Stress may increase the risk for heart disease, especially in younger people.

Researchers writing in BMJ used Swedish data on 136,637 people diagnosed with stress-related disorders, including post-traumatic stress disorder, acute stress reaction and others. They compared them with 171,314 unaffected siblings, and with 1,366,370 people in the general population without a stress disorder diagnosis. They tracked their health for up to 27 years.

After controlling for physical and mental health history, age, sex, income and other factors, they found that a person with a stress disorder was 29 percent more likely to develop cardiovascular disease than a sibling without a stress disorder, and 37 percent more likely than those in the general population. The risk was even greater in the first year after the diagnosis — 64 percent higher than a sibling, and 71 percent higher than the general population.

The association between stress and cardiovascular disease was especially strong for people under 50.

“Our study included only people with a diagnosed stress disorder,” said the lead author, Huan Song, a postdoctoral researcher at the University of Iceland. “But people with depression and anxiety are also at higher risk for cardiovascular disease. In fact, anyone with stress is at higher risk, but here we focused on people with acute stresses and severe psychiatric reactions to them.”