Nocebo effect: what it is and how it affects people

The placebo effect is a hugely popular scientific concept that, perhaps to be an extremely curious phenomenon, has become part of colloquialism. For this reason, many people have a rough idea of ​​what it is and its scope.

The placebo describes a positive effect on the organism after the use of a substance whose chemical properties are really harmless, having become known in particular for its presentation in the form of sugar tablets “disguised” as a real medicine.

The accumulated evidence suggests that they may play a key role in this the person’s beliefs and expectations. In this sense, it is understood that the benefit associated with the analysis of internal variables is essential to understand the individual response to the use of any drug or therapeutic procedure (regardless of its objective impact on the body).

Like many other things in science, there is also an antagonist for the placebo effect: the nocebo effect. This article will focus precisely on him, highlighting the nature of a lesser-known but equally interesting reality.

    The nocebo effect

    The term nocebo comes from Latin. Its form uses a future verbal declension for the verb “nocere”, and its literal translation could be “(I) will do evil”. It is therefore a phenomenon opposite to that of the placebo. This nocebo effect refers to any damage that can occur after the consumption of a substance that does not really have “properties” to explain it, having to resort to hypotheses in which the contribution of the subjective aspects is considered. These harms are often qualified as “harmful”, “undesirable” or even “dangerous”.

    Its description was much later than the one of the placebo, being the original references in texts of years 70, although its definitive conceptual delimitation would have to wait until the first years of the decade of the 80. Pioneering experiments on the issue have used fictitious electric currents to induce so-called “headaches”.. In this case, the researchers deliberately provided false information to the subjects, leading them to believe that they would experience such a symptom after its application. Although no discharge was ever given, almost all of the participants reported experiencing headaches (to some extent) after the trial.

    Theoretical models to explain rely on the role of expectations, as in the case of placebo, but also on classic conditioning and personality variables. The truth is that discovering its nature is important, as it can sometimes affect how a person adheres to pharmacological treatments that could lead to a marked improvement in their health. For this reason, many research projects have been articulated over the past decade to better understand it.

    In general, we know that up to 19% of people report negative side effects from using a substance that the chemist cannot explain. certainly not. Sometimes these are drugs of course legal, for which no consequence or harm has been described in the sense indicated, but which the person expressly perceives (sometimes by past experiences or by erroneous “ideas” about how it works. in the body). The effect is more common in women (30%) than in men (19%).

      Why is this happening?

      The exact mechanisms by which the nocebo effect work together are still largely unknown., Because their study often involves some sort of ethical or moral dilemma. Indeed, it would be a question of lying to the subject about what is administered to him, and in particular to make him believe that he is going to expose himself voluntarily to a dangerous or harmful experimental condition. Because it is necessary for the person to believe in this effect, this would imply the acceptance of conditions of self-harm which escape the ethical codes of the research activity.

      However, at least four variables involved in the onset of the nocebo effect are known today: personal expectations, classical conditioning, personality dimensions and life experience. In this section, we’ll take a look at them all.

        1. Waiting

        The value of expectations is essential to the nocebo effect, so that what the subject expects to experience ends up imposing itself in reality as a tangible result on his organs and tissues. that’s why in the study of this phenomenon, it is essential to offer the person information on the “symptom” that one wishes to arouse, Being this fake (in the sense that the substance or the procedure has no effect on his body), but used with an explicit intention to convince the subject otherwise. It was contrasted, in particular, with the algic (pain) responses.

        With this, and especially by resorting to an authority figure (the researcher), a solid expectation would form with the power to generate the suggested negative effects. For example, beliefs about the emetic effect of chemotherapy (ability to induce nausea or vomiting) are known to be proportionately related to the occurrence of this unpleasant secondaryism.

        2. Conventional packaging

        Classical conditioning has received a lot of credit as one of the procedures on which the possible development of a nocebo effect is based. In this particular case, it would be an association (by contingency and repetition) of an unconditioned stimulus and a neutral stimulus, the first of which has the capacity to provoke a response in the organism (innate). Thus, through repeated exposure to situations in which both occur at the same time, the originally neutral stimulus would acquire the property of a conditioning. This means that it would continue to generate effects similar to those caused by the original unconditional stimulus.

        A simple example of this type of nocebo was found in a work in which a lemon flavored drink was offered to a group of people at the same time they were given a dose of chemotherapy.

        The repeated presentation of this sequence ultimately led to associating lemon soda (neutral stimulus) with the side effect (nausea) of such a treatment (unconditioned stimulus), so that with its consumption in isolation, the response is produced in vomiting. In other words, the lemon would continue to generate this unpleasant sensation in the absence of the treatment, thus becoming a conditioned stimulus. With this process, therefore, a nocebo effect would be acquired by harmless drinks.

        3. Personality factors

        if you know certain personality traits can significantly contribute to the appearance of the nocebo effect. They would therefore be tacit elements of mediation between what was previously reviewed (expectation and classic conditioning) and their occurrence. Regarding these dimensions, it is now known that pessimistic people (that is, people who regularly attract gloomy expectations) are more likely to experience the nocebo effect. Likewise, and perhaps as a direct consequence, they do not refer to placebo or its benefits in a manner equivalent to those who are optimistic (if not much less).

        Likewise, type A personality (which designates a recurring feeling of constraint and competitiveness as an elementary variable in interpersonal relationships) is also associated with a higher risk of the nocebo effect, when compared to the B ( much more “balanced” in time management and social life). The same can be said of neuroticism (tendency to worry and to feel negative emotions). Thus, it is concluded that pessimism, neuroticism and attitudes that focus on competitiveness are important to understanding the phenomenon.

        4. Personal experiences

        Finally, a fourth explanatory factor is found in previous life experiences. Witnessing how a person suffered from side effects of a drug, or building the prediction that they will occur after gaining inaccurate knowledge about how they work in the body, is a risk factor associated with it. learning. All this can be emphasized in the case of the original model of the vicar, From which the expectation was articulated, was someone to whom we were emotionally attached.

        Adverse experiences with the health system as a whole also precipitate the nocebo effect (as they model the belief that these professionals are incompetent or make invalid judgments). In the event that the treatment is carried out during forced admission, against the explicit will of the person to whom it is administered, the problem is also remarkably aggravated. This last modality is currently the subject of great controversy and should only be applied in the event of suspicion of potential risk to the person or to third parties.

        How can we fix it?

        To avoid the occurrence of the unwanted nocebo effect, it is essential to focus on the variables that are sensitive to it, such as the person’s expectations of the drug or the interaction that occurs in the drug. therapeutic space. One of the general recommendations is to give the right information and to do it realistically, emphasizing the tightest possible balance between the pros and cons of all drugs. This is relevant in all intervention settings, but even more so in those which are particularly critical for the expectations that accompany them (for example, chemotherapy, where there are many preconceptions about their effects).

        It is important to provide information in the most direct and truthful manner possible, promote that the person can participate actively in the treatment they will receive, And that the uncertainty about it be minimized as much as possible. In this way, the subject actively collaborates in his recovery or improvement process, and a quality therapeutic link is stimulated. This form of relationship has been shown to decrease the risk of the nocebo effect and is also seen as a means of increasing the person’s satisfaction with the care received.

        In short, the professional’s goal should be to focus on contextualizing the benefits and secondary aspects of the compound to be used, in detecting and correcting misconceptions, seeking active collaboration during the setting process. decision-making, in the appropriate adjustment of expectations and in the construction of human contact with the person being cared for. All this will contribute to the reduction of the nocebo effect and the proportional increase in therapeutic adherence.

        Bibliographical references:

        • Data-Franco, J. and Berk, M. (2012). The nocebo effect: a physician’s guide. The Australian and New Zealand journal of psychiatry, 47 (7), 103-118
        • Kong, J. and Benedetti, F. (2014). Placebo and Nocebo Effects: Introduction to Psychological and Biological Mechanisms. Manual of Experimental Pharmacology, 225, 3-15.

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