Association of chronotype, social jetlag, sleep duration and depressive symptoms in Chinese college students

Short-term exposure to PM2.5 and high pollution events on depressive symptoms among adolescents

Association between short-term exposure to fine particulate matter (PM2.5) and adolescent depressive symptoms is an under-investigated area and is worthy of further research. Based on a government surveillance data for 195,687 Chinese adolescents, the mixed-effects logistic regression combined with a distributed lag nonlinear model was used to assess the cumulative effect of PM2.5 exposure on depressive symptoms. In addition, high pollution events were defined according to World Health Organization (WHO) air quality guidelines (AQGs) and the Chinese ambient air quality standards, and the associations of increased high pollution events with depressive symptoms and the associated excess risk were estimated. Our results showed that association between short-term exposure to PM2.5 and depressive symptoms was most significant at lag 0 weeks, with each 10 μg/m3 increase in PM2.5 concentration associated with a 3.11 % (95 % CI: 0.70 %, 5.58 %) change in ORs for depressive symptoms. High pollution events were found to contribute to a maximum 3.12 % (95 % CI: 0.52 %, 5.74 %) excess risk of depressive symptoms when defined as 24-hour average PM2.5 concentration exceeding 37.5 μg/m3, WHO AQG interim target 3. Our results highlight the importance of air quality improvement for adolescent depression prevention, and recommend increased psychological support during high pollution events.

Non-linear relationship between social jetlag and depressive symptoms among Chinese college students

This study aims to elucidate the relationship between social jetlag and depressive symptoms in college students, with a focus on identifying specific cut points that significantly heighten the risk of depression. A cross-sectional study was conducted among 2,006 students from Jiangsu College of Nursing between October and November 2024. Social jetlag was calculated based on the difference between the midpoints of sleep on workdays and weekends. Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9). Multivariate logistic regression was applied to examine the relationship between social jetlag and depressive symptoms, adjusting for potential confounders. The prevalence of depressive symptoms (PHQ-9 ≥ 10) among participants was 10.1%. A non-linear relationship was observed between social jetlag and depressive symptoms, with the risk of depression increasing significantly beyond a threshold of 1.2 h of social jetlag. Specifically, individuals with social jetlag ≥ 1.2 h had 72% higher odds of depressive symptoms compared to those with lower levels (OR = 1.72, 95% CI: 1.24-2.38). Subgroup analyses revealed that this association was consistent across both grade and gender. Sensitivity analyses further affirmed the robustness of these findings. This study suggests a non-linear association between social jetlag and depressive symptoms in college students, with a marked increase in depression risk for those with social jetlag ≥ 1.2 h. Longitudinal studies are needed to clarify the causal pathways and identify modifiable factors for targeted interventions.

The relationship between chronotype, insomnia and depressive symptoms in Chinese male prisoners

BACKGROUND

This study aimed to estimate the prevalence of chronotypes among male prisoners in China and to examine the relationship between chronotype, insomnia, and depressive symptoms in this population.

METHODS

A total of 1609 male inmates participated in this cross-sectional study by completing the Morning and Evening Questionnaire-5 (MEQ-5), Insomnia Severity Index (ISI), and Patient Health Questionnaire-9 (PHQ-9). Age, time served, insomnia, and depressive symptoms were compared across chronotypes. Binary logistic stepwise regression was used to analyze factors influencing depression. Additionally, a simple mediation model incorporating MEQ-5, ISI, and PHQ-9 was analyzed, with age controlled as a covariate.

RESULTS

The prevalence of morning type (MT), neutral type (NT), and evening type (ET) was 47.2%, 46.7%, and 6.1%, respectively. Being an ET was significantly associated with younger age and increased symptoms of insomnia and depression (P < 0.05). The relative risk of depression was 2.970-fold higher (95% CI, 1.724 to 5.116; P < 0.001) for ET compared to MT. Mediation analysis revealed that insomnia partially mediated the relationship between chronotype and depression, while the direct effect of chronotype on depression was also significant (accounting for 50.51% of the total effect).

CONCLUSIONS

The prevalence of ET is relatively low among male prisoners. Resetting ET tendencies may reduce depressive symptoms in this population.

Group bright light therapy compared to treatment as usual for delayed sleep-wake phase disorder among patients in psychiatric care (the SIP trials): a protocol for a pragmatic, randomised controlled trial

INTRODUCTION

Circadian rhythm sleep-wake disturbances appear to be prevalent in psychiatric populations and may maintain and exacerbate psychiatric symptoms. Bright light therapy (BLT) is, in addition to exogenous melatonin, the treatment of choice for circadian rhythm disorders like delayed sleep-wake phase disorder (DSWPD) and has yielded promising results in patients with comorbid psychiatric illness. However, such patients are rarely offered this treatment in outpatient clinics. The aim of this randomised controlled trial is to investigate whether group BLT for psychiatric outpatients is superior to treatment as usual (TAU).

METHODS AND ANALYSIS

60 patients with moderate-to-severe psychiatric illness who meet the criteria for DSWPD will be recruited from an outpatient psychiatric clinic in Norway. They will be randomised (1:1) to a group-based Sleep School Wake Up! For Circadian (SSWU-C) programme conjointly with TAU or to TAU while on a wait list for SSWU-C. The SSWU-C will be delivered over four biweekly sessions, each lasting 120 min; hence treatment will last 6 weeks. Assessments will be collected at baseline (T1) and after the intervention (T2). The primary outcome will be changes in sleep timing using measures such as sleep diaries, actigraphy and dim light melatonin onset (DLMO) at 6 weeks postintervention. Secondary outcomes include changes in other sleep metrics, symptoms of depression, anxiety, fatigue, problems with work and social adjustment and well-being. Mixed models will be used for data analyses.

ETHICS AND DISSEMINATION

Ethical approval was granted in 2020 by the Regional Ethics Committee in Western Norway (REK 2020/66304). Findings will be published in peer-reviewed journals and be presented at research conferences and in relevant media. The results may document the need for more specific sleep-directed treatments in psychiatric clinics as a way of treating not only circadian rhythm sleep-wake disorders but also as a treatment to alleviate psychiatric symptoms.

TRIAL REGISTRATION NUMBER

NCT05177055.

The association between sleep timing characteristics and food addiction in adolescents

Previous research has repeatedly shown that social jetlag is accompanied by metabolic disorders and obesity. However, the mechanism of association between these phenomena has not been sufficiently studied. This study aims to test the hypothesis that social jetlag is associated with an increased incidence of eating disorders and thus increases the risk of metabolic disorders. The study included 11,535 adolescents (M ± SD 14.2 ± 1.6) aged 13-18 y, with girls accounting for 58.3%. The state of the circadian system and sleep function were assessed using the Munich Chronotype Questionnaire (MCTQ), and food addiction was assessed using the Yale Food Addiction Scale for Children (YFAS-C). Data obtained indicate that in adolescents with insufficient sleep (less than 8 h) (OR = 0.55, 95% CI = 0.49-0.63) and late chronotype (OR = 1.25, 95% CI = 1.12-1.38) the frequency of detection of food addiction is increased. A non-linear J-shaped association between social jetlag and food addiction was noted with a maximal detection rate of food addiction in schoolchildren with negative (p < 0.0001) and high (more than 2 h) social jetlag (p < 0.001). In conclusion, the frequency of detection of food addiction is increased in adolescents with insufficient sleep duration, late chronotype and negative social jetlag.

Moderating effects of insomnia on the association between urinary phthalate metabolites and depressive symptoms in Chinese college students: focus on gender differences

OBJECTIVES

To investigate the rates of depressive symptoms in college students, explore the relationship between urinary phthalate metabolites and depressive symptoms and their gender differences, and further explore the moderating role of insomnia in this association.

METHODS

A total of 1 179 college students were recruited from 2 universities in Hefei and Shangrao cities from April to May 2019. The depressive symptoms and insomnia of college students were investigated by the Patient Health Questionnaire 9 and Insomnia Severity Index. The high-performance liquid chromatography-tandem mass spectrometry was adapted to determine the concentration of urinary phthalate metabolites. The generalized linear model was used to analyze the relationship of phthalate metabolites with depressive symptoms. Moderating analysis was used to examine whether insomnia moderated the relationship of phthalate metabolites with depressive symptoms.

RESULTS

The rates of mild depression, and moderate depression and above in college students were 31.9% and 9.2%, respectively. The phthalate metabolites exhibited a median and mean concentration spanning from 2.98 ∼ 156.55 ng/mL and 6.12 ∼ 205.53 ng/mL. The generalized linear model results showed that monobutyl phthalate (MBP) (β = 1.160, 95%CI: 0.423 ∼ 1.896) and low molecular weight phthalate (LMWP) (β = 1.230, 95%CI: 0.348 ∼ 2.113) were positively correlated with depressive symptoms, and MBP (β = 1.320, 95%CI: 0.453 ∼ 2.187) and LMWP (β = 1.396, 95%CI: 0.351 ∼ 2.440) were positively correlated with depressive symptoms only in female college students after stratified by gender. Furthermore, insomnia has a positive moderating role between MBP, LMWP, and depressive symptoms and has a sex-based difference.

CONCLUSIONS

This study suggests that there is a positive association of phthalate metabolites with depressive symptoms among Chinese college students, as well as insomnia plays a positive moderating role in this association.

Association between sleep duration and depression in adolescents and young adults: a system review of observational studies and a genetic research of Mendelian randomization analysis

OBJECTIVES

This study aimed to explore the causal association between sleep duration and depression in adolescents and young adults.

METHODS

We conducted a systematic review and Mendelian randomization (MR) to research the causal relationship between short sleep duration and adolescent depression risk from an observational and genetic perspective. In the systematic review, we searched observational studies from the PubMed, Embase, and Cochrane Library databases. In the MR analysis part, we screened Single Nucleotide Polymorphism (SNP) significantly relative to short sleep and conforming MR concept to investigate the genetic causality.

RESULTS

All research evidence shows that adolescents who sleep <6 h have the highest rates of depression. According to the MR result, short sleep duration significantly affected the depression risk (odds ratio, 1.034; 95% confidence interval, 1.012-1.058, P = .003). Sleep duration of 7-8 h has the lowest depression incidence. Insufficient sleep (≤6 h) and excessive sleep (≥8 h) also elevates adolescent depression risk. Genetic evidence shows that short sleep duration (<6 h) has significant causal effects on depression risk.

CONCLUSIONS

Sleep duration was causally associated with depression in adolescents and young adults. Sleep duration of <6 h or >8 h daily increases the depression risk in adolescents and young adults.

Association between behavioral jet lag with subjective and objective circadian rhythm among Chinese young adults

BACKGROUND

Behavioral jet lags (social and eating jet lag), the difference in sleep and eating time between weekdays and weekends, are ubiquitous in modern society. However, evidence on the effects of behavioral jet lags on circadian rhythm is limited.

METHODS

Social jet lag was assessed using wrist-worn accelerometers. Eating jet lag was measured through Tencent online form with the method of ecological momentary assessment. Total jet lag was calculated as social jet lag plus eating jet lag. Participants were divided into 3 behavioral jet lag patterns: low (both social and eating jet lag < 1h), medium (social or eating jet lag ≥ 1h), and high (both social and eating jet lag ≥ 1h). Subjective and objective circadian rhythm were assessed by reduced Morningness-Eveningness Questionnaire (rMEQ)-based chronotype and the dim light melatonin onset (DLMO) time in 7 saliva samples, respectively.

RESULTS

The mean age of the sample (n = 140) was 20.7 ± 0.8 years, and 60% were women. Compared to low behavioral jet lag group, medium and high behavioral jet lag group exhibited lower rMEQ score and later DLMO time. Each hour increase in social jet lag was associated with 2.27 point-decrease of rMEQ score, and 24 min-delay of DLMO time; each hour increase in eating jet lag was associated with 1.71 point-decrease of rMEQ score, and 28 min-delay of DLMO time; each hour increase in total jet lag was associated with 1.08 point-decrease of rMEQ score, and 17 min-delay of DLMO time (all P-values <0.05). Additionally, social jet lag explained 6.7% of the variance in the timing of DLMO, which was higher than eating jet lag (4.2%).

CONCLUSION

Higher behavioral jet lags were significantly associated with increased risk of circadian disruption among young adults. Maintaining consistency in daily behavioral cycles may be an effective intervention for the prevention of circadian disruption.

Wearables in Chronomedicine and Interpretation of Circadian Health

Wearable devices have gained increasing attention for use in multifunctional applications related to health monitoring, particularly in research of the circadian rhythms of cognitive functions and metabolic processes. In this comprehensive review, we encompass how wearables can be used to study circadian rhythms in health and disease. We highlight the importance of these rhythms as markers of health and well-being and as potential predictors for health outcomes. We focus on the use of wearable technologies in sleep research, circadian medicine, and chronomedicine beyond the circadian domain and emphasize actigraphy as a validated tool for monitoring sleep, activity, and light exposure. We discuss various mathematical methods currently used to analyze actigraphic data, such as parametric and non-parametric approaches, linear, non-linear, and neural network-based methods applied to quantify circadian and non-circadian variability. We also introduce novel actigraphy-derived markers, which can be used as personalized proxies of health status, assisting in discriminating between health and disease, offering insights into neurobehavioral and metabolic status. We discuss how lifestyle factors such as physical activity and light exposure can modulate brain functions and metabolic health. We emphasize the importance of establishing reference standards for actigraphic measures to further refine data interpretation and improve clinical and research outcomes. The review calls for further research to refine existing tools and methods, deepen our understanding of circadian health, and develop personalized healthcare strategies.

Effect of time of day on outcomes in elective surgery: a systematic review

BACKGROUND

The timing of elective surgery could affect clinical outcome because of diurnal rhythms of patient physiology as well as surgical team performance. Waiting times for elective surgery are increasing in many countries, leading to increasing interest in undertaking elective surgery in the evening or at night. We aimed to systematically review the literature on the effect of the timing of elective (but not urgent or emergency) surgery on mortality, morbidity and other clinical outcomes.

METHODS

We searched databases for relevant studies combining the terms 'circadian rhythm' and 'anaesthesia/surgery'. Additional relevant articles were found by hand-searching the references. All studies were screened for bias. Included studies examined daytime vs. evening/night-time surgery, morning vs. afternoon surgery, multiple timeslots or used time as a continuous variable.

RESULTS

Nineteen retrospective cohort studies, one prospective cohort study and one randomised controlled trial were included (n = 798,914). Evening/night-time elective surgery was associated with a higher risk of mortality when compared with daytime procedures in three studies (n = 611,230), with odds ratios (95%CI) for mortality ranging from 1.35 (1.16-1.56) to 3.98 (1.54-10.30), while no differences were found in three other studies (n = 142,355). No differences were found for morning vs. afternoon surgery (four studies, n = 3277). However, most studies had a low quality of evidence due to their retrospective nature and because not all studies corrected for patient characteristics. Moreover, the studies were heterogeneous in terms of the reported time slots and clinical outcomes.

CONCLUSIONS

We found that evening/night-time elective surgery is associated with a higher risk of mortality compared with daytime surgery. However, the quality of evidence was graded as low, and thus, future prospective research should publish individual patient data and standardise outcome measures to allow firm conclusions and facilitate interventions.

Association between screen time, homework and reading duration, sleep duration, social jetlag and mental health among Chinese children and adolescents

OBJECTIVES

To examine the associations of screen time, homework and reading duration, sleep duration, social jetlag with mental health in children and adolescents, as well as its gender differences.

METHODS

From December 2023 to April 2024, a total of 62 395 children and adolescents were selected from 51 schools in 17 cities of China by stratified cluster sampling. Screen time, homework and reading duration, sleep duration, and social jetlag were calculated by answering the questions about watching TV time, playing smartphones time, doing homework time, reading extracurricular books time, bedtime, wake-up time, and nap time during weekdays and weekends. Mental health was assessed by the Revised Mental Health Inventory-5 (MHI-5). The generalized linear model was used to determine the association between screen time, homework and reading duration, sleep duration, social jetlag, and mental health in children and adolescents.

RESULTS

The generalized linear model results showed that longer watching TV time, longer playing smartphones time, longer homework time, and greater social jetlag were correlated with poorer mental health in children and adolescents, while longer nighttime sleep duration, and longer daytime nap duration were correlated with better mental health. Moreover, in primary school and junior high school, we found that this association was stronger during the weekdays. However, in senior high school, this association was stronger during the weekends. After according to gender stratified, we found that the strength of this association was different in boys and girls at different study phases. Furthermore, our findings also revealed a significant quadratic relationship, indicating the association of better mental health with an optimal amount of sleep duration.

CONCLUSIONS

There was a significant association between screen time, homework and reading duration, sleep duration, social jetlag, and mental health in children and adolescents. This study has the potential to offer useful insights for the prevention and control of mental health issues in children and adolescents.

Association between mental health and male fertility: depression, rather than anxiety, is linked to decreased semen quality

Background

Infertility is increasingly recognized as a global health issue affecting couples of reproductive age, with male factors contributing to approximately 50% of infertility cases. However, the association between depression and anxiety-two of the most prevalent mental health conditions-and impaired male fertility remains a subject of ongoing debate.

Methods

In this cross-sectional study, male participants seeking fertility counseling at an IVF clinic were recruited. Symptoms of depression and anxiety were assessed using the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7), respectively. Generalized linear regression models (GLMs) were employed to investigate the relationships between mental health status and semen parameters.

Results

Status of depression was negatively associated with semen quality parameters, whereas no statistically significant association was recognized between anxiety and semen quality except that sperm concentration was decreased by 25.60 (95% CI, 1.226 to 49.965, P=0.040) ×106/ml in moderate to severe anxiety group referring to normal group. Furthermore, when stratified by sleep duration, moderate to severe depression group showed a great decrease in progressive motility (PR), total motility, concentration and total sperm count (TSC) as referred to normal group in participants with sleep duration less than 7 hours.

Conclusion

The present study revealed that depression rather than anxiety was a negative factor that affected semen quality, especially in individuals with shorter sleep duration.

Using actigraphy to assess chronotype: Simpler is better

Actigraphy provides a unique method for objectively measuring sleep activity patterns, but confusion remains about how to use actigraphy data to determine chronotype. To determine the most suitable parameter, this study made a systematic comparison of actigraphy-derived parameters: the average midpoint of sleep of all record days (aMS-acti), cosine parameter (Bathyphase), and non-parametric parameter (L5-mid) in terms of the consistency with subjective chronotype parameters, test-retest reliability, and external validity. More importantly, we proposed multiple Munich Chronotype Questionnaire (MCTQ)-based actigraphy parameters: considering the difference between weekday (MSW-acti) with weekends (MSF-acti) and the sleep debt (MSFsc-acti). The study collected 5 days of actigraphy and scale data from 1,055 young adults, 138 of whom participated in the retest 2 years later. The results showed that, in terms of consistency with subjective chronotype, aMS-acti generally performed better than other actigraphy parameters. In addition, aMS-acti had the highest test-retest reliability and was more closely related to the Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), and Self-Rating Depression Scale (SDS). The results suggest that the simplest parameter (aMS-acti) is superior to traditional cosine and non-parametric parameters and MCTQ-derived parameters for short-term assessment of chronotype.

Neuroimaging signatures and a deep learning modeling for early diagnosing and predicting non-pharmacological therapy success for subclinical depression comorbid sleep disorders in college students

Objective

College students with subclinical depression often experience sleep disturbances and are at high risk of developing major depressive disorder without early intervention. Clinical guidelines recommend non-pharmacotherapy as the primary option for subclinical depression with comorbid sleep disorders (sDSDs). However, the neuroimaging mechanisms and therapeutic responses associated with these treatments are poorly understood. Additionally, the lack of an early diagnosis and therapeutic effectiveness prediction model hampers the clinical promotion and acceptance of non-pharmacological interventions for subclinical depression.

Methods

This study involved pre- and post-treatment resting-state functional Magnetic Resonance Imaging (rs-fMRI) and clinical data from a multicenter, single-blind, randomized clinical trial. The trial included 114 first-episode, drug-naïve university students with subclinical depression and comorbid sleep disorders (sDSDs; Mean age=22.8±2.3 years; 73.7% female) and 93 healthy controls (HCs; Mean age=22.2±1.7 years; 63.4% female). We examined altered functional connectivity (FC) and brain network connective mode related to subregions of Default Mode Network (sub-DMN) using seed-to-voxel analysis before and after six weeks of non-pharmacological antidepressant treatment. Additionally, we developed an individualized diagnosing and therapeutic effect predicting model to realize early recognition of subclinical depression and provide objective suggestions to select non-pharmacological therapy by using the newly proposed Hierarchical Functional Brain Network (HFBN) with advanced deep learning algorithms within the transformer framework.

Results

Neuroimaging responses to non-pharmacologic treatments are characterized by alterations in functional connectivity (FC) and shifts in brain network connectivity patterns, particularly within the sub-DMN. At baseline, significantly increased FC was observed between the sub-DMN and both Executive Control Network (ECN) and Dorsal Attention Network (DAN). Following six weeks of non-pharmacologic intervention, connectivity patterns primarily shifted within the sub-DMN and ECN, with a predominant decrease in FCs. The HFBN model demonstrated superior performance over traditional deep learning models, accurately predicting therapeutic outcomes and diagnosing subclinical depression, achieving cumulative scores of 80.47% for sleep quality prediction and 84.67% for depression prediction, along with an overall diagnostic accuracy of 82.34%.

Conclusions

Two-scale neuroimaging signatures related to the sub-DMN underlying the antidepressant mechanisms of non-pharmacological treatments for subclinical depression. The HFBN model exhibited supreme capability in early diagnosing and predicting non-pharmacological treatment outcomes for subclinical depression, thereby promoting objective clinical psychological treatment decision-making.

Association between chronotype, social jetlag, sleep quality, and academic burnout among nursing students: A cross-sectional study

Academic burnout in nursing students is a serious problem worldwide that results in emotional exhaustion, cynicism and low professional efficacy. The aim of the current study was to examine the association between sleep quality and circadian rhythm indicators and academic burnout among Iranian nursing students. This cross-sectional study was conducted on 325 undergraduate nursing students studying at Qazvin University of Medical Sciences between November and February 2023. Data collection was carried out using self-report questionnaires including demographic characteristics, The Pittsburgh Sleep Quality Index (PSQI), reduced-Morningness-Eveningness Questionnaire (r-MEQ), and the Maslach Burnout Inventory-Student Survey (MBI-SS). Social jetlag (SJL) was defined as the absolute value of the difference between the midpoint of sleep on free days (MSF) and the midpoint of sleep on workdays (MSW). Data were analyzed using univariate and multivariate linear regression models. About 31.4% of participants had evening chronotype and almost half of them suffered from poor sleep quality. About 47.7% of the participants had SJL ≥ 2 h. In the multivariate linear regression model, students with evening chronotype compared to morning chronotype experienced more academic burnout in emotional exhaustion, cynicism and professional efficacy. PSQI score was only correlated with emotional exhaustion and cynicism subscales. Increased SJL was a predictor on all three subscales of academic burnout. The findings suggested that evening chronotype, poor sleep quality, and high SJL were associated with increased likelihood of academic burnout in nursing students. Assessment of circadian preference and sleep quality is beneficial for timely identification and prevention of academic burnout in nursing students.

Longitudinal associations of social jetlag with obesity indicators among adolescents - Shanghai adolescent cohort

OBJECTIVE

To explore the longitudinal association between social-jetlag (SJL) and obesity development among adolescents, sex-difference and related modifying factors in the association.

METHODS

Based on Shanghai-Adolescent-Cohort during 2017-2021, a total of 609 students were investigated. In grade 6, 7 and 9, the information on SJL was collected using questionnaires, and anthropometric measures were conducted. The fingernail cortisol and progesterone levels in grade 6 (using LC-MS/MS) and body composition in grade 9 (using Inbody-S10) were measured. By the latent-class-mixture-modeling, two trajectories for SJL (high-level vs. low-level) throughout 4 years were developed. The prospective associations of SJL trajectories and weight/fat gains were analyzed by sex and under different (high/moderate/low) cortisol/progesterone stratifications.

RESULTS

In grades 6-9, 39.00%-44.50 % of adolescents experienced at least 1 h of SJL. Compared with the low-level SJL trajectory, the high-level SJL trajectory was associated with greater differences in body-mass-index Z-scores and waist-to-height ratios across 4 years, higher levels of body-fat-percentage and fat-mass-index in grade 9 (P-values<0.05), and such associations were stronger among girls and under moderate-to-high (vs. low) baseline cortisol and progesterone levels. However, no significant associations among boys were observed.

CONCLUSIONS

High-level SJL in adolescents may be associated with the development of obesity, especially among adolescent girls and under relatively high baseline cortisol and progesterone levels.

Association between weekend catch-up sleep and depression of the United States population from 2017 to 2018: A cross-sectional study

Insufficient sleep on weekdays has become a societal norm, and studies have shown that sleep deprivation increases the risk of depression. Although individuals often resort to weekend catch-up sleep (CUS) as a compensatory measure, the present evidence supporting its efficacy in mitigating the risk of depression is limited. This article attempts to explore the relationship between CUS and depression. In this study, a total of 5510 participants were included, characterized into two groups: nondepressed (n = 5051) and depressed (n = 459), with data extracted from the National Health and Nutrition Examination Survey (NHANES). Compared with people without CUS, those practicing CUS exhibited a significantly lower risk of depression (OR = 0.81, P = 0.048). In subgroup analysis, this reduction effect was only observed in males (OR = 0.70, 95 % CI 0.05 to 0.99, P = 0.04), middle-aged (>40, ≤60) (OR: 0.57, 95 % CI: 0.40 to 0.81, P = 0.002), married or living with parents (OR: 0.61, 95 % CI: 0.44 to 0.86, P = 0.004), groups with three or more family members (OR: 0.69, 95 % CI: 0.52 to 0.93, P = 0.01), and individuals without alcohol intake (OR: 0.24,95 % CI: 0.09 to 0.67, P = 0.006). Therefore, in the realm of depression treatment, doctors may consider advising patients to get adequate sleep on weekends as part of their overall treatment plan. At the same time, individuals can also choose weekend sleep as a proactive strategy for regulating their psychological status.

Associations of evening-type and insomnia symptoms with depressive symptoms among youths

BACKGROUND

Evening-type and insomnia symptoms are significantly related to each other and independently associated with depressive symptoms, yet few studies have examined the potential interaction between these two conditions. Therefore, we aimed to examine the associations of evening-type and insomnia symptoms with depressive symptoms among Chinese youths, with a specific focus on the joint effects of the two conditions on depressive symptoms.

METHODS

Participants aged between 12 and 25 were invited to participate in an online survey from December 15, 2022, to May 26, 2023. Multivariate logistic regression models and additive interaction models were used to examine the independent and joint effects of chronotypes and insomnia symptoms on depressive symptoms, respectively.

RESULTS

Of the 6145 eligible youths, the prevalence of evening-type and insomnia symptoms were 24.9 % and 29.6 %, respectively. Both evening-type (adjusted OR, [AdjOR]: 3.21, 95 % CI: 2.80-3.67) and insomnia symptoms (AdjOR: 10.53, 95 % CI: 9.14-12.12) were associated with an increased risk of depressive symptoms. In addition, the additive interaction models showed that there is an enhanced risk of depression related to interaction between evening-type and insomnia symptoms (relative excess risk due to interaction, [RERI]: 11.66, 95 % CI: 7.21-16.11).

CONCLUSIONS

The present study provided additional evidence demonstrating the presence of interaction between evening-type and insomnia symptoms, which can lead to a higher risk of depressive symptoms. Our findings argue the need for addressing both sleep and circadian factors in the management of depressive symptoms in young people.

Digital Dietary Behaviors in Individuals With Depression: Real-World Behavioral Observation

BACKGROUND

Depression is often accompanied by changes in behavior, including dietary behaviors. The relationship between dietary behaviors and depression has been widely studied, yet previous research has relied on self-reported data which is subject to recall bias. Electronic device-based behavioral monitoring offers the potential for objective, real-time data collection of a large amount of continuous, long-term behavior data in naturalistic settings.

OBJECTIVE

The study aims to characterize digital dietary behaviors in depression, and to determine whether these behaviors could be used to detect depression.

METHODS

A total of 3310 students (2222 healthy controls [HCs], 916 with mild depression, and 172 with moderate-severe depression) were recruited for the study of their dietary behaviors via electronic records over a 1-month period, and depression severity was assessed in the middle of the month. The differences in dietary behaviors across the HCs, mild depression, and moderate-severe depression were determined by ANCOVA (analyses of covariance) with age, gender, BMI, and educational level as covariates. Multivariate logistic regression analyses were used to examine the association between dietary behaviors and depression severity. Support vector machine analysis was used to determine whether changes in dietary behaviors could detect mild and moderate-severe depression.

RESULTS

The study found that individuals with moderate-severe depression had more irregular eating patterns, more fluctuated feeding times, spent more money on dinner, less diverse food choices, as well as eating breakfast less frequently, and preferred to eat only lunch and dinner, compared with HCs. Moderate-severe depression was found to be negatively associated with the daily 3 regular meals pattern (breakfast-lunch-dinner pattern; OR 0.467, 95% CI 0.239-0.912), and mild depression was positively associated with daily lunch and dinner pattern (OR 1.460, 95% CI 1.016-2.100). These changes in digital dietary behaviors were able to detect mild and moderate-severe depression (accuracy=0.53, precision=0.60), with better accuracy for detecting moderate-severe depression (accuracy=0.67, precision=0.64).

CONCLUSIONS

This is the first study to develop a profile of changes in digital dietary behaviors in individuals with depression using real-world behavioral monitoring. The results suggest that digital markers may be a promising approach for detecting depression.

Associations of chronotype with anxiety, depression and insomnia among general adult population: A cross-sectional study in Hubei, China

BACKGROUND

The relationship between chronotype and anxiety, depression, and insomnia was inconsistent. We aimed to assess the association between chronotype and mental health and the potential moderating effect of age and socioeconomic status (SES).

METHODS

A multi-stage sampling cross-sectional study with 12,544 adults was conducted. Chronotype, anxiety, depression, and insomnia were investigated by 5-item Morning and Evening, 7-item Generalized Anxiety Disorder, 9-item Patient Health, and the 7-item Insomnia Severity Index Questionnaires. Logistic regression was conducted.

RESULTS

The predominant chronotype was morning chronotype (69.2 %), followed by 27.6 % intermediate and 3.2 % evening chronotype. The prevalence of anxiety, depression, and insomnia was 0.7 %, 1.9 %, and 9.6 %, respectively. Compared with intermediate chronotype, morning chronotype participants had a lower risk of anxiety (OR = 0.28,95%CI:0.18-0.44), depression (OR = 0.54,95%CI:0.41-0.72) and insomnia (OR = 0.67,95%CI:0.58-0.77), while evening chronotype participants had a higher risk of depression (OR = 1.98,95%CI:1.06-3.71) but not anxiety or insomnia. Interactions between chronotype with age and SES on insomnia (Pinteraction < 0.05) were found. A more profound association between morning chronotype and insomnia was observed in <65 years participants (OR = 0.59,95%CI:0.50-0.71) and those with monthly household income ≥10,000yuan (OR = 0.21,95%CI:0.12-0.35), compared with their counterparts.

LIMITATIONS

The cross-sectional design limited causal conclusions. Only adults were included; the findings could not be generalized to children.

CONCLUSIONS

The morning chronotype might be protective for anxiety, depression, and insomnia, while the evening chronotype might be a risk factor for depression. Future studies are needed to assess the efficacy of chronotype-focused intervention for mental health. Insomnia prevention efforts should pay more attention to the elderly and those with lower incomes.

The Japanese version of the reduced morningness-eveningness questionnaire

Circadian typology, or "morningness" and "eveningness," is generally assessed using the Morningness-Eveningness Questionnaire (MEQ), a 19-item scale that could be burdensome in large-scale surveys. To overcome this, a 5-item version known as the reduced morningness-eveningness questionnaire (rMEQ), which is sensitive to the assessment of circadian typology, was developed; however, a validated Japanese version of the rMEQ is yet to be established. This study aimed to develop and validate the Japanese version of the rMEQ. Five essential items for the rMEQ were selected from existing Japanese MEQ data (N = 2,213), and the rMEQ was compiled. We conducted a confirmatory factor analysis for the psychometric properties of the rMEQ and confirmed its robust one-factor structure for evaluating morningness-eveningness (GFI = 0.984, AGFI = 0.951, CFI = 0.935, and RMSEA = 0.091). Reliability was evaluated via internal consistency of rMEQ items using Cronbach's α and McDonald's ω, and the values were 0.618 and 0.654, respectively. The rMEQ scores strongly correlated with MEQ (ρ = 0.883, p < 0.001), and classification agreement (Morning, Neither, and Evening types) between rMEQ and MEQ was 77.6% (Cramer's V = 0.643, Weighted Cohen's κ = 0.72), confirming the validity. The Japanese rMEQ may be a valuable tool for the efficient assessment of circadian typologies.

Sleep deprivation in early life: Cellular and behavioral impacts

Sleep deprivation has become increasingly prevalent in contemporary society, and the consequences of this reality such as cognitive impairment and metabolic disorders, are widely investigated in the scientific scenario. However, the impact of sleep deprivation on the health of future generations is a challenge, and researchers are focusing their attention on this issue. Thus, this review aims to describe the impact of sleep deprivation in early life in animal models, particularly rodents, discussing the molecular physiology impacted by prolonged wakefulness in early life, as well as the changes that interfere with neurodevelopmental processes. Additionally, it explores the changes impacting metabolic mechanisms and discusses both the short- and long-term consequences of these processes on endocrine, behavioral, and cognitive functions. Finally, we briefly address some strategies to mitigate the adverse effects of sleep deprivation.

Association of sleep timing and sleep variability with health-related outcomes in a sample of Brazilian adolescents

OBJECTIVES

This cross-sectional study aimed to examine the relationships of sleep timing and sleep variability with depressive symptoms, health-related quality of life (HRQoL), daytime sleepiness, and body mass index (BMI) in adolescents.

METHODS

Adolescents from three schools (n = 571, 56% female, 16.3 ± 1.0 years) had their sleep examined by actigraphy, their anthropometrics assessed, and answered a survey. Sleep timing was examined by combining groups of median-dichotomized onset and wakeup times (early onset and early wakeup; early onset and late wakeup; later onset and early wakeup; later onset and later wakeup); sleep variability was based on within-participant standard deviations of onset and wakeup; and sleep duration as the length of time between onset and wakeup. The sleep variables were separated for weekdays and weekend. Mixed linear models were fitted to compare each sleep variable with health-related outcomes.

RESULTS

Higher values of daytime sleepiness were observed in adolescents from the late-early and late-late timing group during the week. Greater sleep midpoint and wakeup variability on weekdays were related with higher daytime sleepiness. Adolescents in the late-late and early-late groups showed higher daytime sleepiness. Increased of all sleep variability variables was related with greater daytime sleepiness. Higher depressive symptoms scores were found among adolescents in the late-early subgroup and with the increase of sleep variability. Participants with greater sleep onset variability and sleep midpoint variability reported less HRQoL.

CONCLUSIONS

Not only sleep duration, but sleep timing and variability also relate to health outcomes, and should be addressed by policies and interventions among adolescents.

Factors associated with sleep disorders among university students in Jiangsu Province: a cross-sectional study

Objective

This study aims to establish the precise prevalence of sleep disorders among university students in Jiangsu Province. Utilizing a representative sample of students, we measured their sleep quality based on the Pittsburgh Sleep Quality Index (PSQI). Our objective is to quantitatively assess the magnitude of sleep quality and identify key factors. By detailed analysis of these relationships, our study seeks to provide actionable insights for the development of targeted interventions to enhance sleep quality within this population.

Methods

From October to November 2022, we conducted a cross-sectional web-based survey in Jiangsu Province, China. Using convenient cluster sampling in each college, a total of 8457 participants were selected. The PSQI was applied to assess sleep quality among university students. Data collected included sociodemographic details, scores from the Mobile Phone Dependence Index (MPAI) and psychological resilience measured by the Connor-Davidson Resilience Scale (CD-RISC).

Results

The overall prevalence of poor sleep quality among the participants was 39.30%. Binary logistic regression analysis revealed that higher physical activity (OR = 0.921; 95% CI: 0.779-1.090), earlier roommate bedtimes (OR = 0.799; 95% CI: 0.718-0.888), quieter dormitories (OR = 0.732; 95% CI: 0.647-0.828) and higher psychological resilience (OR = 0.982; 95% CI, 0.979-0.984) were protective factors linked to lower risk of poor sleep quality. Conversely, being a female student (OR = 1.238; 95% CI: 1.109-1.382), being a senior (OR = 1.582; 95% CI: 1.344-1.863), single-child status (OR = 1.195; 95% CI: 1.077-1.326), regular smoking (OR = 1.833; 95% CI: 1.181-2.847), regular alcohol consumption (OR = 1.737; 95% CI: 1.065-2.833), high academic stress (OR = 1.326; 95% CI: 1.012-1.736), high employment stress (OR = 1.352; 95% CI: 1.156-1.582), dissatisfaction with dormitory hygiene (OR = 1.140; 95% CI: 1.028-1.265), poor self-rated physical health (OR = 1.969; 95% CI: 1.533-2.529), poor self-rated mental health (OR = 2.924; 95% CI: 2.309-3.702) and higher mobile phone dependency were risk factors associated with an increased likelihood of poor sleep quality.

Conclusion

The sleep quality among university students should attract immediate attention. The development of public services and mental health education initiatives is crucial in enhancing the sleep health of this population.

Lifestyle factors, dietary patterns, and social determinants of social and eating jetlag: A cross-sectional survey

Social jetlag (SJL) and, more recently, eating jetlag have been linked with an increased risk of non-communicable diseases. Here we aim to investigate lifestyle factors (diet, eating behavior, smoking, perceived stress, time spent sedentary/day) and social determinants (education level, employment status, and place of residence) associated with SJL corrected for sleep duration (SJLsc) and eating jetlag. Self-declared data on age, gender, lifestyle, and eating behavior were collected online from March 2021 to February 2022 of 432 adults. Principal component analysis was used to extract three dietary patterns (Prudent, Western, and Risky). Prevalence of SJLsc was 35.2%, with no significant difference between men and women (p = 0.558). Adults with SJLsc had significantly larger eating jetlag (56.0 min vs 41.2 min, p = 0.001). Increasing SJLsc duration was associated with an increased adherence to a Risky dietary pattern (standardized β coefficient = .165, p = 0.012); increasing eating jetlag duration was associated with an increased adherence to a Western dietary pattern (standardized β coefficient = .127, p = 0.039) and a shorter sleep duration (standardized βcoefficient = -0.147, p = 0.011). Among social determinants analyzed, only being a student or employed was associated with eating jetlag (standardized β coefficient = 0.125, p = 0.044), while none displayed any relationship with SJLsc. Our survey provides evidence on a risky behavior among young persons with SJLsc and eating jetlag, characterized by a higher alcohol consumption, and a diet rich in processed meat and high-fat food, eating during nights, and shorter sleep duration with potential long-term negative health outcomes.

Associations between social jetlag trajectories and body mass index among young adults

STUDY OBJECTIVES

This study employed longitudinal data collected repeatedly from individuals over the course of several years to examine the trajectories of social jetlag from ages 11 to 22 years and their associations with subsequent body mass index (BMI). Potential sex differences were also investigated.

METHODS

Data were obtained from two longitudinal studies conducted in Taiwan (N = 4287). Social jetlag was defined as ≥ 2 hours of absolute difference in sleep midpoint between weekdays and weekends. BMI was calculated using weight (kg)/height(m)2 and categorized as underweight (<18 kg/m2), normal weight (18 kg/m2 ≤ BMI < 24 kg/m2), overweight (24 kg/m2 ≤ BMI < 27 kg/m2), and obese (≥27 kg/m2). Group-based trajectory modeling and multinomial logistic regression were applied to investigate study objectives.

RESULTS

Four distinct trajectories of social jetlag throughout the adolescent years were identified, with corresponding proportions as follows: low-stable (42%), moderate-decreasing (19%), low-increasing (22%), and chronic (17%) trajectories. Among males, the risk of being underweight (aOR, 1.96; 95% CI: 1.35 to 2.84) or obese (aOR, 1.40; 95% CI: 1.02 to 1.92) was higher in individuals with a low-increasing trajectory than in those with a low-stable trajectory. Among females, those with a low-increasing (aOR, 1.61; 95% CI: 1.02 to 2.54) or chronic (aOR, 2.04; 95% CI: 1.27 to 3.25) trajectory were at a higher risk of being obese relative to those with a low-stable trajectory.

CONCLUSIONS

Addressing the development of increasing or chronic social jetlag during adolescence can help prevent abnormal BMI in young adulthood. Practitioners should consider sex differences in treatment or consultation.

Relationship between mid-sleep time and depression, health-related quality of life, and sleep deprivation in the 2018 Korea Community Health Survey

This cross-sectional study examined the relationship of mid-sleep time (MST) with depression, quality of life, and sleep deprivation. This study included 173 284 adults aged ≥ 19 years who participated in the 2018 Korea Community Health Survey. The Patient Health Questionnaire-9 for depression, EuroQol-5 dimension for health-related quality of life, and the Pittsburgh Sleep Quality Index for MST, daytime sleepiness, and sleep quality were used. Regression and logistic regression analysis was used for complex sample analysis. The results showed that individuals with later MST had a higher risk of depression, poor quality of life, poor sleep quality, and excessive daytime sleepiness than intermediate-type individuals, whereas earlier MST was associated with good sleep quality in the total population. This association was significant in both men and women. The later type was associated with all items of health-related quality of life in both men and women. These findings suggest that the later type is a significant predictor of mental health, quality of life, sleep quality, and daytime sleepiness. Identifying an individual's mid-sleep time may help tailor interventions and treatment strategies that optimize sleep, mental health outcomes, and quality of life.

Association between chronotype and metabolic-associated fatty liver disease in employed adults: A longitudinal study in Southwestern China

The circadian system is an essential physiological regulator of mammals, and sleep chronotype may be associated with the risk of metabolic disorders. However, evidence regarding the role of sleep chronotype in the development of metabolic-associated fatty liver disease (MAFLD) is scarce, particularly in employed adults. We conducted a longitudinal study of 1,309 employed adults in Southwestern China with a five-year follow-up from 2017 to 2021. MAFLD was assessed by the presence of hepatic steatosis using abdominal ultrasonography, overweight/obese status, diabetes mellitus, metabolic dysregulation, or elevation of high-sensitivity C-reactive protein. Chronotype was assessed by the Morning and Evening Questionnaire-5 (MEQ-5). The logistic random effects model was applied to analyze the 5-year panel data to estimate the association between chronotype and MAFLD, and the potential effect modification of demographics on such association. The MAFLD prevalence of participants was 38.6% at baseline and showed an increasing trend during follow-up (p for trends < 0.05). Compared with morning chronotype, evening chronotype was positively associated with MAFLD (OR = 2.19, 95%CI: [1.09, 4.40]) after controlled for covariates. Age, sex, ethnicity, and educational level did not modify the association between chronotype and MAFLD. These findings suggest that improving circadian rhythms could reduce the risk of MAFLD and chronic disease burden among employed adults.

Sleep duration is associated with depressive symptoms in Chinese adolescents

BACKGROUND

Depressive symptoms have become one of the most common mental health problems in adolescents. Identifying potential factors associated with adolescent depressive symptoms could be practical and essential for early intervention programs. The association between sleep duration and depressive symptoms in adolescents is inconsistent and needs further exploration.

METHODS

A total of 7330 participants aged 10-19 years were included in this study. Sleep duration was categorized into <7 h, 7-8 h, 8-9 h, and ≥ 9 h per day. The Chinese version of the Center for Epidemiology Scale for Depression was used to assess depressive symptoms. Binary logistic regression analysis was performed to evaluate the association between sleep duration and the risk of depressive symptoms. Restrictive cubic spline analyses were conducted to evaluate the dose-response relationship between sleep duration and depressive symptoms.

RESULTS

Thirty-four percent of the participants suffered from depressive symptoms. The prevalence of depressive symptoms in adolescents with sleep durations of <7 h, 7-8 h, 8-9 h, and ≥9 h per day was 52.66 %, 37.80 %, 27.55 %, and 20.49 %, respectively. After adjusting for potential covariates, long sleep duration was significantly associated with a decreased risk of depressive symptoms in adolescents. A nonlinear relationship between sleep duration and depressive symptoms was identified.

CONCLUSIONS

Long sleep duration is independently associated with a decreased risk of depressive symptoms in Chinese adolescents.

Targeting microbiota to alleviate the harm caused by sleep deprivation

Sleep deprivation has become a common health hazard, affecting 37-58% of the population and promoting the occurrence and development of many diseases. To date, effective treatment strategies are still elusive. Accumulating evidence indicates that modulating the intestinal microbiota harbors significant potential for alleviating the deleterious impacts of sleep deprivation. This paper first reviews the effects of sleep deprivation on gastrointestinal diseases, metabolic diseases, and neuropsychiatric diseases, discussing its specific mechanisms of influence. We then focus on summarizing existing interventions, including probiotics, melatonin, prebiotics, diet, and fecal microbiota transplantation (FMT). Finally, we have discussed the advantages and limitations of each strategy. Compared with other strategies, probiotics showed a high potential in alleviating sleep deprivation-related hazards due to their reduced risk and high security. We suggest that future research should focus on the specific mechanisms by which probiotics mitigate the harms of sleep deprivation, such insights may unveil novel pathways for treating diseases exacerbated by insufficient sleep.

Circadian variability of objective sleep measures predicts the relapse of a mood episode in bipolar disorder: findings from the APPLE cohort

AIM

Sleep disturbance, a core feature of bipolar disorder, is closely associated with mood symptoms. We examined the association between actigraphy sleep parameters and mood episode relapses in patients with bipolar disorder.

METHODS

This prospective cohort study analyzed 193 outpatients with bipolar disorder who participated in the Association between the Pathology of Bipolar Disorder and Light Exposure in Daily Life (APPLE) cohort study. The participants' sleep was objectively evaluated via actigraphy over seven consecutive days for the baseline assessment and then at the 2-year follow-up appointment for mood episode relapses. The actigraphy sleep parameters were presented using the mean and variability (standard deviation) of each sleep parameter for 7 days.

RESULTS

Of the 193 participants, 110 (57%) experienced mood episodes during follow-up. The participants with higher variability in total sleep time had a significantly shorter mean estimated time to mood episode relapses than those with lower variability (12.5 vs. 16.8 months; P < 0.001). The Cox proportional hazards model, when adjusted for potential confounders, demonstrated that variability in total sleep time was significantly associated with an increase in the mood episode relapses (per hour; hazard ratio [HR], 1.407; 95% confidence interval (CI), 1.057-1.873), mainly in the depressive episodes (per hour; HR, 1.477; 95% CI, 1.088-2.006).

CONCLUSIONS

Our findings suggest that consistency in sleep time might be useful, as an adjunct therapy, in preventing the recurrence or relapse of mood episodes in bipolar disorder.

Efficacy of sleep extension therapy using a remote support system in university students with increased social jetlag: a parallel, single-blind, randomized controlled trial

Purpose

The efficacy of sleep extension therapy using a remote support system (SET-R) was investigated in university students with increased social jetlag (SJL).

Methods

For this two-arm parallel randomized controlled trial, we recruited Japanese university students with SJL ≥ 60 min. The SET-R provided an individualized sleep schedule for gradual sleep extension using email and sleep hygiene education, stimulus control therapy, and progressive muscle relaxation as web content. The control group was sent an email that encouraged them to record their sleep. The duration of the intervention program was two weeks. The primary outcome was the mean change in SJL two weeks later, assessed using the Munich ChronoType Questionnaire (MCTQ). The other outcomes included Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale (ESS), Insomnia Severity Index, Patient Health Questionnaire-9 (PHQ-9), and sleep quiz. A follow-up survey was conducted 6 months after the intervention.

Results

Of 54 students, 26 were assigned to an intervention group and 28 to a control group. The difference in the mean change in SJL between the two groups (n = 26, n = 27) at two weeks was statistically significant (27.7 min, P = 0.048). The scores for the ESS, PHQ-9, and sleep quiz were improved in the intervention group relative to the control group. At the 6-month follow-up point, the difference in the mean change in SJL between the two groups (n = 22, n = 27) was not statistically significant, but scores for the PHQ-9, and sleep quiz remained significant.

Conclusions

This study demonstrated the efficacy of the SET-R among university students with increased SJL.

Trial Registration

The study was registered with the UMIN Clinical Trials Registry (UMIN000042634, 2021/02/01).

Associations of social jetlag with depressive symptoms among adults in Southern China: a cross-sectional study

To investigate the associations between social jetlag and depressive symptoms and further analyze the interaction of social jetlag and chronic diseases on depressive symptoms among adults. Data were derived from a cross-sectional survey. Information on social jetlag, depressive symptoms, demographic characteristics, lifestyles, and health situations were collected via a structured self-administered questionnaire. The multivariable logistic regression analyses and restricted cubic splines regression were performed to test the association between social jetlag and depressive symptoms. The multiplicative model was applied to analyze the interaction of social jetlag and chronic disease on depressive symptoms. A total of 5818 adults were included and the prevalence of social jetlag was 22.95%. After multivariable adjustment, adults who experienced more than 2 hours of social jetlag had a significantly greater risk of depressive symptoms (OR = 1.43,95%CI:1.00-2.05, P = 0.049). Compared with participants having<1 hour of social jetlag and no chronic disease, participants having chronic disease were more likely to report depressive symptoms(OR = 3.22,95%CI = 2.59-4.00, P < 0.001). Moreover, among those who have chronic disease, the greater the social jetlag they reported, the greater risk of depressive symptoms they have (OR = 3.81,95%CI = 2.77-5.33, P < 0.001; OR = 4.08,95%CI = 2.24-7.43, P < 0.001). Social jetlag was linearly associated the with risk of depressive symptoms, according to restricted cubic splines. This study shows that 22.95% adults experience more than 1 hour of social jetlag. Social jetlag was positively associated with an increased risk of depressive symptoms. Among those who have chronic disease, the greater the social jetlag they reported, the greater risk of depressive symptoms they have.

Effects of Irregular Mealtimes on Social and Eating Jet Lags among Japanese College Students

College students' social and eating jet lags and chronotypes may be related to irregular eating habits. Therefore, we examined the relationship between social and eating jet lags, chronotypes, variability in first and last mealtimes, and non-eating duration, as well as the effects of snacking between dinner and bedtime on social and eating jet lags, chronotypes, and mealtime variation. A total of 1900 Japanese male college students were recruited in this study. Mean wake-up time, bedtime, sleeping time, first and last mealtimes, snacks between meals, non-eating duration, the midpoint of non-eating duration, social and eating jet lags, and chronotype were calculated. Standard deviations in first and last mealtimes, the midpoint of non-eating duration, and the coefficient of variation in non-eating duration were used to evaluate mealtime variations. Mealtime variations were significantly associated with social and eating jet lags, chronotype, the midpoint of non-eating duration, and the difference in first and last mealtime between school holidays and class days. Chronotype and the midpoint of non-eating duration were significantly delayed with increased snacking after dinner. Mealtime variations were significantly lower in those who avoided snacking than in those who did not. Thus, social and eating jet lags and chronotypes are associated with sleep habits and mealtime irregularities.

Validation of the Munich Chronotype Questionnaire (MCTQ) in Chinese college freshmen based on questionnaires and actigraphy

The Munich Chronotype Questionnaire (MCTQ) was developed to determine an individual's chronotype, and it provides information about sleep and wake times separately for work and free days. However, the MCTQ has not been effectively verified using a large sample based on multiple questionnaires and actigraphy measures. Three sequential studies were conducted. Study 1 used a large sample (n = 1066) to investigate the chronotype of Chinese college freshmen and assess the validity of the MCTQ compared with the reduced Morningness-Eveningness Questionnaire (rMEQ), actigraphy, and other related questionnaires. Study 2 verified the MCTQ compared with a sleep diary. Study 3 examined the test-retest reliability of the MCTQ at the 2-year follow-up. The results showed that MCTQ parameters were significantly associated with rMEQ scores, the actigraphy-based mid-point of sleep, sleep quality, depression, and trait anxiety. In addition, all MCTQ variables were significantly related to the diary-based sleep mid-point. The test-retest reliability of the mid-point of sleep adjusted for sleep debt (MSFsc) and mid-point of sleep on free days (MSF) was acceptable. These results indicate that the MCTQ is a practical and efficient tool with good reliability. Its further development is important for the accurate assessment of chronotypes and clinical diagnoses of sleep.

Associations of social jetlag and insomnia symptoms with depressive symptoms among Chinese adolescents: A large population-based study

OBJECTIVE

This study aimed to evaluate the associations of social jetlag and insomnia symptoms with depressive symptoms among adolescents.

METHODS

A total of 37,871 junior high students completed an online survey between May 24th and Jun 5th, 2022. Insomnia symptoms were assessed by three items based on the Diagnostic and Statistical Manual of Mental Disorders criteria. Social jetlag and depressive symptoms were evaluated by the Munich Chronotype Questionnaire and the Patient Health Questionnaire, respectively. Restricted cubic splines were used to explore the relationship between social jetlag and depressive symptoms. Joint effects of social jetlag and insomnia symptoms on depressive symptoms were estimated using additive interaction models.

RESULTS

The prevalence of depressive symptoms was 13.1%. Depressive symptoms were more common in adolescents with social jetlag ≥2 h (OR: 1.51, 95% CI: 1.39-1.65) and insomnia symptoms (OR: 6.91, 95% CI: 6.41-7.44). There was a J-shaped relationship between social jetlag and depressive symptoms when we took social jetlag as a continuous variable. Moreover, a positive additive interaction of social jetlag ≥2 h and insomnia symptoms on depressive symptoms was found in female adolescents (RERI: 2.30, 95% CI: 0.11-4.49).

CONCLUSIONS

Our findings suggested that social jetlag ≥2 h and insomnia are related to the occurrence of depressive symptoms in adolescents. Their coexistence additively enhances the strength of the association with depressive symptoms. Early screening and intervention for insomnia, as well as methods to reduce social jetlag, should be comprised as part of preventive strategies for depression in adolescents.