People coping with psychological trauma have a heightened risk of developing cardiovascular disease, a large-scale study finds.
Researchers used national health registers to identify 136,637 Swedish patients with no history of cardiovascular disease who were diagnosed with a stress-related disorder — a cluster of mental health conditions, including post-traumatic stress disorder, triggered by acute trauma — from 1987 to 2013. The team compared each of these patients with siblings and with unrelated people of the same age and sex, both of whom had a clear bill of mental and heart health.
In the patients’ first year after being diagnosed, those with a stress-related disorder had a 64 percent higher risk of developing cardiovascular disease than their siblings without a mental health diagnosis, and a 70 percent higher risk than unrelated patients, the scientists report.
The cardiovascular disease accounted for included heart failure, arrhythmia, stroke, hypertension and heart attack. The study found that those with a stress-related disorder were most vulnerable in the year following their mental health diagnosis: They had nearly seven times the risk of heart failure compared with their siblings. After one year, the patients with a stress diagnosis had a 29 percent higher risk for all cardiovascular disease than their siblings.
The researchers followed the patients for up to 27 years. During that period, on average, 10.5 out of every 1,000 people with stress-related disorders developed cardiovascular disease each year. By contrast, 8.4 out of 1,000 people in the siblings group and 6.7 of every 1,000 in the general population developed cardiovascular disease each year
The study, published April 10 in the British Medical Journal, builds on a growing body of research linking mental health with heart disease.
“Researchers have been connecting mental health and cardiovascular disease for at least 40 years,” says Mary Whooley, a professor of medicine at the University of California, San Francisco, who was not involved in the study. But much of the previous research into the link between psychiatric stress and heart health has focused on populations of male veterans with PTSD, says Whooley, who is also director of cardiac rehabilitation at the San Francisco Veterans Affairs health care system.
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“What’s really impressive about this study is the enormous number of patients,” Whooley says. More than half the patients with stress-related disorders were women. By comparing siblings, the study was also able to better control for genetic traits and childhood experiences that might contribute to a person’s risk of developing cardiovascular disease.
How stress and other mental health conditions affect the heart remains a mystery. Previous studies have pointed to physiological mechanisms as well as lifestyle factors. It could be that heightened activity in a brain region called the amygdala, which plays a role in processing emotions, especially fear, triggers inflammation that leads to cardiovascular disease. And people with PTSD are more likely to smoke heavily, which increases their risk of developing heart disease.
“The large majority of humans are at some point in their lives exposed to trauma,” says Huan Song, a postdoctorate student at the University of Iceland who led the study. People lose loved ones, survive accidents and natural disasters and witness violence. “Medical providers should be aware that these vulnerable populations also suffer heightened risks of various cardiovascular diseases,” she says.
Editor’s Note: This story was updated on April 22, 2019, to correct that stress disorder patients have nearly seven times the risk of heart failure compared with their siblings, instead of four times the relative risk, and to correct that each year 10.5 of every 1,000 people diagnosed with a stress disorder developed cardiovascular disease, not 10.5 percent over 27 years.