Depression's Role in Sudden Cardiac Death Downrated

Depression might not play as large a role in increasing the risk of sudden death after acute heart attack as previously believed, according to new research.

"Our study focused on the role of psychological distress and social contact effecting the health of patients who suffer an acute heart attack," said Jane Irvine, DPhil, lead author of the study.

The researchers followed 671 patients for two years after their acute heart attacks. Over the follow-up period, there were 34 sudden cardiac deaths, 16 other cardiac deaths and one vascular death among the patients. The findings appear in the November/December issue of Psychosomatic Medicine.

In clarifying what constitutes distress, the researchers focused particularly on overlapping symptoms such as fatigue and sleep, that are common in depression and heart disease, as well as other physical illnesses.

"Our results raise questions about the extent to which cardiac symptoms such as shortness of breath and fatigue interfere with the assessment of depression in acute heart attack patients," said Irvine. "When these ‘biological' symptoms are no longer considered depressive symptoms, the relative risk of sudden death that is then associated with depressive symptoms is reduced by 30 percent and is no longer statistically significant."

The study conducted by 10 Canadian scientists also found that increased contact with family and friends during the time of the heart attack may actually heighten the risk of sudden death, while participation in pleasurable activities lowers the risk.

The effects of the two social support factors – social network contacts and social participation – were "puzzling" to the researchers. The findings seemed to counter other studies that showed the beneficial effects of social network contacts. The study suggested, however, that social network contacts in older adults may be greater in those who are sicker and thus, is reflective of poorer health status. Social participation, one the other hand was unrelated to illness factors, and like other studies have found, appeared to have a protective effect on health.

The study was funded by a research grant from the Heart and Stroke Foundation of Ontario and by a scholarship award from the Heart and Stroke Foundation of Canada.

###

Psychosomatic Medicine is the official peer-reviewed journal of the American Psychosomatic Society, published bimonthly. For information about the journal, contact Joel E. Dimsdale, MD, at (619) 543-5468.