Journalist Denyse O’Leary co-authored a book with neuroscientist Mario Beauregard titled The Spiritual Brain. The book explores evidence for the existence of mind/soul from the field of neuroscience. One of the evidences they present is the placebo effect. The placebo effect is when people feel better because they think they are supposed to feel better. I would highly recommend the book, but in the meantime I will direct you to a short article Denyse wrote giving concrete evidence of the placebo effect in medicine. It’s very interesting.