Vital exhaustion and somatic depression: the same underlying construct in patients with myocardial infarction?
OBJECTIVE
To test whether vital exhaustion overlaps more with somatic/affective depression than with cognitive/affective depressive symptoms and evaluate the risk of recurrent cardiovascular events associated with these constructs.


METHODS
The Beck Depression Inventory (BDI) and the Maastricht Questionnaire (MQ) were administered to 528 patients hospitalized with myocardial infarction (MI). Principal component analyses (PCAs) were performed to assess the structure of the BDI, the MQ, and both combined. Univariate and multivariate (adjusting for age, sex, left ventricular ejection fraction, Killip Class, and history of MI) Cox proportional hazard regression analyses were used to examine the risk of recurrent cardiovascular events associated with the subscales of the MQ and of both questionnaires together.


RESULTS
PCA on the MQ yielded only one dimension. Per-standard-deviation increase in total MQ score, the multivariate hazard ratio was 1.37 (confidence interval [CI] = 1.15-1.64, p < .001). PCA on the items of MQ and BDI together yielded two dimensions: a somatic/affective and a cognitive/affective dimension. All but two of the items of the MQ loaded on the somatic/affective dimension. The multivariate hazard ratio for recurrent events associated with a 1-standard deviation increase in the somatic/affective dimension was 1.39 (CI = 1.11-1.73, p = .004), which was higher than the risk associated with the cognitive/affective dimension (1.02, CI = 0.82-1.27, p = .83).


CONCLUSIONS
Vital exhaustion and somatic/affective depression strongly overlap and may cover the same underlying construct that increased the risk of new cardiovascular events.
Interdisciplinary Center of Psychiatric Epidemiology, Department of Psychiatry, University Medical Center Groningen, University of Groningen, PO Box 30.001, 9700 RB Groningen, the Netherlands.
Esther M
EM
Vroege
Marij
M
Zuidersma
Peter
P
de Jonge
D003866:Depressive Disorder / Q000453:epidemiology* / Q000523:psychology; D004812:Epidemiologic Methods; D005221:Fatigue / Q000453:epidemiology* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D011379:Prognosis; D011569:Psychiatric Status Rating Scales / Q000706:statistics & numerical data; D012008:Recurrence