That's the conclusion reached by researchers at Pittsburgh's Carnegie-Mellon University.
They surveyed more than 6,300 individuals at intervals between 1983 and 2009.
They found stress had increased 24 percent for men and 18 percent for women over the course of the study.
The study's authors also say stress levels reduce for both men and women as they age.
The findings are published in the Journal of Applied Social Psychology.
