Lots of times the "placebo effect" is what it is all about, it's known as "mind over matter". While some drugs may do a little enabling as far as a cure is concerned, it's actually the body itself that does most of the curing and attitude is of paramount importance. Quite often you have a situation where a guy is down with malaise and then finds he's won the lottery and then in no time is feeling perfectly Okay.
"...it's actually the body itself that does most of the curing..."
In other parts of the world, you might be crowned the "King of Common Sense!" Some of the mystical medicine techniques in the "Far East" are based on exactly that statement above. There is a reason why the body has an immune system, and the fact that we do a lot to weaken it (sh*tty diet, no exercise, etc.) isn't the body's fault. It comes from the thing that sits on our shoulders (head/brain) through some questionable decisions.
There is a whole set of healing practises generally referred to as "energy healing" which basically allow the body to heal itself. Reiki is one, but there are others. They all sound very weird to our society because we've been raised and educated in a different direction...we tend to go after the symptoms and not the cause.
We also tend to reject these "alternative" healing methods out of hand, sometimes rather emphatically. ;-) But, an open mind is always a healthy mind...