Association between depressive symptoms and morningness-eveningness, sleep duration and rotating shift work in Japanese nurses

Mediating roles of sleep quality and resilience in the relationships between chronotypes and mental health symptoms

Sleep and mental health are intrinsically intertwined, but not every individual with problems sleeping develops a mental health disorder. This study examined the association among chronotypes, resilience, sleep quality and mental health symptoms amongst otherwise healthy individuals. Two hundred adults (Mage = 27.75 ± 5.11, 68% female) with no previous diagnosis of mental illness were recruited and filled in a set of questionnaires measuring chronotypes, sleep quality, depression and anxiety symptoms. The findings from the path analysis showed that the morning type had a statistically significant direct effect on a range of sleep quality indices. These included better subjective sleep quality, shortened sleep latency, and fewer daytime dysfunctions, as well as a higher level of resilience. However, it did not significantly affect depression and anxiety symptoms. In addition, the morning type had statistically significant indirect effects on a higher level of resilience and fewer depression and anxiety symptoms through the mediating effect of sleep quality indices. Findings from this study support that morning type is associated with better resilience and psychological health, which is mediated through better sleep quality.

The unfixed light pattern contributes to depressive-like behaviors in male mice

Light pollution is now associated with an increased incidence of mental disorders in humans, and the unfixed light pattern (ULP) is a common light pollution that occurs in such as rotating shift work. However, how much contribution the ULP has to depression and its potential mechanism are yet unknown. Our study aimed to investigate the effect of the ULP on depressive-like behaviors in mice and to explore the links to the circadian-orexinergic system. Male C57BL/6 J mice were exposed to the ULP by subjecting them to an alternating light pattern every 6 days for 54 days. The tail suspension test (TST) and forced swimming test (FST) were conducted to assess depressive-like behaviors. The rhythm of locomotor activity and the circadian expression of cFOS in the suprachiasmatic nucleus (SCN), clock genes in the liver, and corticosterone (CORT) in serum were detected to observe changes in the circadian system. The circadian expression of orexin-A (OX-A) in the lateral hypothalamus area (LHA) and dorsal raphe nucleus (DRN) and serotonin (5-HT) in the DRN were measured to determine alterations in the orexinergic system. The results showed that mice exposed to the ULP exhibited increased immobility time in the TST and FST. The ULP significantly disrupted the circadian rhythm of locomotor activity, clock genes in the liver, and CORT in the serum. Importantly, when exposed to the ULP, cFOS expression in the SCN showed decreased amplitude. Its projection area, the LHA, had a lower mesor of OX-A expression. OX-A projection to the DRN and 5-HT expression in the DRN were reduced in mesor. Our research suggests that the ULP contributes to depressive-like behaviors in mice, which might be related to the reduced amplitude of circadian oscillation in the SCN and hypoactivity of the orexinergic system. These findings may provide novel insights into rotating shift work-related depression.

Association of breakfast skipping with habitual dietary intake and BMI in female rotating shift workers

OBJECTIVE

Higher BMI, lower quality of diet and a higher percentage of breakfast-skippers have been reported among rotating shift (RS) workers compared with day shift (DS) workers. As such, this study examined the association between breakfast skipping, habitual food consumption and BMI in RS workers.

DESIGN

Japanese nurses were studied using a self-administered questionnaire that assessed the height, weight, breakfast consumption habits, dietary consumption, physical activity, sleep habits, chronotype and demographic characteristics of the participants.

SETTING

A cross-sectional study was conducted in a population of nurses in Japan. Dietary and health-related questionnaires were mailed to 5536 nurses aged 20-59 years, working at 346 institutions.

PARTICIPANTS

A total of 3646 nurses at 274 institutions responded to the questionnaire. After removing those who met the exclusion criteria, 2450 participants were included in the statistical analysis.

RESULTS

The RS breakfast-skippers had lower total energy intake, diet quality and higher BMI than DS workers, whereas the RS breakfast-consumers had a higher total energy intake and BMI than the DS workers. In the RS workers, breakfast skipping on the days of DS and the end days of evening/night shift was associated with a poorer diet quality. Additionally, breakfast skipping on the days of DS was positively associated with BMI, independent of the total energy intake and diet quality.

CONCLUSIONS

Breakfast skipping on workdays may contribute to a difference in dietary intake and BMI between RS workers and DS workers and may increase BMI in RS workers, independent of dietary intake.

Association between matched chronotype and poor mental health among shift workers: a systematic review and meta-analysis

BACKGROUND

Nearly 0.7 billion workers are involved in the shift work system, leading to concerns about its potential impacts on the large-scale population mental health. This study aimed to synthesise evidence of the associations between matched chronotype and the risk of poor mental health among shift workers.

METHODS

Six computerised databases were searched from inception to September 2022. Observational studies were selected if they reported any association between common mental health parameters and chronotype scores/types of shift workers. The Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist was followed. We extracted adjusted risk estimates to calculate pooled effect sizes and explore sources of heterogeneity. The study was registered in PROSPERO: CRD42022357437.

RESULTS

Fourteen studies including 49 909 workers were identified. Ever shift workers had a higher risk of poor mental health than the day workers (pooled OR 1.15, 95% CI 1.03 to 1.28; I²=14%, p=0.29), with the evening chronotype ever shift workers having a 1.47 times higher risk than those who worked during the day (pooled OR 1.47, 95% CI 1.13 to 1.91; I²=42%, p=0.16). Sensitivity analysis excluding studies with the highest risk of bias of each group demonstrated consistent findings.

CONCLUSIONS

Evening chronotype ever shift workers have poorer mental health than shift workers with other chronotypes. Chronotype remains unrecognised in the contemporary rostering system, making it a hidden contributor to occupational mental health. Work-related physical and mental stresses may be prevented/mitigated with further investigation on optimising shift work schedule combined with individual chronotype preference.

Characteristics of psychological time in patients with depression and potential intervention strategies

Psychological time reveals information about an individual's psychological state and psychopathological traits and, thus, has become a new perspective through which the occurrence and development of depression can be examined. Psychological time includes time perception, time perspective, circadian rhythms, and passage of time. Patients with depression are characterized by inaccurate time interval estimation, habitual negative thoughts about the past and future, evening-type circadian rhythms, and slow passage of time. Habitual negative thoughts about the past and future and evening-type circadian rhythms influence the formation of depression, and poor time interval estimation and slow passage of time may result from depression. Further study is needed accurately exploring psychological time and influencing factors in patients with depression, and prospective cohort studies could further clarify this complex relationship. In addition, the study of psychological time has important implications for developing effective interventions to reduce depression.

The Relationship between Working Night Shifts and Depression among Nurses: A Systematic Review and Meta-Analysis

BACKGROUND

For many years, occupational physicians have debated whether there is a link between working the night shift and depression and other co-occurring mental health issues, with an emphasis on work-related, biological, individual, and environmental factors. We performed this systematic review and meta-analysis to estimate the overall association between sleep deprivation and depression among nurses working night shifts.

METHODS

A systematic search was carried out across the electronic databases PubMed, Scopus, and Web of Science from inception to 30 September 2022, for studies that reported a relationship between estimated night shift work and depression in nurses. The outcomes were measured using the odds ratio (OR) and matching 95% confidence interval (CI). The I² statistic was used to assess heterogeneity. The Grading of Recommendations Assessment, Development and Evaluation technique was used to evaluate the quality of the evidence, and the Newcastle-Ottawa Scale was utilized to assess the methodological quality of each of the included studies. We determined the overall relationship between working nights and the onset of depression.

RESULTS

A total of 20 studies were included in the systematic review. Furthermore, 8 studies were included in the meta-analysis due to their common use of the OR as an effect measure. The 8 studies gave an overall estimate indicating a statistically significant association between night shift work and depression among nurses (OR = 1.49 95% CI: 1.26, 1.76). The prediction interval for the overall estimate was (0.995, 2.231). This implies that the true OR in a future study would most likely fall within this range, with a 95% certainty.

CONCLUSIONS

The outcome of this systematic review and meta-analysis showed a significant association between night shift work, the circadian and sleep disruption it causes, and the risk of depression in nurses. This demonstrates that nurses who work night shifts are at risk of developing depression.

Associations between the Timing and Nutritional Characteristics of Bedtime Meals and Sleep Quality for Nurses after a Rotating Night Shift: A Cross-Sectional Analysis

The purpose of this study was to investigate the associations of the timing and nutritional characteristics of bedtime meals with sleep quality in nurses after rotating night shifts. In total, 128 nurses from a university hospital in South Korea participated in this cross-sectional study. Data were collected on the first night of two or three consecutive routine night shifts. Participants recorded all food eaten before going to bed after work. An accelerometer was used to objectively measure sleep quality, and subjective sleep quality was assessed by self-report using the Korean version of the Verran and Snyder-Halpern Sleep Scale. The associations of timing and nutritional characteristics of bedtime meals with sleep quality after night shifts were analyzed using multivariate linear regression. A short time interval between meals and sleep was associated with longer objectively measured total sleep time (β = -0.37, p = 0.002), and the proportion of protein in meals was associated with better objectively measured sleep efficiency (β = 0.31, p = 0.007). The shorter the time interval, the better the subjective sleep quality (β = -0.23, p = 0.048), and high-calorie meals were positively associated with subjective sleep quality (β = 0.23, p = 0.043). Based on our findings, we encourage nurses to have protein-rich meals after night shifts and reduce the delay between meals and sleep. Although high-calorie meals were shown to have a positive effect on subjective sleep quality, it is necessary to confirm this effect through additional research.

Impact of atypical working hours on sleep and mood among healthcare workers

BACKGROUND

Atypical working hours have raised serious concerns about health effects, such as sleep disorders and psychological repercussions. These schedules are frequent among health professionals having the obligation to ensure the permanence of health services.

OBJECTIVE

To assess the impact of atypical working hours on sleep, sleepiness, and mood among health personnel (HP).

METHODS

Comparative descriptive cross-sectional study was carried out among HP of a regional hospital in Southern Tunisia from December 2019 to May 2020. Two groups were defined according to their work schedule: group A had a fixed-day work and group B had atypical working hours. The assessment of sleep, sleepiness, and mood was based respectively on the Spiegel questionnaire, the Epworth Sleepiness Scale, and the Hospital Anxiety and Disorder scale.

RESULTS

A total of 101 HP in group A and 135 in group B were included. We found signs of pathological sleep in group B: greater delay in falling asleep (78.1% Vs 53.5%; p = 0.002), altered sleep quality (88.1% Vs 56.4%; p = 0.039), and more frequent occurrence of dreams (37% Vs 31.7%; p = 0.033). The quality of sleep was associated with the professional seniority (p = 0.01), the workplace (p = 0.02), and having dependent children (p = 0.04). The mean score of depression was higher in group B (p = 0.02). Depression was associated with the workplace (p = 0.04) and the quality of sleep (p = 0.01).

CONCLUSION

The results of this study indicate that atypical working hours generate both sleep and mood disorders in HP. It is vital to encourage the occupational physicians to estimate sleep and mood disorders in HP.

Shift work-like patterns effect on female and male mouse behavior

Shift work (work outside of standard daylight hours) is common throughout the Western world. However, there are notable health consequences to shift work, including increased prevalence of mental health and sleep disorders in shift worker populations. Therefore, the health and wellbeing of shift workers is a public health concern that needs to be addressed. Here we investigate the effects of two separate light induced shift work-like patterns on male and female mouse behaviour (anxiety-like, exploration, marble burying, startle reflex and circadian rhythms). After 6 weeks of shift-like disruptions patterns, animals displayed no behavioral differences in exploration, marble burying and startle reflex. Interestingly however, we identified sex specific and disruption specific effects in light aversion and wheel running activities. Notably, analysis of the activity patterns of animals in disruptive conditions demonstrated that they maintained a degree of rhythmicity through the disruption period, which may explain the lack of behavioral differences in most behavioral tests.

Prevalence of depressive symptoms in nurses compared to the general population based on Propensity Score Matching: A nationwide cross-sectional study in China

BACKGROUND

Depressive symptoms have a series of negative effects and are considered especially severe among nurses, whereas there is a lack of quantitative studies comparing the risk of depressive symptoms between nurses and the general population.

METHODS

We respectively conducted a nationwide cross-sectional online survey among 17,582 Chinese nurses from July to August 2018, and 101,120 Chinese community residents from January to February 2019. The questionnaire covered social-demographic characteristics and depressive symptoms for both, work-related factors and life-related factors for nurses. Propensity Score Matching was performed to match nurses and residents by gender, age, educational level, marital status, and habitual residence.

RESULTS

Before Propensity Score Matching, the risk of depressive symptoms in nurses was higher than residents (OR, 2.16; 95% CI, 2.07-2.26). After matching, there were 15,256 nurses and residents respectively, and the risk in nurses was higher (OR, 2.14; 95% CI, 2.02-2.27). Logistic regression showed that longer years of service (OR, 1.54; 95% CI, 1.30-1.83), higher night shift frequency (OR, 1.48; 95% CI, 1.35-1.64), perceived shortage of nurses (OR, 1.98; 95% CI, 1.84-2.13), suffered verbal violence (OR, 2.43; 95% CI, 2.21-2.66) and physical violence (OR, 1.80; 95% CI, 1.64-1.98) were risk factors for depressive symptoms in nurses.

LIMITATIONS

Convenience sampling and online survey were adopted in this cross-sectional study, which may diminish the representativeness of samples.

CONCLUSIONS

Compared with the general population, nurses have a higher risk of depressive symptoms in China. Reasonable work allocation, adequate staffing, scientific shift system and violence emergency system should be implemented.

Sleep-wake rhythm and its association with lifestyle, health-related quality of life and academic performance among Japanese nursing students: a cross-sectional study

Background

Young adults are likely to have activities and go to bed late at night due to their age-dependent delayed endogenous circadian clock. The purpose of the present study was to clarify sleep–wake rhythm and its association with lifestyle, health-related quality of life, and academic performance among nursing students.

Methods

Self-reported questionnaires were distributed to undergraduate nursing students at six universities in Japan. Sleep–wake rhythm was assessed using the morningness-eveningness questionnaire. A quantitative design using the generalized linear mixed effect model was utilized to identify the factors related to the evening type among female nursing students (n = 447).

Results

About 18% of the participants were identified as the evening type. Evening type was associated with living alone, part-time job, and club activity. Sleep duration on weekdays was shorter, meal time duration was the shortest, and the percentages of students who skipped meals and those who gained body weight were higher in the evening type than in the morning type and intermediate type. Mental health-related quality of life was lower in the intermediate type and evening type than in the morning type, while there was no difference in physical health-related quality of life among these groups. The percentages of the nursing students who have experienced absence, tardiness, falling asleep during class, and/or interference with academic achievement were higher in the evening type than in other groups.

Conclusions

The present study has important implications for nursing students’ biological characteristics and lifestyle, which are associated with their health-related quality of life and academic performance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12912-021-00748-3.

Impact of COVID-19 online classes on morningness-eveningness personality among adult college students: A survey study

BACKGROUND

COVID-19 emerged as a serious pandemic in 2019 and billions of people were infected. Various precautionary methods were taken to contain the spread of virus such as social distancing, public lockdown, sanitation, and closure of schools and colleges. Many colleges started online classes to resume their syllabus and to complete the course curriculum. These evening online sessions resulted in late night sleep, long term mobile/computer exposure, and disturbed sleep pattern.

OBJECTIVE

The present study aimed to determine the impact of COVID-19 online classes on morningness- eveningness personality and to compare it with different age groups, gender, and body mass index.

METHODS

The cluster sampling method was used to collect the subjects from the total of 1153 adult college students, 897 subjects were selected based on the selection criteria and instructed to submit an online survey consists of the Morningness-eveningness Questionnaire and demographic and anthropometric data through mail, social media, or through a researcher by direct interview.

RESULTS

The mean score for the 897 participants is 56.7, indicating intermediate morningness-eveningness personality type. On comparing the different groups, the youngest group (18-20 years) scored 4.23%(mean = 46.7), female subjects scored 6.13%(mean = 58.1), the underweight 2.67%(mean = 59.2) and overweight groups scored 2.89%(mean = 59.7) indicating definite eveningness. Among the 897 collected samples of the population 8.13%of the subjects experienced definite eveningness, 14.93%has moderate eveningness, 17.38%are under intermediate category, 22.4%have moderate morningness, and 37.11%have definite morningness.

CONCLUSIONS

Subjects with eveningness personality have high risk of developing mental illness, thus it's important to determine the eveningness personality among student population to avoid serious complications in later age.

Using Mendelian Randomisation methods to understand whether diurnal preference is causally related to mental health

Late diurnal preference has been linked to poorer mental health outcomes, but the understanding of the causal role of diurnal preference on mental health and wellbeing is currently limited. Late diurnal preference is often associated with circadian misalignment (a mismatch between the timing of the endogenous circadian system and behavioural rhythms), so that evening people live more frequently against their internal clock. This study aims to quantify the causal contribution of diurnal preference on mental health outcomes, including anxiety, depression and general wellbeing and test the hypothesis that more misaligned individuals have poorer mental health and wellbeing using an actigraphy-based measure of circadian misalignment. Multiple Mendelian Randomisation (MR) approaches were used to test causal pathways between diurnal preference and seven well-validated mental health and wellbeing outcomes in up to 451,025 individuals. In addition, observational analyses tested the association between a novel, objective measure of behavioural misalignment (Composite Phase Deviation, CPD) and seven mental health and wellbeing outcomes. Using genetic instruments identified in the largest GWAS for diurnal preference, we provide robust evidence that early diurnal preference is protective for depression and improves wellbeing. For example, using one-sample MR, a twofold higher genetic liability of morningness was associated with lower odds of depressive symptoms (OR: 0.92, 95% CI: 0.88, 0.97). It is possible that behavioural factors including circadian misalignment may contribute in the chronotype depression relationship, but further work is needed to confirm these findings.

Depression and empathy in health professionals who work in the long-term care institutions for older adults

Empathy is an important factor to guarantee the quality of care provided in the long-term care institutions (LTCIs) for older adults, and depression is a factor that affects the health of the professional and, consequently, the care. Thus, it is important that studies are conducted on the relationship of these variables in this context.

Sleep Quality and Mood State in Resident Physicians during COVID-19 Pandemic

Since the novel coronavirus (SARS-CoV-2) has spread worldwide, healthcare workers—resident physicians in particular—have been hugely involved in facing the COVID-19 pandemic, experiencing unprecedented challenges in fighting the disease. We aimed to evaluate the prevalence of poor sleep quality, daytime sleepiness, and alterations in mood state profiles in this category. This cross-sectional study, conducted in 2020, enrolled 119 subjects from a university hospital in southern Italy. Epworth Sleepiness Scale (ESS), Pittsburgh Sleep Quality Index (PSQI), and Profile of Mood States (POMS) questionnaires were administered to physicians divided into four areas: anesthesiology, medicine, service, and surgery. In the overall sample, approximately 45% reported poor sleep quality, although only nine subjects (8%) reported an ESS score that suggested excessive daytime sleepiness. Alterations in mood profiles were also observed; the Vigor and Fatigue factors were the most altered. In particular, anesthesiologists seem to be the most affected category, showing a profound decrease in Vigor with a concomitant increase in Fatigue. Considering the possible consequences of the COVID-19 pandemic, preventive measures should be adopted, especially those aimed at facilitating a better turnover of physicians, optimizing the working schedule, and improving the organization of work.

Do depression and its associated factors differ in women daytime and shift workers?: an analysis of the Korea National Health and Nutrition Examination Survey 2018

Purpose

This study examined health behaviors, use of health services, and depression among women who perform daytime and shift work in Korea, as well as factors related to depression.

Methods

We conducted a secondary analysis using data from the 2018 data of the 7th Korea National Health and Nutrition Examination Survey. Data on women, 1,493 regular daytime workers and 322 shift workers, were analyzed.

Results

Women shift workers were younger (χ2=43.97, p<.001), had a lower education level (χ2=45.56, p<.001), and lower personal income (χ2=16.85, p=.030) than their daytime counterparts. A higher proportion of shift workers were unmarried (χ2=37.47, p<.001) and they typically worked fewer than 40 hours per week (χ2=69.94, p<.001). The depression score of shift workers was higher than that of daytime workers (t=2.85, p=.005). A higher proportion of shift workers also drank alcohol (χ2=6.49, p=.032) and smoked (χ2=30.79, p<.001). Over 8% of shift workers typically slept fewer than 5 hours per night (χ2=14.17, p=.024). It was confirmed that depression in women shift workers was affected by age, personal income, marital status, health status, and smoking status, in addition to cancer screening participation, unmet medical care needs, and unmet dental care needs.

Conclusion

More attention should be given to the health needs of women working shifts. Health promotion programs specific for women shift workers are needed to improve their physical and mental health, encourage use of medical care services, and improve public health policies and systems.

Diurnal preference and depressive symptomatology: a meta-analysis

Eveningness, a preference for later sleep and rise times, has been associated with a number of negative outcomes in terms of both physical and mental health. A large body of evidence links eveningness to Major Depressive Disorder (MDD). However, to date, evidence quantifying this association is limited. The current meta-analysis included 43 effect sizes from a total 27,996 participants. Using a random-effects model it was demonstrated that eveningness is associated with a small effect size (Fisher's Z = - 2.4, 95% CI [- 0.27. - 0.21], p < 0.001). Substantial heterogeneity between studies was observed, with meta-regression analyses demonstrating a significant effect of mean age on the association between diurnal preference and depression. There was also evidence of potential publication bias as assessed by visual inspection of funnel plots and Egger's test. The association between diurnal preference and depression is small in magnitude and heterogenous. A better understanding of the mechanistic underpinnings linking diurnal preference to depression and suitably powered prospective studies that allow causal inference are required.

The Associations between Sleep Duration, Academic Pressure, and Depressive Symptoms among Chinese Adolescents: Results from China Family Panel Studies

Depressive symptoms are a common mental health problem among adolescents, which may affect their physical and mental health development and impose heavy burdens on individual families and society. This study aimed to examine the associations between sleep duration, academic pressure, and depressive symptoms among Chinese adolescents and to construct the mediation model to explore the mediating effect of sleep duration. The data are from the China Family Panel Studies (CFPS). Methodologically, the aforementioned associations were explored by constructing a structural equation model and applying multivariate multilevel logistic regression. In this study, we found that approximately 6.49% of the 3724 Chinese adolescents had depressive symptoms. Sleep duration of <6 h/night (OR = 2.39, 95%CI = 1.33-4.32) and high/maximum academic pressure (high: OR = 1.43, 95%CI = 1.02-1.99; maximum: OR = 2.43, 95%CI = 1.58-3.73) were both associated with an increased risk of depressive symptoms in adolescents. Meanwhile, the multiplicative interaction between sleep duration and academic pressure was significantly associated with depressive symptoms in adolescents (p < 0.001). The sleep duration played a partial mediating role in the relationship between academic pressure and depressive symptoms (a*b = 0.006, 95%BootCI = 0.001-0.012). Our study highlights that it is essential to mitigate the academic pressure of adolescents to increase their sleep duration and further reduce the occurrence of depressive symptoms by adopting corresponding preventive measures.

Objectively measured chronotype and social jetlag are associated with habitual dietary intake in undergraduate students

This study aimed to investigate the associations between objectively measured sleep timing and habitual dietary intake among university students. We hypothesized that a later chronotype and larger social jetlag (SJL) are associated with an undesirable dietary intake. The 82 healthy university students included in this study were asked to undertake a seven-day wrist activity recording. All the participants also completed a self-administered questionnaire during the recording period, including questions on demographic characteristics and habitual dietary intakes. Dietary intake and the score for adherence to the Japanese Food Guide Spinning Top (food guide score) over the previous month were evaluated using a self-reported diet history questionnaire. Nocturnal sleep timing and total sleep time for each night were estimated using the recorded wrist activity. Chronotype was calculated as weekend (WE) mid-sleep time corrected for catch-up sleep on weekdays (WDs). SJL was calculated by subtracting WD mid-sleep time from WE mid-sleep time. Multivariable linear regression showed that a later chronotype was significantly (P < .05) associated with a lower consumption of eggs, greater consumption of grains, and lower food guide score. Multivariable linear regression also showed significant (P < .05) associations of a larger value in SJL with a lower total energy intake, lower consumption of grains, and greater consumption of sugar and confectioneries. The results suggest that chronotype and SJL may be differently associated with undesirable dietary intake in young adults. These findings have important implications for developing novel strategies, focusing on sleep timing, for improving dietary intakes and preventing lifestyle-related diseases.

Mental health service use and its associated factors among nurses in China: a cross-sectional survey

Background

To facilitate mental health service planning for nurses, data on the patterns of mental health service use (MHSU) among nurses are needed. However, MHSU among Chinese nurses has seldom been studied. Our study aimed to explore the rate of MHSU among Chinese nurses and to identify the factors associated with MHSU.

Methods

A self-designed anonymous questionnaire was used in this study. MHSU was assessed by the question, “Have you ever used any kind of mental health services, such as mental health outpatient services or psychotherapies, when you felt that your health was suffering due to stress, insomnia, or other reasons?” The answer to the question was binary (yes or no). Sleep quality, burnout, and depressive symptoms were assessed using the Chinese version of the Pittsburgh Sleep Quality Index , the Chinese version of the Maslach Burnout Inventory-General Survey and the two-item Patient Health Questionnaire, respectively. Chi-square tests and binary logistic regression were used for univariate and multivariate analyses.

Results

A total of 10.94% (301/2750) of the nurses reported MHSU. 10.25% (282/2750) of the nurses had poor sleep quality, burnout and depressive symptoms, and only 26.95% of these nurses reported MHSU. Very poor sleep quality (OR 9.36, 95% CI [5.38-16.29]), mid-level professional title (OR 1.48, 95% CI [1.13-1.93]) and depressive symptoms (OR 1.66, 95% CI [1.28-2.13]) were independent factors associated with MHSU.

Conclusions

Most of the nurses have experienced burnout, poor sleep quality or depressive symptoms and the MHSU rate among them was low. Interventions to improve the mental health of nurses and to promote the use of mental health services are needed.

Association of shift work with mood disorders and sleep problems according to chronotype: a 17-year cohort study

Both evening chronotype and shift work are associated with depressive symptoms. This study examined whether the association between shift work and mood disorders and sleep problems varies by chronotype. The study population included 10637 participants from the Finnish Hospital Personnel Cohort Study. Work schedule was assessed using repeated questionnaires between 2000 and 2017. Chronotype, assessed using a single item from the Diurnal Type Scale, was categorized into definite morning, somewhat morning, somewhat evening, and definite evening types. The presence of mood disorders was identified by the 12-item General Health Questionnaire. Sleep problems were assessed by self-reported frequency of difficulty falling asleep and maintaining asleep. Longitudinal fixed effects models were used to examine the associations between shift work and the presence of mood disorders and sleep problems, stratified by chronotype. We found that fixed night work was associated with mood disorders among somewhat evening (adjusted odds ratio [OR] 1.91, 95% CI 1.09-3.34) and definite evening-type workers (adjusted OR 2.05, 95% CI 1.06-3.98). Shift work with night shifts was associated with mood disorders among definite evening-type workers (adjusted OR 1.75, 95% CI 1.18-2.60). Similarly, fixed night work was associated with difficulty maintaining sleep only among evening-type workers. In conclusion, evening chronotype increase the vulnerability to mood disorders and sleep disturbances related to night work.

Circadian Functioning and Quality of Life in Substance Use Disorder Patients With and Without Comorbid Major Depressive Disorder

Aim: Although a relationship between circadian disruption and development of several psychiatric disorders, such as major depressive disorder (MDD) and substance use disorder (SUD), has been observed, knowledge on this area is scarce yet. Therefore, this study aims to analyze the circadian functioning and quality of life (QOL) in SUD patients with and without comorbid MDD, two highly prevalent clinical entities with difficult therapeutic management. Methods: One hundred sixty-three male patients under treatment, 81 with SUD and 82 with SUD comorbid major depressive disorder (SUD + MDD), were evaluated. For the circadian functioning assessment, we calculated Social Jet Lag (SJL) and used the reduced Morningness-Eveningness Questionnaire (rMEQ) and the Pittsburgh Sleep Quality Index (PSQI). QOL was measured using the shortened version of the World Health Organization's Quality of Life Questionnaire (WHOQOL-BREF). We collected sociodemographic and clinical variables to evaluate their possible influence on the circadian functioning. Intergroup differences among the variables were examined by different analyses of covariance (ANCOVA and MANCOVA). The possible relationships of quantitative clinical variables with rMEQ, PSQI, and WHOQOL-BREF were explored using bivariate correlation analysis. Results: Lower SJL appears in the SUD + MDD group compared with SUD. The intermediate-type was more prevalent in the SUD group, while a higher percentage of morning-type patients was found in the SUD + MDD. Sleep quality (including latency and daytime dysfunction) was worse for SUD + MDD patients than for SUD even after controlling age and age of SUD onset variables. Last, QOL was poorer in patients with SUD + MDD and, for them, psychological health had a negative relationship with SJL and severity of depression. Conclusions: Our data support and extend previous findings indicating that SUD + MDD is associated with worse clinical characteristics, more sleep problems, and poorer QOL than SUD patients. These results underline the importance of a precise assessment of these measurements in future studies conducted in SUD patients with/without MDD comorbidity that could be considered from a therapeutic point of view.

Depression and anxiety symptoms correlate with diurnal preference, sleep habits, and Per3 VNTR polymorphism (rs57875989) in a non-clinical sample

BACKGROUND

Evidences suggest that alterations in circadian rhythms trigger the development of mental disorders. Eveningness, sleep behavior, and circadian genes polymorphisms have been associated with depression and anxiety symptomatology. However, the mechanism underlying these interactions is not well understood. We investigated the contribution of diurnal preference, sleep habits, and PER3 VNTR polymorphism (rs57875989) to depression and anxiety symptoms in a Northeast sample from the Brazilian population.

METHODS

Eight hundred and four young adults completed the Morningness-Eveningness (MEQ), Munich Chronotype (MCTQ), Center for Epidemiologic Studies - Depression (CES-D), and Beck Anxiety Inventory (BAI) questionnaires. All participants were genotyped and linear regression was performed to test the interactions between the genetic /behavioral variants and depression/ anxiety symptoms.

RESULTS

Eveningness and sleep behaviors (bedtime, wake-up time, sleep duration, and midpoint of sleep) were correlated with depression symptomatology, specifically in somatic factors of the CES-D questionnaire. No correlation was found between diurnal preference/sleep habits with anxiety symptoms for both BAI total score and its factors. However, women with PER3^4/4 genotype showed less interpesonal affect in depression symptomatology and more anxiety symptoms in four factors of the BAI questionnaire.

LIMITATIONS

Mainly because this study was based on self-report questionnaires and was limited to undergraduate students aging 18 to 30 years old.

CONCLUSION

These results reinforce a role for sleep and diurnal preference in depression, and PER3 VNTR polymorphism in anxiety symptomatology, particularly in women.

The Association Between Shift Work And Affective Disorders: A Systematic Review

Atypical working time patterns are known to be associated with adverse physical health consequences. The impact of chronic exposure to shift work on psychological wellbeing and mental health is also reported, but not fully appreciated. We conducted a systematic review of the literature on the association between shift work and affective disorders using the electronic databases Medline, PsycINFO, Embase, Web of Science and Google Scholar. Data extracted included detailed characteristics of shift work, the affective disorders under study, and the population targeted. Some 25 extracted articles satisfied all inclusion and exclusion criteria. Findings of these articles reveal shift work is associated with increases in depressive symptoms (12 studies), anxiety (2 studies), and depression and anxiety (7 studies). Only three studies found no association between shift work and depression. The findings of this review suggest that shift work increases the symptoms of depression and anxiety.

The effect of circadian preferences on insomnia severity and depressive symptoms via sleep hygiene in older adults with depression and healthy controls

BACKGROUND

The elderly population is increasing globally. Thus, researches focus on the causes and treatment of insomnia, a noteworthy ageing problem. This study aims to investigate the relationship between chronotype and insomnia and whether sleep hygiene mediates this relationship in older adults with depression (OAD).

METHODS

We assessed subjective insomnia severity, sleep hygiene, chronotype, depressive symptoms, and anxiety symptoms of 82 OAD and 70 healthy controls using the Sleep Hygiene Index (SHI), Insomnia Severity Index (ISI), Morningness-Eveningness Questionnaire (MEQ), Beck Depression Inventory (BDI), and Beck Anxiety Inventory (BAI).

RESULTS

The mediation effect of SHI and ISI scores were evaluated in the relationship between MEQ and BDI total scores in OAD. The results showed that MEQ performed its effect on BDI through ISI with full mediation (effect = -0.16, SE: 0.07, 95% CI: -0.3230 to -0.0336). The mediation effect of SHI and BDI scores were evaluated in the relationship between MEQ and ISI total scores in OAD. In this model, it was found that MEQ significantly performed its effect on ISI through SHI and BDI. BDI and SHI predicted the ISI variable as partial mediators (respectively, effect = -0.05, SE: 0.03, 95% CI: -0.1073 to -0.0100; effect = -0.06, SE: 0.02, 95% CI: -0.1051 to -0.0129).

CONCLUSIONS

Sleep hygiene practices could be essential for the natural functioning of the biological clock and the interrelation of depression and insomnia. Longitudinal follow-up studies of structured sleep hygiene approaches are needed in terms of cost-effectiveness, in OAD.

Sleep disturbance-related depressive symptom and brain volume reduction in shift-working nurses

Disturbed sleep is the most common effect of shift work. A large corpus of research indicates an association between sleep disturbance and depressive symptom in shift workers. In this study, we proposed the mediating role of grey matter (GM) structure in the relationship between sleep disturbance and depressive symptom. We collected structural MRI (sMRI) data as well as assessing the level of sleep disturbance and depressive symptom with the Pittsburgh Sleep disturbance Index and Zung Self-Rating Depression Scale, respectively, in 20 shift-working nurses and 19 day-working nurses. The shift-working nurses reported greater severity of sleep disturbance and depressive symptom, and furthermore, they exhibited reduced GM volume in the left postcentral gyrus (PostCG), right PostCG, right paracentral lobule, and left superior temporal gyrus (STG), compared to the day-working nurses. For each of the four brain regions, we formulated a mediation hypothesis by developing a mediation model that represents a causal chain between GM volume, sleep disturbance, and depressive symptom. Tests of the hypothesis on the mediation of GM volume revealed that inter-individual variations in left PostCG volume and left STG volume accounted for the influence of sleep disturbance on depressive symptom. These results suggest that structural alterations in PostCG and STG play an intervening role in the development of depressive symptom following sleep disturbance. We propose the need of considering neuroanatomical abnormalities in explaining and understanding symptomatic changes induced by sleep disturbance.

Sleep duration is associated with depressive symptoms among expatriate nurses

BACKGROUND

There is limited data on sleep and its impact on mental health among expatriate nurses in Saudi Arabia. This study aimed to assess the association between sleep duration and symptoms of depression among expatriate nurses.

METHODS

Nurses in government healthcare facilities in Al-Qassim, Saudi Arabia responded to an electronic survey (n = 977) on demography, lifestyle, job features, and symptoms of depression (Depression Anxiety Stress Scale 21). Binary and multinomial logistic regression, respectively, assessed the adjusted associations of daily sleep hours (≤5, 6-7, ≥8) with having any (no, yes) or degree of symptoms (no, mild to moderate, and severe to extremely severe).

RESULTS

There was a dose-response relationship between sleep hours and depressive symptoms (any as well as degree) (p-values for trend <0.05). For nurses who slept 6-7 h, the odds ratio (OR) of having any symptoms of depression was 1.6 (95% CI: 1.2 - 2.2), 'mild to moderate' symptoms 1.5 (95% CI: 1.1 - 2.2), and 'severe to extremely severe' symptoms 1.9 (95% CI: 1.1 - 3.4). For nurses who slept ≤5 h, the OR of having any symptoms was 2.1 (95% CI: 1.4-3.3), 'mild to moderate' symptoms 1.7 (95% CI: 1.0-2.6), and 'severe to extremely severe' symptoms 4.2 (95% CI: 2.2-8.1) (reference group ≥ 8 h).

LIMITATIONS

The sleep data pertained to duration only and not to sleep quality.

CONCLUSION

There was a strong association between sleep duration and symptoms of depression among expatriate nurses.

Impact of shift work schedules on actigraphy-based measures of sleep in Hispanic workers: results from the Hispanic Community Health Study/Study of Latinos ancillary Sueño study

Study Objectives

To describe sleep characteristics of shift workers compared with day workers from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sueño ancillary study and test the hypothesis that shift work is associated with shorter sleep duration, worse sleep quality, greater sleep variability, and other sleep/health-related factors.

Methods

Employed adults (N = 1253, mean age 46.3 years, 36.3% male) from the Sueño study were included. Measures of sleep duration, timing, regularity, and continuity were calculated from 7 days of wrist-activity monitoring. Participants provided information on demographics, employment, work schedule (day, afternoon, night, split, irregular, and rotating), sleepiness, depressive symptoms, medications, caffeine, and alcohol use. Survey linear regression adjusting for age, sex, background, site, number of jobs, and work hours was used.

Results

In age and sex-adjusted models, all shift work schedules were associated with delayed sleep timing. Night and irregular schedules were associated with shorter sleep duration, greater napping, and greater variability of sleep. Afternoon and rotating shifts were associated with lower sleep regularity. In fully adjusted models, night and irregular schedules remained associated with shorter sleep duration, later sleep midpoint, and greater variability in sleep measures compared with day schedules. Split schedules were associated with, less time in bed, less sleep fragmentation, and less wake during the sleep period than day schedules.

Conclusions

Work schedule significantly affects sleep-wake with substantial differences between day work and other types of schedule. Detailed assessment of work schedule type not just night shift should be considered as an important covariate when examining the association between sleep and health outcomes.

Demographic and lifestyle correlates of brain-derived neurotrophic factor in a working population: The Furukawa Nutrition and Health Study

This study aimed to examine the cross-sectional association of demographic and lifestyle factors with serum brain-derived neurotrophic factor (BDNF) concentrations in a Japanese working population. Participants were 1678 men and 172 women aged 19-69 years who received health check-ups and participated in a nutrition and health survey. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Dietary intake was assessed using a validated self-administered diet history questionnaire. Serum BDNF concentrations were measured using a solid phase sandwich enzyme-linked immunosorbent assay. Multiple linear regression analysis was used to estimate the mean and 95% confidence interval of serum BDNF concentrations according to demographic and lifestyle factors. Higher body mass index (BMI) was significantly associated with higher circulating BDNF concentrations. Current smokers had significantly higher mean BDNF concentrations than never-smokers. BDNF concentrations were not associated with folate and 25-hydroxyvitamin D concentrations in serum, or dietary eicosapentaenoic acid and docosahexaenoic acid intake. Serum BDNF concentrations were not associated with depressive symptoms or CES-D score per se. In this study, higher BMI and smoking were associated with higher concentrations of serum BDNF, while nutrients that have been linked to depression were not associated with BDNF concentrations among Japanese workers.

Identifying shift worker chronotype: implications for health

Shift workers are at risk for developing serious health issues due to short sleep. One cause of short sleep is circadian misalignment: sleep time is not synchronized with the body's natural circadian rhythms. Although circadian rhythms are strongly driven by the light/dark cycle, humans have individualized sleep time preferences (chronotypes) based on genetics, development, and external influences. Evening chronotype individuals fall asleep later than average and have a higher risk for developing various noncommunicable diseases. What is unclear is the association between chronotype, shift work, and risks for acquiring chronic conditions. This review is focused on shift worker chronotype and associations with obesity. Because of the paucity of research, other health issues connected with circadian misalignment were included, allowing for a total of 21 research studies. Evidence from this review supports chronotype and certain health issues are associated with shift work, even after adjusting for short sleep duration. In addition, there is evidence to support future research on how shift worker chronotype matched with shift timing impacts worker health. Through better understanding of this interface, occupational health providers can provide more comprehensive worker education on the risks associated with shift work and sleep disturbances.

[The prognostic significance of biological rhythms assessment in depression]

AIM

To assess the prognostic significance of biological rhythms in depression on the example of the individual chronotype.

MATERIAL AND METHODS

One hundred patients (women 68%), aged 18-77 years, mean age 48±16, were examined before and after 8 weeks of treatment. The Morningness-Eveningness Questionnaire (MEQ) was used. Treatment response (a decrease of 50% in total MADRS scores to the 8^th week of treatment) and dynamics of depression severity (dMADRS; R) were assessed.

RESULTS AND CONCLUSION

Evening chronotype was found to be associated with poor prognosis. TCAs and SSRIs were more effective in eveningness, other antidepressants - in morningness. MEQ changes during and after treatment may reflect the resynchronizing activity of antidepressants.

Chronotype and Mental Health: Recent Advances

PURPOSE OF REVIEW

Evening chronotype is increasingly recognized as a correlate of, and perhaps a contributor to, mental illness. The current review evaluates recent evidence for the association between chronotype and mental illness and putative mechanisms underlying the association, while highlighting methodological advances and areas of research that are relatively under-examined in the literature.

RECENT FINDINGS

While evening chronotype is most consistently associated with severity of mood disorder symptoms, emerging evidence implicates evening chronotype as a transdiagnostic correlate of substance use severity, anxiety symptoms, attentional difficulties, and maladaptive behaviors such as aggression. Longitudinal studies point to the possibility that evening chronotype precedes problematic substance use, depression, and anxiety. Neural processes related to reward and affective regulation may underlie associations between evening chronotype and illness. The literature on chronotype and mental illness has evolved to (1) include associations with a broader range of psychiatric symptom profiles; (2) explore underlying mechanisms; and (3) expand on earlier research using objective measures and more sophisticated study designs. In addition to further mechanistic research, additional work is needed to examine the stability and key subcomponents of the chronotype construct, as well as more attention to pediatric and special populations. This research is needed to clarify the chronotype-mental health relationship, and to identify how, when, and what aspects of chronotype can be targeted via therapeutic interventions.

Serum brain-derived neurotrophic factor predicting reduction in pulse pressure after a one-hour rest in nurses working night shifts

Night shift work is associated with cardiovascular disease and central nervous system disorders in female nurses. Brain-derived neurotrophic factor (BDNF) exerts protective effects on neural and endothelial functions. This study examined the association between serum BDNF levels and pulse pressure after rest in female nurses working night shifts. In this study, blood samples were collected for BDNF measurement after a night shift when nurses had been working night shifts for three continuous weeks. Blood pressure was assessed before and after a one-hour morning rest within a week of resuming the night shift after one month without any night shift work. The pulse pressure of nurses (n = 48, age 29 ± 5 years) was significantly reduced (from 43 ± 7 to 41 ± 6 mmHg, P = 0.003) after rest, and serum BDNF were significantly and inversely correlated with pulse pressure changes (r = −0.435, P = 0.002). Higher serum BDNF was an independent factor for greater reduction in pulse pressure (95%CI = −0.609 ‒ −0.174, P = 0.001). Using a receiver operating characteristic curve analysis, serum BDNF >20.6 ng/mL predicted a pulse pressure reduction after a one-hour rest (sensitivity 66.7%, specificity 77.8%). In conclusion, higher serum BDNF predicted greater recovery of pulse pressure after a one-hour rest in female nurses after night shift work.

Reduced Effective Emotion Regulation in Night Owls

Previous research has demonstrated a clear link between late chronotype and depression. The vulnerability factors underpinning this link, however, are unclear. Here the relationship between two specific emotion regulation strategies, cognitive reappraisal and expressive suppression, and chronotype was investigated using multiple regression. Two hundred and forty participants (age range 18-80, 189 females) completed validated self-report questionnaires assaying chronotype, neuroticism, depressive symptomatology, sleep quality, and emotion regulation. Eveningness was associated with increased expressive suppression, and morningness was associated with increased cognitive reappraisal after controlling for age, gender, depressive symptomatology, neuroticism, and sleep quality. Trait expressive suppression and reduced cognitive reappraisal are known to increase depression risk. Our results suggest that eveningness is associated with impaired emotion regulation, which may confer risk for future depression. These findings suggest modifiable markers that could be therapeutically targeted to prevent the onset of depression in late chronotype individuals.