Cognitive complaints mediate the influence of sleep disturbance and state anxiety on subjective well-being and ill-being in adult community volunteers: a cross sectional study.

BACKGROUND: Sleep disturbance, state anxiety, and cognitive complaints (CCs) have been recognized as important issues in public health. Although the mediating role of CCs has been proposed, their role in the relationships between sleep disturbance, state anxiety, and subjective well-being (SWB) and subjective ill-being (SIB) are not yet fully understood. This study used path analyses to investigate whether CCs mediate these relationships. METHODS: The study recruited 523 Japanese adult volunteers using convenience sampling. Participants completed the Pittsburgh Sleep Quality Index, State-Trait Anxiety Inventory (Form Y), Cognitive Complaints in Bipolar Disorder Rating Assessment, and Subjective Well-Being Inventory to evaluate sleep disturbance, state anxiety, CCs, and SWB and SIB, respectively. Path analyses were conducted to assess the mediating effects of CCs. RESULTS: The path analyses showed significant indirect associations of sleep disturbance and state anxiety with SWB (p = 0.024 and p = 0.012) and SIB (p < 0.001 and p < 0.001), respectively, mediated by CCs. Furthermore, there were significant indirect associations of sleep disturbance with CCs (p < 0.001), SWB (p < 0.001), and SIB (p < 0.001), via state anxiety, respectively. CONCLUSIONS: This study suggests that CCs mediate the associations of sleep disturbance and state anxiety with SWB and SIB, respectively, in adult community volunteers. To address SWB and SIB associated with sleep disturbance and state anxiety, evaluating CCs may be useful in public mental health. Our findings will encourage health care workers to assess CCs more systematically. Future studies may need to target CCs to develop interventions for SWB and SIB.

Psychotropics use and occurrence of falls in hospitalized patients: A matched case-control study.

AIM: Several studies have suggested the use of psychotropics as a possible risk factor for falling. However, there were several limitations to these previous studies, such as the use of data obtained from administrative databases and the lack of information about the time interval between psychotropics use and falling. Therefore, in this study, we aimed to assess the association between psychotropics use and falling in hospitalized patients, using reliable data collected from medical records. METHODS: A matched (age, sex, and inpatient department) case-control study of patients hospitalized at Tokyo Medical University Hospital was performed using the new-user design, based on data extracted from medical records. The outcome was the occurrence of falls. The use of four classes of psychotropics (antipsychotics, antidepressants, anxiolytics, and hypnotics) was compared between 254 cases (patients who experienced falls) and 254 controls (patients without falls). Multivariable logistic regression analysis was performed to clarify the associations between falling and the use of these psychotropics. RESULTS: Univariable analyses demonstrated that the use of every class of psychotropic was statistically significantly associated with falling. Moreover, the association of the use of hypnotics with falls remained significant in the multivariable logistic regression model built including potential confounding factors, such as age, sex, inpatient department, body mass index, fall risk score measured by a fall risk assessment sheet completed on hospital admission, and the use of other classes of psychotropics. CONCLUSIONS: Our findings suggest that the use of hypnotics may be a risk factor for falling in hospitalized patients.

Association of sleep duration on workdays or free days and social jetlag with job stress.

AIM: The aim of this study was to investigate the impact of sleep problems on job stress in office workers. METHODS: This study included 4645 office workers from 29 companies who completed the study questionnaires between April 2017 and April 2019 in Japan. Sleep duration was assessed based on the participants' subjective sleep schedule on workdays and free days. The midpoint of sleep on free days (sleep-corrected) and social jetlag were calculated in accordance with the Munich Chronotype Questionnaire. To assess job stress, we used the 57-item Brief Job Stress Questionnaire. RESULTS: Multivariate logistic regression analysis revealed that the following factors were significantly associated with high job stress in office workers: a sleep duration <6 h on workdays (OR = 1.77, 95% CI = 1.46-2.15, P < 0.001), a sleep duration <6 h on free days (OR = 1.40, 95% CI = 1.05-1.87, P = 0.022), a sleep duration of at least 8 h on free days (OR = 1.31, 95% CI = 1.06-1.60, P = 0.011), and more than 2 h of social jetlag (OR = 1.33, 95% CI = 1.04-1.70, P = 0.022). CONCLUSION: This study suggests that insufficient sleep, long sleep durations on free days, and social jetlag may be associated with high job stress in office workers.

Childhood parental bonding affects adulthood trait anxiety through self-esteem.

INTRODUCTION: The association between trait anxiety and parental bonding has been suggested. However, the mechanism remains uncertain and there is no study focused on general adult population. We investigated the association and the mechanism between childhood parental bonding and adulthood trait anxiety in the general adult population. MATERIAL AND METHODS: A cross-sectional retrospective survey was conducted in 2014 with 853 adult volunteers from the general population. The Parental Bonding Instrument, Rosenberg Self-Esteem Scale, and State-Trait Anxiety Inventory Form Y (STAI-Y) were self-administered. Structural equation modelling was used for the analysis. RESULTS: Childhood parental bonding affected adulthood trait anxiety indirectly mediated by self-esteem. Trait anxiety was decreased by parental care and increased by parental overprotection through self-esteem. This model explained 51.1% of the variability in STAI-Y trait anxiety scores. CONCLUSIONS: This study suggests an important role of self-esteem as a mediator between childhood parental bonding and adulthood trait anxiety.

Internet-based survey of factors associated with subjective feeling of insomnia, depression, and low health-related quality of life among Japanese adults with sleep difficulty.

BACKGROUND: This study was conducted to determine what symptom components or conditions of insomnia are related to subjective feelings of insomnia, low health-related quality of life (HRQOL), or depression. METHOD: Data from 7,027 Japanese adults obtained using an Internet-based questionnaire survey was analyzed to examine associations between demographic variables and each sleep difficulty symptom item on the Pittsburgh Sleep Quality Index (PSQI) with the presence/absence of subjective insomnia and scores on the Short Form-8 (SF-8) and Center for Epidemiologic Studies Depression Scale (CES-D). RESULTS: Prevalence of subjective insomnia was 12.2% (n = 860). Discriminant function analysis revealed that item scores for sleep quality, sleep latency, and sleep medication use on the PSQI and CES-D showed relatively high discriminant function coefficients for identifying positivity for the subjective feeling of insomnia. Among respondents with subjective insomnia, a low SF-8 physical component summary score was associated with higher age, depressive state, and PSQI items for sleep difficulty and daytime dysfunction, whereas a low SF-8 mental component summary score was associated with depressive state, PSQI sleep latency, sleeping medication use, and daytime dysfunction. Depressive state was significantly associated with sleep latency, sleeping medication use, and daytime dysfunction. CONCLUSION: Among insomnia symptom components, disturbed sleep quality and sleep onset insomnia may be specifically associated with subjective feelings of the disorder. The existence of a depressive state could be significantly associated with not only subjective insomnia but also mental and physical QOL. Our results also suggest that different components of sleep difficulty, as measured by the PSQI, might be associated with mental and physical QOL and depressive status.

Factors associated with hypnotics polypharmacy in the Japanese population.

OBJECTIVE: Insomnia disorder is a global public health issue, commonly treated with hypnotics. However, long-term use of benzodiazepine derivatives (BZDs), especially polypharmacy with this kind of drug, carries risks for dependence and abuse. This study using large-scale medical insurance records investigated the causes of polypharmacy through the treatment of insomnia disorder. METHODS: A cross-sectional study analyzed anonymized medical record data from July 2014 to March 2018 provided by a nationwide Japanese health insurance association covering 405,952 individuals. Outpatients prescribed at least one sleep medication were included. Demographic data, pharmacological classification of the drugs, and comorbidities were assessed using hierarchical logistic regression analysis to explore their associations with polypharmacy. RESULTS: Of the 33,212 outpatients who were prescribed sleep medications, 32.5 % were prescribed multiple types. After adjusting for demographics and type of sleep medications as covariates, hypnotic polypharmacy was significantly associated with younger age, the presence of certain kinds of comorbidities, and using BZD anxiolytics before bedtime with the highest adjusted odds ratios (8.01-9.39) when referenced with BZD hypnotics. On the other hand, usage of orexin receptor antagonists, melatonin receptor agonists, and Z-drugs indicated lower odds ratios (0.74-0.87). CONCLUSIONS: Hypnotic polypharmacy is relatively common in the Japanese general population. With the introduction of non-pharmacological therapy in mind, assessing patients' comorbidities and avoiding the use of benzodiazepines, especially BZD anxiolytics, before bedtime would be recommended to prevent polypharmacy.

Association between social jetlag and weight and fat reduction in dieting.

Objectives: Social jetlag (SJL), the discrepancy between an individual's inherent circadian rhythm and external social schedule, is associated with obesity. This study aimed to investigate whether SJL also influences body weight and body fat loss during dieting. Methods: This was an observational study from 2015 to 2018 with participants who had joined an exercise and nutrition program at a private personal training gym. Data from 11,829 individuals provided by the gym along with their sleep logs were analyzed. Differences in change in body mass index (BMI) and body fat percentage (%body fat) were compared by the degree of SJL. Regression was conducted for the change in BMI and %body fat on SJL, adjusted for gender, age, engagement duration in the program, initial BMI, initial %body fat, chronotype, and dietary intakes. Results: The subjects comprised 3,696 men and 8,133 women with a mean age of 40.4 years. Greater SJL was associated with a lower efficacy of BMI and %body fat reduction. The change in BMI (+ 0.56 / hour: SJL) and %body fat (+ 1.40 / hour: SJL) was associated with SJL after adjusting for each variable including dietary intake. Conclusion: SJL was associated with the effect of exercise and nutrition instruction on BMI and body fat reduction, even after adjustment for covariates related to dietary intake. Maintaining consistent sleep-wake rhythms may be crucial for enhancing the efficacy of weight loss programs. Supplementary Information: The online version contains supplementary material available at 10.1007/s41105-024-00539-8.

Moderation by better sleep of the association among childhood maltreatment, neuroticism, and depressive symptoms in the adult volunteers: A moderated mediation model.

BACKGROUND: Previously, we demonstrated that childhood maltreatment could worsen depressive symptoms through neuroticism. On the one hand, some studies report that sleep disturbances are related to childhood maltreatment and neuroticism and worsens depressive symptoms. But, to our knowledge, no reports to date have shown the interrelatedness between childhood maltreatment, neuroticism, and depressive symptoms, and sleep disturbance in the one model. We hypothesized that sleep disturbance enhances the influence of maltreatment victimization in childhood or neuroticism on adulthood depressive symptoms and the mediation influence of neuroticism between maltreatment victimization in childhood and adulthood depressive symptoms. SUBJECTS AND METHODS: Total 584 Japanese volunteer adults recruited through convenience sampling from 4/2017 to 4/2018 were assessed regarding their characteristics of demographics, history of childhood maltreatment, sleep disturbance, neuroticism, and depressive symptoms with questionnaires self-administered. Survey data were analyzed using simple moderation models and a moderating mediation model. RESULTS: The interaction of sleep disturbance with childhood maltreatment or neuroticism on depressive symptoms was significantly positive. Furthermore, the moderating effect of sleep disturbance on the indirect effect of childhood maltreatment to depressive symptoms through neuroticism was significantly positive. LIMITATIONS: Because this was a cross-sectional study, a causal relationship could not be confirmed. CONCLUSIONS: Our findings indicate that individuals with milder sleep disturbance experience fewer depressive symptoms attributable to neuroticism and childhood maltreatment. Additionally, people with less sleep disturbance have fewer depressive symptoms arising from neuroticism owing to childhood maltreatment. Therefore, improvement of sleep disturbance will buffer the aggravating effect of childhood maltreatment, neuroticism caused by various factors, and neuroticism resulting from childhood maltreatment on depressive symptoms.

Discovery of novel protective agents for infection-related delirium through bispectral electroencephalography.

Delirium is a multifactorial medical condition of waxing and waning impairment across various domains of mental functioning over time. Importantly, delirium is also one of the greatest risk factors for prolonged hospitalization, morbidity, and mortality. Studying this important condition is challenging due to the difficulty in both objective diagnosis in patients and validation of laboratory models. As a result, there is a lack of protective treatments for delirium. Our recent studies report the efficacy of bispectral electroencephalography (BSEEG) in diagnosing delirium in patients and predicting patient outcomes, advancing the concept that this simple measure could represent an additional vital sign for patients. Here, we applied BSEEG to characterize and validate a novel lipopolysaccharide (LPS) mouse model of infection-related delirium. We then applied this model to evaluate the protective efficacy of three putative therapeutic agents: the conventional antipsychotic medication haloperidol, the neuroprotective compound P7C3-A20, and the antibiotic minocycline. Aged mice were more susceptible than young mice to LPS-induced aberration in BSEEG, reminiscent of the greater vulnerability of older adults to delirium. In both young and old mice, P7C3-A20 and minocycline administration prevented LPS-induced BSEEG abnormality. By contrast, haloperidol did not. P7C3-A20 and minocycline have been shown to limit different aspects of LPS toxicity, and our data offers proof of principle that these agents might help protect patients from developing infection-related delirium. Thus, utilization of BSEEG in a mouse model for infection-related delirium can identify putative therapeutic agents for applications in patient clinical trials.

Treatment strategies for insomnia in Japanese primary care physicians' practice: A Web-based questionnaire survey.

BACKGROUND: It is unclear how primary care physicians manage insomnia after the introduction of novel hypnotics such as orexin receptor antagonists and melatonin receptor agonists. This Web-based questionnaire survey aimed to examine treatment strategies for insomnia in Japanese primary care practice. METHODS: One-hundred-and-seventeen primary care physicians were surveyed on the familiarity of each management option for insomnia on a binary response scale (0 = "unfamiliar"; 1 = "familiar") and how they managed insomnia using a nine-point Likert scale (1 = "I never prescribe/perform it"; 9 = "I often prescribe/perform it"). Physicians who were unfamiliar with a management option were deemed to have never prescribed or performed it. RESULTS: Regarding medication, most physicians were familiar with novel hypnotics. Suvorexant was the most used hypnotic, followed by lemborexant and ramelteon. These novel hypnotics averaged 4.8-5.4 points and 4.0-4.7 points for sleep onset and sleep maintenance insomnia, respectively. By contrast, most benzodiazepines were seldom used below two points. Regarding psychotherapy, only approximately 40% of the physicians were familiar with cognitive behavioral therapy for insomnia (CBT-I) and they rarely implemented it, at an average of 1.5-1.6 points. More physicians were familiar with single-component psychotherapies (i.e., relaxation, sleep restriction therapy, and stimulus control) compared to CBT-I, and 48-74% of them implemented it slightly more often, with scores ranging from 2.6 to 3.4 points. CONCLUSION: This study suggests that Japanese primary care physicians seldom use CBT-I to treat insomnia. In addition, they use novel sleep medications more frequently than benzodiazepines in terms of pharmacotherapy. The use and availability of CBT-I in Japanese primary care might be facilitated by: educating primary care physicians, implementing brief or digital CBT-I, and/or developing collaborations between primary care physicians and CBT-I specialists.

Neuroticism mediates the association between childhood abuse and the well-being of community dwelling adult volunteers.

BACKGROUND: Previous studies reported that the experience of maltreatment in childhood reduces subjective well-being in adulthood and that neuroticism is negatively associated with subjective well-being. However, the interrelationship between childhood maltreatment, adult life events, neuroticism, and subjective well-being has not been analyzed to date. METHODS: A total of 404 adult volunteers provided responses to the following questionnaires: 1) Childhood Abuse and Trauma Scale, 2) Life Experiences Survey, 3) Neuroticism Subscale of the Shortened Eysenck Personality Questionnaire-Revised, and 4) Subjective Well-Being Inventory. The path model was used to analyze possible interrelationships among these parameters. RESULTS: The effect of childhood abuse on subjective well-being was indirect and was mediated by neuroticism. The effect of neuroticism on the negative, but not positive, change score on the Life Experiences Survey was significant. The indirect effect of neuroticism on subjective well-being was not significant via either negative or positive change scores. CONCLUSIONS: This study demonstrated that age, subjective social status, neuroticism, and negative and positive life events were significantly associated with subjective well-being. Furthermore, using path analysis, we demonstrated the mediating role of neuroticism in the indirect effect of childhood abuse on subjective well-being.

Delayed sleep-wake phase disorder and its related sleep behaviors in the young generation.

Delayed sleep-wake phase disorder (DSWPD) is a sleep disorder in which the habitual sleep-wake timing is delayed, resulting in difficulty in falling asleep and waking up at the desired time. Patients with DSWPD frequently experience fatigue, impaired concentration, sleep deprivation during weekdays, and problems of absenteeism, which may be further complicated by depressive symptoms. DSWPD is typically prevalent during adolescence and young adulthood. Although there are no studies comparing internationally, the prevalence of DSWPD is estimated to be approximately 3% with little racial differences between Caucasians and Asians. The presence of this disorder is associated with various physiological, genetic and psychological as well as behavioral factors. Furthermore, social factors are also involved in the mechanism of DSWPD. Recently, delayed sleep phase and prolonged sleep duration in the young generation have been reported during the period of COVID-19 pandemic-related behavioral restrictions. This phenomenon raises a concern about the risk of a mismatch between their sleep-wake phase and social life that may lead to the development of DSWPD after the removal of these restrictions. Although the typical feature of DSWPD is a delay in circadian rhythms, individuals with DSWPD without having misalignment of objectively measured circadian rhythm markers account for approximately 40% of the cases, wherein the psychological and behavioral characteristics of young people, such as truancy and academic or social troubles, are largely involved in the mechanism of this disorder. Recent studies have shown that DSWPD is frequently comorbid with psychiatric disorders, particularly mood and neurodevelopmental disorders, both of which have a bidirectional association with the pathophysiology of DSWPD. Additionally, patients with DSWPD have a strong tendency toward neuroticism and anxiety, which may result in the aggravation of insomnia symptoms. Therefore, future studies should address the effectiveness of cognitive-behavioral approaches in addition to chronobiological approaches in the treatment of DSWPD.

Identification of the simultaneous use of multiple hypnotics as a risk factor for falls in hospitalized patients by a matched case-control study.

AIM: The risk of falls owing to simultaneous use of multiple hypnotics has not been clarified. The aim of this study was to assess the association between the simultaneous use of 2 hypnotics and the occurrence of falls in hospitalized patients. METHODS: A matched case-control study was conducted at Tokyo Medical University Hospital in Tokyo, Japan, utilizing data from medical records. Cases were 434 hospitalized patients who experienced falls during their hospital stay between January 2016 and December 2016, and controls were 434 hospitalized patients without falls, individually matched by age, sex, and clinical department. The outcome was the occurrence of an in-hospital fall. The associations between the use of 1 hypnotic and falls, and between the use of 2 hypnotics and falls were assessed by conditional logistic regression analyses. The main multivariable conditional logistic regression model was adjusted for potential risk factors, including the use of other classes of psychotropics (antipsychotics, antidepressants, and anxiolytics), in addition to patient characteristics. RESULTS: The main multivariable conditional logistic regression analyses showed that the simultaneous use of 2 hypnotics (odds ratio [OR] = 2.986; 95% confidence interval [CI], 1.041-8.567), but not the use of a single hypnotic (OR = 1.252; 95% CI, 0.843-1.859), was significantly associated with an increased OR of falls. CONCLUSION: The simultaneous use of 2 hypnotics is a risk factor for falls among hospitalized patients, whereas the use of a single hypnotic may not.

Mediating Effects of Trait Anxiety and State Anxiety on the Effects of Physical Activity on Depressive Symptoms.

BACKGROUND: Previous studies have reported that physical activity can prevent the onset of depression and reduces anxiety. In the present study, the hypothesis that total physical activity time influences depressive symptoms via state and trait anxiety was tested by a path analysis. METHODS: Self-administered questionnaires were used to survey 526 general adult volunteers from April 2017 to April 2018. Demographic information, physical activity, and state and trait anxiety were investigated. RESULTS: The association between physical activity time and depressive symptoms was expressed as a U-shape curve. The results of the covariance structure analysis showed that differences from the optimal physical activity time (DOT) had direct positive effects on state and trait anxiety. DOT affected depressive symptoms only via trait anxiety, and this was a complete mediation model. CONCLUSION: The present study suggests that an optimal physical activity time exists for depressive symptoms. The path model demonstrated an association between the three factors of optimal physical activity time, trait anxiety, and depressive symptoms, and the effect was fully mediated by trait anxiety.

Optimal Physical Activity Is Associated with the Reduction of Depressive Symptoms via Neuroticism and Resilience.

BACKGROUND: Personality traits, such as neuroticism, that results in vulnerability to stress, and resilience, a measure of stress coping, are closely associated with the onset of depressive symptoms, whereas regular physical activity habits have been shown to reduce depressive symptoms. In this study, the mediating effects of neuroticism and resilience between physical activity duration and depressive symptoms were investigated by a covariance structure analysis. METHODS: Between April 2017 and April 2018, 526 adult volunteers were surveyed using self-administered questionnaires. Demographic information, habitual physical activity duration (PAD), neuroticism, and resilience were investigated. The effects of these factors on depressive symptoms were analyzed by a covariance structure analysis. This study was conducted with the approval of the Medical Ethics Committee of Tokyo Medical University. RESULTS: The dose-response curves of physical activity duration and depression scores were U-shaped: the optimal physical activity duration for the lowest depression score was 25.7 h/week. We found that the greater the difference from the optimal PAD, the higher the neuroticism and the lower the resilience, and the more severe the depressive symptoms. Covariance structure analysis demonstrated that neuroticism and resilience significantly and completely mediated the effects of the difference from the optimal PAD on depressive symptoms (coefficient of determination R2 = 0.349). CONCLUSION: Our study suggests that there is an optimal PAD that reduces depressive symptoms, and that a greater difference from the optimal PAD increases depressive symptoms through neuroticism and resilience.

Treatment strategy for insomnia disorder: Japanese expert consensus.

Purpose: There is a lack of evidence regarding answers for clinical questions about treating insomnia disorder. This study aimed to answer the following clinical questions: (1) how to use each hypnotic and non-pharmacological treatment differently depending on clinical situations and (2) how to reduce or stop benzodiazepine hypnotics using alternative pharmacological and non-pharmacological treatments. Methods: Experts were asked to evaluate treatment choices based on 10 clinical questions about insomnia disorder using a nine-point Likert scale (1 = "disagree" to 9 = "agree"). The responses of 196 experts were collected, and the answers were categorized into first-, second-, and third-line recommendations. Results: The primary pharmacological treatment, lemborexant (7.3 ± 2.0), was categorized as a first-line recommendation for sleep initiation insomnia, and lemborexant (7.3 ± 1.8) and suvorexant (6.8 ± 1.8) were categorized as the first-line recommendations for sleep maintenance insomnia. Regarding non-pharmacological treatments for primary treatment, sleep hygiene education was categorized as the first-line recommendation for both sleep initiation (8.4 ± 1.1) and maintenance insomnia (8.1 ± 1.5), while multicomponent cognitive behavioral therapy for insomnia was categorized as the second-line treatment for both sleep initiation (5.6 ± 2.3) and maintenance insomnia (5.7 ± 2.4). When reducing or discontinuing benzodiazepine hypnotics by switching to other medications, lemborexant (7.5 ± 1.8) and suvorexant (6.9 ± 1.9) were categorized as first-line recommendations. Conclusion: Expert consensus indicates that orexin receptor antagonists and sleep hygiene education are recommended as first-line treatments in most clinical situations to treat insomnia disorder.

Ultra-low-dose early night ramelteon administration for the treatment of delayed sleep-wake phase disorder: case reports with a pharmacological review.

Delayed sleep-wake phase disorder (DSWPD) is a common circadian sleep-wake phase disorders brings serious social impairment of the patients. Melatonin is the main medication option; however, it has not been approved in some countries, and over-the-counter melatonin is under poor quality control. The melatonin receptor agonist ramelteon might be a potential treatment option, but there are few reports regarding its use in DSWPD patients. Existing pharmacological and chronobiological studies suggest that an ultra-low dose of ramelteon in the early night is beneficial for DSWPD. Here, we present our clinical experience together with a pharmacological review and discussion. Twenty-three DSWPD patients, of whom 18 patients had a treatment history of a normal dose of ramelteon, were prescribed low-dose ramelteon (median: 0.571 mg, 1/14 of a tablet) to be taken in the early night (mean: 18:10). After the treatment, the mean sleep schedule was significantly advanced, and clinical symptoms were improved. CITATION: Shimura A, Kanno T, Inoue T. Ultra-low-dose early night ramelteon administration for the treatment of delayed sleep-wake phase disorder: case reports with a pharmacological review. J Clin Sleep Med. 2022;18(12):2861-2865.

Paradoxical association between chronotype and academic achievement: eveningness reduces academic achievement through sleep disturbance and daytime sleepiness.

There are conflicting reports about the association between chronotype and academic achievement. Eveningness persons tend to have lower academic achievement, but have higher cognitive abilities. We hypothesized that sleep disturbance and daytime sleepiness, which are known to affect academic achievement, will interact with this association. To investigate the association, a sleep survey and covariance structure analysis was performed on high-school students. Among a total of 344 first-year high-school students, 294 students validly completed the questionnaire. The association between the recent change in their academic achievement, chronotype, daytime sleepiness, and sleep disturbance were analyzed. A simple comparison demonstrated that not chronotype but sleep disturbance and excessive daytime sleepiness were significant associated factors. Chronotype affects academic achievement through sleep disturbance and daytime sleepiness. Chronotype did not have a significant total effect on the reduction in academic achievement, whereas morningness had a significant direct effect and a significant indirect inverse effect through better sleep and less daytime sleepiness. This model accounted for 13.0% of the variance of the reduction in academic achievement. When discussing the association between chronotype and academic achievement, the effect of sleep disturbance and daytime sleepiness should be considered. Reducing sleep disturbance and daytime sleepiness with consideration to the chronotype of each person would be beneficial for the improvement of academic achievement.

On workdays, earlier sleep for morningness and later wakeup for eveningness are associated with better work productivity.

INTRODUCTION: Misalignment of chronotype and social schedules result in sleep and health impairments. Presenteeism, the work productivity loss caused by health problems, has much more social costs than absenteeism and is associated with sleep disturbance. However, little is known about the link between chronotype and presenteeism. In this study, the associations between chronotype, sleep schedules, presenteeism, and the mediating role of sleep disturbance were examined. METHODS: A cross-sectional survey was conducted on 8155 office workers from 42 companies in Japan, from 2017 to 2019. The participants answered self-administered questionnaires asking about presenteeism (Work Limitations Questionnaire [WLQ]), sleep disturbance (Pittsburgh Sleep Quality Index [PSQI]), and habitual sleep schedules which enable to calculate the midpoint of sleep on free days, sleep corrected (MSFsc). The mediating effect was examined by using structural equation modeling (SEM). RESULTS: The participants comprised 4462 males and 3677 females (mean age: 36.7 years), and their mean productivity loss was 5.97%. A later sleep onset (+0.29%/h), early wakeup (+0.14%/h), and eveningness (+0.27%/h, MSFsc) were associated with presenteeism in all participants; however, the effect size and significance differed depending on their chronotype. SEM demonstrated a complete mediation model between chronotype and presenteeism, mediated by sleep disturbance and adjusted by age. CONCLUSIONS: Chronotype did not directly, but indirectly affected presenteeism through sleep disturbance. Eveningness leads to sleep disturbance, which then causes presenteeism. On workdays, early sleep times for morningness people, and late wakeup times for eveningness people may improve their work productivity.

Resilience Moderates the Association of Sleep Disturbance and Sleep Reactivity with Depressive Symptoms in Adult Volunteers.

Purpose: Depression poses a substantial burden worldwide. Therefore, elucidating the pathophysiological mechanism of depression is important. Sleep disturbance and sleep reactivity are symptoms of depression and are also known to exacerbate depressive symptoms. On the other hand, it is well known that resilience ameliorates depressive symptoms. To our knowledge, there have been no reports to date regarding the interaction effects among sleep disturbance, sleep reactivity, and resilience on depressive symptoms. We hypothesized that resilience buffers the aggravating effects of sleep disturbance and sleep reactivity on depressive symptoms. To test this hypothesis, we conducted hierarchical multiple regression analyses. Subjects and Methods: A total of 584 Japanese adult volunteers were recruited between April 2017 and April 2018 by convenience sampling. Their demographic characteristics, sleep disturbance, sleep reactivity, resilience, and depressive symptoms were investigated using self-administered questionnaires. The data were analyzed using hierarchical multiple regression analyses. Results: Sleep disturbance and sleep reactivity were significantly positively associated with depressive symptoms, whereas resilience was significantly negatively associated with depressive symptoms. Moreover, there was a significant interaction between sleep disturbance or sleep reactivity and resilience on depressive symptoms. Resilience significantly alleviated the aggravating effect of sleep disturbance and sleep reactivity on depressive symptoms. Conclusion: Our results indicate that people with lower resilience have more severe depressive symptoms that are associated with sleep disturbance and sleep reactivity. Therefore, there is a possibility that the enhancement of resilience will buffer the aggravating effects of sleep disturbance and sleep reactivity on depressive symptoms, and that improving sleep quality might alleviate the negative effect of low resilience on depressive symptoms.