Answer: Placebo effect
Explanation: Placebo effect is the experience of positive outcome due to expectations.
It is a phenomenon where one's brain convince the body that an inactive substance (like diluted sugar, sterile water) taken or consumed can lead to a relief from an ailment or that a sham treatment can lead to a relief from an ailment which in turn truely cause a relief from the ailment, not because of the inactive substance taken or the sham treatment taken but because of how the brain stimulates the body chemically to believe it actually works.
Such effect is known as the placebo effect.
