Working long hours at the office could more than double your risk of developing depression, research has revealed.
The study at the Finnish Institute of Occupational Health found that those who spend more than 11 hours a day - or 55 hours a week - at their desk face an increased risk with younger workers, women and those on low pay with moderate alcohol consumption being the most susceptible.
Lead researcher Dr Marianna Virtanen and her team questioned more than 2,000 Whitehall civil servants between the ages of 35 and 55, with a range of jobs, salaries and working hours, all of whom were recruited in the early 1990s.
After following up with the participants six years later they found a significant link between overtime and depression.
Of those questioned, 66 had experienced a "major depressive episode" during the six-year period.
Those who worked 11 or more hours a day were two and a half times as likely to have one than those who worked seven or eight hours.
Men with higher-paid jobs were less affected by depression. The researchers believed this could be because they were more likely to have a job they enjoyed or higher levels of "social support".
Conversely, higher-earning women were more likely to suffer depression. They believed this could be as a result of women juggling multiple responsibilities, such as family, outside work.
Co-author Professor Stephen Stansfeld, of Queen Mary, University of London, said: "People working very long hours may be working less efficiently, and need to be thinking about their health and stress it may be causing in their home life as well."