MD, PhD, FMedSci, FSB, FRCP, FRCPEd

The following short passage originates from the abstract of an article that I published in 1998; it is entitled TOWARDS A RISK BENEFIT EVALUATION OF PLACEBOS: the benefits of placebos are often not clearly defined. Generally speaking, the potential for benefit is considerable. The risks are similarly ill defined. Both direct and indirect risks are conceivable. On balance, the risk-benefit relation for placebo could be favourable. Under certain conditions, the clinical use of placebos might therefore be a realistic option. In the final analysis, however, our knowledge for a conclusive risk-benefit evaluation of placebo is incomplete.

Today, I would phrase my conclusion differently: the benefits of placebo therapy are uncertain, while its risks can be considerable. Therefore the use of placebos in clinical routine is rarely justified.

What brought about this change in my attitude?

Lots of things, is the answer; 18 years are a long time in research, and today we know much more about placebo. In my field of inquiry, alternative medicine, we know for instance that, because the mechanisms by which placebos operate are now better understood, some alt med enthusiasts are claiming that placebo effects are real and therefore justify the use of all sorts of placebo treatments, from homeopathy to faith healing. They say that these ineffective (i.e. no better than placebo) therapies are not really ineffective because they help many patients via the well-documented placebo response.

If you are of this opinion, please read the excellent article David Gorski recently published on this issue. Here I want to re-visit my question from above: WHAT DO WE KNOW ABOUT THE RISKS BENEFIT BALANCE OF PLACEBO?

The benefits of placebo can seem impressive on first glance: after receiving placebos, patients can feel better, have less symptoms, need less medication and improve their quality of life. Who would be against any of these outcomes, particularly considering that placebos are usually inexpensive and readily available everywhere?

However, before we get too enthusiastic about the benefits of placebos, we need to consider that they are unreliable. Nobody can predict who will respond to placebo and who won’t. Despite intensive research, it has not been possible to identify placebo-responders as a distinct group of individuals from non-responders. The usefulness of placebos in clinical routine is therefore quite limited. Furthermore, placebo effects are normally only of short duration. Therefore they are not suited for any long-term therapy.

Crucially, placebos almost never effect a cure. They may improve subjective symptoms, but they do not normally cure the disease or remove its causes. A placebo therapy will reduce pain, for instance, and thus it can ease the suffering. If a back pain is caused by a tumour, however, a placebo will not diminish its size or improve the prognosis.

The notion that placebos might cause harm seems paradoxical at first glance. A placebo pill contains no active ingredient – how can it then be harmful? As I have stressed so often before, ANY INEFFECTIVE TREATMENT BECOMES LIFE-THREATENING, IF IT IS USED AS A REPLACEMENT FOR AN EFFECTIVE THERAPY OF A SERIOUS DISEASE. And this warning also applies to placebos, of course.

Seen from this perspective, the much-praised symptomatic relief brought about by a placebo therapy can become a very mixed blessing indeed.

Let’s take the above example of the patient who has back pain. He receives a placebo and subsequently his agony becomes more bearable. Because this approach seems to work, he sticks with it for several month. Eventually the analgesic effect of the placebo wears off and the pain gets too strong to bear. Our patient finally consults a responsible doctor who diagnoses a bone cancer as the cause of his pain. The oncologist who is subsequently consulted regrets that the patient’s prolonged placebo therapy has seriously diminished his chances to cure the cancer.

This may look like an extreme example, but I don’t think it is. Exchange the term ‘placebo’ with almost any alternative treatment, or replace ‘back pain’ and ‘cancer’ with virtually any other conditions, and you will see that such events cannot be rare.

In most instances, placebos may seem helpful but, in fact, they offer little more than the illusion of a cure. They very rarely alter the natural history of a disease and usually achieve little more than a slight, short-term improvement of symptoms. In any case, they are an almost inevitable companion to any well-administered effective treatment. Prescribing pure placebos in clinical routine is therefore not responsible; in most instances, it amounts to fraud.

5 Responses to Placebo = the illusion of a cure

  • I often wonder if the magical thinking among the alt med crowd isn’t due to a pervasive yet undiagnosed psychosis induced by widespread use of marijuana. Then again, maybe its a placebo response. Once placebo responses wear off, which they almost always do, the underlying pathology rears its ugly head and the patient is worse off than before.

  • Accepting this could be rather embarrassing for those in British medicine who have to justified their behaviour by claiming that they should be respected for their ability to develop and provide treatments that seem no more effective than placebo.

    Last year Simon Wessely, President of the Royal College of Psychiatrists argued that:

    “The placebo is one of the best interventions we have.”
    https://twitter.com/wesselys/status/573918127005786113

    How much of the controversy which surrounds his career, and his approach to Chronic Fatigue Syndrome, is likely to have stemmed from his willingness to promote costly and time consuming treatments as ‘evidence based medicine’ to patients when they have no good evidence of being any more ‘effective’ than placebo?

  • My opinion is that 1. patients need placebo treatment. 2. Of course, a clear diagnose of patients shall be obtained at the same time. At least to tell the relative or patient him/herself that the future of the disease, even for incurable disease.

    Your case of delayed diagnose of cancer patient only illustrate that the second principle shall not to be violated. It did not refute the first principle.

    Even for cancer, the placebo treatment can ease the pain. The severe mistake of the alternative therapist results from his ignorant to disease diagnose. I also wonder even the patient were diagnose as early as possible, will his/her problem be cured? Sometime, we found out patients get earlier diagnose and being treated with Chemo or radio therapies die very fast. This maybe results from the immature of the treatments and the aggressiveness of the treatment. It destroys the immune system of the patients. Or from the stress of the patient him/herself knowing the diagnose, which caused a opposite results to placebo.

    I think the attitude of this article is more appropriate. http://www.nature.com/news/consider-all-the-evidence-on-alternative-therapies-1.18547?WT.ec_id=NATURE-20151015&spMailingID=49776155&spUserID=NDE0NTQ2MTc5MAS2&spJobID=781896658&spReportId=NzgxODk2NjU4S0

    In addition, my father is a cancer patient who survived for 26 years. He stopped the conventional treatment after the first year. I notice the positive thinking etc. (placebo) really benefit his recovery.

    Regards,

    • @ Zhang
      My opinion is that 1. You have misunderstood what placebo is. Per definition, placebo is an inert (=fake) facsimile of the real therapy under investigation. Placebo is not something you give patients to procure the placebo effect.
      The Placebo effect is the measurable degree of positive change that may be attributed to the inert therapy. Credible evidence and logic suggests that a large part of what has been called the placebo effect is not due to the subjects belief that they are are receiving genuine therapy but due to normal self-healing AKA regression to the mean, which is to be expected anyway. Please read David Colquhoun’s post here: http://www.dcscience.net/2015/12/11/placebo-effects-are-weak-regression-to-the-mean-is-the-main-reason-ineffective-treatments-appear-to-work/
      2. You are very mistaken if you think that alternative therapies have not been investigated thoroughly. The Americans have spent hundreds of millions of dollars on real research but those who benefit from them i.e. the charlatans who sell it, refuse to listen. A good example is chelation therapy which has been investigated for more than 30 million dollars but without finding a benefit from it. https://www.sciencebasedmedicine.org/misinterpreting-tact-no-chelation-does-not-outperform-statins-for-heart-disease/

      Here you can see one of the biggest alt-med research activities in the world. They have found very little of value:
      https://nccih.nih.gov/

      I am happy for you and your father that the year of conventional therapy perhaps saved his life and he has been able to live so long after.

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