A placebo is “a substance or procedure a patient accepts as medicine or therapy, but which has no specific therapeutic activity”. In other words, it simulates a medical treatment and deceives the patient. Is this why practitioners of spurious complementary and alternative medicine (sCAM) are so keen to “harness the power of the placebo”? You bet.
The deception component of giving a placebo is critical to it having any effect and as such is why in general practice and conventional medicine in general you will not find sugar pills being prescribed except as part of a clinical trial. That said, there is anecdotal evidence and a few limited studies that show even when told they are to receive a proverbial “sugar pill” some patients will see some recovery from whatever ails them.
sCAM artists, of course, usually prescribe nothing but placebos. The likes of Reiki, crystal healing, homeopathy etc are pure placebo. In the case of the increasingly common use of homeopathy for “drug-free” malaria prophylaxis CAM is even more dangerous than no intervention at all as it lulls patients into a false sense of security.
David Gorski writes at length on the ethics of placebos in his latest column for Science Based Medicine and points out that: “Using placebos outside of a clinical trial is now generally considered at best paternalistic and at worst downright unethical, because it violates informed consent and patient autonomy.”
That is certainly not stopping those in sCAM exploiting patient ignorance of the nature of the placebo effect and the recent surge of scientific interest in how various factors affect recovery even when they have no direct physiological activity.