In the study, which appears in the journal Circulation: Cardiovascular Quality and Outcomes, Denollet and his colleagues re-analyzed data from 19 studies comprising more than 6,000 people. (Denollet led many of the studies himself.) They found that heart patients with type D personalities were 3.7 times more likely than those with other personality types to experience future heart problems. In addition, the Type D patients were three times more likely to experience depression, anxiety, and other forms of emotional distress.
The link between heart risk and Type D personality persisted even after the researchers took into account whether the study participants were depressed. This suggests that Type D personality presents a health risk independent of depression, a condition that itself increases the risk of heart disease.
Type D personality and depression are not the same thing, although there is some overlap between them. While depression tends to occur in episodes, the emotional distress associated with Type D personality is chronic and may never reach the level of clinical depression, according to the study.
The findings shine a light on a high-risk population, Dr. Goldberg says, adding that doctors should ask patients about their social support systems in an effort to identify those who may have Type D traits. (For just that purpose, Denollet and his colleagues have developed a questionnaire that asks patients to rank how well 14 statements—such as “I take a gloomy view of things” and “I find it hard to start a conversation”—apply to them.)
Type D personalities aren’t doomed to heart problems, but they should be aware of their risk and take precautions, such as enrolling in cardiac rehabilitation if they’ve had a heart attack, the researchers say.
“Type Ds need to take a more active approach toward their own health,” Denollet says. “They may benefit from counseling, so that they can learn how to deal with everyday stressful situations in a more adaptive way. There are some proactive tools and actions that these people can take to get rid of the negative emotions they keep inside.”