Depression, especially its physical signs, such as fatigue and kiss of appetite, may contribute to thickening arteries, an early sign of cardiovascular disease.
Previous research has suggested that negative emotions like anxiety and anger can increase the risk for heart disease. But in the new study, depression—and its physical symptoms—was the emotional linchpin to early signs of heart disease.
In other studies, anxiety, depression, anger and hostility have all separately been linked to future risk of heart disease," said lead researcher Jesse C. Stewart, a member of the psychology department at Indiana University-Purdue University Indianapolis. But the problem with those studies was that they didn't look at these negative emotions together. And since their symptoms can overlap, it has been hard to tell which emotion plays the most important role in heart disease.
Stewart's team looked for emotional links to heart disease among 324 men and women with an average age of 60.6 years old. To determine early signs of heart disease, the scientists ex-amined carotid artery intima-media thickness, which is a measure of the inner layers of the arteries and is related to early-stage heart dis-ease. Measurements were taken at the start of the study and again three years later.
"We found that mild to moderate depressive symptoms were associated with greater progression of subclinical atherosclerosis (hardening of the arteries)—greater increase of the artery wall," Stewart said. In contrast, anxiety symp-toms, hostility and anger were not at all related to a change in the blood vessel thickness."
What's more, analysis showed that only the physical symptoms of depression predicted the progression of atherosclerosis. And it appears that the symptoms of depression exist before the signs of atherosclerosis.
Stewart isn't sure why depression has this effect. "Depression has been associated with some physiological changes, including in the immune system. These physiological changes probably explain this association," he said.
The study also found that the 5% of study participants taking antidepressants fared better than those with depression who weren't taking the drugs. "They had significantly reduced progression of atherosclerosis," Stewart said.
But, because the sample was so small, it isn't possible to make a definitive statement about the value of selective serotonin reuptake inhibitors (SSRIs) in reducing atherosclerosis. "There is in-triguing evidence that SSRIs may be associated with reduced progression of atherosclerosis." Stewart said.
"Identifying the harmful aspects of emotion could lead to the identification of people who are at risk for heart disease due to their tendency to experience negative emotions and who may benefit from psychological and pharmacological intervention," he said. "Identifying these harmful aspects could also lead to the development of more focused and potent interventions.”
Dr. Nieca Goldberg, chief of women's cardiac care at Lenox Hill Hospital in New York City, noted that depressed people are less likely to take care of themselves and have more risk factors for heart disease.
"People who are depressed don't adopt a healthy lifestyle," said Goldberg, a spokeswoman for the American Heart Association and au-thor of The Women's Healthy Heart Program. They overeat, smoke more, and may drink more. In addition, people who have depression have platelets that are more likely to clot."
Goldberg thinks doctors should pay closer attention to depression and other psychological factors that can affect patient health. "For too long, the medical system has amputated the head from the rest of the body," she said. "It is important for us to consider the psychological aspects of our patients’ lives, because that is an important factor in our care of a patient.”