Heart disease can be depressing—literally. About 50% of hospitalized heart patients have some depressive symptoms, and up to 20% develop major depression. And depression affects heart health: Patients who are depressed at the time of hospitalization for heart conditions are two to five times more likely than average to die or to suffer further cardiovascular events such as heart attack, stroke, or severe chest pain in the following year. The February issue of the Harvard Mental Health Letter notes that recurrence of cardiovascular events is more closely linked to depression than to high cholesterol, smoking, high blood pressure, or diabetes.

Mind and mood can affect the cardiovascular system directly by creating a state of emergency readiness, in which stress hormone levels rise, blood vessels constrict, and heartbeat speeds up. If a person is seriously depressed or anxious, the emergency response becomes constant, damaging the blood vessels and making the heart less sensitive to signals telling it to slow down or speed up as the body’s demands change, reports the Harvard Mental Health Letter.

Research suggests that the type of antidepressants called selective serotonin reuptake inhibitors (SSRIs) may benefit depressed heart patients and possibly reduce their risk for future heart problems. Cardiac rehabilitation programs that sustain patients’ morale and urge them to take better care of themselves may also help reduce the damage depression does to the heart.

It’s hard to determine the precise cause and effect in the relationship between depression and heart disease. Symptoms may be similar, and the damage depression does to the cardiovascular system may trigger further depression. Still, the connection is real. Cardiologists should ask their patients about stress and depression, and patients should not hesitate to bring up these subjects.