Article Text

Original research
Predicting new major depression symptoms from long working hours, psychosocial safety climate and work engagement: a population-based cohort study
  1. Amy Jane Zadow1,
  2. Maureen F Dollard1,2,
  3. Christian Dormann3,
  4. Paul Landsbergis4
  1. 1Centre for Workplace Excellence, University of South Australia, Adelaide, South Australia, Australia
  2. 2School of Medicine, Institute of Work, Health and Organisations, University of Nottingham, Nottingham, UK
  3. 3Faculty of Law, Management and Economics, Johannes Gutenberg University Mainz, Mainz, Germany
  4. 4Department of Environmental and Occupational Health Sciences, State University of New York Downstate School of Public Health, Brooklyn, New York, USA
  1. Correspondence to Dr Amy Jane Zadow; amy.zadow{at}


Objectives This study sought to assess the association between long working hours, psychosocial safety climate (PSC), work engagement (WE) and new major depression symptoms emerging over the next 12 months. PSC is the work climate supporting workplace psychological health.

Setting Australian prospective cohort population data from the states of New South Wales, Western Australia and South Australia.

Participants At Time 1, there were 3921 respondents in the sample. Self-employed, casual temporary, unclassified, those with working hours <35 (37% of 2850) and participants with major depression symptoms at Time 1 (6.7% of 1782) were removed. The final sample was a population-based cohort of 1084 full-time Australian employees.

Primary and secondary outcome measures The planned and measured outcomes were new cases of major depression symptoms.

Results Long working hours were not significantly related to new cases of major depression symptoms; however, when mild cases were removed, the 41–48 and ≥55 long working hour categories were positively related to major depression symptoms. Low PSC was associated with a threefold increase in risk for new major depression symptoms. PSC was not related to long working hours, and long working hours did not mediate the relationship between PSC and new cases of major depression symptoms. The inverse relationship between PSC and major depression symptoms was stronger for males than females. Additional analyses identified that WE was positively related to long working hours. Long working hours (41–48 and ≥55 hours) mediated a positive relationship between WE and major depression symptoms when mild cases of major depression were removed.

Conclusion The results suggest that low workplace PSC and potentially long working hours (41–48; ≥55 hours/week) increase the risk of new major depression symptoms. Furthermore, high WE may increase long working hours and subsequent major depression symptoms.

  • mental health
  • occupational & industrial medicine
  • depression & mood disorders

Data availability statement

Data are available in a public, open-access repository. The data are stored in the Australian Data Archive (ADA) at the Australian National University. The website for this resource is and the email address is

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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Data availability statement

Data are available in a public, open-access repository. The data are stored in the Australian Data Archive (ADA) at the Australian National University. The website for this resource is and the email address is

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  • Contributors AJZ conceived and designed the study, assisted with the statistical analysis and drafted the manuscript. MFD completed the statistical analysis and substantially assisted with the manuscript draft. CD and PL advised on statistical aspects, data interpretation, and contributed to the manuscript draft. All authors reviewed the manuscript and approved the final version to be published. All authors had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

  • Funding This study was supported by three Australian Research Council grants: (1) DP087900 Australian Research Council Discovery Grant. Dollard MF, Winefield AH, LaMontagne AD, Taylor AW, Bakker AB, Mustard C. Working wounded or engaged? Australian work conditions and consequences through the lens of the job demands-resources model. (2) LP100100449 Australian Research Council Linkage Grant. Dollard MF, Winefield AH, Taylor AW, Smith PM, Nafalski A, Bakker A, Dormann C. State, organisational, and team interventions to build psychosocial safety climate using the Australian Workplace Barometer and the StressCafé.(3) FL200100025 Australian Research Council Laureate Fellowship. Dollard MF.

  • Disclaimer The research was designed, conducted, analysed and interpreted entirely by the authors independent of the funding sources.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.