What is the placebo effect and how does it work?

A psychological effect caused by suggestion. We find out exactly how it works.

In our daily lives we often take medication and undergo different treatments in order to improve our health or overcome a specific problem. On more than one occasion we have heard about the advantages of some techniques that do not enjoy scientific recognition and yet seem to work for many people.

In these cases, as in many other more recognized treatments, it is legitimate to ask ourselves if what we take or do really has a real effect on our health. In other words, is the treatment I am following really effective or does the improvement itself have another explanation? Perhaps we are facing a case of placebo effect?. Let us now see what this means and how this phenomenon is taken into account in the clinical context.

What is the placebo effect?

We understand the placebo effect to be that positive and beneficial effect produced by a placeboThis is an element that by itself does not have a curative effect on the problem that is being treated by the mere fact of its application. That is to say, the substance or treatment does not have qualities that produce an improvement in the symptomatology, but the fact that a treatment is being received provokes the belief that it will improve, which in itself provokes the improvement.

The consideration of placebo is not limited only to substances, but can also appear under psychological treatments, surgeries or other interventions.

In the case that by placebo we refer to a substance, this can be a totally innocuous element (a saline solution or sugar, for example) also called pure placebo, or a substance that does have a therapeutic effect for some disease or disorder but not for the one for which it has been prescribed. In this second case we would be dealing with a pseudoplacebo.

How it works

The functioning of this phenomenon is explained at the psychological level by two basic mechanisms: classical conditioning and expectations.

In the first place, the patient who receives the placebo has the expectation of recoveringFirstly, the patient receiving the placebo has the expectation of recovery, based on the learning history followed throughout his or her life, in which an improvement generally occurs after following a treatment.

These expectations condition the response to the treatment, favoring the response of health recovery (this fact has been demonstrated in the immunological response). The greater the expectation of improvement, the greater the placebo effect, so that the conditioning will be greater and greater. However, in order to work properly, the first step must be successful.

Other factors influencing this psychological effect

The placebo effect is also mediated by the professionalism and sense of competence projected by the person administering it, the context in which it is taken, the type of problem being faced and other characteristics such as cost, presentation, materials or rituals required to take it.

Placebos that are more expensive and more elaborate in appearance tend to be more effective.. For example, a sugar pill is more effective as a placebo if it is in the form of a capsule than if it is in the form of a lump. Somehow, the appearance of uniqueness causes expectations about its efficacy to rise or fall in parallel with it.

The neurological basis of placebo

At the neurophysiological level, it has been demonstrated that the application of the placebo stimulates the frontal cortex, the nucleus accumbens, the gray matter and the amygdala, activating the dopaminergic and (to a lesser extent) the serotonergic pathways. This activation causes a feeling of reward and relaxation that coincides with the improvement perceived by patients.

Patients with pain, somatic symptoms, Parkinson's, dementia or epilepsy have benefited from the use of placebos in research settings, improving their situation. The effects are especially marked in those suffering from pain, with the greater the placebo and the greater the initial pain, the greater the effect.

However, the mechanism of action of the placebo effect remains partly a mystery. remains, in part, a mystery. The intriguing thing about this process is that it seems to be a phenomenon in which abstract thinking comes to influence very basic and primitive mental processes, which act in a similar way in non-human animals.

For example, it is difficult to explain that a belief can interfere with something like pain processing, a Biological mechanism that appeared more than 100 million years ago in the evolutionary chain leading up to our species and that has been consolidated because of its great usefulness for our survival. However, evidence shows that the suggestion produced, for example, by hypniosis, is capable of making this sensation significantly more

Contexts of occurrence and application

Having briefly explored what the placebo effect is and how it works, it is worth asking the question where this phenomenon is usually actively applied.

As we shall see, the placebo effect is especially used in research, although it is also occasionally linked to clinical practice.

At the research level

Treatments used in clinical practice must be tested in order to verify their real effectiveness. For this purpose, a case-control methodology is frequently used, in which two groups of individuals are established. One of the groups is given the treatment in question, and the second, known as the control group, is given a placebo..

The use of a placebo in the control group makes it possible to observe the efficacy of the treatment in question, since it makes it possible to check whether the differences between pretreatment and post-treatment perceived in the group receiving the treatment are due to the treatment or to other external factors.

At the clinical level

Although it involves a number of ethical conflicts, the placebo effect has sometimes been applied in clinical practice.. The reasons most frequently given have been unjustified demand for medication by the patient, or the need to calm them down, or the exhaustion of other therapeutic options.

Likewise, many alternative and homeopathic therapies benefit from this effect, which is why, in spite of not having mechanisms of action related to real efficacy effects, they sometimes have a certain effectiveness.

Relationship with other effects

The placebo effect is related to other similar phenomena, although there are notable differences between them.

Hawthorne effect

The placebo effect can sometimes be confused with other types of effects. An example of this is the confusion with the Hawthorne effect. The latter refers to behavior modification when we know we are being observed or evaluated. (for example, when there is someone analyzing our actions, such as a superior at work or simply an external observer in a class), without the possible improvement in functioning being due to any cause other than the measurement itself.

Similarities with the placebo effect are found in the fact that in general there is a perceptible improvement in the individual's vital state and functioning. However, the placebo effect is something totally unconscious, and occurs in the belief that an improvement will actually be produced by the application of a supposed treatment, whereas the Hawthorne effect is a form of reactivity to the knowledge that a characteristic, situation or phenomenon is being measured or evaluated.

Nocebo effect

The placebo effect has a counterpart, known as the nocebo effect. In this effect, the patient suffers a worsening or a side effect due to the application of a treatment or a placebo, which is inexplicable due to the mechanism of action of the drug.This effect cannot be explained by the mechanism of action of the drug.

Although there is less research on this phenomenon because it is less frequent, it can be explained by the same mechanisms of expectation and conditioning as the placebo: it is expected that a negative symptom will occur. An example of this is the occurrence of secondary symptoms that patients have seen in a leaflet despite the fact that at the biological level there are no threats.

Applied to research, the nocebo effect is also what makes studies based on replacing the control group with one of patients on the waiting list not entirely valid, since this psychological phenomenon means that these patients tend to feel worse than they would if they were not waiting for treatment, as they are well aware that nothing has yet been administered to cure them.

It should be borne in mind that research on the nocebo effect is complicated, since it raises ethical dilemmas, and is therefore studied indirectly on the basis of phenomena that exist outside any research program.

Pygmalion or self-fulfilling prophecy effect

The Pygmalion effect is clearly related both to the placebo effect and to the previous ones. This effect is based on the fact that the expressed expectation that a certain situation or phenomenon will occur leads the subject to end up performing actions that lead to the initially expected situation. Thus, its functioning is very similar to that of the placebo effect at the cognitive level, in that the belief that one will improve causes the improvement itself.

As a type of placebo effect, this phenomenon leads people to feel better because of the expectation that this is what is expected of them.. In this way, an idea leads to the emergence of a new material reality in accordance with the idea that (in part) provoked it.

Paying for ineffective therapies does not count.

It should be noted that simply paying for a session of services offered as therapy does not usually generate a placebo effect. This means that pseudotherapies or ineffective therapies cannot be promoted under the ethical pretext that they produce a placebo effect.

For example, homeopathy, which statistically does not bring any benefit to patients, does not make people benefit from the illusion that they are introducing something curative into their body. For this psychological phenomenon to work, other conditions must be present that have nothing to do with the pure nature of the transaction reached with the practitioner.

To conclude

It should be noted that the placebo effect can be found even in treatments of proven effectiveness.. A clear example can be seen in an immediate recovery or improvement after taking a medication, such as an antidepressant. Although the effectiveness of the treatment may be proven, it usually takes weeks for these drugs to be effective, so that very early improvement may be due to the placebo effect. Thus, both this phenomenon and the healing produced by the mechanism of effectiveness of psychotherapy or a drug may overlap with the placebo effect.

It is also important to bear in mind that the placebo effect is not imaginaryIt is also important to keep in mind that the placebo effect is not imaginary; there is a real improvement in the psychic or even physical state (the immune and neuroendocrine systems in particular), that is, in many cases it is objectively verifiable and generates physical changes, although generally not radical ones.

On the other hand, although the usefulness of this effect has been demonstrated in some medical treatments, it is necessary to take into account the possibility of a perverse use of it.being used with the objective of obtaining economic benefit in a multitude of "miraculous" products.

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