Everything You Need to Know About the Nocebo Effect

Both the placebo and the nocebo effect must be taken into account during a clinical trial or when prescribing a treatment. Both alter the body's perception of a treatment, changing the final result. Learn more in this article!
Everything You Need to Know About the Nocebo Effect

Last update: 04 October, 2021

Not many people know about the nocebo effect, which is a concept used in medicine, psychology, and pharmacy. It could be defined as the opposite of the famous placebo effect. It’s when a person starts suffering the possible side effects of treatment just because they believe these effects can occur.

As of yet, few studies explain this mechanism. However, it needs to be considered in any treatment. It shows that the negative expectations of a treatment can cause adverse reactions.

For this reason, experts need to take both the placebo and nocebo effect into account when establishing a treatment, or even when conducting clinical trials.

In this article, we explain everything you need to know about it.

What’s the nocebo effect?

When experts conduct a clinical trial to test the effectiveness of a drug, they usually use two groups of people. One group receives the real drug, while the other a placebo. A placebo is a substance that doesn’t contain an active substance, meaning that it doesn’t have pharmacological properties, nor real effects.

Experts do this to see the real effects of the drug, without the participants actually knowing what they’re taking. The so-called placebo effect is when a patient begins to benefit from a drug only due to their expectations of the treatment.

However, the opposite can also occur. On some occasions, patients who receive the placebo begin to suffer the possible side effects of the treatment, even though they aren’t taking the active drug. This is the nocebo effect.

In other words, the nocebo effect is when someone suffers the negative effects of a treatment only due to their expectations of it. These effects aren’t caused by any active ingredient but are psychogenic instead. It means that they’ve been induced by the brain.

A doctor holding some pills.
When a doctor prescribes a drug to a patient, they may suffer the nocebo effect due to their expectations of it.

What causes this effect?

The nocebo effect makes the patient suffer real symptoms and signs. For example, nausea, sleep problems, itching, and even pain may appear. What experts don’t know is what factors definitively lead to it, nor who the most susceptible individuals are.

A study published in the journal Science points out that the price of the treatment is associated with the development of the placebo and nocebo effect. Similarly, it seems that the dissemination of information about possible reactions is closely related to both.

This article may interest you: How to Identify Allergic Reactions to Drugs

Differences and similarities between the nocebo and placebo effect

Some pills on a table.
The pharmaceutical industry knows of the existence of the nocebo effect and takes it into account in its experimentations.

However, as we mentioned above, there aren’t many studies on the nocebo effect, meaning that certain aspects of it are unknown. For example, both effects occur in the same brain areas. Similarly, they seem to have a genetic influence.

In addition, the expectations a patient has about the drug are key. The truth is that not only a drug can cause these effects, but other types of therapies as well.

Neither the nocebo nor the placebo effect is related to the action of any substance, as they’re caused by psychological mechanisms. What differentiates them is that the placebo effect is very beneficial for any therapy, while the nocebo is detrimental

Experts have observed that a percentage of people have dropped out of clinical trials due to this effect. For this reason, experts should conduct more studies on it.

The nocebo effect in clinical practice

It’s clear that the nocebo effect must be taken into account in any treatment. This is because certain measures, such as giving the patient adequate information, can completely change their perspective and the development of this effect. This can alter treatment adherence.

On the other hand, it’s the patient’s responsibility to solely rely on official information about the drugs they’re taking. Internet searches on untrusted sites contribute to psychogenic adverse reactions.

It might interest you...
What Are Drug Excipients?
Step To Health
Read it in Step To Health
What Are Drug Excipients?

To find out which drug excipients are contained in a medication, all you have to do is look at the package insert or the labeling.