Inflammation in the body is linked with a host of ills: cancer, heart disease , obesity, autoimmune disorders , digestive diseases, to name some of the biggies. And if you had any of those diseases, it’s only logical you’d feel bummed out, and possibly depressed . Most Men Don’t Realize They’re Depressed. Here’s How to Recognize the Signs and Seek Help. But what if depression isn’t always a logical reaction to illness, or even to stress? Edward Bullmore, professor of psychiatry at the University of Cambridge, in the U.K., proposes that for some, depression is actually the direct result of inflammation—which helps explain why, for some, the typical treatments (medication, talk therapy, even deep brain stimulation for severe cases of depressive disorder) provide incomplete or fleeting relief. We asked Bullmore about his startling theory. It’s hard to overstate how pivotal—and potentially controversial—this theory is. What led you to theorize that inflammation and depression were relat