The Melancholy Body

From Top Stories from U.S. News & World Report | The Melancholy Body:

Increasingly, it appears that what we call depression is not strictly psychological but is, instead, a condition that occupies the whole body. "Depression is really the only systemic disease that affects--and complicates--almost all other diseases," says Philip Gold, the chief of clinical neuroendocrinology at the National Institute of Mental Health. In fact, depression not only affects and complicates existing disorders like diabetes, heart disease, cancer, even osteoporosis; it might also trigger them.

2005 Update: I removed the link to USN&WR because it was no longer valid.