Stress-related disorders, including post-traumatic stress disorder (PTSD), may be linked to a greater risk of cardiovascular disease (CVD), according to a new Swedish study published in The BMJ.
Stress-related disorders are a group of psychiatric conditions triggered by stressful life events or mental distress. This includes post-traumatic stress disorder (PTSD), acute stress reaction and adjustment disorder. The presence of a life threatening traumatic event is a prerequisite for PTSD and acute stress reaction, whereas adjustment disorder generally refers to mental or physical distress triggered by a significant life change.
Stressful life events may include the death of a loved one, a diagnosis of a life threatening illness, natural disasters, or violence, write the authors.
The new findings show that the risk of severe and acute CVD events — such as cardiac arrest and heart attack — was particularly high in the first six months after diagnosis of a stress-related disorder, and within the first year for other types of CVD.
Previous studies have shown that severe stress reactions triggered by significant life events or trauma are linked to the development of CVD. But most research on this issue has focused on male veterans or those currently active in the military with PTSD or PTSD symptoms. And because of the smaller size of these samples, data on the effects of stress reactions on different types of CVD are limited.
So to shed some light on this, the new study used Swedish population and health registers to investigate the role of clinically diagnosed PTSD, acute stress reaction, adjustment disorder, and other stress reactions in the development of CVD. They controlled for family background, medical history and underlying psychiatric conditions.
The research team matched 136,637 patients diagnosed with a stress-related disorder between January 1987 and December 2013 with 171,314 full siblings who were free of stress-related disorders and CVD.
For each patient, 10 people from the general population who were unaffected by stress-related disorders and CVD at the date of the patient’s diagnosis were randomly selected. Exposed and unexposed people were then individually matched by birth year and sex.
Severe stress reactions to significant life events or trauma were associated with a greater risk of several types of CVD, especially during the first year after diagnosis, with a 64 percent higher risk among patients with a stress-related disorder compared to their unaffected sibling. The findings were similar for patients with a stress-related disorder compared to the general population.
There was also a stronger link between stress-related disorders and early onset CVD — cases of disease which developed before the age of 50 — than later onset ones.
Out of all studied CVDs, the excess risk during the first year was strongest for heart failure, and for major blood clots (embolism and thrombosis) after one year.
There were similar associations across sex, calendar period, medical history, and family history of CVD. But those who were diagnosed with a stress disorder at a younger age had a heightened risk of CVD.
Since this is an observational study, it can’t establish cause. The researchers point out evidence from other studies suggesting a biological link between severe stress reactions and cardiovascular disease development. And they can’t rule out the role of other unmeasured behavioral factors, such as smoking and alcohol intake.
But they say that their study is the first to investigate the link between a number of stress-related disorders and several types of CVD using sibling-based comparisons, among both men and women.
The researchers add that doctors should be aware of the “robust” link between stress-related disorders and a higher subsequent risk of cardiovascular disease, particularly during the months after diagnosis.
“These findings call for enhanced clinical awareness and, if verified, monitoring or early intervention among patients with recently diagnosed stress related disorders,” they conclude.