Health-and-Age

Long, long before clinical trials were being done to provide evidence of a drug’s activity, the placebo effect was used by physicians to provide relief to patients with a wide range of symptoms. At the extreme end there was the snake oil of the travelling “doctor” in the West, but there’s little doubt that many medicines prescribed by family physicians in the early 1900s contained little more than a bitter-tasting substance put up in colored water. Nowadays a placebo is defined by its inert content and its use as a negative control substance in clinical trials.  The trouble with an otherwise perfect experimental set-up is that the intended inert, negative control produces a measurable beneficial effect – the placebo effect.  A good example is the rigid testing protocols for evaluating new antidepressant drugs, where the placebo effect may produce a good response in 30% to 40% of patients. An “effective” drug then has to produce a comparable (or better) response in 60% or more of the patients.  

Recent research shows that placebo effects are genuine psychobiological events, and studies are reported showing that a placebo effect can be of several different kinds, and may even occur when no placebo has actually been given. This is the subject of an Australian publication in the Lancet.

The researchers cite a large study of patients with irritable bowel syndrome.  Patients were given either no treatment at all, a placebo (a sham acupuncture treatment) or the placebo (sham acupuncture) plus supportive care (the clinician followed a script to convey attention, warmth, confidence, and thoughtful silence as he inserted the needles).  The response rates in the 3 groups were 28% (no treatment), 44% (sham acupuncture alone), and 62% (sham acupuncture plus supportive care).  Clearly the placebo effect of supportive care was added to that of the sham acupuncture; i.e. different sorts of placebo effect can be additive.  Side effects can also be induced by placebos.  In a similar study, patients given an inert pill were told they might experience adverse effects such as drowsiness, while those in another group were informed about the side effects of acupuncture.  Both groups reported a 30% incidence of side effects, but in the first they were of the drowsiness type, and in the sham procedure they were those of acupuncture.  Both these studies indicate that the placebo effect is the result of suggestibility.

So why shouldn’t the placebo effect be used deliberately in treatment, as in the bad old days?  Maybe because it raises ethical issues, given our modern array of drugs and treatments that have been proven to be effective (at least to the FDA’s satisfaction).  The Australian group point out that supportive care is clearly ethical, but only as an additive. They go on to suggest that one way a placebo pill might be given alone would be to tell the patient “this pill has no active drug and will work through psychological mechanisms to promote self-healing”.  Good luck with that, as they say. 

However, now it’s been shown that supportive care has a placebo effect, there’s no reason not to encourage all treatment regimens to include additional supportive care, without any practice of deception.