Stress is the key to understanding the association between depression and heart disease. Stress can lead to depression, and depression, in turn, can become stressful. The body’s immune system fights stress as it would fight a disease or infection. In response to stress, the immune system produces proteins called cytokines, including interleukin-6. Initially, this inflammatory response protects against stress. But over time, a chronic inflammatory response can lead to arteriosclerosis (hardening of the arteries) and cardiovascular disease.
It’s a vicious cycle: depression triggers a chronic inflammation, which leads to heart disease, which causes depression, which leads to more heart disease. Clinical depression typically begins in young adults. "Treating depression expertly and vigorously in young age can help prevent cardiovascular disease later on," Halaris said.
Physicians often work in isolation, with psychiatrists treating depression and cardiologists treating cardiovascular disease. Halaris is proposing that psychiatrists and cardiologists work together in a multidisciplinary Psychocardiology subspecialty.