Mental anguish is hard on your health. People suffering from depression have three times the risk of experiencing a cardiac event. In fact, depression affects the entire body. It weakens the immune system, increasing susceptibility to viral infections and, over time, possibly even some kinds of cancer—a strong argument for early treatment of depression. It interferes with sleep, adding to feelings of lethargy, compounding problems of focus and concentraton, and generally undermining health. Those suffering from depression also experience higher rates of diabetes and osteoporosis.