Denollet J, Pedersen SS. Prognostic Value of Type D Personality Compared With Depressive Symptoms. Arch Intern Med. 2008;168(4):431–432. doi:10.1001/archinternmed.2007.120
The association between depression and coronary artery disease (CAD) is complex, and a more detailed subtyping of high-risk patients is needed.1- 3 Type D personality (the tendency to experience negative emotions and to be socially inhibited) is also related to poor prognosis.4 There has been vigorous debate about whether Type D personality adds to the evidence concerning depression.3 It is important to show that the predictive validity of Type D personality extends beyond that which can be predicted by depression, but to our knowledge, no study to date has compared the cognitive-affective symptoms of depression, as measured by the Beck Depression Inventory (BDI), with the Type D personality construct.
We therefore examined the relative effect of Type D personality and depressive symptoms on 5-year cardiac prognosis in 337 Belgian patients with CAD (297 men; mean age, 57.0 years).4 Covariates included exercise tolerance, index myocardial infarction (MI), and left ventricular ejection fraction (LVEF). The BDI–short form (BDI-SF) has a correlation of 0.96 with the 21-item BDI5 and was used to evaluate cognitive-affective symptoms of depression (eg, sadness, hopelessness, sense of failure, guilt, suicidal thoughts, self-hate, dissatisfaction, indecisiveness, and fatigue). A score greater than 5 on the BDI-SF denotes those with depressive symptoms5 and proved to be the optimal threshold for identifying patients at risk of cardiac events in the present study. The DS16 scale was used to assess personality4; 98 patients (29%) were classified as Type D personality.
At baseline, 181 patients (54%) displayed no or low levels of distress. Among the 156 emotionally distressed patients, only one-third (n = 55) had elevated scores for both Type D personality and depression; 28% (n = 43) had a Type D personality but were not depressed; and 37% (n = 58) were depressed but did not have a Type D personality. Shared variance between Type D personality and depression was only 9% (Φ coefficient, 0.31). Diagnosis of Type D personality was not a function of sex (P = .84), age (P = .27), or disease severity as indicated by exercise tolerance (P = .34), index MI (P = .43), or LVEF (P = .49).
After 5 years of follow-up, 46 patients (14%) had experienced a major adverse cardiac event (MACE, defined as a composite of cardiac death, MI, coronary artery bypass graft, or percutaneous coronary intervention), including 12 cardiac deaths or MIs. The Table shows that MACE was associated with index MI, LVEF of 40% or lower, and no coronary artery bypass graft. Both Type D patients and depressed patients had an increased event rate compared with non–Type D (P = .001) and nondepressed (P = .01) patients, respectively. When entering both factors in a multivariable model, Type D personality (odds ratio, 2.44 [95% confidence interval, 1.25-4.76]; P = .009) but not depression (odds ratio, 1.71 [95% confidence interval, 0.88-3.33]; P = .12) was significantly associated with MACE.
After adjustment for MI, LVEF, and coronary artery bypass graft, Type D patients had a 3-fold increased risk of MACE (Table, bottom); depression did not predict MACE. Analyses using continuous scores for the Type D personality and depression measures did not change the results, nor did the use of a different cutoff score for the depression measure. Finally, Type D patients had a greater risk for cardiac death or MI compared with non–Type D patients (7 of 98 [7%] vs 5 of 239 [2%]; odds ratio, 4.84 [95% confidence interval, 1.42-16.52]; P = .01); depression was not related to this end point (P = .25).
These findings show that Type D personality may have unique prognostic value beyond that of depressive symptoms. Only one-third of distressed patients with CAD had both a Type D personality and were depressed (28% had Type D personality and were nondepressed and 37% had a depressed and non–Type D personality), Type D personality was associated with a 3-fold increased risk of MACE, controlling for depression, and Type D personality but not depression predicted MACE, adjusting for disease severity. Another study also showed that Type D personality was associated with increased cortisol levels in patients with CAD, whereas depression as assessed by the BDI was not.6 Hence, Type D personality is more than just a marker of depression and should be assessed in its own right in patients with CAD.
Correspondence: Dr Denollet, Department of Medical Psychology, Tilburg University, PO Box 90153, 5000 LE Tilburg, the Netherlands (email@example.com).
Author Contributions:Study concept and design: Denollet and Pedersen. Acquisition of data: Denollet. Analysis and interpretation of data: Denollet. Drafting of the manuscript: Denollet. Critical revision of the manuscript for important intellectual content: Denollet and Pedersen. Statistical analysis: Denollet. Administrative, technical, and material support: Pedersen.
Financial Disclosure: None reported.