Jeremy Laurance: If it makes you better, it doesn't really matter how it works

Medical Life

I am not a doctor, but my family sometimes require me to act as if I were, there being no-one else to examine their rash, bad knee, sore lip. The trouble is that my standard prognosis – "Don't worry, do nothing and you'll get over it" – is not seen as taking matters sufficiently seriously.

Now a fascinating review in the Lancet of the placebo effect has confirmed my view that all you need to get over most illnesses is the confidence that you will recover. Everyone knows how believing a medicine can make you better is enough to make it so, even when the "medicine" contains no active ingredient at all.

But I didn't know that you don't need a placebo to have a placebo effect. It is part of routine medical practice and potentially active every time a patient enters a "therapeutic context" such as the doctor's surgery.

This is illustrated by the device of delivering a drug to a patient using a "computer pump" so that they cannot tell whether they are receiving it or not. Logic would suggest that how someone gets a drug – we are talking orthodox medicines, with powerful active ingredients – would not alter its effect.

Not so. When patients given drugs via the pump, who had no contact with a doctor, were compared with patients who were given drugs by a doctor in the conventional way, they did less well. It turns out that many drugs are less effective when you don't know you are receiving them. There is also a dose response to placebo effects. This, too, appears to defy logic. How can more of nothing be better than nothing? Yet research shows that when "factors involved in the therapeutic context are reduced" – for instance by shortening the consultation with the doctor – the "placebo component of therapy is diminished".

This has a bearing on the question of whether alternative medicine should be funded by the NHS – the subject of a scathing report on homeopathy by the Commons Science and Technology Committee last week. I am a sceptic about all things alternative – but why not exploit placebo effects where we see them?

Instead, the Commons committee dismissed them. It argued that it was unethical to offer placebo treatments without admitting what they were, and the act of explaining would diminish their power. I wonder if that is true.

If alternative medicine depends on the placebo effect, what's wrong with that? So does orthodox medicine – more than we realise. Alternative medicine may produce less bang for the bucks – but this could be hard to prove in the context of the sore throats and bad backs that fill the average GP's surgery, for which conventional medicine can do little.

My instinct is to side with the Committee's rationalist approach. But at the same time I resist their reductionism. In harnessing the healing power of the mind, the placebo effect may be one of the most under-used weapons in the medical arsenal. We should see it as a virtue, not a vice, and find ways to exploit it.