived stress on the sleep quality of the non-diseased general public and developed a moderated mediation model to explain said relationship.

METHODS

Questionnaire-based surveys were conducted online from February 18-25, 2020 with 1630 Chinese participants (aged 18-68 years).

RESULTS

Around one-third (36.38%) of participants were poor sleepers during the COVID-19 pandemic. Moreover, higher perceived stress was significantly associated with higher anxiety levels, which, in turn, was associated with lower sleep quality. Self-esteem moderated the indirect effect of perceived stress on sleep quality through its moderation of the effect of perceived stress on anxiety. This indicated that the mediation effect of anxiety was stronger in those with low levels of self-esteem than in those with high levels of self-esteem.

CONCLUSIONS

These findings suggest that both the sleep quality and perceived stress levels of the non-diseased general public required attention during the COVID-19 pandemic. Our findings also identify personality characteristics related to better sleep quality, demonstrating the important role of self-esteem in environmental adaptation.

The bidirectional association between sleep problems and anxiety symptoms in adolescents: a TRAILS report

BACKGROUND

Previous studies have suggested a bidirectional association between sleep problems and anxiety symptoms in adolescents. These studies used methods that do not separate between-person effects from within-person effects, and therefore their conclusions may not pertain to within-person mutual influences of sleep and anxiety. We examined bidirectional associations between sleep problems and anxiety during adolescence and young adulthood while differentiating between person effects from within-person effects.

METHODS

Data came from the Dutch TRacking Adolescents' Individual Lives Survey (TRAILS), a prospective cohort study including six waves of data spanning 15 years. Young adolescents (N = 2230, mean age at baseline 11.1 years) were followed every 2-3 years until young adulthood (mean age 25.6 years). Sleep problems and anxiety symptoms were measured by the Youth Self-Report, Adult Self-Report and Nottingham Health Profile. Temporal associations between sleep and anxiety were investigated using the random intercept cross-lagged panel model.

RESULTS

Across individuals, sleep problems were significantly associated with (β = 0.60, p < 0.001). At the within-person level, there were significant cross-sectional associations between sleep problems and anxiety symptoms at all waves (β = 0.12-0.34, p < 0.001). In addition, poor sleep predicted greater anxiety symptoms between the first and second, and between the third and fourth assessment wave. The reverse association was not statistically significant.

CONCLUSIONS

Within-person associations between sleep problems and anxiety are considerably weaker than between-person associations. Yet, our findings tentatively suggest that poor sleep, especially during early and mid-adolescence, may precede anxiety symptoms, and that anxiety might be prevented by alleviating sleep problems in young adolescents.

Overanxious and underslept

Are you feeling anxious? Did you sleep poorly last night? Sleep disruption is a recognized feature of all anxiety disorders. Here, we investigate the basic brain mechanisms underlying the anxiogenic impact of sleep loss. Additionally, we explore whether subtle, societally common reductions in sleep trigger elevated next-day anxiety. Finally, we examine what it is about sleep, physiologically, that provides such an overnight anxiety-reduction benefit. We demonstrate that the anxiogenic impact of sleep loss is linked to impaired medial prefrontal cortex activity and associated connectivity with extended limbic regions. In contrast, non-rapid eye movement (NREM) slow-wave oscillations offer an ameliorating, anxiolytic benefit on these brain networks following sleep. Of societal relevance, we establish that even modest night-to-night reductions in sleep across the population predict consequential day-to-day increases in anxiety. These findings help contribute to an emerging framework explaining the intimate link between sleep and anxiety and further highlight the prospect of non-rapid eye movement sleep as a therapeutic target for meaningfully reducing anxiety.

Precuneus-Dominant Degeneration of Parietal Lobe Is at Risk of Epilepsy in Mild Alzheimer's Disease

Introduction: Alzheimer's disease (AD) is the leading cause of cognitive decline. Epilepsy is a frequent comorbid condition of AD. While previous studies analyzed the risk factors of AD-related epileptic seizures, we still lack biomarkers of epilepsy in mild AD cases.

Purpose: The aim of our study was to analyze the correlations between neuropsychology, cortical thickness, and brain volumetric measurements in mild Alzheimer patients with concomitant epileptic seizures.

Materials and methods: We selected mild AD patients from our database to examine them with structural magnetic resonance imaging, 24 h electroencephalography, and detailed neuropsychology. We made the diagnosis of epilepsy based on epileptology data including neurophysiology. We retrospectively analyzed the neuropsychology pattern, clinical and epidemiologic features, cortical thickness, and volumetric values of mild AD patients with and without overt clinical seizures using covariance weighted general linear model.

Results: We found epileptic seizures in 26% of mild AD patients. Patients with seizures performed worse in visuo-spatial scores than patients without (p = 0.003). Patients with seizures had smaller parietal thickness (p = 0.018), being associated to reduced thickness of left (p = 0.007), and right precunei (p = 0.005). The visuo-spatial performance positively and strongly correlated with the thickness of the parietal lobe (r = 0.67; p = 0.002) and with the volume of the precuneus (r = 0.612; p = 0.005).

Conclusion: Epileptic seizures are common even in mild AD. We found that a prominent deficit in visuo-spatial skills is a red flag for epileptic seizures in the initial phase of AD, indicating the early involvement of parietal lobe in the neurodegenerative process. Because our findings suggest that the degeneration of precuneus is a sensitive marker of seizures associated to mild AD, clinicians need to pay special attention to the pattern of atrophy shown by structural MRI. Our results confirm previous data suggesting that epileptic seizures might be associated to a faster progressing type of AD with the early degeneration of posterior cortical areas.

Risk factors for possible REM sleep behavior disorder: A CLSA population-based cohort study

OBJECTIVE

To assess sociodemographic, socioeconomic, and clinical correlates of idiopathic REM sleep behavior disorder (RBD) in a 30,097-person national cohort.

METHODS

Participants 45 to 85 years of age in Canada were collected as part of the Canadian Longitudinal Study on Aging. Possible RBD (pRBD) was screened with the REM Sleep Behavior Disorder Single-Question Screen, a questionnaire with 94% specificity and 87% sensitivity. To improve diagnostic accuracy, those screening positive for apnea or non-REM parasomnia (young-onset pRBD) and those self-reporting dementia or Parkinson disease were excluded. A series of sociodemographic, lifestyle, and mental health variables were analyzed cross-sectionally. Potential correlates were assessed via multivariable logistic regression.

RESULTS

Of 30,097 participants, 958 (3.2%) were identified as having pRBD. Male sex (odds ratio [OR] 2.09, 95% confidence interval [CI] 1.78-2.44) and lower education (OR 0.95, 95% CI 0.92-0.98) were associated with pRBD. Participants with pRBD had smoked more (pack-years OR 1.01, 95% CI 1.00-1.01) and were more likely to be moderate to heavy drinkers (OR 1.25, 95% CI 1.04-1.51). There was a strong association between pRBD and self-reported antidepressant treatment for depression (OR 2.77, 95% CI 2.23-3.45), psychological distress (OR 1.61, 95% CI 1.44-1.80), mental illness (OR 2.09, 95% CI 1.75-2.49), and posttraumatic stress disorder (OR 2.68, 95% CI 1.97-3.65).

CONCLUSIONS

Our study replicated previous reported associations between pRBD and smoking, low education, and male sex and found previously unreported links with alcohol use and psychological distress. Risk factors for pRBD differ from those previously defined for neurodegenerative synucleinopathies.

Hyperarousal during sleep in untreated primary insomnia sufferers: A polysomnographic study

Because some evidence favors the hyperarousal model of insomnia, we sought to learn more about the dynamics of this phenomenon during sleep. Polysomnographic data from 30 normative subjects and 86 untreated primary insomnia sufferers recruited from the database of the sleep laboratory were studied for whole nights and in terms of thirds of the night. Untreated primary insomnia sufferers had an increased sleep latency and excess of WASO, together with a deficit in REM and NREM sleep during the entire night. In terms of thirds of the night, they presented a major excess of WASO during the first and last thirds of the night but an excess of lesser importance during the middle third. A deficit in SWS was found during the first third of the night, but for REM, the deficit was present during both the first and last thirds. Primary insomnia sufferers had no SWS or REM deficit during the second third of the night. We found that the hyperarousal phenomenon occurs mainly during the sleep-onset period of the first and last thirds of the night and is less important during the middle third. These results open new avenues for understanding the pathophysiology of primary insomnia.