What is a nocebo?

Nocebo is an inert drug which when administered to a patient causes harmful effects in her, not because of any inherent chemical characteristics, but because she has negative feelings about it. It’s the opposite of a placebo, a sugar pill supposed to produce a therapeutic effect because the patient has faith in the drug or doctor administering it. In Latin, ‘nocebo’ means ‘I will harm’. Walter Kennedy chose the term in 1961. Although the effect of a nocebo or placebo is not scientifically established, many believe that they work by their power of suggestion. They are used for control groups in clinical trials, and in drug-related experiments.