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Placebo 1 - the deceptive effect


In this series of posts I will deal with one of the most fascinating, complex and controversial phenomena I have come across so far - the placebo effect, or Placebo in English. In Hebrew the term is called "inbo" for reasons that will be clarified immediately. Since I like the soft English sound better, and think that the Hebrew concept forces a certain interpretation of the phenomenon, I will use the term "placebo".
The phenomenon embraces many and diverse fields: medicine in its various fields, psychology, philosophy (body-mind issue) and even morality, and this is also where the enormous complexity of the subject comes from. During the last decade, research in the field has flourished, which guarantees that we will come across many recent studies during our journey.
In the Hebrew Wikipedia it is defined: Placebo effect Occurs when a patient receives a dummy treatment (which he thinks should help him), or a treatment that does not include the "active" ingredient in the medicine, but his condition improves. The phenomenon also occurs in real treatments - the patient's condition partially improves regardless of the medicine he received.
In the English Wikipedia is defined: The placebo is a dummy substance or therapeutic procedure has no medical effect for an illness or other medical condition, whose purpose is to deceive the patient Sometimes patients receiving placebo treatment will benefit From perceived or real improvementIn their medical condition, a phenomenon called the placebo effect.
From a brief look at these definitions, many questions arise, such as:
  • What is the meaning of "no medical effect" on the one hand, and "real improvement in their medical condition" when they are said in the same sentence?
  • How is it possible that the patient's condition improves following a treatment that does not include the active ingredient?
  • Are there other hidden factors that may cause an improvement in the patient's condition that are not related to the same "dummy treatment" given? Are they part of the placebo effect?
  • What is hidden behind "the purpose of deceiving the patient"? Is this always the case? And maybe its purpose is to help the patient? Because in the same sentence it is said "sometimes patients... will enjoy themselves." From perceived or real improvement in their medical condition".

Here we have already covered some of the key points that we will deal with in detail later.

I will try to lay out in an orderly and clear manner as much as I can (and as much as possible) what is currently known on the subject. The main difficulty I encountered in preparing this investigation was the plurality of opinions in the field from different researchers, to the point of complete contradictions in the conclusions they reach. A large part of the contradictions have been resolved over the years by defining concepts more clearly, making better distinctions between cases and separating the facts from their interpretation. Nevertheless, significant disagreements still exist in the field.

The series has five parts, and it will take us on a volatile journey, full of upheavals and requiring concentration.
The last episode in the series will focus on the more charged aspects of the subject, so I would suggest holding back on the heated debates about ethics, the connection between placebo and alternative medicine, etc., and manage them following the last episode, after we have gained updated knowledge in the field.

My thanks to Dr. Karen Landsman, a specialist in epidemiology and public health, who read the material and made helpful comments. You are welcome to visit her blog - The end of the world - a view from the stands (On reality and other diseases). Also thanks to Itzik Shohat - an intern, who also reviewed the material and made his comments.
Let's go!

A little history

Franz Messer. From Wikipedia
Franz Messer. From Wikipedia

Franz Messmer who operated in France at the end of the 18th century, claimed to be able to cure a host of diseases using Magnetized water, who work, according to him, on the "animal magnetism of the patients". The effects of the treatment were extremely dramatic. People even came to fainting as a reaction to those special waters.

But there were also skeptics. In 1785, Louis XVI convened a royal commission to examine the issue. The committee, which included Benjamin Franklin, conducted experiments in which one glass of "magnetized" water was placed between four identical glasses filled with normal water. Volunteers chose a cup at random and drank from it. There were still cases of fainting, but not exactly from drinking the magnetized water...

At the end of the experiment, the situation became clearer: No connection was found between the glass from which the volunteers drank and the symptoms that they developed or did not develop. The conclusion - the reactions resulted from the expectation only that something would happen, regardless of the type of water that was in the glass. Another conclusion was that Mesmer was a fraud. This was probably one of the first recorded clinical trials in history, in which the concept of blindness, that is, a situation in which the patients do not know whether they are receiving the expected treatment or a fake treatment. (Ironically, but predictably for those who have already followed the ways in which illusions spread, the "animal magnetism" movement not only did not wane but even strengthened thanks to the publicity she received following all the involvement in the issue).

A few years later, in 1796, a similar thing happened in America. The first US medical patent was granted to Elisha Perkins, who invented a pair of metal rods capable of drawing pain out of people. Tractors he called them ("Moshen").

It was enough to flutter the rods over the painful area for a few minutes for them to suck up the "harmful electric fluid that lies at the root of the pain". (In every era, fraudsters use concepts from the forefront of science to give their charlatanism a scientific face. In that era it was electricity. Nowadays, they use "quantum theory" or "chaos theory" for this purpose).

Perkins boasted thousands of satisfied patients, won the support of medical schools and interest from famous figures such as George Washington, for example, who purchased a pair of rods. Soon Perkins' son also joined the family business and both of them made a lot of money from providing treatments and selling rods at sky-high prices, prices which they justified by claiming that the rods were made of rare metal alloys that gave them their special healing powers.

But even here the skeptic finally arrived who decided to look into the issue. This time it was an English doctor named Haygarth (Haygarth), who made a pair of fake poles (made of wood coated with metallic paint) that are indistinguishable from the real ones. Four out of five subjects reported improvements in their health whether the real or fake rods were used.

Haygarth explained the surprising findings by saying that the strong effects of the rods on disease are created through imagination alone. That is, A patient's belief alone that he is receiving effective treatment can result in an improvement in his condition, or at least make him believe that his condition has been improved.

For example, when Haygarth treated a woman with a locked elbow with the fake rods, the woman claimed that her mobility improved. In fact her elbow remained locked, but she compensated for the limitation by increasing the rotation of her shoulder and wrist. We will return to this interesting point later.
The placebo effect It is the name given to the better feeling that a person gets as a result of a futile treatment that lacks any medical efficacy. The origin of the word placebo is in Latin, and it means "I Shall Please".

Haygarth realized a few other important things. He realized that the placebo effect actually enhances effective treatments, and asked himself how the effect could be increased even more. Since the effect was due to his opinion From the trust that the patient acquires in the treatment and the therapist, he concluded that the higher the reputation of the doctor, the cost of the treatment and the degree of innovation, the greater the placebo effect. Another 200 years passed before these hypotheses were scientifically proven.

We skip forward about 150 years, to another famous researcher of the placebo effect: the American Henry Beecher (Henry Beecher). His interest in the subject began during the Second World War, against a background of severe distress in the means to properly treat the war wounded. When the supply of morphine ran out, Beecher decided to conduct a daring experiment. He injected the wounded man with saline but told the wounded man that it was a strong pain reliever. to his surprise The injured man calmed down immediately and showed no signs of pain. The miracle happened again and again with many other injured people!
After the war, Beecher laid the foundations for organized research in the field.

The effectiveness of a new treatment
We will use the opportunity to stop for a moment and think - how do we know if medical treatment is effective? (This can be medication, physical therapy, surgery, etc.).

Let's say that Liusi has a headache. Yossi swallows an experimental medicine against headaches and indeed the next day the pain is gone. Is the drug effective? Naomi, on the other hand, swallowed the medicine, and her headache only got worse, but it went away two days later. Is the medicine ineffective?

It is difficult to learn something from two cases. It is possible that other factors are not related to the treatment at all they who were responsible for the change in the situation. In order to offset the influence of such and other unknown factors, the treatment must be checked Multiple as many people as possible.

Let's say that 100 people received the experimental drug, and 50 of them improved significantly within two days. Is the treatment successful?

There is no way to determine this of course, if not Compare the results to a group of other people who suffered from the same problem but did not receive the treatment. If the number of healers is significantly large among the group receiving the treatment, it can be said that it is effective.

But in light of the cases we described earlier, it is clear that there is a big problem in evaluating the effectiveness of the treatment, since it is possible that the condition of the patients has improved Not as a result of the specific treatment, but only out of the expectation that their condition will improve! How can we distinguish between the two?
Those historical pioneers that we met earlier actually found the solution to the issue: it is necessary to ensure that the patients do not know whether they are receiving treatment or not. The experimental group is given the real treatment and the control group is given Sham treatment, in such a way that the subjects do not know which of them receives what. That way, everyone's expectation will be the same, and this factor will be removed from the comparison. If a distinct advantage is found for those who received the real treatment, then it has an added value beyond the placebo effect. If the results in both groups are the same (as good as they will be), then the treatment has no real medical benefit in itself.

If the real treatment is the administration of a certain pill, the dummy treatment will be a pill that looks exactly the same even contains no active ingredient. If the treatment is an injection of a certain substance, the sham treatment will be an injection without an active substance, etc.

From the patient's point of view There must not be any difference between the real treatment and the sham treatment, so that there is no difference in expectations. The treatment should take place in the same place, by the same therapists, the patients should receive the same explanations, the same treatment, and the results should be monitored with the same frequency and in exactly the same way. Such an experimental method is called The blinding method (Blind).

But it turned out that not only the patient affects the placebo effect, The therapist too related to the effect. If the therapist Knows which of the patients is receiving real treatment and which is not, he may pass this information on to the patient unconsciously. Something in the tone of voice may be different, in the length of the explanations, in relation.
An instructive example of indirect influence of the researcher can be found In the next study, who examined patients suffering from postoperative pain. The patients were divided into two groups. to the patients Both groups were told the same thing - they would receive either a placebo or a real painkiller.
to caregivers In contrast, subjects in one group were said to receive only a placebo, while some subjects from the other group would receive a real pain reliever.
In practice, the placebo effect was much smaller in the group about which they believed the caregivers Because there is no chance that its patients will receive a real pain reliever. All this without an exchange of words between the therapists and the patients!
Therefore the accepted protocol is double-blind in it Neither the therapist nor the patient Know who gets real treatment and who gets fake treatment.
This is the highest standard today for clinical trials in new treatments: A large group (thousands of subjects), randomly divided into two groups - an experimental group (receiving the real treatment) and a control group (receiving a sham treatment). The distribution is done double blind (no one knows who is in which group).
In addition, it is desirable that those who analyze the results of the experiment do not know who received a real treatment and who received a sham. Such a situation is called triple-blindness (Triple blind). Such a protocol cleans up all the biases we mentioned.
[An example of embarrassing results reached by researchers (real or simulated) when they do not use double and triple blinding protocols we met here for example – “What for all the blip are they talking about?! – The Japanese and his ice crystals"].

The amazing power of the placebo
In 1955, Beecher published the founding and most cited article in the field - "The Powerful Placebo", in which he reviewed 15 clinical trials and found that the condition of about a third Out of over 1000 subjects, the placebo treatment alone improved.
Over decades of clinical trials of new drugs, the phenomenon repeated again and again: tens of percent of the group receiving the dummy drug reported an improvement in their condition. Some of them even developed side effects attributed to the drug!
Furthermore, there are recorded cases in which people opened Withdrawal difficulties with cessation of placebo treatment. for example, In an experiment in which hormonal treatment was given to women and tested the effect of stopping it, it was found that 40% of women from the control group who received a placebo Suffer from side effects!

As good as placebo? Disqualified!

And here comes a strict guiding rule in the process of developing a new drug: If no clear and significant advantage is found for the experimental group over the control group (placebo recipients), the treatment is declared a failure and its development process is stopped. Years of clinical trials and tens of millions of dollars go down the drain. Examples are not lacking:

  • Shares of a company that developed an anti-allergy drug (Peptide Therapeutics) fell by 33% after it became clear that the drug is no more effective than a placebo: during the experiments on subjects who were allergic to a certain food, 75% reached a situation where they overcome the side effects of eating food that they were never able to eat. The surprise came when it turned out that 75% of the subjects in the control group also benefited from the same improvement!
  • The pharmaceutical company Merck announced the cessation of development of an anti-depressant drug (MK-869) that was expected to have similar success to Prozac, since the placebo worked just as well.

Depressing facts about antidepressants?

Super review From 1998, trials of antidepressants found that 75% of their effectiveness can be attributed to the placebo effect and other general factors rather than to the treatment itself. Another review which also included unpublished experiments (probably those whose results were less favorable, but their inclusion gives a truer picture of the situation of course), found that There is no significant difference between the drugs and the placebo, except in extreme cases of severe depression. Additionally, no significant difference was found between the rates of suicide or suicide attempts between those taking antidepressants and those taking placebo.
Here is a quote from Washington Post article from 2002: "In most of the experiments conducted by the pharmaceutical companies in the last decades, the performance of sugar pills [synonymous with placebo] did not fall, and even rose on the performance of antidepressants. Companies had to make many attempts just to get two trials that show positive results of the drugs - the minimum required by the FDA in order to approve a drug. The manufacturer of Prozac needed 5 trials to get 2 positive results, and the manufacturer of Paxil and Zoloft needed even more."

Before we look at the article on the subject, I will point out that this information is controversial.

Placebo is not only in medicine. Even in surgeries!

Over the years, more and more evidence has been accumulated of the effect of the patient's faith on his feelings, even when he was not given any real treatment. Here are some famous examples:

Internal thoracic artery ligation surgery - In the middle of the 20th century, it was customary to treat cases of angina (which manifests itself in chest pain) by an operation in which one of the arteries was tied. The assumption was that the ligature would raise the blood pressure in the coronary arteries, and improve blood flow and oxygen supply to the heart muscle. According to the testimony of the patients, the operation provided relief for several months.

In 1955, a cardiologist named Cobb suspected the effectiveness of the treatment, since post-mortem examinations of patients showed no sign of improvement in flow. Cobb performed a placebo-controlled trial: in half of the patients he performed the usual surgery, and in the other half he only performed an incision, No Tie off the artery, and sew it back up. The results were the same! Most patients From two The groups reported a significant relief that lasted about 3 months, then the situation returned to normal. There was no meaning in tying the artery!

Knee surgeries to remove damaged cartilage - In the mid-90s, an orthopedic surgeon suspected the effectiveness of a certain type of knee surgery that was practiced mainly among athletes. Hundreds of thousands of such surgeries were performed each year, at a cost of thousands of dollars per surgery. It was known that the condition of About half Of those who were operated on, it was getting better, but it was not clear what the mechanism of the improvement was. in the research that was carried out To test the issue, 180 patients with osteoarthritis were divided into three groups who received the following treatments:

  • Group A - full treatment: 3 incisions, removal of cartilage and rinsing with salt water.
  • Group B - partial treatment: 3 incisions and rinsing with salt water.
  • Group C - placebo: 3 incisions only, without any additional activity.

The members of groups A and B were very satisfied with the treatment, felt a significant improvement in walking ability and said that they would recommend the surgery to their friends. Surprisingly, the improvement in the condition of group C berries was the same!

You can see a video about the experiment here.
It seems that the reality of the placebo exceeds all imagination!
But let's not rush. In the next post What we have learned about the placebo effect is about to undergo a significant upheaval...


  1. Placebo in Hebrew is not "inbo", but "dummy drug".
    Here are the words of the Hebrew Language Academy:

    A dummy drug [an inactive substance given as a drug. To test the effect of a drug, it is given to an experimental group, and a control group is given a dummy drug. Sometimes the dummy drug is given to the patient in order to test the mental effect caused to him by the very treatment of his disease, without him actually taking the drug]

  2. Ernest,

    I don't know why you feel you represent the readers of this site. You can only represent yourself. You sure don't represent me!!

    I found the article interesting and I learned a lot of things - I will continue to read the following articles.

    And as always - if the article does not interest you - or if you already know everything - you can always move on to the next article. There is no reason to let go of Gilad's hands, who is doing a beautiful and interesting job.

    Thanks, Gilad, for the article, keep it up, and don't let anyone let go of your hands.
    Guy penetrated.

  3. Eyal. A
    Thanks, but I asked for data and not an opinion.
    The child is exposed to information, and he does know what asthma is.
    And as for all the other ills of the warnings, even if they are true, that is not really true.
    They should significantly increase morbidity among smokers and also among the general public.
    Ignoring warnings does not eliminate exposure to warnings, they are two completely different things.

    And there are also inhalers for asthma that are themselves a placebo, so you cannot claim that there is no psychological connection here.

    The placebo effect is so strong, to the point that some people get headaches and dizziness just from smelling something that smokes, without being exposed to smoke.

  4. Well done Gilad, self-taught without impressive degrees, who does a very thorough job.

  5. This is the power of healing through faith. This phenomenon has an ancient record in the Gospel books and even in the Bible. For example, the Bible attributes to priests the power to reveal hidden things and tells, among other things, about their ability to verify that adultery has been committed. A woman suspected of adultery is brought to the priest. He offers her to drink some kind of potion, but before that he warns her that if she is not telling the truth, she is expected to suffer severe pain and a visible change will take place in her body (Sefer Bamadbar, chapter XNUMX, verses XNUMX-XNUMX). In this long story of twenty verses, only one verse explicitly states that the potion has the power to harm (ibid., verse XNUMX). But in fact it is a completely innocent potion, and the described phenomena are caused as a purely mental reaction to the priest's warning. However, understanding things in this light removes from the process its power and from the Torah its holiness, and generations of religious people, priests and rabbis alike, chose to accept the biblical text as it is.

  6. monument

    It was correct to check the connection between an external psychological state and the health state, as it is known or accepted in modern medicine. And if it is indeed accepted that there is an effect, then the whole placebo thing does not renew anything. And certainly not surprising.

    Then the question arises, what is the purpose of the article, after all, there is no scientific, medical or other innovation in it..

  7. Danish,

    Regarding the first warning: not relevant. The child is not exposed to information at all, let alone knows what asthma is.

    Regarding the second and fourth: not relevant. In order to really be harmed by the placebo effect, the smoker needs to develop anxieties or chronic fear that is sufficiently strong and prolonged that it will give its signals on the body in the form of a higher chance of a heart attack or a physiological change of the skin. It doesn't happen, because smokers elegantly ignore these warnings. A smoker who is really anxious because of the warnings (tendency to anxiety) is likely to stop smoking, otherwise as mentioned this information completely disappears from his eyes.

    Regarding the third: again irrelevant. What's the matter anyway? Do you even understand what a placebo is? No need to comment.

    Regarding the fifth: maybe. Although it is known that there are two types of addictions - the physiological and the psychological. The first is easy (there are no crises like in detoxing from hard drugs that are really addictive, unlike cigarettes and soft drugs). The second is the problematic one and depends directly on the personality and character of the smoker. The chance that the psychological addiction is increased following the exposure to this warning sentence is not high, if only because of the same disregard I mentioned.

    And asthma, what do you say? More psychological?? Maybe I fed a troll?

  8. This article is the first of five, as I mentioned in the body of the article. Also, things are not as simple as they may appear from the first part. I also mentioned this, and ended with a teaser for the second part, which presents completely different things. And it's not the end of the story either. Patience 🙂

  9. Eliyahu and Gilad

    What is happening here is simple, an incredibly amateurish article in the world of science, research, evidence and statistics leads to a completely superficial discussion, I believe that the great majority of readers here do not expect this type of article.

  10. Does anyone have data on the placebo effect of warnings! The cigarette packs on the health of smokers and the public, by how many percentages have they increased the diseases and mortality in the population, since they started to advertise them on the cigarette packs.

    warning! Medical studies state that children of parents who smoke suffer more from asthma.
    warning! Medical studies state that 75% of heart attacks up to the age of 45 are among smokers
    warning! Cigarette smoke harms the health of your children and everyone around you
    warning! Smoking causes premature aging of the facial skin
    warning! Medical studies state that cigarettes cause addiction
    and more…..

    The number of children of smoking parents who suffer from asthma, a disease that is more psychological, has increased by several percentages
    By how many percentages is the percentage of those who quit cigarettes smaller (due to emphasizing the addiction effect)
    and so…..

  11. Mesmer worked at a time when bloodletting was the solution to almost every disease - and if so, then it is better to drink "healing" water. And it is also worth mentioning that during his experiments with the magnets he fought the same bloodletting. What infuriated the "doctors" of that time.

    In addition, to the placebo surgeries, you can add the thousands of brain resections that earned the doctor, the "inventor" of the surgeries, a Nobel Prize.

  12. I somewhat agree with Ernst.

    The writer presents the placebo effect as a new and very surprising idea, although this is not the case.

    What amazes me more is that I did not see the word statistics even once in the article.
    (although clearly stated)

    The placebo effect has been known for many years.
    There is nothing new here.

  13. Ross, as we will see later, this is not accurate.

    Seriously, it's getting complicated. Why do you think she doesn't belong here?

  14. monument

    This is definitely a great article, nice and popular, in my opinion, it doesn't belong here.

  15. Our body can fight many diseases, the placebo effect simply allows the mind to do what Western medicine and science took from us - allow the body to heal itself

  16. Nice topic!

    I suggest reading the fascinating book Placebo Therapy by Jeffreson Fish - who took the effect one step further and uses it - openly and intentionally, and not as a side and secondary effect - in psychological therapy.

    And of course the amazing writings of Thomas Szasz.

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