Placebo: A pleasing effect

Abstract

Some patients, though conscious that their condition is perilous, recover their health simply through their contentment with the goodness of the physician. Hippocrates (c460 bc–c377 bc), Precepts, VI Placebo means ‘I will please’ in Latin. The word is used in the funeral mass, the Vespers for the Dead: ‘Placebo domine in regione vivorum’ (Ps. cxvi, 9) translates as ‘I will please the Lord in the land of the living’. In the fourteenth century, a placebo was used to describe a hired mourner paid to pretend to weep at a funeral. The English used placebo as a term of abuse to denote a sycophant or flatterer. In The Canterbury Tales, Chaucer writes ‘Flatteres been the develes chappeleyns that singen were Placebo’. The word placebo later evolved to describe an inactive substance. The Oxford English Dictionary, however, recognises the existence of a beneficial placebo effect, defining placebo as ‘an inactive or other sham form of therapy administered to a patient usually to compare its effects with those of a real drug or treatment, but sometimes for the psychological benefit to the patient through believing they are receiving treatment’. The placebo effect has been studied intensively. Does the patient improve because of a belief that the placebo works or is it primarily a function of the doctor–patient relationship? Placebo seems most likely to work in diseases with a strong psychological component. A recent study of patients with irritable bowel syndrome, a condition with a strong psychosomatic component, tried to tease out this question.1 Patients were randomised to be observed, to be given placebo acupuncture or to be given placebo acupuncture plus a warm patient–practitioner relationship (including an initial 45-min visit) for 3–6 weeks. The proportion of patients reporting adequate relief was 28% for observation, 44% for placebo acupuncture and 62% for placebo acupuncture plus patient–practitioner relationship. The patient–practitioner relationship was the most robust component.1 One intriguing aspect is that some patients improved even when they received sham acupuncture but were told by their practitioner that it was a research study so the practitioner was not allowed to talk to them while giving the treatment. Is it ethical to prescribe placebo deliberately, outside a trial? A survey found that 46–58% of US internists and rheumatologists prescribed placebo treatments regularly, usually over-the-counter analgesics (41%) or vitamins (38%), but also potentially harmful treatments such as antibiotics (13%) and sedatives (13%). Two thirds of the physicians who prescribed placebo told the patients it was a potentially beneficial treatment not usually used for this condition, not exactly a lie but a bit economical with the truth, while 5% disarmingly told the patients they were receiving an inactive drug.2 A study from Duke University found that patients given an identical placebo, but told either that it was a regular-cost placebo ($2.50 per tablet) or a cut-price placebo (10¢ per tablet), got better pain relief if they thought they were getting the more expensive placebo.3 This study won a 2008 IgNobel prize, prizes awarded for studies that make you laugh and then make you think (see http://www.bmj.com/cgi/section_pdf/337/oct08_1/a1998.pdf). The message I take home is that the psyche is complex, and it is best to develop a caring, trusting relationship with patients and their families. Knowingly prescribing an inactive treatment, particularly a potentially harmful one, sits uncomfortably with the concept of the importance of trust. It is ironic that placebo, a word that started as a term of abuse to describe an impostor who feigned real emotions, evolved to describe a treatment with no effect, only to find that the ‘ineffective’ treatment was sometimes effective because it affected emotions.