The biggest headache for any drug-company executive is the placebo, or ‘sugar pill’, used in controlled trials to show that a drug in question works. Patients are divided into two groups, one of which is given the active drug, while the other takes the placebo, but no one knows who got what, not even those giving the pills. The idea is ...

Dr Bruce Moseley, an orthopaedic specialist at Methodist Hospital in Houston, TX, was convinced of the powerful effect of the human mind on healing. He recruited 180 patients with severe knee osteoarthritis and divided them into three groups, two of which underwent true surgery to clear out degenerative tissue and debris. The third group underwent ...