A heavy heart is a hard heart. Chronic depression contributes greatly to the development of heart disease. Depression produces sustained inflammation of the blood vessels, which can lead to hardening of the arteries, or atherosclerosis. This condition causes the heart to pump harder through narrowed vessels, and hardened pieces of the wall can break off forming a clot. Low-serotonin levels associated with chronic depression also come with elevated heart rate, increasing blood pressure. This phenomena also contributes to hardened arteries. In addition, low-serotonin results in thicker blood-- since the neurotransmitter is responsible for platelet activity that keeps the blood pumping smoothly. Sooner or later you've got a heart attack on your hands.
Other effects of depression on the heart include a constant production of cortisol, a stress induced hormone that serves as a key player in 'flight or fight' reaction. Constant high levels of cortisol contribute to high blood pressure, increased bad cholesterol and insulin levels, as well as an excess of abdominal fat.
