Yes positive thoughts can do us very good . My mother always says this thing about being positive she uses the words from the Bible . She always tells me to stop thinking negative . I make it worse . Mind over matter does heal us too ! That’s what my sons therapist is trying to teach him to help him . Negative thoughts from the brain she said makes you make bad decision she’s trying to teach him mediation to help heal his mind and body . She said studies shows it works when medicine doesn’t . It helps heal the body .