Type D Personality and Cardiovascular Outcomes

Recent debate [1–3] on the association between type D (distressed) personality and cardiovascular outcomes includes the suggestion [3] that ‘pulling the plug [on type D research] is better than keeping it on life support’. The authors [1–3] rightly argue that the practice of dichotomization of the interaction of negative affectivity (NA) and social inhibition (SI) has been methodologically problematic in type D studies. However, it has been suggested that type D is better represented as a dimensional (i.e., NA × SI) rather than categorical construct [4]. Furthermore, the DS14 (the measure for type D) appears to have sound psychometric properties, including temporal stability and predictive, convergent and construct validity [5]. De Voogd and colleagues [3] further argue that type D studies might have overestimated the association between type D and cardiovascular outcomes. This finding again might be a methodological consequence of type D dichotomization in previous studies. The impact of type D or “general psychological distress” [6] on mortality and morbidity in some cardiac (e.g. chronic heart failure) patient groups is yet to be determined as three studies have reported null findings with regard to mortality [7, 9]. Also, in general in research conducted by others outside of Denollet's research group, the follow-up period of patients rarely exceed 2 years. Conceptually, it makes sense to investigate who is at risk of greater distress in these populations over a long period of time given that type D is a cumulative and systematic measure of personality. It has been shown that those with type D use more passive and maladaptive avoidance coping strategies [10], which are associated with higher levels of perceived stress and burnout symptoms. Yet there is accumulating evidence that type D patients are not doomed because they have type D personality: The majority of type D studies indicate that the effect of type D may be altered over time [6]. Also, we view maladaptive coping processes as modifiable risk factors for cardiovascular and other diseases. Targeted interventions have the potential to teach new coping strategies to deal more effectively with stress and improve social skills. Systematic reviews and meta-analyses of type D studies have shown an association with poor cardiovascular outcomes [1, 11]. Even though other research yields equivocal results, we suggest that abandoning type D research is premature. Rather, we should reanalyse all relevant published data using appropriate statistical approaches to identify whether and to what degree there is an association between type D and poor cardiovascular outcomes.