Physiologic and psychologic factors related to depression in patients after myocardial infarction: a pilot study.

OBJECTIVE

To examine physiologic and psychologic factors contributing to depression in patients one year after myocardial infarction.

DESIGN

Convenience, correlational design.

SETTING

A university-affiliated cardiology clinic, a health maintenance organization, and a private cardiology group in a southwestern city.

SUBJECTS

Fifteen men and six women 10 to 14 months after myocardial infarction.

OUTCOME MEASURES

Oxygen saturation, somatic symptoms, and functional status in three areas (social, physical, and emotional) were correlated to depression scores by use of the Zung Self-rating Depression Scale (SDS) and the Symptom Questionnaire (SQ).

RESULTS

Spearman rho correlations showed that depression measured with the Zung SDS and SQ depression subscale were inversely related to somatic symptoms, social function, physical function, emotional function, and total function. There was a significant inverse relationship between depression 9as measured by the Zung SDS) and both oxygen saturation and physical function. Although there was an inverse relationship between depression (as measured by the SQ subscale) and both oxygen saturation and physical function, it was not statistically significant. A Mann-Whitney U test for differences showed that mean SDS scores for Hispanic subjects (n = 5) and white subjects (n = 16) differed significantly. Stepwise multiple regression showed that overall functional status accounted for 56% of the variance for depression in the SDS and for 59% in the SQ depression subscale. Oxygen saturation accounted for less than 1% of the variance in both depression scales.

CONCLUSIONS

The results of this study indicate that depression is negatively correlated with overall functional status in a select group of patients one year after myocardial infarction. A moderate negative correlation was also found between depression and hypoxia. Hispanic subjects had significant differences in their mean Zung SDS scores as compared with white subjects.