Singapore: A psychiatrist named Dr Angelos Halaris at the US-based Loyola University Medical Center has proposed a new subspecialty to diagnose and treat patients, who suffer both depression and heart disease, calling it "Psychocardiology." Dr Halaris is medical director of Adult Psychiatry and a professor in the Department of Psychiatry and Behavioral Neurosciences at the medical center.

In his recent study, Dr Halaris and colleagues found that an inflammatory biomarker, interleukin-6, was significantly higher in the blood of 48 patients diagnosed with major depression than it was in 20 healthy controls. Interleukin-6 has been associated with cardiovascular disease. Dr Halaris presented his findings at a joint congress of the World Psychiatric Association and International Neuropsychiatric Association in Athens, Greece. At the congress, Dr Halaris formally proposed creation of a new Psychocardiology subspecialty.

Forty-to-60 percent of heart disease patients suffer clinical depression and 30-to-50 percent of patients who suffer clinical depression are at risk of developing cardiovascular disease. 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.

Dr Halaris said that, "Treating depression expertly and vigorously in young age can help prevent cardiovascular disease later on. "It is only through the cohesive interaction of such multidisciplinary teams that we can succeed in unraveling the complex relationships among mental stress, inflammation, immune responses and depression, cardiovascular disease and stroke."