We know that placebo drugs – often sugar pills with no medical benefit – can relieve symptoms, even if those taking them are told that they aren’t taking medicine. To work we had thought the person taking the placebo had to understand why it can be effective. But it may be possible to get the benefits of placebos without such detailed explanations.
One reason doctors rarely use such placebos in practice is that they require too much explanation. But Tobias Schneider at the University of Basel in Switzerland and his colleagues found that may not always be the case.
They used electric shocks to create acute pain in 32 healthy men between the ages of 18 and 37. Half the men were given placebos intravenously during the electric shocks, while the other half only received the electric shocks.
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Of those given a placebo, half were given a very thorough explanation of how they produce a biological effect while the other half were just given leaflets about the placebo with a short description of how it works.
On average, all the men given a placebo rated their pain as 21 per cent lower than those not given one. The level of education about the placebo had no effect on participants’ pain ratings.
These results suggest extensive education may not be required when using placebos, says Schneider. He says placebos cannot replace pain relieving drugs but argues that they might be able to prolong their effects or reduce their dosage, lessening side effects such as nausea, vomiting or difficulty breathing.
Felicity Bishop at the University of Southampton, UK, says the results suggest there is a potential role for such placebos clinically, but adds that “more evidence is needed as to the effectiveness, safety and acceptability – to patients and doctors – of such practices.”
Anaesthesiology
