What is the placebo effect and how does it work?

In our daily life, it is common for us to take medications 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 are not scientifically recognized and despite everything, they seem to work for many people.

Both in these cases and in many other more recognized treatments, it is legitimate to ask whether 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? Maybe we are facing a case of placebo effect. Let us see below 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 as that positive and beneficial effect produced by a placebo, an element that by itself does not have a curative effect on the problem being treated by the mere fact of its application. That is, the substance or treatment does not have qualities that produce an improvement in the symptoms, but the fact of that you are receiving a treatment causes the belief that you will get better, which in itself causes the improvement.

The placebo consideration 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 a pure placebo, or a substance that does have a therapeutic effect for some disease or disorder but not for which it has been prescribed. In this second case we would be facing a pseudoplacebo.

Its operation

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

First, the patient receiving the placebo has the expectation of recovery, depending on the learning history followed throughout his life, in which an improvement generally occurs after following a treatment.

These expectations condition the response to treatment, favoring the health recovery response (This fact has been demonstrated in the immune response). The greater the expectation of improvement, the greater the effect of the placebo, with which the conditioning will be greater and greater. Of course, for it 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 the sense of competence projected by the person who administers it, the context in which it is carried out. how the shot is carried out, the type of problem faced and other characteristics such as cost, presentation, materials or rituals necessary to take it.

More expensive looking and more elaborate placebos tend to be more effective. For example, a sugar pill is more effective as a placebo if it is capsule-shaped than lump-shaped. Somehow, the appearance of exclusivity causes expectations about its effectiveness to rise or fall in parallel with it.

The Neurological Basis of Placebo

At the neurophysiological level, it has been shown that the application of 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 the patients.

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

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

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

Contexts of appearance and application

Once we have briefly explored what the placebo effect is and how it works, it is worth wondering where this phenomenon is usually applied actively.

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

At the research level

The treatments used in clinical practice must be tested in order to verify their real effectiveness. For this, the use of a case-control methodology is frequent, 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 allows us to observe the efficacy of the treatment in question, since it allows us to check whether the Differences between pretreatment and posttreatment perceived in the group receiving the treatment are due to this or other factors external to him.

At the clinical level

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

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

Relationship with other effects 

The placebo effect is related to other similar phenomena, although there are remarkable 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 a external observer in a class), without the possible improvement in functioning being due to any cause other than the measurement.

The similarities with the placebo effect are found in the fact that in general there is a perceptible improvement in the vital state and functioning of the individual. However, the placebo effect is something totally unconscious, and occurs in the belief that an improvement is really going to occur when an assumption is applied. treatment, while the Hawthorne effect is a form of reactivity to the knowledge that a characteristic, situation or characteristic is being measured or evaluated. phenomenon.

Nocebo effect

The placebo effect has a counterpart, known as nocebo effect. In this effect, the patient suffers a worsening or a side effect due to the application of a treatment or a placebo, this being inexplicable by the mechanism of action of the drug.

Although the investigation of this phenomenon is less since it is less frequent, it can be explained by the same expectation and conditioning mechanisms as placebo: a negative symptom is expected to occur. An example of this is the occurrence of secondary symptoms that patients have seen in a leaflet despite the fact that there are no biological 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 are not entirely valid, since this psychological phenomenon makes these patients tend to feel worse than they would if they weren't waiting for treatment, bearing in mind that they have not yet been given anything to cure them.

It should be noted that research on the nocebo effect is complicated, since it raises ethical dilemmas, and For this reason, it is studied indirectly from phenomena that exist outside of any program of investigation.

Pygmalion or self-fulfilling prophecy effect

The pygmalion effect it has a clear relationship with both the placebo effect and the previous ones. This effect is based on the expressed expectation that a certain situation or phenomenon will occur leads to the subject ending up taking actions that lead to causing the expected situation initially. Thus, its functioning is very similar to that of the placebo effect at the cognitive level, in that the belief that it will improve causes the improvement itself.

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

Paying for ineffective therapies doesn't count

It should be taken into account that the simple fact of 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 report any benefit for patients, does not Nor does it make people benefit from the illusion that they are introducing something healing into their Body. For this psychological phenomenon to work, other conditions must be met that have nothing to do with the pure nature of the transaction reached with the professional.

In conclusion

Keep in mind 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 from taking a drug, such as an antidepressant. Although the effectiveness of the treatment may be proven, these drugs generally take weeks to be effective, so a very early improvement may be due to the placebo effect. In this way, both this phenomenon and the healing produced by the efficacy mechanism of psychotherapy or a drug can overlap

It is also important to take into account that the placebo effect it is not imaginary; there is actually an improvement in the mental or even physical state (the immune and neuroendocrine system especially) real, that is, in many cases it is objectively verifiable and generates physical changes, although generally not radical.

On the other hand, although the usefulness of this effect has been shown in some medical treatments, the possibility of a perverse use of it must be taken into account, being used with the aim of obtaining economic benefit in a multitude of "miracle" products.

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