Here's some positive news about the economy: A bad one may be good for your health.

Researchers at the Institute for Social Research at the University of Michigan have concluded that life expectancy rose and general health improved during the Great Depression and economic recessions between 1920 and 1940.

"The finding is strong and counterintuitive," Tapia Granados, the lead author of the study, said in a press release. "Most people assume that periods of high unemployment are harmful to health."

Life expectancy rose from 57.1 in 1929 to 63.3 years in 1932, according to the analysis by Granados and Ana Diez Roux, the press release said. The increase occurred for both men and women, and for whites and non-whites, the study found.

Conversely, the researchers also found that mortality increased and life expectancy declined during times of economic expansion in the same 20-year period.

The study did not analyze why this trend occurred, but the researchers offered some possible explanations.

Granados said there is less work to do during recessions so employees can work at a slower pace. There is more time to sleep, and because people have less money, they are less likely to spend as much on alcohol and tobacco, the press release said.

The release listed several other possible causes, including the fact that pollution tends to increase during times of economic expansion and businesses may hire inexperienced workers who may be more likely to injure themselves.

The study was published in the current issue of the Proceedings of the National Academy of Sciences.