Type D breaks medical psychology

The  scientific spotlight is on the Department of Medical Psychology and its study of the type D personality and its relation to recovery after a heart attack. The link between increased mortality and having a type D personality, according to the critics, cannot be proved. The scientists claim that the findings in the type D research are based on a too small group of patients and that they are exaggerated. Individuals with a Type D personality have the tendency to experience increased negative emotions across time and situations and tend not to share these emotions with others, because of fear of rejection or disapproval.

People with type D personality, according to the department chairman Johan Denollet (professor of medical psychology at TiU) face an increased risk of death, re-experiencing a heart attack or getting a cardiac arrest, independently of traditional risk factors such as disease severity. Currently there are four articles in the scientific press that question the relationship between reduced recovery after a heart attack and type D personality,  two articles of the spring issue of The Society of Behavioral Medicine and two articles in the Journal of Psychosomatic Research from July and September.

The critics question the methods used, the statistics and the concept of the study. All surveys are repeated on people from the same study group, and that’s why the critics talk about the scientific inbreeding. New, larger studies outside the Tilburg research group have not established any link between the increased risk of death after a heart attack and having a depressed personality.

Comment from Denollet

Johan Denollet gave the following response: “Certainly, I take the articles in the magazines  seriously. There are legitimate issues raised, issues that I’ve always sensed and which I will certainly study myself.”

Scientific inbreeding? “It is true that we repeated our own research a few times and that we have published a lot about it. This is normal, we made  fifteen years ago and we have done thorough research on it. ”

But what do you think of the fact that research outside of your department could not find any relationship between type D personality and reduced recovery after a heart attack? “The studies  that show no link were probably done with patients not after a heart attack, but with older patients with heart failure, the final stage of a long illness. In my opinion, this is no coincidence. Indeed, there are also many physical causes (such as kidney failure and diabetes) that may play a role, so the relationship between type D and mortality is difficult to show. In 2010 we were the first group who published that there might be no such link in case of elderly patients with heart failure. We did the same research with 56-57 years old patients and, on average, we could prove that the link exists. There are also recent studies by other research groups in Germany, Sweden and England, that also showed a connection between type D personality and heart disease. Meanwhile, the type D questionnaire is validated in more than 20 languages, and future research in all these countries will give more clarity about the scientific importance. “