Editorial: Use and misuse of the placebo effect

Published in The Hindu on March 16, 2011

Are placebos inert substances with no real therapeutic effect? Placebos go back to the origins of medicine as a science and as an art and have been part of the stock-in-trade of charlatanism and quackery. Today they are routinely used in human clinical trials for comparing the efficacy of experimental drugs; this is based on the premise that placebos containing inactive substances have nil therapeutic potential. But, although their use in clinical care for treating patients with imaginary or real ailments is reportedly showing some promise, their undisclosed use is considered questionable and even unethical — and hence is not formally approved by medical authorities anywhere in the world. Yet doctors in several developed countries are using them even when effective medicines are available. Anecdotal evidence suggests that many doctors in India have long been doing so. A recent study by the German Medical Association (BAK) found that half of German doctors were prescribing placebos to ‘treat’ depression and stomach complaints. The percentage of general practitioners taking advantage of the placebo effect to treat their patients shot up to nearly 90 per cent in Bavaria. That nearly 60 per cent of patients who had upset stomach and about a third of those with depression stood to gain shows that the placebo effect could be real. The placebo effect was maximised when administered as an injection, and factors such as size and colour of a pill determined the success rate. Being convinced that doctors understood their concerns and were taking them seriously played a major role.

This is not the first time placebo effects yielding positive results in clinical settings have been documented. A 2008 study covering nearly 680 U.S. internists and rheumatologists found that about half of them had prescribed placebos (without the patients being aware of it) over the past one year. Though the intent was to promote positive therapeutic expectations, it was considered unethical as the patients were kept in the dark. Withholding information amounts to cheating and threatens trust, so very central to clinical practice. Advocates of placebo treatment note that positive results can be achieved even without deception. But whether it can be adopted in clinical care after eliminating all kinds of deception is not fully known. Placebos given along with drugs in trials produced positive results but at reduced levels when patients knew of their doubtful efficacy. Evidence-based practice must wait for further research and for the formulation of clear guidelines for placebo use.