Placebo – simplified

by TheEditor

Categories: Diagnosis, Investigative, Medicine

This is about the nature of the placebo (and related) effects. I’m not giving a definition on this occasion. Readers can jump on the net and find whatever definitions they like. This is not an academic analysis.

I’m sharing some experience and knowledge of the placebo effects. Some of these will have references to information on the net, and some will not. My mission is not primarily to ‘explain’ the placebo effect, though I may touch on some possible mechanisms.


The placebo effect is where a thing that could possibly have no effect ends up associated with improving something, but it has no real efficacy. This can occur in human beings, organisations or systems. In other words it is basically a ‘false positive‘. I have not asserted that it is a false effect. It is possible for a thing to have an associated or correlated effect but still no causal effect. The positive effect is highly rewarding and creates an almost unshakeable belief that the ‘intervening thing’ is of value. Many will have missed the word ‘efficacy‘ or assumed what it meant.


Medication – A doctor says that s/he thinks you have condition X and prescribes a pill which s/he is fairly confident will improve the symptoms of the condition. You take this and after a few days you feel better. To most people this means that the pill is working. It is simple and sweet – symptom relief. But after a further few weeks symptoms do not continue to improve or actually grow worse. So now you think, maybe it wasn’t working that well. It is easy in the initial part of treatment for belief to be rewarded by improvement. Doubt sets in when symptoms return.

In Business – a company is having some problem with marketing a particular product. After a consultation exercise, they decide to implement some plan. Things improve over the next few months. They breath a sigh of relief – and conclude that their strategy was effective. They roll out the plan wider to the organisation, then in the next year it all goes pear shaped.

What’s happening there? In both there was expectation that the intervention would improve things. Following the intervention they concluded that the ‘treatment’ was effective. B followed A which led to causal thinking, instead of a deeper understanding of confounding variables. Some of those variables were missed and came back to bite.

In social life – people often report to each other that A, B, or C thing helped them with this or that problem. Numerous such reports are convincing – due to the herd effect. The herd effect is a powerful influencer from our psycho-evolutionary inheritance. So, individuals become convinced based on herd reports, then try A (for example) and get ‘symptom relief‘. Expectation of relief (a psychological thing) could have driven the reduction in symptoms, while dangerous underlying pathology (for some) remained roaring below the surface (a sort of poultice effect). Powerful beliefs develop as a result of these social myths about ‘what’s good for what’. Any fool can jump on the internet and find a range of remedies for any ailment known to man (or woman) – from vaginal eggs to urine! Even prayer and exorcism can have placebo effects.


Relief from physical or financial pain, is a powerful reward mechanism. It is very convincing. It leads people to conclude that there is efficacy. In medical conditions the symptom, not unusually represents a deeper problem. I’m not talking about the common average headache here. The unusual recurring headache could be due to any one of dozens of serious conditions.

Similarly in business operations, a failure in one area may be connected to several other deeper complex problems. In other words the one has to be cautious not to rely on the ‘poultice‘ effect.

People are naturally attracted to simplicity – everybody likes the simple and neat solution. This is why ‘pain relief‘ is often taken as efficacy. However, efficacy is a very different concept in medical circles and it does not mean just improving symptoms. Efficacy is about targeting the mechanisms of a disorder so as to bring about more lasting symptom relief – but more importantly correcting an underlying pathology. In other words an effective treatment is not like a plaster on a sore (figuratively speaking).

Normally people look for anatomical or biological changes that can be seen and measured. That’s fine. But what about a treatment where there can be no measure of the substance of biological change? Take Cognitive Behavioural Therapy (CBT). The efficacy of CBT is to be measured not just by clinical opinion, but by longer term psychological measures of enduring change. But no one in their right minds will put patients improved post-CBT into a brain scanner to find which part of the brain has ‘healed’. That would be a costly and pointless exercise.

Placebo trials and new findings

Placebo is a big part of Double-blind Randomised Controlled Trials (DRCT). These use placebo – an inert substance that is not disclosed. Both the real treatment and the placebo are made identical in appearance, taste etc. Patients consent to the trial not knowing which is the test (real experimental) treatment from the placebo. It was always known from many years ago that the placebo effect could be around 60-80%. So a new treatment has to beat that significantly.

Concealment of the placebo was thought to be necessary i.e. the subject must not know which is the real test pill from the placebo. However, Prof Kaptchuk upset ‘the applecart’ around 2010 by doing trials where the test subject were allowed to know that they were actually receiving a placebo. This is quite different to DRCT, where test-treatment would not be distinguishable from the placebo. Shockingly some patients who expected receiving no benefit from the known placebo – because they were told the pill was inert – then improved significantly, to their total surprise.

Key points only on the above research (from this point):

  1. 30% of people improved with no treatment.
  2. 60% of people improved when they knew they were given a placebo (normally they wouldn’t be told that it is a placebo, in placebo controlled trials).

Caution: This does not mean that the results apply in every situation. It only highlights the power of the placebo, even when patients know they are receiving an inert substance with no effect. Finer details of the research outcome requires careful study.


I’m using ‘pain relief’ to cover a range of issues in medical complaints (of symptoms) and other scenarios. When you get that pain relief, you’re convinced that whatever it is that brought relief will continue to work in the future. That’s fine for mild symptoms without underlying complexity or complications. But the average Joe or Jane won’t know what’s mild and uncomplicated until too late.

The first danger is of everybody turning into a hypochondriac – and rushing to GP’s surgeries demanding ‘X-rays’ and other tests. The next danger is the exact opposite i.e. doing nothing.

The social value of some remedy – in the realm of myth – becomes pretty powerful. Hence, we see roaring debates between pure scientists and ‘the herd’ about the efficacy of homeopathy, chiropractic and alternative medicine. The way this works is that ‘some’ people will say that A, B, or C works for ‘some people’ some of the time. But even this does not mean efficacy. Again the word ‘works‘ is important to focus on, because what people really mean by that is symptom relief. They are certainly not talking about a ‘treatment’  or ‘intervention’ that targets the core of some pathological process.

But it gets more complicated because some of the alternative treatments become wrapped in a ‘quasi-science’ which is appealing and ‘makes sense’ – but still lacking in hard evidence of mechanism of aetiology or actual enduring change in underlying pathology post-intervention. I will avoid going into each of those ‘alternative treatments’ which occupy my mind because I know it is a total waste of my time engaging in myth busting.

This post is not about ‘advice’, so I’m not here to tell people what to do.

Wrapping up

  1. The human mind can believe whatever it wants.
  2. Unconscious determinants of belief are numerous and can be powerful and risky.
  3. Seemingly conscious determinants of belief based for example on herd effects are equally risky.
  4. Symptom does not mean illness.
  5. Symptom relief does not mean effective treatment of an unseen underlying pathology.
  6. Quasi-science is attractive and dangerous.
  7. Anticipation of positive effect is a powerful predeterminant.
  8. The placebo effect is powerful and potentially dangerous.

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