Women who work more than 55 hours a week are at a higher risk of depression - with about 4.6% more depressive symptoms found in women who worked for all or most weekends.

This was uncovered in research by University College London and Queen Mary University of London, in a study of 20,000 adults.

After taking into account age, income, health and job characteristics, women who worked extra-long hours had 7.3% more depressive symptoms than women working a standard 35-40 week.

Meanwhile, working on the weekend was linked to a higher risk of depression among both sexes. Women who worked for all or most weekends had 4.6% more depressive symptoms on average compared to women working only weekdays. Men who worked all or most weekends had 3.4% more depressive symptoms than men working only weekdays.

However, the researchers could not share the exact causes for the relationship, stating that it is "an observational study." However, Gill Weston (UCL Institute of Epidemiology and Health Care), PhD candidate and lead author of the study, pointed out that women who work most weekends tend to be concentrated in low-paid service sector jobs, which have been linked to higher levels of depression.

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The study also showed the following about the working hours of men and women, and their impact:

  • Men tended to work longer hours in paid work than women.
  • Having children: Mothers tended to work fewer hours than women without children, fathers tended to work more hours than men without children.
  • Two thirds of men worked weekends, compared with half of women.
  • Those who worked all or most weekends were more likely to be in low skilled work and be less satisfied with their job and earnings than those who only worked weekdays or some weekends.

"Women in general are more likely to be depressed than men, and this was no different in the study," Weston said. "Independent of their working patterns, we also found that workers with the most depressive symptoms were older, on lower incomes, smokers, in physically demanding jobs, and who were dissatisfied at work."

She added: "We hope our findings will encourage employers and policy-makers to think about how to reduce the burdens and increase support for women who work long or irregular hours - without restricting their ability to work when they wish to.

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