Depression and Its Effects on Physical Health


Depression is not just a psychological disease. It impacts the whole body, and especially impacts the cardiovascular system.

Depression is one of the strongest predictors of cardiac disease. Even minor depression increase the risk of cardiac disease by 50 percent. Major depression increases risk by 3 to 4 times. For those with pre-existing coronary artery disease, risk is increased 5 times!

You might be thinking that this is no surprise. Perhaps depressed people smoke more, exercise less, eat more bacon, etc. What is surprising is that the numbers in the preceding paragraph are after adjusting for lifestyle and behavior! The raw numbers are even higher!

Why is this? What is the mechanism by which depression reeks havoc with the cardiovascular system?

There are several possible mechanisms. One is through the impact on blood clotting.

Blood clotting is controlled by cells in the blood called platelets. The stickier the platelets are, the more likely you are to develop blood clots, which can lead to stroke or heart attack. Depressed patients have stickier platelets.

Another mechanism is stress. Depressed patients are under constant physiological stress, with excess stress chemicals circulating in their blood. This may raise blood pressure and cause other changes that affect the cardiovascular system.

So what happens if you treat depression? Does this reduce risk of cardiovascular disease?

Studies of antidepressants given after heart attack show a 30 to 40 percent reduction in subsequent heart attacks and deaths. 

Antidepressants improve the outcomes after stroke as well. When stroke patients were given either antidepressants or placebo, 66 percent of the antidepressant group survived 2 years, but only 35 percent  of placebo group.

Other physical triggers like treatment with interferon for hepatic C and melanoma can also cause depression. In fact, 50 percent of patients who receive interferon will get seriously depressed.  Depression in these cases is serious because it can cause the person to stop taking a potentially life-saving treatment.

Antidepressants help even in these cases of drug induced depression. One study found that treatment with Paxil, an antidepressant, reduced depression from 45 percent to 11 percent. 

What are the implications of these finding?


  1. All patients who have had a heart attack or a stroke should probably take an antidepressant.
  2. All patients taking long-term interferon treatment should begin taking an antidepressant several weeks before starting the interferon.
  3. Probably most seriously ill cancer patients should take an antidepressant as well.
  4. Counseling that focuses on evaluating and treating depression should be part of any seriously ill medical patient?s treatment regimen.

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