Depression affects about 20% of Americans in their lifetime, and is one of the leading causes of disability. The rates of depression are even higher in those with cardiovascular disease (CVD). Depression affects 38% of patients undergoing coronary artery bypass graft surgery, and the risk of depression is three times as high in patients who have experienced a heart attack compared with the general population. Depression also makes it much more likely that CVD patients will be readmitted to the hospital and report heart-related symptoms.
Yet much of the time, symptoms of depression in those with CVD go unrecognized. And as we all know, if we don’t identify a problem it’s very difficult to find a solution.
Depression makes adherence to healthy behaviors less likely
Depression matters to cardiologists because patients with both depression and CVD have increased mortality rates, and significant reductions in their quality of life. Depression can often stem from feeling increased stress and lack of control regarding a chronic health condition like heart disease. In other cases, depression may already exist, and continue or worsen in response to CVD.
By affecting mood, sleep, and energy, among other things, depression can greatly impact a person’s ability to optimally manage their CVD. For example, depression makes it less likely that someone will take their medications as prescribed. And depression can make it very difficult to adhere to lifestyle recommendations such as eating a healthy diet or getting regular exercise.
The brain-heart connection
In addition to affecting behaviors, depression is also associated with physiologic mechanisms that help to explain the poor prognosis in patients with CVD. These mechanisms highlight the connection between the brain and the heart.
For example, depression can cause autonomic dysfunction, which negatively impacts resting heart rate, heart rate variability, and blood pressure. Depression can affect underlying inflammation, leading to elevated levels of potentially harmful circulating inflammatory molecules. Depression can also worsen insulin resistance, leading to further inflammation and diabetes. And depression can affect platelet reactivity, making blood stickier and, in turn, making a recurrent or new heart attack more likely.
Screening for depression
In April 2019, the Journal of the American College of Cardiology published a review in which they discussed a practical approach to the screening and management of depression in patients with CVD.
The review is a practica