The loss of interest, ruminations of suicide and feelings of guilt and sadness that are the hallmarks of depression may be debilitating. But it is depression's physical warning signs -- fatigue, sleep disturbance and appetite changes -- that are the most corrosive to the heart, a new study concludes.
The study is published this week in the Journal of the American College of Cardiology, and an abstract can be found here. It builds on longstanding findings that link depression and heart disease. While the two seem to be fellow travelers -- one in five heart patients suffers from depression -- the question of whether one causes the other remains a mystery, and an active field of research.
A group of Dutch and American researchers used data gathered in the "Heart and Soul" study in Northern California to explore which of depression's symptoms seemed to contribute most to worsening heart disease. To do so, they followed for an average of six years 1,024 patients who already had been diagnosed with heart disease after having had a heart attack or a surgical procedure to open blocked arteries. At the start of the study, all subjects were considered medically "stable," having had their heart attack or surgery at least six months before. Each got a comprehensive assessment of how serious his or her heart disease was, and each completed a checklist of depression symptoms.