Wow...unbelievable how powerful the mind is. It's amazing to me how linked the mind & body are, even in terms of hormones (besides cortisol), and other almost seemingly "purely" physical things. It isn't anything new that we're finding out either. I recall a recent study about hotel maids who were trying to lose fat. A group that was "told" about how many calories they actually burn working and moving around all day ended up getting out of their fat loss stagnation, compared to the other group who wasn't told and did the same amount of hourly work.
Sometimes perception is reality I suppose?