AP Medical Writer
WASHINGTON — Severe depression may silently break a seemingly healthy
woman's heart. Doctors have long known that depression is common after a heart
attack or stroke, and worsens those people's outcomes. Monday, Columbia
University researchers reported new evidence that depression can lead to heart
disease in the first place.
The
scientists tracked 63,000 women from the long-running Nurses' Health Study
between 1992 and 2004. None had signs of heart disease when the study began,
but nearly 8 percent had evidence of serious depression.
The
depressed women were more than twice as likely to experience sudden cardiac
death — death typically caused by an irregular heartbeat, concluded the 12-year
study, published Monday in the Journal of the American College of Cardiology.
They also had a smaller increased risk of death from other forms of heart
disease.
The
big surprise: Sudden cardiac death seemed more closely linked with
antidepressant use than with the depression symptoms the women reported.
That
might simply mean that women who used antidepressants were, appropriately, the
most seriously depressed, cautioned lead researcher Dr. William Whang. But he
said the finding merited more research.
Studies
of the newer antidepressants most often used today so far haven't signaled a
risk of irregular heartbeat, and some even have suggested protection, noted Dr.
Redford Williams of Duke University, a specialist in how psychosocial factors
affect health.
The
drug question aside, Williams said the work adds to growing evidence that
depression is an independent risk factor for heart disease — on top of the
classic risks of high blood pressure, diabetes, high cholesterol and smoking.
The
predominantly white Nurses' Health Study may underestimate it, Williams said.
"If anything, the impact in African-American women is probably greater,"
he said, adding that it's time for the next step: A study testing whether
properly treating depression lowers the risk.
Why
might depression have that effect? The study found that the more severe the
women's reported depression symptoms, the more likely she was to have
traditional heart risk factors. Also, stresses like depression have been linked
to such physical effects as a higher resting heart rate.
Perhaps
a more straightforward reason: Depression can make people do a worse job taking
care of themselves. Indeed, the American Heart Association last year
recommended that everyone who already has heart disease be regularly screened
for depression — because depressed patients may skip their medications, sit
indoors instead of exercising, and eat particularly poorly.