What Is the Link Between Depression and Heart Disease?
November 7, 2015
What is the link between heart disease and depression? Is a person with depression more likely to develop heart disease?
Reader Question • 478 votes
A person with depression is at higher risk for heart disease, and a person with heart disease is at higher risk for depression.
The link between the two diseases is complex and not entirely understood. Many of the effects of depression — feeling unable to exercise or eat properly, for example — and the behaviors associated with depression, like smoking and abusing alcohol, are well established risk factors for heart disease. Some studies have suggested that insomnia, another symptom of depression, may also increase the risk for cardiovascular illness.
Depression can also make heart disease worse. Heart patients with depression may find it more difficult to take medications and comply with the behavioral demands of living with heart disease. Depression may also have destructive physiological effects on heart rhythm, blood pressure, stress hormone levels and blood clotting, studies have shown. These may be among the reasons why depressed patients with stable cardiovascular disease, or those who have survived a heart attack or had coronary bypass surgery, are at two to three times higher risk of dying than similar patients without depression.
Treating depressed heart patients with drugs like Prozac may help. These drugs, known as selective serotonin reuptake inhibitors, or S.S.R.I.’s, in addition to relieving depression, have blood-thinning effects that may be beneficial against heart disease. “It is clear that treatment with an S.S.R.I. reduces cardiac mortality in depressed patients post heart attack,” said Dr. Steven P. Roose, a professor of psychiatry at Columbia. “What is not clear is whether the reduction in mortality results from the antidepressant effect of the medication or the anti-platelet effect of the medication.”
Inflammation, which increases heart disease risk and mortality, may also play a role in the connection. Dr. Lauren M. Osborne, an assistant professor of psychiatry at Johns Hopkins University, said that the first suggestion that inflammation might be involved in depression came when doctors noticed that giving patients medicines that increased levels of inflammatory molecules in the blood also tended to intensify depression.
Some studies have shown that cytokines, a kind of inflammatory molecule sometimes elevated in the blood of people with depression, can cross the blood-brain barrier, where they can affect the synthesis of neurotransmitters in the brain or damage neurons. “Those are all routes by which cytokines in the brain may be affecting depression,” Dr. Osborne said, “but we can’t yet make a causal link.”
Regardless of whether a person has heart disease, treating depression is essential, and there are medications and psychotherapeutic treatments that have been proven effective.