03/12/2026
ON THE PLACEBO EFFECT
In conversations with colleagues, I often encounter a surprising misunderstanding of the placebo effect. Not simply a lack of familiarity with the term, but a misunderstanding of the very essence of this phenomenon.
At first glance the concept seems simple. However, the placebo effect is often misunderstood even by medical professionals, and this misunderstanding can lead to serious errors when evaluating the effectiveness of different treatments.
Meanwhile, understanding the placebo effect is of considerable importance for any medical professional.
WHAT IS PLACEBO EFFECT
In its original meaning, a placebo is a substance with no apparent therapeutic properties that is used to imitate treatment when studying the effectiveness of a real medication.
In the simplest version of such a study, two homogeneous groups of patients with the same disease are formed. One group receives the real drug, while the other receives a placebo. The condition of the patients in both groups is then compared. If the condition of patients (or the severity of certain symptoms) improves significantly in the group receiving the real medication compared with the group receiving the placebo, this means that the drug indeed has a therapeutic effect.
Over time it was noticed that some improvement can also occur in the placebo group. Although this improvement is usually much less pronounced, it nevertheless exists. The improvement observed under such circumstances came to be known as the placebo effect.
Later, this effect began to be observed not only in studies of medications but also in studies evaluating various medical interventions.
EXAMPLE OF A PLACEBO-CONTROLLED ULTRASOUND STUDY
As an example, one can consider a study of therapeutic ultrasound for nonspecific low back pain. In the experiment, two groups of patients were used. The first group received standard ultrasound therapy. In the second group, the therapist performed the same movements with the ultrasound probe over the skin, but the device itself was turned off. The patients did not know which group they were in—that is, whether they were receiving real treatment or an imitation of it.
The results were then evaluated using several criteria, including the level of pain and functional status. If the positive effects in the group receiving the real intervention are greater than those in the placebo group, this indicates the presence of a specific therapeutic effect of the method.
The actual experiment showed improvement in both groups. According to the authors, the results in the group receiving real ultrasound treatment were somewhat better. However, the difference between the groups amounted to only about 0.8 points on the pain scale.
CHARACTERISTICS OF THE PLACEBO EFFECT AND SIMILAR EFFECTS
It is important to understand that the placebo effect by itself does not lead to a real cure. Some improvement in well-being or reduction of symptoms may occur, but such changes are usually temporary and do not eliminate either the cause of the disease or the mechanisms of its development.
Another important point is that the placebo effect should be distinguished from other situations that may look similar but are not directly related to it and can also lead to improvement in symptoms.
One such example is the statistical phenomenon known as regression to the mean, which can be observed in sufficiently large groups of observations.
Another factor is related to the natural attempts of the body itself to fight disease. As a result, spontaneous remissions may occur—that is, improvement in the patient’s condition without any specific treatment.
It is also necessary to distinguish the placebo effect from the weak but real effect of certain therapeutic procedures. Externally these situations may appear similar: in both cases only a moderate improvement in symptoms is observed. However, the fundamental difference is that the placebo effect is not directly related to the therapeutic intervention, whereas a weak therapeutic effect is the natural and direct result of the intervention itself.
Therapeutic massage in certain medical conditions can serve as an example. Massage often produces a modest, but fully expected and consistent effect that can and should be used in clinical practice.
It should be understood that the use of placebo as a method of treatment in itself—especially in situations where more effective and evidence-based medical interventions exist—is unethical and may lead to a worsening of the patient’s condition due to loss of time.
Another example can be found in numerous studies evaluating the effectiveness of acupuncture. In such studies, one group of patients receives needle insertion strictly according to the traditional rules of acupuncture. In control groups, needles may be inserted into arbitrary areas of the skin outside known acupuncture points, or the needle insertion may be imitated at the same points without actually penetrating the skin.
The results of such studies provide a fairly clear statistical picture: in most cases, no significant difference between the groups is found, indicating the absence of a pronounced specific effect of the procedure itself.
At the same time, these studies clearly demonstrate how strong the placebo effect can be and how misleading the observed result may sometimes appear.
PLACEBO EFFECT AND TREATMENT
It is obvious that the placebo effect is not something that should be relied upon in everyday medical practice, and certainly not something to count on as an independent therapeutic factor.
Above all, the placebo effect demonstrates how carefully and critically the effectiveness of different therapeutic interventions must be evaluated. This is particularly important in those areas of medicine where physical and manual methods of treatment, including therapeutic massage, are widely used.
For this reason, new and insufficiently substantiated methods require especially careful verification. Observed improvement alone is not proof of their effectiveness—it is necessary to make sure that the result truly exceeds the placebo effect.
