Job burnout strikes doctors more often than it does other employed people in the United States, according to a national survey that included more than 7,000 doctors.

More than four in 10 U.S. physicians said they were emotionally exhausted or felt a high degree of cynicism, or "depersonalization," toward their patients, said researchers whose findings appeared in the Archives of Internal Medicine.

"The high rate of burnout has consequences not only for the individual physicians, but also for the patients they are caring for," said Tait Shanafelt of the Mayo Clinic in Rochester, Minnesota, who led the research.