Discover the nocebo effect, placebo’s “evil twin”



Conceptualized as a negative expectation regarding medications or vaccines, the problem can exacerbate feelings of pain, anxiety, nausea and fatigue. Communication between doctors and patients is highlighted as a solution.

“Someone comes up and says, ‘My God, you look horrible, are you going to get sick?’, and then suddenly you really get sick,” he says. Charlotte Blease, when recalling a recent bus trip from Belfast to Dublin. “You already have this expectation, and this increases the symptoms.”

Blease, a health researcher at Uppsala University in Sweden, and one of the authors of the book The Nocebo Effect: When Words Make You Sick (The nocebo effect: when words make you sick, in free translation), he was feeling nauseous and sick, trying to distract himself with any other thought. And she knew that if someone interrupted her, it would trigger the nocebo effect.

“The nocebo effect is negative health outcomes that arise from negative expectations,” explains Blease.

The problem can exacerbate the feeling of pain, anxiety, nausea and fatigue.

Nocebo is not placebo

The nocebo effect is the negative mirror image of the placebo. Imagine a medical study. One group is given a real medicine to treat headaches. Another group receives sugar pills, without the active ingredient.

When patients in this second group report relief from their headaches, doctors say they are experiencing a placebo effect, because they thought they were taking painkillers, just like the patients in the first group, and that positive thinking led to a result in their treatment. This is a phenomenon recognized by medicine.

And the nocebo effect is slowly gaining similar recognition from healthcare professionals, and this is exactly what opposite: when negative thinking influences results in a, of course, negative way.

Nocebo, covid and vaccine hesitancy

During the Covid-19 pandemic, researchers discovered that people’s expectations before being vaccinated against the disease could be linked to how they felt afterwards.

A team of scientists from Israel and the United Kingdom analyzed a group of 756 Israeli adults over 60 years of age. Everyone had received a booster dose, that is, a third dose against Covid-19.

“We measured vaccine hesitancy, that is, the negative attitude or expectations toward the vaccine, and the number of subjectively reported side effects,” explains Yaakov Hoffman, lead author of the study and professor in the Department of Social and Science Sciences. Health at Bar-Ilan University, in Israel.

Published in the journal Scientific Reports in December 2022, the results indicated that people who had negative expectations before the second dose were more likely to experience side effects after the third.

“The greater the anxiety about the vaccine, its safety and its side effects, the more likely the person is to experience side effects,” Hoffman explains to DW.

And when the nocebo effect and vaccine hesitancy were combined, Hoffman said, there was potential for this to become a vicious cycle: A person who was hesitant to take the vaccine, perhaps because they had read about the side effects on the internet, would be more likely to suffer these effects.

These consequences would then be recorded and reported by their doctors. This, in turn, would contribute to more media coverage of side effects and more people feeling hesitant about vaccines, and so on.

How doctors deal with the effect

Talking to patients without triggering the nocebo effect can be a challenge.” Doctors are obligated not to harm the patient, or to mitigate harm whenever possible, but they also have the obligation to tell the truth“, said Blease.

In the case of a vaccine with relatively minor side effects, according to Hoffman, facing the nocebo effect head on may make sense.

“Maybe it’s better to call things by their name and say, ‘There’s a certain percentage of the side effects you’re experiencing that are nocebo effects. Which means you are actually experiencing them, but that doesn’t necessarily mean danger,” says Hoffman, who emphasizes, however, that this is just speculation and that further investigation is needed in order to provide solid evidence.

The importance of information

Other experts in the field agree that the way doctors communicate with patients can help avoid nocebo effects.

“The way doctors talk to patients can influence therapy outcomes. Until now, the communication has been seen primarily as a welfare issue. We need greater awareness of how crucial it is”, says Ulrike Bingel, professor of Clinical Neurosciences, who directs a pain research unit at the University Hospital of Essen, Germany.

When it comes to vaccines, for example, doctors are required to disclose all possible side effects. But rather than making a list of side effects that might scare the patient, Bingel says doctors should conceptualize side effects as a sign that the immune system is working well.

This way, the patient can have less negative expectations and experience fewer side effects.

Nocebo effect may be evolutionary

But how can negative ideas in our mind affect our body? First, it is important to understand that the nocebo effect It’s real, not a figment of imagination pessimism of a patient.

“The nocebo and placebo effects involve complex neuroscientific processes. When you are experiencing a nocebo effect, your body stops applying the pain brakes. Your brain receives more brain impulses and you feel more pain”, explains Bingel.

The problem is that researchers cannot explain why this happens. At least until now. But they believe that this may have to do with our evolution.

“It was important for our ancestors to learn how to come into contact with a wild animal or a poisonous plant. The body [ficava] prepared for next time,” adds Bingel.

In other words, early humans’ negative expectations prepared them in case they had to run for their lives.

“The nocebo effect It could be a hangover from the past, [mas] this is incompatible with today’s modern medical environment,” concludes Blease.

The article is in Portuguese

Tags: Discover nocebo effect placebos evil twin



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