What Is Nocebo Effect? (Working Mechanism & Experiment)

Nocebo Effect

We are going to talk about the nocebo effect. It is the opposite of the placebo effect. Placebo has been a standard testing methodology, and it means when you think something or expect something is going to be good for you, the brain and the body manifest that. The nocebo is the opposite of it. If we believe something will be bad for us, the brain can create that too.

The nocebo effect is like the dark side of the placebo effect. Essentially it’s when we have a negative outcome because we believe we’ll have a negative result. So one of the ethical concerns for doctors is that they’re likely to experience a side effect that can have a nocebo effect if you say to someone. People expect a negative outcome, so they share the negative result.

What is nocebo effect?

The nocebo effect is when a detrimental impact on health is produced by psychological or psychosomatic factors such as negative treatment expectations or prognosis. The nocebo effect comes from the Latin meaning “I will harm.” It’s the power of the mind to make you feel worse and ill.

There is no medical reason to feel sick before chemotherapy, but most people believe it. If you think you’ll get sick, you’re more likely to get sick, and that’s a very general term. People are actively researching this, and we haven’t done this for all illnesses.

If there are possible side effects, you’re all warned about the side effects. But 20% of people will develop side effects, and sometimes these side effects will be so severe. They cause you to drop out of the clinical trial. The Department of Health in New York calls it a mass psychogenic illness. What is the cause of the nocebo effect? At the biochemical level, there are changes at the brain level at the hormonal level that affect patients’ outcomes.

If you believe taking a particular medicine will be wrong, you will react poorly. You’re going to get every one of the side effects that’s listed on the insert. Our mindset and belief system as to whether or not something’s going to be good for us or bad for us makes all the difference. It means when you expect something to happen, your brain can create it out of thin air. If you expect something to be wrong for you, the brain can make that. It is a expectations predictive coding that the brain can create, which you desire.

How does the nocebo effect work?

Researchers believe that it may be explained by a substance in the body that sends signals along the nerves. For example, if a person is anxious, they’re likely to experience more pain than a calm person. This effect can be seen in the brain. Imaging studies have shown that pain is more intense when people expect it than when they do not. This is linked to changes in specific brain regions.

Nocebo effect in brain
Nocebo effect in the brain

If a patient does not believe that a treatment will work, it will likely be detrimental to their health. When working with placebos, if people believe that their treatment will work, they have a positive attitude. So positive health benefits can occur.

Nocebo showcases the negative effects of thinking or anticipation. It’s what’s at work when sugar pills cause real negative side effects. For example, in one medical trial of a drug for fibromyalgia syndrome marked by widespread chronic pain, over 10% of volunteers given a placebo dropped out of the study because of the side effects like nausea and dizziness that they’ve been warned about it.

Even though the drug was inert, the mere suggestion that they might feel side effects caused the side-effects. The nocebo effect can also occur in patients taking actual drugs. This means if a doctor lists possible side effects, a patient is more likely to experience them. Half of the patients were told the medicine might cause erectile dysfunction during trials for a drug designed to reduce enlarged prostates. The other half were not informed. Only 15% of the uninformed men reported the side-effect.

While he was whopping, 44% of the men, who were told, had trouble in the bedroom. In the end, we’re still not sure how placebo and nocebo responses work. It’s likely the mechanisms vary depending on the circumstances. But Ted Kaptchuk, director of Harvard University’s program in placebo studies and the therapeutic encounter, suspects the bottom line might be pretty straightforward.

Natural drugs are essential but compassionate care and the act of trusting your caregiver are critical. Kaptchuk believes that the placebo effect has more to do with the attention, warmth, eye contact, and empathy given by a physician than the belief that a pill is natural. In that case, placebos are all about the ritual of medical care and the trust we put into it.

Experiment of Nocebo effect

The first experiment looks at the placebo effect and the nocebo effect together. We were looking at is patients who were experiencing arm pain. We assigned these participants to two different groups. We gave them a pill in one group, and we said this pill would help with your arm pain.

In the second group, we did acupuncture, whereas essentially, it’s not about putting the needles in any specific place. We put the needles anywhere, and they say that that will help with the arm pain. What happened was that both groups?

They felt better after receiving the treatment. But also both groups experienced these nocebo effects. They weren’t even told about them. So they weren’t told that there would be any side effects. But the participants from both groups said they felt sluggish from receiving these treatments but that they were not treatments.

So you could argue that something like homeopathic medicine, which is essentially like taking a sugar pill, could be quite a good thing. Because it doesn’t harm patients, but it could have this positive placebo effect.

However, if you don’t contextualize that correctly and are homeopathic, saying this could negatively affect you. Then you also could be doing something quite unethical. Patients will experience those negative effects as well on the other side. When it comes to doctors treating patients, doctors need to communicate side effects and effectiveness.

Doctors believe that if patients believe the treatment’s effectiveness, they will benefit more from that treatment.

More Articles:

What Is Placebo Effect With Working, Psychology

What is Flynn effect On IQ Score


Barber, Theodore Xenophon. “Death by suggestion. A critical note”. Psychosomatic Medicine.
Barker, Scared to Death: An Examination of Fear, its Cause and Effects. London: Frederick Muller.
Barsky, Arthur J.; Saintfort, R.; “Nonspecific Medication Side Effects and the Nocebo Phenomenon.”
Cannon, Walter. “‘Voodoo’ Death.” American Anthropologist.
Charcot, J.M. “The Faith-Cure.” The New Review.

Julia Rose

My name is Julia Rose. I'm a registered clinical therapist, researcher, and coach. I'm the author of this blog. There are also two authors: Dr. Monica Ciagne, a registered psychologist and motivational coach, and Douglas Jones, a university lecturer & science researcher. I would love to hear your opinion, question, suggestions, please let me know. We will try to help you.

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