Are depression and heart disease connected?

You’ve likely heard that obesity, smoking, and diabetes increase the likelihood of cardiovascular problems. Ditto with high cholesterol, advanced age, and family history. Now there’s another big risk factor for heart disease, and it’s one that 17.3 million adult Americans live with: depression.

Depression, a condition characterized by prolonged feelings of sadness and a loss of interest in once pleasurable activities, has profound effects on the body. It can cause loss of energy, changes in appetite, sleep disruptions, difficulty concentrating, and—more and more studies are finding—heart disease. 

Research has found that adults with depression have a 64% greater chance of developing heart disease than people without depression. Other studies put the risk at closer to 80%. What’s more, people with depression and heart disease have a 59% greater risk of having a heart attack or dying from heart disease than their nondepressed counterparts. The American Heart Association (AHA) now recommends that cardiac patients be screened for depression. 

Depression may even be as important a risk factor for heart attack as diabetes, smoking, hypertension, and obesity are, suggests David Corteville, MD, a clinical cardiologist at Rochester Regional Health’s Sands-Constellation Heart Institute.

Is depression associated with heart disease?

How can your mental health affect your heart health? Scientists think there may be a variety of ways.

• Lifestyle factors: It’s no big surprise that it’s hard to stay motivated to eat well and exercise when you’re feeling down. People with depression may be more likely than those in the general population to overeat and not exercise. And we know that obesity and inactivity are two driving forces of heart disease. 
• Inflammation: Depression produces low-grade inflammation in the body. That inflammation can narrow arteries and make it more likely that plaque (cholesterol deposits in the arteries) will break away from the arterial walls, thereby clogging vessels and interrupting the flow of blood to the heart. Oxidative stress and autonomic dysfunction (which are both increased in the depressed) are also implicated in the multifactorial reason for increased risk of heart disease in the depressed. 
• Platelet clumping: Platelets are tiny cells in the blood that are necessary for blood clotting. Research shows that people with depression tend to have more “reactive” platelets, meaning they’re more likely to form clots that impede blood flow to the heart.
• Heart arrhythmias: Depression seems to increase one’s chance of developing atrial fibrillation, an irregular heartbeat. Scientists aren’t exactly sure why, but they suspect the increased levels of inflammation often seen in people with depression may be a factor. 

Can heart disease cause depression?

Having a life-threatening condition like heart disease, the number-one killer in America, is bound to take its toll on anyone’s mental health. 

“An estimated 20% [of people with heart disease] have depression and as many as two thirds have depression after a heart attack,” says Todd Hurst, MD, a cardiologist with Banner University Medical Center in Phoenix, Arizona. “This is likely due to multiple causes, such as social isolation, pain, being ill, lower functional status, fear, anxiety, and uncertainty.” 

There’s also an increased risk for depression after heart surgery. “Thirty to 40% of these patients develop depression,” comments Dr. Corteville. “That’s higher than the general population.”

Another possible factor in post heart attack depression? Some studies point to the very drugs used to treat heart disease. “Beta blockers [drugs used to lower blood pressure and control the body’s stress hormone adrenaline] such as atenolol, metoprolol, and carvedilol have been associated with an increased risk for depression in some studies, but not all,” says Dr. Hurst. More research is needed before any definite conclusions are drawn. Beta blockers decrease a patient’s maximal heart rate and may decrease resting heart rate, which can make patients feel sluggish and mentally down.

And while beta blockers may increase the risk of depression, it’s important to note that their benefits can outweigh their risks.

“Beta blockers have been strongly demonstrated to reverse heart failure, and every 10 mmHg drop in systolic pressure will decrease the probability of a heart attack and stroke by about 50%,” explains Carl Tong, MD, Ph.D., a cardiologist and associate professor at Texas A&M University College of Medicine.

Does treating depression reduce the risk of heart disease?

It stands to reason then, that if you control depression, you decrease the risk of heart disease. 

In one study, people with depression who were treated with antidepressants or therapy before developing heart disease symptoms lowered their risk of having a cardiac event by 48%. 

“Selective serotonin reuptake inhibitors, or SSRIs, [a class of antidepressants] have been shown to be safe and effective in cardiac patients,” says Dr. Corteville. “Many cardiac patients are on multiple medications and we need to consider drug-drug interactions. Among the SSRIs, those with the fewest drug-drug interactions are escitalopram and sertraline. Wellbutrin has also been shown to be safe as well.” Most SSRIs are dosed once a day, known to be safe, and have been used for decades. 

When it comes to therapy, cognitive behavioral therapy (CBT) has been shown to be the most effective in treating depression and should be considered a first-line therapy. CBT is a form of psychotherapy that helps people reframe negative thoughts or emotions into more positive ones. “Combining CBT with an SSRI has been shown to be more effective [in treating depression] than using just one or the other,” explains Dr. Corteville. “Treatment of depression reduces the risk of cardiovascular events such as heart attack, stroke, and death.”

Reducing your risk of depression and heart disease

Reducing your risk of any serious health condition often comes down to what healthcare providers call “Life’s Simple 7:” 

1. Eat a healthy diet
2. Be physically active
3. Quit smoking
4. Control blood pressure
5. Keep blood sugar in check
6. Maintain healthy cholesterol levels
7. Stay within a healthy weight range (a BMI of 20-25)

“Consistent aerobic exercise has been demonstrated to be as effective as taking an antidepressant,” says Dr. Tong. The AHA recommends 150 minutes of moderate-intensity aerobic exercise per week (brisk walking, for example) or 75 minutes of intense exercise weekly. In addition, activity helps with blood pressure, blood sugar, and a healthy weight.

“Research shows an 80% decrease in heart attacks and a 50% decrease in stroke in those who optimize all seven factors compared to those who don’t,” Dr. Hurst says. “This applies to all of us, whether we have depression or not. However, treating depression would likely make it easier for someone to change their lifestyle.”

If you have depression, make sure you’re evaluated for heart disease. And if you have heart disease, make sure you’re screened for depression. Depression and heart disease often go hand in hand and effectively treating each with the proper heart medications, antidepressants, and CBT can improve your overall quality of life—physically and mentally.