Far from being just a psychiatric disorder, depression wreaks havoc on the entire body by throwing the stress response out of whack. The amount of damage it causes takes a greater toll on health than chronic angina, arthritis, asthma, or diabetes, according to a September report from the World Health Organization. And a growing body of research indicates that it triggers certain diseases:
Heart disease. Under stress, blood produces more clotting factors to prepare for a wound, which can cause clots to form in the arteries—setting the stage for a heart attack or stroke. Increased stress hormones can also lead to inflammation in the heart.
Osteoporosis. Depression's link to high levels of the stress hormone cortisol may speed bone loss, raising the risk of fractures even in premenopausal women, according to one new study.
Diabetes. Increased cortisol also raises blood sugar levels, which new research suggests may cause diabetes in those over age 65. Inflammation may also play a role.
Cancer. Studies show that depressed folks have high levels of immune system chemicals called cytokines, which may hamper the body's ability to destroy malignant cells.