
@Chris: Depression not an illness?
Try telling that to the person who physically can't get themselves out of bed, after having sleep 20 hours a day.
There are demonstrated problems with serotonin and dopamine producers and receptors in people with severe depression. It might be harder to detect on people with mild depression, but that's not to say it's not real. My personal opinion on it is that there is a feedback cycle. You get depressed, it alters your body chemistry. You alter your body chemistry, and you get depressed.
Depression isn't an illness? Sure. Paraplegia isn't real either, because people can pretend to be unable to walk.