Stress is a major contributor to heart disease, so it’s no surprise that researchers have associated anxious Type A personalities with a greater risk of heart attack. Now they’ve connected another personality profile with heart problems: Type D.
People who are Type D, says Johan Denollet, a professor of psychology at Tilburg University in The Netherlands, have a negative outlook on life and tend to suppress these dour feelings and emotions. For the most part, they are reserved and socially inhibited. But, he insists, they are not necessarily depressed. Individuals classified as Type D do not exhibit all the symptoms of clinical depression, which include changes in mood that vary more than the chronic consistency of personality traits. (More on Time.com: Watch a video on the mouth guard that may help you cope with stress)
In a study published in Circulation, Denollet and his colleagues pooled 19 studies involving more than 6,000 heart patients with Type D personalities and measured their rates of recurrent heart events compared to non–Type D individuals. Those with the Type D profile were three times more likely to have additional heart problems, primarily heart attack or death due to heart disease, than those with more upbeat personalities.
Even after accounting for the depressive effect that having heart disease may have on a person’s outlook, the researchers found the association remained strong. They also controlled for the nature of patients’ recovery from heart procedures. “The prognostic effect of the Type D personality cannot be explained away by the adverse reactions to bypass [procedures] or the severity of the cardiac disorder,” says Denollet. “Type D personality was really an independent prognostic factor.” (More on Time.com: Under Stress? You Might Suffer Less If You’re Male)
This doesn’t mean everyone who walks around under a cloud is primed for a heart attack. But Type D personalities may share some biological features with the high-risk Type A group. Because they internalize their feelings, people with negative outlooks tend to have high levels of the stress hormone cortisol, and they also harbor enhanced levels of inflammatory factors that can damage heart arteries and promote atherosclerosis.
And because they are less likely to be open to constructive changes in their lifestyle, they are also more likely to smoke and be physically inactive, says Denollet. The net of these factors is that Type D individuals may experience heart disease sooner than other personality types, according to Denollet’s study. (More on Time.com: Even More Evidence for the Health Benefits of Drinking)
So can Type D people lower their risk of heart problems? Perhaps. Denollet notes that it’s not easy for these individuals to open up about whatever stresses or negative feelings they are holding inside, so it’s important for physicians who recognize the profile in their patients and spend more time attempting to draw these patients out. Helping them address their sources of anxiety, through counseling or active intervention to change whatever may be causing them stress, can help them brighten their negative outlook. It’s also useful, he says, to involve family members such as spouses to determine whether personality traits are putting patients at higher risk of heart problems.
Denollet is hoping to expand his work beyond just heart patients. He is collaborating with a group in Iceland to determine whether a Type D profile can identify healthy individuals who are at greatest risk of a heart event. The personality test is made up of 14 items that take a few minutes to complete, he says, which should make it an relatively easy screen for doctors to use during regular checkups.
More on Time.com: