A state of depression so mild that most A doctors might not notice it significantly increases the long-term risk of death for people who have heart failure, a study finds.
After tracking 1,005 heart failure patients for seven years, researchers found that those who were identified as mildly depressed based on their score on a standard psychiatric test were 44% more likely to die compared with people who scored in the normal range.
Surprisingly, the death rate was higher-51% --for patients whose score indicated somewhat milder depression.
Dr. Wei Jiang, an assistant professor of internal medicine and psychiatry at Duke University Medical Center, says she undertook the study because other trials have linked depression to an increased risk of death from other cardiac conditions, such as heart attacks.
Patients were given the Beck's Depression Inventory (BDI), a test that asks people to rate the veracity of 21 statements, such as "I am disappointed in myself" and "I hate myself."
People who have a BDI score of 10 are considered mildly depressed. The 44% increase in mortality in the study was recorded for people who scored 10 or higher. However, the 51% increase in mortality was found in people who scored only 7 or higher, Jiang notes.
"The majority of patients in our study would not be regarded as having clinical depression," says Jiang.
It's not known why depression is related to greater risk of death, but some research has linked it to physical effects—such as a decreased ability of the heart to respond to the stresses of everyday life. In addition, depressed people are more likely to miss doctors' appointments and less likely to stick with exercise programs and drug regimens, Jiang says. Depressed patients may also make unhealthy lifestyle choices, such as smoking and not following a proper diet.
The lesson: Pay close attention to heart patients' psychological outlook, Jiang says.
Jiang has begun a study to learn whether antidepressants can improve the outcome for patients who have heart failure as well as mild depression.
Placebos Help Heart Patients Survive
Heart failure patients have a better chance of survival if they're conscientious about taking their medication even if those pills are placebos, according to a Duke University Medical Center study.
After analyzing international data on 7,599 heart failure patients, researchers found lower death rates in patients who regularly took their "medication" compared with those who didn't -whether that medication was a real drug to relax and dilate blood vessels or an ordinary sugar pill with no active medicine.
"Our findings that adherence to placebo was an important and independent predictor of better outcomes suggests that adherence itself is a marker for other unmeasured variables that can determine outcome," says researcher Bradi Granger.