In clinical trials with a randomized control group, it is appropriate to measure the extent to which the belief in receiving the experimental treatment influences the degree of improvement reported by the volunteers. Lessebo effect
The placebo effect is widely known in research, which can be defined as the improvement perceived by the participants, who believe they have received the effective treatment, despite not being the case.
However, the placebo effect is not the only one that can occur in these types of trials. The lessebo effect, together with the nocebo, are also the product of suggestion . Next we will see what the lessebo effect is, in addition to relating it to the other two.
The lessebo effect and relationship with the research
In science, when creating a new clinical intervention, be it a drug, a new type of therapy or any new treatment, it is necessary, first of all, to check if it really works. For this, it is usual that clinical trials are carried out, in which voluntary participants who have the medical or psychiatric condition that the new intervention is believed to improve will participate.
However, to correctly detect the therapeutic capacity of the new intervention, it is normal for these trials to have at least two groups: one experimental and the other control . The experimental group will be made up of participants who are going to receive the intervention, with the intention of seeing what effects this has on their health, whether there is improvement or worsening of symptoms. On the other hand, the participants in the control group will not be given any therapeutic treatment. Both the participants in the control group and those in the experimental group do not know which group they have received. Lessebo effect
The objective of forming these two groups is to know to what extent the improvement (and also deterioration) of the participants is attributable to the application of the intervention .
The idea is that if there is improvement in the experimental group and not in the control group, the improvement is attributable to the treatment. In the event that in both groups there is some type of improvement, it will not be related to the intervention, but attributable to the course of the medical or psychiatric condition that is intended to be treated. Indeed, there are medical illnesses and mental disorders that can simply improve over time.
Let’s start at the beginning: the placebo effect
So far everything has its meaning, but surely a question comes to mind: if the experimental group receives the treatment to be tested, what does the control group receive? The volunteers in the control group have to receive something, otherwise they will know that they are in such a group and it is something that we do not want. What is wanted in research is to verify the pure and hard effectiveness of the treatment, and for this we need that those who are receiving it do not know that they are receiving it but show improvement if it is effective.
For this reason, all participants in the experiment receive something. If the experimental treatment is applied to the experimental group, a placebo is applied to the control. A substance or placebo treatment is any intervention that those who apply it know or assume that it does not have any type of effect, neither therapeutic nor harmful . For example, in pharmaceutical research, if the experimental group is given the drug that is believed to work, the control will be given something that looks like a drug, in the form of a pill or syrup, but without any active component.
And this is where we have to talk about the placebo effect. This effect is essential to be taken into account in research, since it can perfectly question the effectiveness of the new intervention. The placebo effect occurs when the control group, despite not receiving the experimental treatment, reports improvement . The participants that form the control group have the expectation of having received the experimental treatment, and believe that it is being applied to them, perceiving an improvement that is nothing more than suggestion. Lessebo effect
It is important to understand that, before participating in an experiment, participants are given informed consent. It explains that the experimental treatment being tested can have both benefits and unwanted health effects, and that the goal of the experiment is to find out what they are. In addition, they are told that they may receive this treatment or they may be given a placebo. Despite knowing this information, it is not strange that the participants want to be part of the experimental group, and believe that they have been touched by that group, feeling a supposed improvement.
The use of placebo is the norm in randomized controlled trials . The logic behind the application of placebos derives from the need to distinguish between the real benefit observed by the participant and the benefit that is the product of their desire to improve. The mind is very powerful and is capable of deceiving us, covering symptoms and making us believe that we have improved.
Although the placebo effect has been known for quite some time and medical, pharmaceutical, psychological and psychiatric investigations have had it in doubt, the existence of two other effects given in an experimental context has been raised: the nocebo effect and the effect lessebo. Both effects are very important, like the placebo effect itself, and can actually skew the interpretation of the results of the experiment.
The nocebo effect
Before talking more about the lessebo effect, it is worth briefly understanding what the nocebo effect is . “Nocebo” comes from Latin, meaning “I must do harm”, in contrast to the term “placebo”, which is “I must pleasure”. The knowledge of the nocebo effect is considered something quite revealing about how everything related to the placebo (ineffective intervention) and its homonymous effect should be applied and interpreted, since even what should have no effect can be harmful .
As we have already commented, the placebo effect is, in essence, the improvement perceived by the participants in the control group despite the fact that they have not been administered anything that is known to have any effect. The nocebo effect would be the opposite: it is the worsening of the symptoms or signs of a health condition due to the expectation, conscious or not, of undesirable effects of an intervention. Lessebo effect
In experimentation there is always an informed consent and, as we have previously mentioned, it explains that the intervention can have positive and negative effects . If the placebo effect is to believe that the intervention is received and the positive effects are had, in the case of the nocebo it is also to believe that this intervention is being received, but that its adverse effects are manifesting. The participant has pessimistic expectations that make him believe that the treatment is harmful.
What characterizes the lessebo effect?
For a long time, research was only concerned with monitoring the suggestion and expectations of the control group, both positive and negative. Under the logic that something must necessarily happen in the experimental group, both a therapeutic effect and adverse effects, the effects of suggestion were not monitored in that same group. Fortunately, although relatively recently, more attention has begun to be paid to how pessimistic expectations in the experimental group can negate the actual therapeutic effects of the intervention.
If placebo is the perceived improvement in the control group and nocebo the worsening, the lessebo effect is the perception of less improvement, nullification of the effects or worsening in the experimental group . That is, the participants in the experimental group, who are receiving the treatment, believe that they have either been given a placebo or are suffering the adverse effects of the treatment, believing that their condition is getting worse.
This can be due to multiple causes . It may be that, as with the nocebo effect, the participants have a pessimistic view of the effects of the experimental treatment, thinking that they are more likely to experience its unwanted effects than the therapeutic ones. Another thing that has been seen is that there are not a few participants who, despite reading the informed consent, do not understand it, and think that “placebo” is synonymous with “harmful”. They think that experimental treatment is beneficial and that control is necessarily bad.
Scientific implications
It is clear that both the placebo effect and the nocebo affect research if they are not taken into account, but the effects of lessebo are even worse . As we have commented, it may be that the participant who is being given an effective treatment thinks that it is or it is not or that it is a placebo, and he auto-suggests himself to think that he is not improving or even worse.
Discarding something that, objectively speaking, is working but that volunteers report as harmful due to their pessimistic expectations not only implies discarding a treatment that works, but also implies loss of financial resources and time. Whether it is a drug, a new psychological therapy or any other type of treatment, its design and application implies the mobilization of many efforts, and that it is discarded due to biases of the experimental participants is a true error.
It is for this reason that based on the new research focused on studying the lessebo effect, it should be considered how reliable the participant is , in the sense of what kind of expectations they have about the experiment and if they present an unrealistic thinking style. Whether you tend towards pessimism or optimism, you need to know this thought pattern, and find out to what extent that participant is not going to bias the results of the experiment.
