Monday August 29, 2005
Comment, The Guardian
Sceptics, and the placebo effect, are easily misunderstood. Since I’ve made a modest second career out of rubbishing alternative therapies (or rather the pseudoscience of the claims behind them), you might expect me to be pleased with a new analysis of 110 placebo-controlled randomised trials of homoeopathy, published in the Lancet, showing there is no evidence that homeopathic tablets perform any better than placebos. Obviously, it’s an important and useful finding. But it misses the mark.
The placebo is arguably the most interesting phenomena in medicine, because it goes far beyond the effectiveness of little white sugar pills, into the cultural meaning of treatment. It has been shown, for example, that green sugar pills are a more effective treatment for anxiety than red sugar pills, because of the cultural meaning, we might parsimoniously assume, of the colours green and red.
Likewise, studies have found that salt-water injections can be a more effective placebo treatment than white sugar pills – not, I might add, because there is anything particularly useful about salt water injections, but because the ceremony of performing an injection is a far more invasive, authoritative and dramatic intervention.
It gets far stranger. A placebo operation in the 1950s was found to be as effective for the treatment of angina as the real operation it was being compared with. Reading the paper 50 years later, the most striking part is the discussion section, where they quietly drop the operation and nobody stands up to point out the incredibly strange discovery that a placebo operation works for anything, let alone angina.
Branding, of course, is the key to the efficacy of little white sugar pills. Marketing, after all, is nothing if not engineered cultural meaning. A four-way comparison among sugar pills and aspirin, in either unbranded aspirin boxes or packaging mocked up to look like the Disprin brand, showed that the brand-name packaging works, because of the huge wealth of cultural background material – the adverts, the word-of-mouth endorsement, the childhood experiences – that packaging plays on. The change in packaging had almost as big an impact on pain as whether the pills actually had any drug in them.
The implication for rationalists, who reach for generic, unbranded medications like aspirin and ibuprofen in preference to Disprin or Nurofen, is clear. It’s perfectly rational to believe that expensive Nurofen is more effective than cheap unbranded ibuprofen, even if they’ve both got the same active ingredient – but only, in a peculiar tautology, if that’s what you believe.
This, of course, is the key also to alternative medicine: homeopathy is what you might call a “complex intervention”, rich in cultural meaning and drawing on such attractive contemporary ideas as individualism, patient empowerment and personalised healthcare. But all alternative therapies also offer something very much missing from modern medicine, the idea of containment of symptoms.
Transparent modern medics often say: “I don’t know what the cause of your problem is. This might make it better, but it might not, and it might have these side effects.” They sometimes follow this with: “What do you think?”
Enter the alternative therapist, who understands your problems whatever they are, who is privately employed and has time to listen, who has an answer and who gives a complicated (often wilfully obscure but always authoritative) explanation of what is going on, maintaining the power imbalance in the therapeutic relationship with his or her exclusive access to arcane knowledge. If that’s not old-fashioned medical paternalism, I don’t know what is, and the paradox is clear: while modern medicine, without even pausing to discuss the question, has championed patient autonomy and informed consent – and thrown the placebo effect out of the window – the market has shown that the old paternalism, in a new guise, is still very popular.
Whether mainstream medics would want to go back to the old ways and embrace the placebo-maximising wiles of the alternative therapists is an easy question: no thanks. The didactic, paternalistic, authoritative, mystifying mantle has passed to the alternative therapist, and to wear it requires one thing most doctors are uncomfortable with, dishonesty.
So the fact stands, not even slightly mocking us, that in many cases homeopathy does seem to help, as a complex intervention, laden with branded cultural meaning, at least better than “doing nothing”. It is no better than placebo, because it is placebo, in all its rich glory.
But the homeopaths themselves can never admit this clear, compelling, evidence-based and parsimonious explanation: they need the memory of water, the power of arcane knowledge and all the rest. Homeopathy and the others can only work as long as their myths and meanings survive, and so medics, alternative therapists – and smarmy sceptics – will always, mercifully, be in business.
Â· Ben Goldacre is a doctor and writes the Bad Science column in the Guardian