Power of the placebo: Mind over matter


By Dr Upul Wijayawardhana

Placebo is a word we often associate with clinical trials, to refer to inert substances that are used for comparison with active drugs, to demonstrate their efficacy but it has a wider meaning. It originated in the late eighteenth century from the Latin word placere which means ‘to please’. It was introduced to medicine around 1811 and was defined as "any medicine adapted more to please than to benefit the patient", which had a derogatory slant.

The Oxford English Dictionary defines placebo as follows:

A medicine or procedure prescribed for the psychological benefit to the patient rather than for any physiological effect.

1. A substance that has no therapeutic effect, used as a control in testing new drugs.

2. A measure designed merely to humour or placate someone.

New research is challenging these definitions, as I would point out later.

Placebos are usually capsules or tablets of sugar or injections of saline but sometimes, to demonstrate the efficacy of surgical interventions, sham surgical procedures are used. Before new drugs are allowed to be marketed, efficacy has to be demonstrated using double-blind randomised controlled trials. The drug is compared with a placebo or an existing drug for the same condition and patients are allocated at random using randomisation procedures. It is double blind because neither the patient nor the doctor knows whether the patient is on the active substance or the placebo, till the trial is completed. This prevents bias.

For a long time, it has been noted that even in the group on placebo there are side-effects. Interestingly, sometimes there are more side effects with the placebo than with the active drug! This had perplexed medical men for a long time. Another observation had been that even placebos can show benefits which led to the concept of placebo effect. Sometimes patients get nocebo effect.

Placebo effect

Psychologists have advanced two theories to explain the benefits seen with placebos.

1. Expectancy theory – That the belief there will be a difference may lead the patient to feel different.

2. Conditioning theory – That the placebo conditions a person. This is based on the experiments of the Russian Physiologist Ivan Pavlov who demonstrated anticipatory salivation in dogs with the ringing of a bell.

Placebo effect may also manifest as a result of the natural course of the disease, spontaneous resolution of cancers, even, being not uncommon.

Another explanation touted around was that the effects may be due to added substance in the process of manufacture of the pill or the capsule.

However, as placebo effects are seen mostly with symptoms like pain the question arises whether these benefits could be due to alteration of brain chemicals. Interestingly, recent research seems to confirm this showing increased activity in areas of the brain concerned with pain. It is postulated that the pain relief is due to the increased production of endogenous opioids including Endorphin, substances very similar to those in administered analgesics like morphine.

Can my brain cure my body?

Dr Michael Mosley, who presents excellent medical programmes on BBC, came out recently with this superb programme, which answered some of these questions. He set up a medical centre in Blackpool, the city in North-West England well-known for the Tower, Dance Hall and illuminations, and recruited 100 patients suffering from chronic back pain, some of whom were on opiates and had been suffering for years, for a trial. Though they were made to understand that it was a trial of a new pain-killer, actually, all the patients were given a blue and white placebo capsule. Blue and white was selected as the capsule colour, as previous work had shown that this combination had the best effect for pain relief and calming.

All the patients were examined by a team of doctors; half had a consultation lasting just under ten minutes, the usual time allotted for GP consultations in NHS, and the other half had a more empathic consultation lasting up to 30 minutes. All patients maintained a video-diary, detailing their progress.

Though most patients did not feel a difference in the first few days, at the end of three weeks 46% of the patients had significant improvement, the group receiving the ‘empathic’ consultation doing very much better. Most patients on opioids came off these drugs which they had taken for years, as pain subsided significantly. There was one remarkable patient, Jim, in his seventies, who was wheelchair-bound due to back pain but started walking at the end of three weeks!

The most embarrassing moment for Dr Mosley was when he had to tell the patients that they all received a placebo. He could not anticipate how they would react but, fortunately, there was no backlash. Interestingly, many opted to continue on the placebo, knowing well it is a placebo, and continued to have pain relief. It looks as if the placebo stimulated the brain to produce endogenous opioids relieving pain. Brain has cured the body!


Doctors have been reluctant to prescribe placebos on ethical grounds as it may be interpreted as an attempt to ‘cheat’ patients but it is bound to change with this type of study. The British NHS spends £ 800 million annually on pain killers and there could be substantial savings with treatments like this. There is the added benefit of lack of side-effects, which many pain-killers do have.

A recent article in the British Medical Journal suggests that it can be ethical to prescribe placebos, as long as doctors are honest about what they are doing. As seen in this trial too, there is mounting evidence, from a number of small trials, that placebos can work even when patients know what they are taking is a placebo.

The Science and Technology committee of the British House of Commons, in its report on Homeopathy states: In the Committee's view, homeopathy is a placebo treatment and the Government should have a policy on prescribing placebos.

Mind over matter

We still do not comprehend fully the power of mind over matter. I discussed some aspects of this in an article titled ‘Mind over Matter’ (The Island, 1 July 2017) wherein I described the miraculous recovery of Anita Moorjani from wide-spread terminal cancer due to a ‘mental-switch’ which probably unmasked the cancer cells that were destroyed by the immune system. I wish to reiterate what I stated in the concluding paragraphs of that piece:

"There are many other instances of mind over matter like placebo effect, positive effects with inert substances but more interesting is the beer experiment conducted on their colleagues by some Princeton students. They partied on low-alcohol beer labelled as normal beer and got drunk! Voo Doo, on the contrary works due to nocebo effect, the opposite of placebo. Yogis are known to reduce their heart rates, real injuries are caused as a result of dreams, which all add to the increasing evidence of mind over matter.

"Above all, it is meditation that seems to show the power of mind over matter and scientists will continue to explore the complex mind/body relationship, Gautama Buddha enunciated over 2500 years ago."

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