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Howick on What Counts as a Placebo

The use of placebos in medicine raises a large number of serious ethical issues. Do they involve deceiving patients, or violating their autonomy in some way? Are they harmful to certain patients, in research trials where the actual treatment being trialled is thought likely to be successful? Can placebos – if medically warranted – be funded through a health care budget? All these questions require us to be able to say what a placebo is, and that is more tricky than one might think.

In ‘What counts as a placebo is relative to a target disorder and therapeutic theory: defending a modified version of Grünbaum’s scheme’, a fascinating lecture given at Oxford in the St Cross Special Ethics Seminar series on Thursday 12 June, Dr Jeremy Howick began by asking his audience to think of their own definition of a placebo. He then went through the various definitions that have been offered in recent years – including that in the Oxford English Dictionary – and noted problems with each. At this point, he asked the audience whether anyone’s definition was still standing: no one responded.

Howick then presented his own account of a placebo, a development of that offered by Grünbaum in the 1980s. On this kind of view, medical interventions can be said to have both ‘characteristic’ and ‘incidental’ features. Consider Prozac: its characteristic feature is the chemical fluoxitene, while its incidental features in any particular form would include, for example, the bulking agent used in making the pill. If Prozac is administered to a depressed patient, and that patient’s health improves as a result of the fluoxitene, then the treatment is not a placebo. But if a sugar pill is administered, then any improvement can be put down as the effect of a placebo.

A wide-ranging and lively discussion followed, concerning issues such as the measurement of outcomes in cases involving possible placebos, Bruce Moseley’s fake knee surgery, deception and consent, the role of belief and expectation in complementary medicine, and reporting bias in research.

The main message I took away from Howick’s talk was that it is a mistake to think that what seem to be placebos can have no therapeutic effect. Consider standard versus ‘fake’ knee surgery. If both are effective, then we seem to have two different kinds of treatment, one which operates via physiology, and another that does so through patient beliefs and expectations. But what if we now claim that the ‘characteristic feature’ of fake knee surgery is, say, ‘comforting the patient’, and this leads to relevant improvement in the patient’s health? That would turn fake knee surgery into a ‘standard’ treatment (albeit an unusual one!). So it may be that we can hang onto the common intuition that placebos have no therapeutic effect, though we would have to accept that fake knee surgery (if sufficiently effective) doesn’t count as a placebo after all.

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