In most medical traditions, there is an awareness that patients need to trust the treatments being offered by their doctors. Since the early 1900s doctors have recognised that any treatment which the patient expects to work may bring some improvement in the patient’s condition. This effect is known as the placebo effect (placebo is a Latin word which means ‘I will please’).
Similarly, a patient may get better, or feel better, having been given lots of attention from a respected practitioner. Most doctors are aware of the placebo effect when they carry out their diagnosis. A survey of doctors in Denmark in 2003 found that half of them had prescribed a placebo in the previous year.
So important is this placebo effect that it has to be taken into account for valid testing of new drugs: has the patient improved because of the new treatment, or just through taking part in the experiment? For this reason, new treatments are tested using what is known as a ’double blind’ trial: some of the patients receive the drug to be tested, while others receive a chemically neutral, but similar-looking, drug. Records are carefully kept so that neither the experimenter nor the patient knows who received which. Those who received only the placebo form the control group.
Some historians have cited the placebo effect to explain the enduring support for belief-based medicine. Certainly, where both patient and practitioner believe a treatment will be effective, remarkable things can happen.