PLACEBO

n. tablet that contains no medication but has medical effects due to purely psychological reasons

Placebo effect is the term applied by medical science to the therapeutical and healing effects of inert medicines and/or ritualistic or faith healing manipulations. . When referring to medicines, placebo is a preparation which is pharmacologically inert but which may have a therapeutical effect based solely on the power of suggestion. It may be administered in any of the ways in which pharmaceutical products are administered. Regarding procedures drawing on the placebo effect, psychic surgery and faith healing are two possible examples.
See more at Wikipedia.org...

Placebo /pla·ce·bo/ [L.] any dummy medical treatment; originally, a medicinal preparation having no specific pharmacological activity against the [more]Placebo - Community and Resources

Noun
1. an innocuous or inert medication; given as a pacifier or to the control group in experiments on the efficacy of a drug
(hypernym) medicine, medication, medicament, medicinal drug
(hyponym) active placebo
2. (Roman Catholic Church) vespers of the office for the dead
(hypernym) vesper
(classification) Roman Catholic, Western Church, Roman Catholic Church, Church of Rome, Roman Church

n. placebo, tablet that contains no medication but has medical effects due to purely psychological reasons