That figure is three percentage points higher than in the 2012 findings.
But the rise in stress is most alarming among young people. One in four Swiss employees under 30 said they were very often or always stressed at work, up from 19 percent five years ago.
That stress affects men and women equally, according to the survey.
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Just under half (49 percent) of people suffering these high levels of stress said they were emotionally exhausted at work and were therefore more likely to suffer a burnout.
People suffering from emotional exhaustion are six times more likely to suffer bouts of moderate to serious depression, according to the authors of the Swiss Health Study.
In 2017, one in every two employees suffered from at least three of nine so-called “psychosocial risks” including fear of the workplace, discrimination or violence at work, or time pressure.
Men were more likely to experience time pressure (54 percent against 50 percent for women) and lack of social support (21 percent against 18 percent for women).
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Meanwhile, problems such as discrimination and violence were more likely to affect women (21 percent versus 18 percent for their male colleagues). Women also had more emotional demands placed on them (26 percent against 23 percent for men).
Rise in the number of sick days
The new Swiss Health Survey comes in the wake of a study last year showing the number of sick days taken by people in Switzerland because of stress and other mental health issues had shot up by 35 percent in the last five years.
And another study showed that a more balanced work-life relationship could represent a boost to the Swiss economy of 6.5 billion Swiss francs (€5.68 billion), approximately 1 percentage point of GDP.
Full-time employees in Switzerland can work a maximum of 45 to 50 hours a week depending on the sector.
According to the Swiss statistics office in 2016 the average hours worked was 41 hours and ten minutes (down 13 minutes on the previous year). That’s relatively high compared to other countries, with France on 35 hours (at least, by law) and the UK on 36.5 hours, according to the World Economic Forum.
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