Much of the placebo effect seen in clinical trials is the combination of the natural tendency of patients to get better and measurement error.

FORBES: The Medical Power of Ritual

If you get all jazzed up about a mysterious placebo effect, that positive thinking may help you feel even slightly better on subjective scales.

FORBES: Harvard Placebo Study Was Seriously Overhyped

"What's happened to me has had a very positive effect on people around me because they think if it could happen to me then I better get it checked out, " he said.

BBC: Terry Conroy