Psychological stress tends to lower productivity and performance among workers, says a new study.

“There is a large economic cost and a human cost,” said Debra Lerner, director of the Institute for Clinical Research and Health Policy Studies at Tufts Medical Centre, who led the study.

Depression has a greater effect on attendance and productivity than the “vast majority” of other health conditions with the exception of musculoskeletal problems and insomnia, said Ronald Kessler, professor in health care at Harvard Medical School.

Researchers screened 14,268 adult employees and ultimately compared 286 depressed workers to 193 who were not depressed. They recruited participants between 2001 and 2003 from doctors’ offices.

“They’re often very fatigued and have motivational issues. They also may have difficulty handling the pacing of work, managing a routine, performing physical job tasks and managing their usual workload,” said Ms. Lerner.

The findings suggest that there is a link between productivity and an employee’s ability to control his or her work, according to a Tufts university release.

“The workplace does play an important part,” Mr. Lerner said.

The study is slated for publication in the January/February issue of the American Journal of Health Promotion.