The presence of depressive symptoms when patients are hospitalized for a heart attack seems to reduce survival in the next 5 years, Canadian researchers report. However, a long-standing history of depression appears to have little effect on survival and may even be associated with an increase in the survival rate.
Dr. Sherry L. Grace, from York University, and her associates in Toronto recruited 750 patients who had a heart attack or angina between 1997 and 1999. Patients were asked about any history of depressed mood lasting for more than two weeks and were assessed for current symptoms of depression.
A total of 446 subjects did not have a history of depression or current depression and 130 subjects had no history of depression but a current depression test score of 10 or higher, which suggests the presence of moderate to severe depressive symptoms.
According to the investigators’ report in the American Journal of Cardiology, there were 115 deaths during 5 years of follow-up.
The death rate was highest among those with no history of depression but had a current depression test score of at least 10 to 24 percent.
“Depression at the time of an event is not just a response to having a heart attack, and it’s not something that should be overlooked,” Grace told Reuters Health. “Physicians need to screen patients for depression and refer them on for treatment, because depression can predict mortality up to 5 years later.”
For those with minimal depressive symptoms at present, death occurred among roughly 15 percent of patients, regardless of their depression history. The death rate was lowest among those with a history of depression but with no current symptoms - 6 percent.
These findings are the opposite of what her team had hypothesized, Grace noted.
“They suggest that people with a history of depression had learned how to overcome the depression on their own,” she said, “so when they had this life-threatening event they were better at coping with the heart attack and hospital experience itself.”
Only a small percentage of subjects were taking antidepressant medication or had received psychotherapy in the past, she continued, “so it could be that people are coping with depression on their own or enlisting social support from family and friends.”
Whatever the mechanism, Grace believes her group’s findings “beg for future research.”
SOURCE: American Journal of Cardiology, November 1, 2005.
Revision date: June 20, 2011
Last revised: by Sebastian Scheller, MD, ScD