Occupational factors associated with major depressive disorder: A Brazilian population-based study

Associations of occupational physical activity and active transport with depressive symptoms in a middle-income country

OBJECTIVE

This study investigated the associations of occupational physical activity and active transport with depressive symptoms, stratified by income range, among Brazilian working adults.

STUDY DESIGN

This cross-sectional study drew on data from the 2019 Brazilian National Health Survey.

METHODS

We used the Patient Health Questionnaire (PHQ-9) to assess depressive symptoms in working adults aged 18-65 years, with physical activities (occupational physical activity and active transport) self-reported through a specially developed questionnaire. Crude and adjusted logistic regression models were fitted.

RESULTS

Individuals at the highest level of occupational physical activity (odds ratio [OR] 1.35; 95% confidence interval [95% CI] 1.19-1.53) and at the moderate level of active transport to work (OR 1.66; 95% CI 1.24-2.22) returned increased odds of depressive symptoms as compared with those who were inactive in these domains. Stratified by income group, light active transport to work (OR 0.57; 95% CI 0.34-0.95) in the lower income group (Range 1) was associated with lower odds of depressive symptoms. On the other hand, individuals at the highest level of active transport to work returned higher odds of depressive symptoms in the low- and intermediate-income groups, Ranges 3 and 4 (OR 1.92; 95% CI 1.22-3.00 and OR 2.91; 95% CI 1.71-4.95, respectively).

CONCLUSION

Our results suggest that occupational physical activity and active transport may be a risk factor for depressive symptoms. They also point to differences in this relationship by income range. Further studies are needed to pursue the analysis of how specific domains of physical activity contribute to depressive symptoms.

How race and socioeconomic status moderate the association between moderate-to-vigorous physical activity and depressive symptoms: a cross-sectional study with compositional data

OBJECTIVES

This study explored how race and socioeconomic status (SES) moderated the association between moderate-to-vigorous physical activity (MVPA) and depressive symptoms with compositional data.

METHODS

Participants were 2803 US adults from the 2005-2006 cycle of the National Health and Nutrition Examination Survey. Accelerometers were used to measure MVPA, light-intensity physical activity (LPA) and sedentary behaviours (SB). Participants self-reported sleep duration and depressive symptoms. SES was derived by latent class analysis using household income level, education attainment and occupation. The association between the relative time of MVPA and depressive symptoms and the moderating effects of race and SES were investigated through compositional data analysis. Isotemporal substitution analysis was employed to estimate the association of time reallocation from other movement behaviours to MVPA with depressive symptoms.

RESULTS

Increased time spent in MVPA relative to time spent in LPA, SB and sleep was inversely associated with depressive symptoms (OR (95% CI)=0.679 (0.538-0.855)). The relative time of MVPA significantly interacted with race and SES for depressive symptoms (P for interaction <0.05). Reallocating 10-30 min from sleep, SB or LPA to MVPA was associated with lower odds of depressive symptoms solely among non-Hispanic white individuals and those with higher SES.

CONCLUSION

This study used compositional data to reveal a reverse association between MVPA and depressive symptoms among white individuals and those with higher SES. Our results provide evidence of how race and SES moderate the relationship between MVPA and depressive symptoms. Future research is needed to further explore these racial and socioeconomic differences.

Circadian Disruption and Mental Health: The Chronotherapeutic Potential of Microbiome-Based and Dietary Strategies

Mental illness is alarmingly on the rise, and circadian disruptions linked to a modern lifestyle may largely explain this trend. Impaired circadian rhythms are associated with mental disorders. The evening chronotype, which is linked to circadian misalignment, is a risk factor for severe psychiatric symptoms and psychiatric metabolic comorbidities. Resynchronization of circadian rhythms commonly improves psychiatric symptoms. Furthermore, evidence indicates that preventing circadian misalignment may help reduce the risk of psychiatric disorders and the impact of neuro-immuno-metabolic disturbances in psychiatry. The gut microbiota exhibits diurnal rhythmicity, as largely governed by meal timing, which regulates the host's circadian rhythms. Temporal circadian regulation of feeding has emerged as a promising chronotherapeutic strategy to prevent and/or help with the treatment of mental illnesses, largely through the modulation of gut microbiota. Here, we provide an overview of the link between circadian disruption and mental illness. We summarize the connection between gut microbiota and circadian rhythms, supporting the idea that gut microbiota modulation may aid in preventing circadian misalignment and in the resynchronization of disrupted circadian rhythms. We describe diurnal microbiome rhythmicity and its related factors, highlighting the role of meal timing. Lastly, we emphasize the necessity and rationale for further research to develop effective and safe microbiome and dietary strategies based on chrononutrition to combat mental illness.

Perceived Occupational Noise Exposure and Depression in Young Finnish Adults

We investigated the association between perceived occupational noise exposure and depressive symptoms in young Finnish adults and whether noise sensitivity moderates this association. This study was based on an ongoing longitudinal twin study. We included those who had been working daily (n = 521) or weekly (n = 245) during the past 12 months (mean age 22.4, SD 0.7, 53% female). We asked about occupational noise exposure at age 22 and assessed depressive symptoms using the General Behavior Inventory (GBI) at age 17 and 22. Noise sensitivity and covariates were used in linear regression models. Perceived daily occupational noise exposure was associated, as a statistically independent main effect with depressive symptoms at age 22 (beta 1.19; 95% CI 0.09, 2.29) among all, and separately for females (beta 2.22; 95% CI 0.34, 4.09) but not males (beta 0.22; 95% CI -1.08, 1.52). Noise sensitivity was independently associated with depressive symptoms among all (beta 1.35; 95% CI 0.54, 2.17), and separately for males (beta 1.96; 95% CI 0.68, 3.24) but not females (beta 1.05; 95 % CI -0.04, 2.13). Noise sensitivity was independent of perceived occupational noise exposure. Pre-existing depressive symptoms at age 17 were predictive of perceived occupational noise exposure, suggesting complex interactions of noise and depression.

The Influence of Long Working Hours, Occupational Stress, and Well-Being on Depression Among Couriers in Zhejiang, China

Objective:

This study aimed to examine the association between long working hours, occupational stress, depression, and well-being, and to explore the intermediary effect of occupational stress and well-being between working hours and depression among couriers in Zhejiang, China.

Methods:

The study used a cluster random sampling method to select 1,200 couriers from mainstream express companies in Zhejiang, China. The data were collected and analyzed using the Core Occupational Stress Scale (COSS) to measure occupational stress, the Patient Health Questionnaire-9 (PHQ-9) scale to evaluate depression, and the World Health Organization five-item Well-Being Index (WHO-5) scale to assess well-being. Structural equation modeling (SEM) was used to test the hypothesized relationship among the variables.

Results:

The phenomenon of long working hours (75.1%) was quite common among couriers in Zhejiang, China. Working hours had a direct positive effect on depression (β = 0.008, p < 0.001) and on occupational stress (β = 0.009, p < 0.001), and working hours had a negative effect on well-being (β = −0.013, p < 0.001). Occupational stress had a direct positive effect on depression (β = 0.272, p < 0.001), but well-being had no significant direct effect on depression. Working hours had an indirect effect on depression through the mediating effect of occupational stress while the mediating effect of well-being was not found.

Conclusion:

Long working hours is associated with occupational stress, well-being, and depression. Our results confirmed that working hours, occupational stress, and well-being were strong predicators of depression. Working hours had a significant indirect effect on depression via occupational stress. The result of this study showed that decreasing working hours and reducing occupational stress would be effective for couriers to prevent depression. However, more studies are needed to verify the relationship between working hours and depression.

Occupational stress and associated factors among general practitioners in China: a national cross-sectional study

BACKGROUND

Occupational stress among general practitioners (GPs) is a public health concern. This study aimed to investigate the prevalence and factors associated with occupational stress among GPs in China.

METHODS

A cross-sectional design was used. Data were collected from 3,236 GPs in eastern, central, and western China (response rate, 99.75%) between October 2017 and February 2018 using a structured self-administered questionnaire. An ordinal logistic regression model was used to identify the factors associated with occupational stress among GPs.

RESULTS

Among these respondents, 313 (9.67%), 1,028 (31.77%), and 1,895 (58.56%) of GPs had a low, medium, and high level of occupational stress, respectively. GPs from central China, with temporary work contracts, without management responsibility, receiving a moderate level of income, and with moderate occupational development opportunities had a lower level of occupational stress. GPs with greater than 40 working hours per week and those who worked overtime occasionally or frequently had a higher level of occupational stress.

CONCLUSIONS

The prevalence of occupational stress among GPs is high in China. Substantial regional variation in determinants of occupational stress among GPs was observed. These findings should inform the design of policies to reduce the occupational stress of GPs.

Does stressful workplace characteristics moderate or confound the association between occupational physical activity and elevated depressive symptoms? A large study including 36,442 adults

BACKGROUND

We tested whether stressful workplace characteristics confound or moderate the association between occupational physical activity and depressive symptoms.

METHOD

We used data of 36,442 employed adults (16,992 women), with a mean age of 39.3 ± 12.6y, from the 2013 Brazilian National Health Survey. Depressive symptoms were assessed through the Patient Health Questionnaire-9 (cut-point: ≥10). Occupational physical activity was self-reported and classified using the cut-point of 150 min/week and the highest quintile. Ten stressful workplace characteristics (e.g. exposure to stress, noise, violence) were also self-reported dichotomously. Logistic regression models were used considering the adjustment for potential confounders.

RESULTS

Most of the stressful workplace characteristics were associated with elevated depressive symptoms (8/10 characteristics) and higher occupational physical activity (9/10 characteristics). Although there were no interactions in combined associations, we found that the association between occupational physical activity and depressive symptoms consistently reduced after adjusting for the cluster of positive screening for at least two stressful workplace characteristics in men [highest quintile: OR_unadjusted: 1.63 (95%CI 1.22-2.17) vs OR_adjusted: 1.36 (1.08-1.91); ≥150 min/week: OR_unadjusted: 1.43 (1.09-1.88) vs OR_adjusted: 1.25 (0.95-1.64)], and women [highest quintile: OR_unadjusted: 2.15 1.73-2.66) vs OR_adjusted: 1.83 (1.47-2.29); ≥150 min/week: OR_unadjusted: 2.11 (1.68-2.65) vs OR_adjusted: 1.80 (1.42-2.27)].

LIMITATIONS

The cross-sectional design limits the causal inference.

CONCLUSIONS

Stressful workplace characteristics did not moderate, but acted as confounders in the association between occupational physical activity and elevated depressive symptoms and should be considered in future studies.

The relationship between domain-specific physical activity and depressive symptoms in Korean adults: Analysis of the Korea National Health and Nutrition Examination Survey

BACKGROUND

This study aimed to investigate the associations of domain-specific physical activity (PA) with the prevalence of depressive symptoms.

METHODS

We analyzed data from 11,679 (5,056 men and 6,623 women) participants aged ³19 years in the Korea National Health and Nutrition Examination Survey (2016 and 2018 waves). Depressive symptoms were measured using the Korean version of the Patient Health Questionnaire-9 (PHQ-9), with a cut-off score for depression of 11. The participants were first categorized by sex, and then by their PA level in different PA domains into three different groups. We examined the correlations between domain-specific PA and depressive symptoms using logistic regression analysis after controlling for confounders.

RESULTS

Total amount of PA was not associated with depressive symptoms. However, in both sexes, those high in leisure and transport PA had lower levels of depressive symptoms compared with those with no leisure and transport PA (p for trend <0.001). After adjusting for covariates, those high in work PA showed a significantly higher likelihood of having depressive symptoms both in male (OR= 2.74, 95% CI 1.56-4.82) and female participants (OR= 2.84, 95% CI 1.70-4.49), compared to those with no work PA.

LIMITATION

Cross-sectional nature of the data prevents causal associations.

CONCLUSIONS

Although the total amount of PA participation was not associated with depressive symptoms, domain-specific PAs were differently associated with depressive symptoms. Specifically, higher amount of work PA was significantly associated with higher prevalence of depressive symptoms; this topic deserves further attention and future investigation.

Noise Exposure and Quality of Life Among Nurses

BACKGROUND

The purpose of this study was to describe the relationship between noise exposure, selected health conditions, and well-being among nurses.

METHODS

A secondary analysis was performed on data obtained from 3,818 U.S. nurses who responded to a survey regarding noise exposure, health conditions, stress, professional quality of life, and workplace support.

FINDINGS

Those who reported high noise exposure reported more health conditions, higher stress and burnout scores, and lower supportive environments. High noise exposure was significantly associated with lower professional quality of life.

CONCLUSION/APPLICATION TO PRACTICE

Noise may impact the health and quality of professional life of nurses. Occupational health nurses should advocate for the regular monitoring of nurses' exposure to hazardous noise at work, compare it to OSHA permissible levels, and collaborate with the occupational health team to ensure safe noise levels are maintained. Occupational health nurses should advocate for expanded research on effects of noise on health.

Sex and Gender Differences in Occupational Hazard Exposures: a Scoping Review of the Recent Literature

PURPOSE OF REVIEW

Comparative research on sex and/or gender differences in occupational hazard exposures is necessary for effective work injury and illness prevention strategies. This scoping review summarizes the peer-reviewed literature from 2009 to 2019 on exposure differences to occupational hazards between men and women, across occupations, and within the same occupation.

RECENT FINDINGS

Fifty-eight studies retrieved from eight databases met our inclusion criteria. Of these, 30 studies were found on physical hazards, 38 studies on psychological/psychosocial hazards, 5 studies on biological hazards, and 17 studies on chemical hazards. The majority of studies reported that men were exposed to noise, vibration, medical radiation, physically demanding work, solar radiation, falls, biomechanical risks, chemical hazards, and blood contamination; while women were exposed to wet work, bullying and discrimination, work stress, and biological agents. Within the same occupations, men were more likely to be exposed to physical hazards, with the exception of women in health care occupations and exposure to prolonged standing. Women compared to men in the same occupations were more likely to experience harassment, while men compared to women in the same occupations reported higher work stress. Men reported more exposure to hazardous chemicals in the same occupations as women. The review suggests that men and women have different exposures to occupational hazards and that these differences are not solely due to a gendered distribution of the labor force by occupation. Findings may inform prevention efforts seeking to reduce gender inequalities in occupational health. Future research is needed to explain the reasons for sex/gender inequality differences in exposures within the same occupation.

Health and work in Brazil: physical and psychosocial demands

This study aims to describe the prevalence and factors associated of physical and psychosocial demands among Brazilian workers. Data were obtained from the 2013 Brazilian National Health Survey. Physical demand was defined as jobs that require intense physical effort or excessive walking, whereas psychosocial demand was defined as involvement in stressful activities. Multivariate logistic regression was used to estimate the association between demands and health conditions, occupational characteristics, and work conditions. Out of 39,590 participants, 54.4% reported physical demands and 35.5% psychosocial demands at work. After adjustment for sociodemographic characteristics, health conditions, occupational characteristics, and work conditions remained significantly associated with physical or psychosocial workload. The results suggest that in Brazil the work has a high level of physical and psychosocial demands, which are associated with occupational features and health conditions. It is necessary to incorporate work activities as significant factors to investigate the causes of diseases. And the interventions and policies aimed at preventing the negative occupational exposures are urgent, and can contribute to improve physical and psychosocial health at the workplace.

Leisure-time exercise is associated with lower depressive symptoms in community dwelling adults

Physical activity has been associated with enhanced mental health among adults. However, it is not clear in the literature which domains (occupational, transport and leisure-time exercise) and intensities (moderate, vigorous and moderate-to-vigorous) of activity provide the greatest benefits. The aim of the present study was to describe the association of different domains and intensities of physical activity with depressive symptoms in adults. This was a cross-sectional observational study conducted among 209 adults (≥18 years) in Brazil. Depressive symptoms were assessed using the HADS questionnaire (Hospital Anxiety and Depression Scale). Physical activity intensities (moderate, vigorous and moderate-to-vigorous) were device-measured by accelerometry. Physical activity in different domains (occupational, transport, and leisure-time exercise) was self-reported using a questionnaire. Chronological age, ethnicity, body mass index, highest academic achievement, employment status, alcohol consumption, tobacco smoking, chronic morbidity and soft-drink ingestion were adopted as adjustment confounding factors. Linear regression analysis revealed that total self-reported physical activity [β = -0.100 (95%CI: -0.180 to -0.019)] and leisure-time exercise [β = -0.311 (95%CI: -0.468 to -0.155)] were negatively associated with depressive symptoms, but only leisure-time exercise remained significant after adjustment for confounding factors [β = -0.243 (95%CI: -0.409 to -0.076)]. Thus, leisure-time exercise was cross-sectionally associated with lower depressive symptoms in community-dwelling adults.Highlights Leisure-time physical activity was the only physical activity domain associated with lower depressive symptoms.This association appears to be independent of potential confounders.Potential interventions should focus on leisure-time domain.

Psychosocial determinants of physical activity among workers: an integrative review

Knowledge of the psychosocial determinants of physical activity is critical to informing preventive and therapeutic interventions in the workplace. This study reviewed available evidence on psychosocial factors that have been associated with physical activity among workers. Studies were selected in December 2019 from the Scopus, Web of Science, and PubMed databases, with no date limits, using the following search terms: “physical activity”, “physical exercise”, “psychosocial”, “workers”, and “working-age”. Thirty-nine studies published between 1991 and 2019 were evaluated. The determinants of physical activity investigated among workers were smoking status, stress, psychosocial working conditions, depression, anxiety, social relationships, work ability, job satisfaction, burnout, and self-efficacy. Some consistencies and controversies were observed in the associations among these determinants and physical activity and are discussed, as are suggestions for future studies. The findings of this review may be of interest to physical activity interventions designed to reduce psychosocial risks factors in work environments.

Associations of multiple occupational exposures with major depressive and generalized anxiety disorders: Findings from the French National Working Conditions Survey

BACKGROUND

There have been numerous studies on the associations between psychosocial work factors and mental health, but very few of them explored the cumulative effects of these factors. The objectives were to study the associations between multiple occupational exposures and two common mental disorders, major depressive episode (MDE) and generalized anxiety disorder (GAD), among employees in France.

METHODS

The data came from the 2016 French National Working Conditions Survey based on a representative sample of 20,430 employees (8579 men and 11,851 women) aged 15-65 years. MDE and GAD were assessed using the MINI (Mini International Neuropsychiatric Interview) standardized diagnostic interview. Occupational exposures included 21 psychosocial work factors grouped into five dimensions, four factors related to working time/hours, and four physical work exposures. Logistic regression modeling for weighted data was performed to evaluate the associations of occupational exposures with MDE and GAD in men and women separately.

RESULTS

The prevalence of MDE and GAD was higher among women (8.6% and 8.7%, respectively) than among men (4.3% and 4.6%). Most psychosocial work factors were associated with MDE and/or GAD. A linear increase in the risk of MDE/GAD with the number of psychosocial work factors was found for each dimension, except workplace violence. The risk of MDE also increased linearly with multiple physical work exposures.

CONCLUSIONS

Our results showed that a wide variety of occupational exposures were associated with clinical depression and anxiety, and that the risk of disease increased with multiple exposures to psychosocial and physical factors at work.

Disrupted circadian rhythms and mental health

During the evolution of life, the temporal rhythm of our rotating planet was internalized in the form of circadian rhythms. Circadian rhythms are ~24h internal manifestations that drive daily patterns of physiology and behavior. These rhythms are entrained (synchronized) to the external environment, primarily by the light-dark cycle, and precisely controlled via molecular clocks located within the suprachiasmatic nucleus of the hypothalamus. Misalignment and/or disruption of circadian rhythms can have detrimental consequences for human health. Indeed, studies suggest strong associations between mental health and circadian rhythms. However, direct interactions between mood regulation and the circadian system are just beginning to be uncovered and appreciated. This chapter examines the relationship between disruption of circadian rhythms and mental health. The primary focus will be outlining the association between circadian disruption, in the form of night shift work, exposure to light at night, jet lag, and social jet lag, and psychiatric illness (i.e., anxiety, major depressive disorder, bipolar disorder, and schizophrenia). Additionally, we review animal models of disrupted circadian rhythms, which provide further evidence in support of a strong association between circadian disruption and affective responses. Finally, we discuss future directions for the field and suggest areas of study that require further investigation.

Occupational Risk for Post-Traumatic Stress Disorder and Trauma-Related Depression: A Systematic Review with Meta-Analysis

There is evidence suggesting that occupational trauma leads to post-traumatic stress disorder (PTSD) and depression. However, there is a lack of high-quality reviews studying this association. We, therefore, conducted a systematic review with a meta-analysis to summarize the evidence of occupational trauma on PTSD and depression. After a database search on studies published between 1994 and 2018, we included 31 studies, of which only four had a low risk of bias. For soldiers exposed to wartime deployment, the pooled relative risk (RR) was 2.18 (95% CI 1.83-2.60) for PTSD and 1.15 (95% CI 1.06-1.25) for depression. For employees exposed to occupational trauma, there also was an increased risk for PTSD (RR = 3.18; 95% CI 1.76-5.76) and for depression (RR = 1.73; 95% CI 1.44-2.08). The overall quality of the evidence according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was moderate; the evidence was high only for the association between workers after exposure to trauma and development of PTSD. The study results indicate an increased risk of PTSD and depression in soldiers after participation in war and in employees after occupational trauma.

The effect of occupational stress on depression and insomnia: a cross-sectional study among employees in a Ghanaian telecommunication company

BACKGROUND

Depression and insomnia are major psychiatric conditions predicted by occupational stress. However, the influence of occupational stress on these two conditions is under-explored in telecommunication companies, especially in Africa. This research was conducted to assess occupational stress in a Ghanaian telecommunication company and its effect on depression and insomnia.

METHODS

An analytical cross-sectional study was conducted among employees at a telecommunication company in Accra. Structured self-administered questionnaires were used in collecting data from 235 respondents using simple random sampling. The Chi-square test of independence and Wilcoxon Rank-Sum test were employed to assess the significance of associations with subsequent sensitivity analysis using Multiple logistic, Poisson and Probit regression models. Occupational stress was matched on four variables: age of the workers, marital status, responsibility for dependents and work experience, to improve on the estimation of its impact on symptomatic depression and insomnia using the coarsened exact matching procedure.

RESULTS

More males (52.8%) than females participated in this study. The age range for study participants was 20-49 years with a mean of 30.8 ± 6.9 years. The prevalence of excessive occupational stress reported by the employees was 32.8% (95% CI = 26.7-38.8). More than half of respondents (51%) reported depressive symptoms in the past week and only a few (6%) reported being diagnosed with insomnia in the past year. Age, responsibility for dependents and work experience were the only background characteristics that were significantly associated with excessive occupational stress. After controlling for background characteristics, the estimated risk of reporting symptoms of depression among employees who reported excessive stress from work was only 5% higher [ARR; 95% CI = 1.05 (0.94-1.17)] whereas it was 2.58 times the risk of reporting insomnia [ARR; 95% CI = 2.58(0.83-8.00)] compared to those who did not report excessive stress from their jobs. The relative risk reduced to 2.46[ARR; 95% CI = 2.46(0.77-7.87)] and 1.03[ARR; 95% CI = 1.03(0.91-1.17)] for insomnia and depression respectively after employing Poisson regression with CEM.

CONCLUSION

The study found a higher risk of insomnia among employees who reported excessive occupational stress compared to those who did not. However, this study did not find a statistically significant relationship between depression and occupational stress.

Independent relationships between different domains of physical activity and depressive symptoms among 60,202 Brazilian adults

OBJECTIVE

To analyze the association between four key different physical activity (PA) domains and depressive symptoms among Brazilian adults.

METHODS

Data from the Brazilian National Health Survey (n = 60,202; ≥18 years) were used. PA across four different domains (leisure, transport, occupational and household) was collected through specific questionnaires. The cutoff point adopted in each domain was 150 min/week. Depression was evaluated through the Patient Health Questionnaire-9. Multivariable adjusted linear and logistic regression models were applied.

RESULTS

Leisure PA was associated with lower depressive symptoms [β: -0.008 (95% CI: -0.010 to -0.005); OR: 0.69 (95% CI: 0.59 to 0.81)]. Transport PA was also associated with lower depressive symptoms among older adults [β -0.008 (-0.012 to -0.003); OR: 0.70 (95% CI: 0.53-0.94)] but not middle-aged adults. On the other hand, occupational PA [β: 0.003 (95% CI: 0.002 to 0.005); OR: 1.62 (95% CI: 1.38 to 1.91)] and household PA [β: 0.009 (95% CI: 0.006 to 0.012); OR: 1.57 (95% CI: 1.37 to 1.79)] were associated with higher depressive symptoms.

CONCLUSION

The association between PA and depression symptoms varies according to the domains of PA and some appear independent from each other. While leisure PA is associated with fewer depressive symptoms; occupational and household PA appear to be associated with an increased depression risk.

Circadian rhythm disruption and mental health

Circadian rhythms are internal manifestations of the solar day that permit adaptations to predictable environmental temporal changes. These ~24-h rhythms are controlled by molecular clockworks within the brain that are reset daily to precisely 24 h by exposure to the light-dark cycle. Information from the master clock in the mammalian hypothalamus conveys temporal information to the entire body via humoral and neural communication. A bidirectional relationship exists between mood disorders and circadian rhythms. Mood disorders are often associated with disrupted circadian clock-controlled responses, such as sleep and cortisol secretion, whereas disruption of circadian rhythms via jet lag, night-shift work, or exposure to artificial light at night, can precipitate or exacerbate affective symptoms in susceptible individuals. Evidence suggests strong associations between circadian rhythms and mental health, but only recently have studies begun to discover the direct interactions between the circadian system and mood regulation. This review provides an overview of disrupted circadian rhythms and the relationship to behavioral health and psychiatry. The focus of this review is delineating the role of disruption of circadian rhythms on mood disorders using human night shift studies, as well as jet lag studies to identify links. We also review animal models of disrupted circadian rhythms on affective responses. Lastly, we propose low-cost behavioral and lifestyle changes to improve circadian rhythms and presumably behavioral health.

Associations between occupational factors and self-rated health in the national Brazilian working population

BACKGROUND

The literature remains seldom on the topic of self-rated health (SRH) among the national working populations of emerging countries. The objectives of the study were to examine the associations of occupational factors with SRH in a national representative sample of the working population in Brazil.

METHODS

This study relied on a cross-sectional sample of 36,442 workers, 16,992 women and 19,450 men. SRH was the studied health outcome. Sixteen occupational factors related to four topics were studied: employment characteristics, working time/hours, psychosocial work factors and physical and chemical work exposures. The associations between occupational factors and SRH were studied using logistic regression models with adjustment for sociodemographic characteristics (age, ethnicity and marital status). The analyses were performed for each gender separately and using weights.

RESULTS

The prevalence of poor SRH was 26.71%, this prevalence being higher among women (29.77%) than among men (24.23%). The following risk factors for poor SRH were found among men and women: working as a self-employed worker, clerk/service worker, manual worker, part-time (≤ 20 h/week), exposure to work stress, exposure to high physical activity and exposure to sun. The risk factors for poor SRH among women only were: working as a domestic worker and exposure to noise, and among men, working in the agriculture sector.

CONCLUSIONS

Our study suggested that occupational factors related to both physical and psychosocial work environment may be associated with SRH in the working population in Brazil. Improving working conditions may be beneficial for health at work in Brazil.