Psychosocial working conditions and depressive disorder: disentangling effects of job control from socioeconomic status using a life-course approach

Factors affecting major depression in Iran: a mixed-method study

Depression is a major cause of disability and, if left untreated, can increase the risk of suicide. Evidence on the determinants of depression is incomplete, making it challenging to interpret results across studies. This study aims to identify the social, economic, environmental, political, and technological factors influencing the great recession in Iran. The study was conducted in two parts. The first step involved a literature review to identify the factors, using PubMed, Scopus, and Web of Science for the search. The reference lists of all identified articles were reviewed to find relevant studies, and the extracted information was summarized and reported descriptively. The second steps involved compiling and consulting 14 experts from different fields, using a framework analysis method. Twenty-four articles were used as primary sources of information, and a total of 28 factors were found to exist. After removing duplicates and related factors, 19 of these were subsequently declared as factors, resulting in a total of 36 determinants being identified. Most of these factors belong to the social category. The health policies implemented have a significant impact on disease risk factors and ultimately their occurrence. Political decisions and policy-making processes play a crucial role in all areas, particularly in addressing disease risk factors. Severe depression can disrupt all aspects of the healthcare system, underscoring the importance of access to care. Policies concerning physical education, transportation, nutrition, employment, green spaces, recreational facilities, and tobacco are vital in this context. The influence of health policies on disease risk factors and disease occurrence is profound. Severe depression can have far-reaching effects on the healthcare system, emphasizing the critical need for access to care. The formulation of policies to combat depression must be thoroughly evaluated in terms of economic, political, social, technological, and environmental factors. The findings suggest that addressing social inequalities and emphasizing the role of political action, as highlighted by the social determinants of health, should be top priorities in addressing depression. Efforts to prevent depression should incorporate ecological approaches that consider the impact of the socioeconomic environment on depressive symptoms.

Does adolescent depression modify the association between psychosocial job stressors and mental health in emergent adulthood?

BACKGROUND

Job stressors can be particularly harmful to the mental health of disadvantaged groups through differential exposure, differential sensitivity to the effects of exposure, or both. In this paper, we assess the extent to which emergent adult workers with an adolescent history of high depression symptoms may be differentially sensitive to the effect of job stressors on mental health.

METHODS

We conducted a secondary analysis of three waves of the Australian arm of the International Youth Development Study (n = 1262). We used multivariable linear regression to assess whether self-reported measures of high depression symptoms at one or two time points in adolescence (ages 11-16 years) modified the cross-sectional association between four self-reported job stressors (job demands, job control, job strain, and incivility at work) and psychological distress (Kessler-10 scores) in emergent adulthood (ages 23-27 years).

RESULTS

For all four job stressors, there was a consistent pattern of approximately a doubling in the magnitude of association for participants with a history of high depression symptoms at two points in adolescence compared with those with no history of depression. However, results of effect modification analysisfor only job demands and job strain excluded chance as a potential explanation.

CONCLUSIONS

Findings showed partial support for the hypothesis that a history of high depression symptoms in adolescence predicts stronger associations between job stressor exposures and psychological distress among those employed in emergent adulthood. The limitations of this secondary analysis suggest a need for purpose-designed studies to answer this important research question more definitively.

Work-related causes of mental health conditions and interventions for their improvement in workplaces

Mental health problems and disorders are common among working people and are costly for the affected individuals, employers, and whole of society. This discussion paper provides an overview of the current state of knowledge on the relationship between work and mental health to inform research, policy, and practice. We synthesise available evidence, examining both the role of working conditions in the development of mental disorders, and what can be done to protect and promote mental health in the workplace. We show that exposure to some working conditions is associated with an increased risk of the onset of depressive disorders, the most studied mental disorders. The causality of the association, however, is still debated. Causal inference should be supported by more research with stronger linkage to theory, better exposure assessment, better understanding of biopsychosocial mechanisms, use of innovative analytical methods, a life-course perspective, and better understanding of the role of context, including the role of societal structures in the development of mental disorders. There is growing evidence for the effectiveness of interventions to protect and promote mental health and wellbeing in the workplace; however, there is a disproportionate focus on interventions directed towards individual workers and illnesses, compared with interventions for improving working conditions and enhancing mental health. Moreover, research on work and mental health is mainly done in high-income countries, and often does not address workers in lower socioeconomic positions. Flexible and innovative approaches tailored to local conditions are needed in implementation research on workplace mental health to complement experimental studies. Improvements in translating workplace mental health research to policy and practice, such as through workplace-oriented concrete guidance for interventions, and by national policies and programmes focusing on the people most in need, could capitalise on the growing interest in workplace mental health, possibly yielding important mental health gains in working populations.

Hussenoeder F, Conrad I, Riedel-Heller S, Romero Starke K. Psychosocial Occupational Exposures and Mental Illness

BACKGROUND

The purpose of this study is to investigate the exposure-risk relationship between psychosocial occupational stress and mental illness.

METHODS

We conducted a systematic review with meta-analyses as an update of a systematic review published in 2014. The study protocol was registered in PROSPERO (CRD42020170032). Literature searches were carried out in the MEDLINE, PsycINFO, and Embase databases. All procedural steps were performed independently by two reviewers; discordances were solved by consensus. All of the included full texts were subject to a methodological appraisal. Certainty of evidence was determined with the GRADE procedure.

RESULTS

The pooled risk of depression was found to be approximately doubled in workers exposed to high job strain, which is defined as high work demands combined with low job control (effect estimate [EE] = 1.99, 95% CI [1.68; 2.35], heterogeneity [I2] = 24.7%, n = 8). In particular, high work demands are associated with incident depression (ES = 13.8 [1.19; 1.61], I2 = 69.0%, n = 9) and with incident anxiety disorder (ES = 1.79 [1.44; 2.23], I2 = 48.1%, n = 5). There were only a small number of methodologically adequate studies available on burnout, somatoform disorders, suicidal ideation, and suicide. Thus, no pooled risk estimates were calculated, although some individual studies showed a considerably increased risk.

CONCLUSION

Psychosocial occupational stress is clearly associated with depression and anxiety disorders.

Low Job Control and Racial Disparities in Breastfeeding

BACKGROUND

Low job control may predict shorter breastfeeding (BF) among working mothers and may contribute to racial disparities in BF.

METHODS

We used demographic, employment, and health data for n = 631 observations from the Panel Study of Income Dynamics. Job control scores came from a job-exposure matrix.Using path analysis, we assessed whether job control predicted BF and mediated Black-White BF differences. We controlled for education, working hours, marital status, and low birthweight.

RESULTS

Lower job control predicted decreased odds of BF for at least 6 months (odds ratio, 0.61; 95% confidence interval, 0.31-0.90; reference, no BF). Low job control explained 31% of the Black-White difference for both shorter-term and longer-term BF.

CONCLUSIONS

Low job contributes to shorter BF and to BF disparities by race. Intervening to enhance job control could improve BF.

Job control, job demands and job strain and suicidal behaviour among three million workers in Sweden

OBJECTIVE

To investigate the association between job control, job demands and their combination (job strain) and suicide attempts and deaths among male and female workers in Sweden.

METHODS

Job control and demands were measured separately for men and women using a job exposure matrix, which was linked to around three million individuals based on their occupational title in 2005. Suicide attempts and deaths were measured in the hospital and cause of death registers from 2006 to 2016. HRs were estimated using discrete proportional hazards models with annually updated age as the time axis. Models were adjusted for sociodemographic, family, health, labour market and childhood factors, as well as the time-varying effects of unemployment, sick leave and family factors during follow-up.

RESULTS

Low job control was associated with an increased risk of suicide attempts and deaths among both men and women while high job demands tended to be associated with a decreased risk. The combination of job control and job demands (job strain) reflected the increased risk of low control jobs and the decreased risk of high demand jobs. Associations were attenuated but still present after adjustments.

CONCLUSIONS

Low job control is related to suicide attempts and deaths, and this is only partially explained by important covariates measured both prebaseline and during follow-up. Attempts to increase job control among workers may be beneficial in preventing suicide.

The effect of exposure to long working hours on depression: A systematic review and meta-analysis from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury

BACKGROUND

The World Health Organization (WHO) and the International Labour Organization (ILO) are developing the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury (WHO/ILO Joint Estimates), supported by a large number of individual experts. Evidence from previous reviews suggests that exposure to long working hours may cause depression. In this article, we present a systematic review and meta-analysis of parameters for estimating (if feasible) the number of deaths and disability-adjusted life years from depression that are attributable to exposure to long working hours, for the development of the WHO/ILO Joint Estimates.

OBJECTIVES

We aimed to systematically review and meta-analyse estimates of the effect of exposure to long working hours (three categories: 41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on depression (three outcomes: prevalence, incidence and mortality).

DATA SOURCES

We developed and published a protocol, applying the Navigation Guide as an organizing systematic review framework where feasible. We searched electronic academic databases for potentially relevant records from published and unpublished studies, including the WHO International Clinical Trial Registers Platform, Medline, PubMed, EMBASE, Web of Science, CISDOC and PsycInfo. We also searched grey literature databases, Internet search engines and organizational websites; hand-searched reference lists of previous systematic reviews; and consulted additional experts.

STUDY ELIGIBILITY AND CRITERIA

We included working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State but excluded children (aged <15 years) and unpaid domestic workers. We included randomized controlled trials, cohort studies, case-control studies and other non-randomized intervention studies with an estimate of the effect of exposure to long working hours (41-48, 49-54 and ≥55 h/week), compared with exposure to standard working hours (35-40 h/week), on depression (prevalence, incidence and/or mortality).

STUDY APPRAISAL AND SYNTHESIS METHODS

At least two review authors independently screened titles and abstracts against the eligibility criteria at a first stage and full texts of potentially eligible records at a second stage, followed by extraction of data from qualifying studies. Missing data were requested from principal study authors. We combined odds ratios using random-effects meta-analysis. Two or more review authors assessed the risk of bias, quality of evidence and strength of evidence, using Navigation Guide and GRADE tools and approaches adapted to this project.

RESULTS

Twenty-two studies (all cohort studies) met the inclusion criteria, comprising a total of 109,906 participants (51,324 females) in 32 countries (as one study included multiple countries) in three WHO regions (Americas, Europe and Western Pacific). The exposure was measured using self-reports in all studies, and the outcome was assessed with a clinical diagnostic interview (four studies), interview questions about diagnosis and treatment of depression (three studies) or a validated self-administered rating scale (15 studies). The outcome was defined as incident depression in all 22 studies, with first time incident depression in 21 studies and recurrence of depression in one study. We did not identify any study on prevalence of depression or on mortality from depression. For the body of evidence for the outcome incident depression, we had serious concerns for risk of bias due to selection because of incomplete outcome data (most studies assessed depression only twice, at baseline and at a later follow-up measurement, and likely have missed cases of depression that occurred after baseline but were in remission at the time of the follow-up measurement) and due to missing information on life-time prevalence of depression before baseline measurement. Compared with working 35-40 h/week, we are uncertain about the effect on acquiring (or incidence of) depression of working 41-48 h/week (pooled odds ratio (OR) 1.05, 95% confidence interval (CI) 0.86 to 1.29, 8 studies, 49,392 participants, I² 46%, low quality of evidence); 49-54 h/week (OR 1.06, 95% CI 0.93 to 1.21, 8 studies, 49,392 participants, I² 40%, low quality of evidence); and ≥ 55 h/week (OR 1.08, 95% CI 0.94 to 1.24, 17 studies, 91,142 participants, I² 46%, low quality of evidence). Subgroup analyses found no evidence for statistically significant (P < 0.05) differences by WHO region, sex, age group and socioeconomic status. Sensitivity analyses found no statistically significant differences by outcome measurement (clinical diagnostic interview [gold standard] versus other measures) and risk of bias ("high"/"probably high" ratings in any domain versus "low"/"probably low" in all domains).

CONCLUSIONS

We judged the existing bodies of evidence from human data as "inadequate evidence for harmfulness" for all three exposure categories, 41-48, 48-54 and ≥55 h/week, for depression prevalence, incidence and mortality; the available evidence is insufficient to assess effects of the exposure. Producing estimates of the burden of depression attributable to exposure to long working appears not evidence-based at this point. Instead, studies examining the association between long working hours and risk of depression are needed that address the limitations of the current evidence.

Psychosocial working conditions and the risk of diagnosed depression: a Swedish register-based study

BACKGROUND

High job demands, low job control, and their combination (job strain) may increase workers' risk of depression. Previous research is limited by small populations, not controlling for previous depression, and relying on the same informant for reporting exposure and outcome. This study aims to examine the relationship between objectively measured workplace factors and the risk of developing clinical depression among the Swedish working population while controlling for previous psychiatric diagnoses and sociodemographic factors.

METHODS

Control, demands, and job strain were measured using the Swedish Job Exposure Matrix (JEM) measuring psychosocial workload linked to around 3 million individuals based on their occupational titles in 2005. Cox regression models were built to estimate associations between these factors and diagnoses of depression recorded in patient registers.

RESULTS

Lower job control was associated with an increased risk of developing depression (HR 1.43, 95% CI 1.39-1.48 and HR 1.27, 95% CI 1.24-1.30 for men and women with the lowest control, respectively), and this showed a dose-response relationship among men. Having high job demands was associated with a slight decrease in depression risk for men and women. High strain and passive jobs (both low control jobs) were associated with an increased risk of depression among men, and passive jobs were associated with an increased risk among women.

CONCLUSION

High job control appears important for reducing the risk of developing depression even when accounting for previous psychiatric diagnoses and sociodemographic factors. This is an important finding concerning strategies to improve occupational and in turn mental health.

How do employment conditions and psychosocial workplace exposures impact the mental health of young workers? A systematic review

PURPOSE

To assess the quality of the research about how employment conditions and psychosocial workplace exposures impact the mental health of young workers, and to summarize the available evidence.

METHODS

We undertook a systematic search of three databases using a tiered search strategy. Studies were included if they: (a) assessed employment conditions such as working hours, precarious employment, contract type, insecurity, and flexible work, or psychosocial workplace exposures such as violence, harassment and bullying, social support, job demand and control, effort-reward imbalance, and organizational justice; (b) included a validated mental health measure; and (c) presented results specific to young people aged ≤ 30 years or were stratified by age group to provide an estimate for young people aged ≤ 30 years. The quality of included studies was assessed using the Risk of Bias in Non-randomized Studies of Exposures (ROBINS-E) tool.

RESULTS

Nine studies were included in the review. Four were related to employment conditions, capturing contract type and working hours. Five studies captured concepts relevant to psychosocial workplace exposures including workplace sexual harassment, psychosocial job quality, work stressors, and job control. The quality of the included studies was generally low, with six of the nine at serious risk of bias. Three studies at moderate risk of bias were included in the qualitative synthesis, and results of these showed contemporaneous exposure to sexual harassment and poor psychosocial job quality was associated with poorer mental health outcomes among young workers. Longitudinal evidence showed that exposure to low job control was associated with incident depression diagnosis among young workers.

CONCLUSIONS

The findings of this review illustrate that even better studies are at moderate risk of bias. Addressing issues related to confounding, selection of participants, measurement of exposures and outcomes, and missing data will improve the quality of future research in this area and lead to a clearer understanding of how employment conditions and psychosocial workplace exposures impact the mental health of young people. Generating high-quality evidence is particularly critical given the disproportionate impact of COVID-19 on young people's employment. In preparing for a post-pandemic world where poor-quality employment conditions and exposure to psychosocial workplace exposures may become more prevalent, rigorous research must exist to inform policy to protect the mental health of young workers.

Cumulated and most recent job control and risk of disability pension in the Danish Work Life Course Cohort (DaWCo)

BACKGROUND

Previous studies have found low job control to be associated with a higher risk of disability pension (DP). Most studies have measured job control only at one time-point, and there is a lack of knowledge regarding the role of exposure duration. This study examines the prospective association between job control and DP measuring exposure both cumulated throughout work life and most recent.

METHODS

We included 712 519 individuals (about 4.5 million person-years) from The Danish Work Life Course Cohort which follows young employees in Denmark from their entry into the labour market. Job control was assessed with a job exposure matrix and DP with register data on public transfer payments. We adjusted for several potential life course confounders, including physical demands at work and parental socioeconomic position and psychiatric and somatic diagnoses.

RESULTS

Employees in occupations with low job control had a higher risk of DP. There were effects of both cumulated and most recent job control when mutually adjusted. Fully adjusted hazard ratios (HRs) were 1.14 [95% confidence intervals (CIs) 1.11-1.17] and 1.15 (95% CI 1.02-1.29) for cumulated and most recent job control, respectively. Without mutual adjustment, estimates were 1.15 (95% CI 1.13-1.18) and 1.55 (95% CI 1.39-1.72) for cumulated and most recent low job control, respectively.

CONCLUSIONS

Low job control predicts a higher risk of DP, even after adjustment for physical demands at work. The results indicate both gradual and short-term effects of low job control on DP risk.

Cumulative impact of high job demands, low job control and high job insecurity on midlife depression and anxiety: a prospective cohort study of Australian employees

OBJECTIVE

There is a lack of evidence concerning the prospective effect of cumulative exposure to psychosocial job stressors over time on mental ill-health. This study aimed to assess whether cumulative exposure to poor quality jobs places employees at risk of future common mental disorder.

METHODS

Data were from the Personality and Total Health Through Life project (n=1279, age 40-46 at baseline). Data reported on the cumulative exposure to multiple indicators of poor psychosocial job quality over time (ie, a combination of low control, high demands and high insecurity) and future common mental disorder (ie, depressive and/or anxiety symptom scores above a validated threshold) 12 years later. Data were analysed using logistic regression models and controlled for potential confounders across the lifespan.

RESULTS

Cumulative exposure to poor-quality work (particularly more secure work) on multiple occasions elevated the risk of subsequent common mental disorder, independent of social, health, verbal intelligence and personality trait confounders (OR=1.30, 95% CI 1.06 to 1.59).

CONCLUSIONS

Our findings show that cumulative exposure to poor psychosocial job quality over time independently predicts future common mental disorder-supporting the need for workplace interventions to prevent repeated exposure of poor quality work.

Cohort profile: the Danish Work Life Course Cohort study (DaWCo)

PURPOSE

The Danish Work Life Course Cohort (DaWCo) was initiated to study relations between working conditions, health and labour market affiliation using repeated measures of these factors throughout the working life, while accounting for health-differences pre-existing labour market entry.

PARTICIPANTS

The cohort encompasses all 15-30-year-old individuals residing in Denmark who entered the labour market during the years 1995-2009 (960 562 individuals and 7 136 188 observations). Data include information on working conditions measured by job exposure matrices linked with registers on health, labour market affiliation and sociodemographics for both the cohort members and their parents. The median age at cohort entry was 20 years and men and women were equally represented.

FINDINGS TO DATE

Currently, one study has been published, which found that low job control was associated with increased risk of depressive disorder, independently from indicators of socioeconomic position measured throughout the life-course. The present cohort profile presents data regarding the transitions of cohort members between states of labour market affiliation and data on health services use. All cohort members were employed in their year of entry, but this proportion decreased across the years to 82.4% in the 10th year since cohort entry. The proportion of students peaked at 5 years since cohort entry with 13.9%.

FUTURE PLANS

This large prospective cohort offers the possibility to study associations between psychosocial working conditions and rare outcomes and to examine the potential accumulation of effects while accounting for health-differences pre-existing labour market entry. Currently, we are working on analyses on risk of hospital-diagnosed incident depression and disability pensioning. The study is ongoing, and we are planning to extend the study to include the years 2010-2018 and expand the cohort with individuals entering the Danish workforce during these years.