Depression symptoms mediate the association between workplace stress and interleukin 6 in women, but not men: The Whitehall II study

How does lowering psychosocial risks influence sickness absence? A prospective cohort study analyzed as a quasi-experiment

BACKGROUND

We examined how reducing work-related psychosocial stressors affected long-term sickness absence of younger and older employees.

METHODS

We used data from 43 843 public sector employees in Finland who participated in surveys in 2018 and 2020. We assessed psychosocial factors, such as job demands, job control, work effort, job rewards and worktime control. We obtained sickness absence data from registers for spells longer than 10 consecutive working days. We applied age-specific propensity score weighting and generalized linear models to estimate the effects of changes in psychosocial factors between 2018 and 2020 on sickness absence in 2020.

RESULTS

Among employees under 50 years, increasing job rewards by 1 SD reduced the risk of sickness absence by 17% [risk ratio (RR) 0.83, 95% CI 0.72-0.96]. Among employees aged 50 years or older, decreasing job demands by 1 SD reduced the risk of sickness absence by 13% (RR 0.87, 95% CI 0.78-0.98), and increasing job control by 1 SD reduced the risk by 12% (RR 0.88, 95% CI 0.76-1.01). Changes in efforts and worktime control had no significant associations with sickness absence.

CONCLUSIONS

Reducing psychosocial stressors can lower the occurrence of long-term sickness absence, but the associations differ by age group. Younger workers benefit more from enhancing job rewards, while older workers benefit more from lowering job demands and increasing job control. To establish the causal impact of psychosocial risk reduction on sickness absence across age groups, future research should employ randomized controlled trials as the methodological approach.

Estrogen, the Peripheral Immune System and Major Depression – A Reproductive Lifespan Perspective

Major depression is a significant medical issue impacting millions of individuals worldwide. Identifying factors contributing to its manifestation has been a subject of intense investigation for decades and several targets have emerged including sex hormones and the immune system. Indeed, an extensive body of literature has demonstrated that sex hormones play a critical role in modulating brain function and impacting mental health, especially among female organisms. Emerging findings also indicate an inflammatory etiology of major depression, revealing new opportunities to supplement, or even supersede, currently available pharmacological interventions in some patient populations. Given the established sex differences in immunity and the profound impact of fluctuations of sex hormone levels on the immune system within the female, interrogating how the endocrine, nervous, and immune systems converge to impact women’s mental health is warranted. Here, we review the impacts of endogenous estrogens as well as exogenously administered estrogen-containing therapies on affect and immunity and discuss these observations in the context of distinct reproductive milestones across the female lifespan. A theoretical framework and important considerations for additional study in regards to mental health and major depression are provided.

Within subject rise in serum TNFα to IL-10 ratio is associated with poorer attention, decision-making and working memory in jockeys

Jockeys work in high-risk environments that rely heavily on attention- and decision-making to perform well and safely. Workplace stress literature has often overlooked the impact of stress on cognition, and designs that include physiological measures are rare. This study assessed the prospective concurrent relationships between workplace stress, depression symptoms and low-grade inflammation with cognitive performance among professional jockeys. Professional jockeys (N = 35, M_age = 32.29) provided information on workplace stress and depression symptoms, with serum levels of inflammatory cytokines (IL-6, IL-10, TNFα) and cytokine balance (IL-6: IL-10, TNFα: IL-10) quantified with SIMOA, and cognitive performance with CogSport computer-based testing battery. These measures were repeated after a twelve-month interval. Increased workplace stress between testing intervals was associated to an increased cytokine imbalance (β = 0.447, p = .015) after controlling for age and gender. Increases in cytokine imbalance occurred in unison with decreases in attention (β = 0.516, p = .002), decision-making (β = 0.452, p = .009) and working memory (β = 0.492, p = .004). These preliminary findings suggest the underlying mechanisms linking workplace stress and reduced cognitive performance may be influenced by measures of low-grade inflammation and specifically a cytokine imbalance. Our findings suggest a measure of cytokine balance may explain the heterogenous findings in previous studies that have focussed solely on the association of workplace stress with pro-inflammatory cytokines. Future work is needed however, to provide a broader evidence-base for our claims to better inform designs to intervene in the higher workplace stress-poorer cognition relationship.

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Increases in workplace stress are associated with increased cytokine imbalance.

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Increased cytokine imbalance is associated with reduced cognitive performance.

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Workplace stress better predicts cytokine imbalance than individual cytokines.

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Cytokine imbalance better predicts cognition than individual cytokines.