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.
Having any depression symptoms increased a subject's likelihood of suffering another heart attack, stroke, heart failure or death. But even after taking account of the severity of a patient's illness and the factors that influence his or her risk of worsening health, the large numbers of patients who reported suffering depression's physical symptoms -- tiredness, appetite changes, sleep disruptions -- fared worse than the smaller group who reported they were extremely sad, felt guilty or worthless or had suicidal thoughts.
Many heart patients suffer from depression in the wake of a heart attack or surgery to open blocked blood vessels. But finding the symptoms of depression that seem to predict whose heart disease will worsen is important, because cardiologists can focus not only on treating patients with those symptoms most aggressively, but on treating those symptoms first, the authors wrote.
It may also suggest what kind of treatment heart patients should get, along with their heart medications and exhortations to change their diet. While psychotherapy is often offered to such patients, it seems to be more effective in addressing feelings of sadness than poor sleep and appetite. Exercise programs seem to do the most to positively influence sleep and appetite, the researchers wrote.
-- Melissa Healy / Los Angeles Times