According to findings published in the journal PloS ONE on Wednesday, people who regularly work 11 hours or more each day are more than twice as likely to experience a major episode of depression than colleagues who stick with an eight-hour work day.
Researchers from the Finnish Institute of Occupational Health and Queen Mary University of London examined records of more than 2,000 London-based white-collar workers in a five-year study. None of the recruits had a recent history of depression when they were enrolled in the study.
Those who worked 11 hours or more each day were between 2.3 and 2.5 times more likely to develop a major depressive episode than those who worked seven-to-eight-hour days. Researchers controlled for other factors, such as smoking, alcohol consumption, and general health.
"Long working hours don't just affect us because of the pressure and intensity of work itself, they affect us because we don't have enough time for all the other things we need for good mental health, such as good quality sleep, relationships, and opportunities for rest and exercise," Paul Farmer, chief executive of leading British mental health charity Mind, told WebMD. "Every time we squeeze more work in, many of us will be squeezing something else out.
While other studies have been done on work hours and depression, "results have not been conclusive because there is no standardized benchmark for what constitutes a 'normal' working day," reports WebMD.
A previous study by the same researchers, which also relied on the same database of London-based workers, found that overtime was linked with a 60 percent increase in coronary heart disease.