Combination of long hours, overwork increases depression risk: Study

Employees who work long hours with high job demands are more likely to develop depression, according to a recent study. Researchers found workers who initially had the long hours/overworked combination were 15 times more likely to have depression when re-evaluated one to three years later.

The researchers analyzed job and workplace factors affecting depression risk in a group of 218 Japanese clerical workers. They found that employees who worked long hours (at least 60 per week) and had high job demands (defined as "usually" having too much work) were at higher risk of depression, found the report in the August Journal of Occupational and Environmental Medicine, the official publication of the American College of Occupational and Environmental Medicine (ACOEM).

On adjustment for other factors, workers who went from long hours/overworked to non-long hours/overworked status were at lower risk of depression, while those who moved from non-long hours/overworked to long hours/overworked were at increased risk. The risk of depression in long hours/overworked workers seemed to increase over time.

Previous studies have reported mixed results regarding the physical and mental health effects of long work hours. The new study highlights the importance of high job demands and feeling overworked — combined with long work hours — as a risk factor for depression in employees.

The authors, Takahashi Amagasa and Takeo Nakayama of Kyoto University School of Public Health, concluded:

"By targeting long hours/overworked, especially changes in this status, mental health measures that effectively reduce the occurrence of major depressive disorder will become possible by controlling factors in the occupational environment."