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Thursday, 28 March 2013

Placebos? Over-excitement can be a side effect

Placebos are in the news lately. Doctors are confessing to prescribing inert medicines. New and intriguing research is published indicating that placebos may work, even when the patients know they are inert. And a pharmaceutical company has patented a new, and questionable, way of conducting placebo-controlled trials (see links below).
Doctors may approve of the placebo effect because the patient’s symptoms may improve without the need for expensive drugs.
Alternative practitioners usually approve because the benefits of their methods seem to rely heavily on the placebo effect.
Psychologists love them because, well, they are intrinsically fascinating. Why should pills of different colours induce different degrees of placebo effect? Such phenomena are fascinating in the extreme.
Drug companies are not so keen on them, because all too often their shiny new products fail to work significantly better than the placebos used in trials.
And the rest of us may think they are a “good thing” because, lets face it, we’d all like to think that positive thinking of one kind or another can bring about miraculous cures.
But the existence of the placebo effect is no reason to get carried away. And completely carried away some folks do seem to be when they argue thus:
1.    The placebo effect exists, therefore your mind can control your body.
2.    The placebo effect is a kind of positive thinking
3.     Therefore my kind of positive thinking can cure cancer, AIDS and other serious diseases.
Fortunes have been made selling books and conducting lectures along these lines but there are a few flaws in the argument, lurking beneath that therefore like ants, teeming beneath a stone.
Firstly, not everyone is susceptible to the placebo effect. In any controlled experiment, some subjects who have received a placebo will report they feel much better. While others report no improvement. It is not a consistent or predictable effect – not in the least.
Secondly, the placebo effect may alleviate symptoms, but nothing more. It may bring about less pain, less nausea, better mood, that kind of thing. These are symptoms, not diseases. It does not work as a method of shrinking cancers, curing for AIDS or repairing damaged heart muscle.
If you read the “miracle cure” literature it is sprinkled with “case studies” – or rather, anecdotes, in which people claim that their methods have cured serious illnesses. But they offer no research to back these claims.
So we should not get over-excited about the placebo effect. It may have its uses in the control of symptoms, but panacea it is not.

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