The stress is rooted in poverty and can be brought on by money woes, work loads, insufficient health insurance and other factors, said Craig Gundersen of the University of Illinois, who led the study.

• 领导这项研究的伊利诺斯大学的克雷格说，这些压力是根植于贫困和金钱的危机带来的，工作的负荷，不足的健康保险和其他因素。