Sweden may be one of the richest and safest countries in the world, but being a pastor there is a risky business. That's according to a new survey which says female clergy are the most at-risk group for having time off work with psychological illnesses. Their male colleagues fare little better, being third on the list of at-risk occupations.

The figures come from Sweden's Social Insurance Agency, which doesn't offer an explanation of what factors might be responsible for the trend. Church leaders have suggested it may be because many clergy are 'on call' in a way which is usual for the rest of the country.

Sweden recently introduced a six hour work day and although clergy technically abide by this ruing, a spokesperson for the union which represents them said, "There's a culture that requires you as a priest to be reachable even when you're off. As a priest, you do not say to a person who is in great need to talk, 'sorry but I'm off to go and play golf.'" The country also has more paid leave than most others in the EU – but again, this doesn't seem to be helping stressed out clergy.

Priests, pastors and ministers are working more hours than teachers and those in the tech industry according to separate research. That's despite figures showing the Sweden has one of the lowest rates of church attendance in the West.

There have been concerns for pastors in other countries too, with the New York Times reporting, "members of the clergy now suffer from obesity, hypertension and depression at rates higher than most Americans."

British ministers aren't immune from the problem either. A recent report from the Church Times suggested, "More than three-quarters of the clergy questioned in a survey about their mental health would welcome help with managing stress."