While some 13 million Americans are out of work these days, those still with jobs might have a strange new thing to worry about — getting a promotion can be bad for you, a new study suggests.

British researchers found that when people get promoted, they suffer on average about 10 percent more mental strain and are less likely to find the time to go to the doctor.

"Getting a promotion at work is not as great as many people think. Our research finds that the mental health of managers typically deteriorates after a job promotion, and in a way that goes beyond merely a short-term change," said Chris Boyce of the University of Warwick. "There are no indications of any health improvements for promoted people other than reduced attendance at GP surgeries [i.e. doctors visits], which may itself be something to worry about rather than celebrate."

Other research has found stress can be deadly, raising the risk of everything from the common cold to cancer. Other recent revelations about stress:

Those who were promoted reported on average a 20 percent fall in their visits to a doctor following their promotion. The researchers figure this owed to the stress of the new job and the sudden lack of time.

The research, using data from an annual survey of Brits, included information about about 1,000 people who had been promoted. The findings will be presented later this month at a conference of the Royal Economic Society.