The Nocebo Effect: What to Know About the Placebo's Counterpart

Table of ContentsView AllTable of ContentsNocebo and PlaceboSigns of a Nocebo ResponseExamples of the Nocebo EffectExplanationsChallenges

Table of ContentsView All

View All

Table of Contents

Nocebo and Placebo

Signs of a Nocebo Response

Examples of the Nocebo Effect

Explanations

Challenges

Close

We’ve all worried about medication side effects from time to time, especially when you think about the laundry list ofside effectsthat accompany any pharmaceutical ad. Whether it’s drowsiness, flu-like symptoms, sexual side effects, or unfortunate gastrointestinal situations, nobody wants to feelworseafter taking our medicine. Sometimes, though, we can’t help but worry about that exact possibility, and that is where the nocebo effect comes in.

The nocebo effect, also known as the nocebo response, happens when a person’s negative expectations of treatment lead to negative side effects. An example of a nocebo response would be expecting that your medication will cause negative side effects and then having those unpleasant side effects, even though the medication that they are taking is actually an inert substance.

People tend to be more familiar with the nocebo effect’s counterpart, theplacebo effect. In medical studies, a group of participants known as thecontrol groupwill be given a sham treatment, often a sugar pill, that they believe is the real treatment. As a result of believing that the treatment is real, participants will sometimes have positive results such as feeling better or an improvement in their symptoms.

In the placebo effect, people experience positive effects as a result of their positive expectations. The nocebo effect is its opposing counterpart. The suggestion that there might be side effects leads people to actually experience those side effects, even when the treatment isn’t real.

At a GlanceWhere the placebo effect makes a person feel better beyond the actual therapeutic effects of the treatment, a nocebo effect causes people to feel worse. Many medicationsdohave some serious side effects, which is a major factor contributing to this fear even when a given medication is not known to cause those effects.It’s important to remember that for a treatment—specifically medication—to be approved for use, it has gone through many rounds of trials in order to determine its safety and that any side effects (yes, even diarrhea) are worth the upside of the treatment.That said, your medical choices are a deeply personal matter, and any concerns should be discussed with your doctor before undergoing treatment.

At a Glance

Where the placebo effect makes a person feel better beyond the actual therapeutic effects of the treatment, a nocebo effect causes people to feel worse. Many medicationsdohave some serious side effects, which is a major factor contributing to this fear even when a given medication is not known to cause those effects.It’s important to remember that for a treatment—specifically medication—to be approved for use, it has gone through many rounds of trials in order to determine its safety and that any side effects (yes, even diarrhea) are worth the upside of the treatment.That said, your medical choices are a deeply personal matter, and any concerns should be discussed with your doctor before undergoing treatment.

Where the placebo effect makes a person feel better beyond the actual therapeutic effects of the treatment, a nocebo effect causes people to feel worse. Many medicationsdohave some serious side effects, which is a major factor contributing to this fear even when a given medication is not known to cause those effects.

It’s important to remember that for a treatment—specifically medication—to be approved for use, it has gone through many rounds of trials in order to determine its safety and that any side effects (yes, even diarrhea) are worth the upside of the treatment.

That said, your medical choices are a deeply personal matter, and any concerns should be discussed with your doctor before undergoing treatment.

Adverse effects can vary from one individual to the next, cannot be attributed to the pharmacological activity of the drug, and are not dependent upon the dose.

Nocebo effect symptoms often include:

Some examples of the nocebo effect that have been observed in research include the following:

Such effects are not confined to research labs or clinical trials. The nocebo effect has the potential to cause serious consequences in real-world medical settings where people receive care.

That said, some generics do indeed cause a greater number of side effects or lack the efficacy of the brand name because of variability in formulation and ingredients, so it may be hard to differentiate between actual, real adverse effects and the nocebo effect.

The exact explanations for the nocebo effect are not well understood, but researchers have found that a few factors influence how likely it is to occur. These include:

Researchers have found that the phenomenon is both surprisingly common and serious. It can have an important impact on both research and treatment, suggesting that it is something that requires consideration from scientists and medical practitioners.

Informed Consent

This can create an ethical dilemma for doctors, nurses, psychologists, and other healthcare professionals. Telling people about all of the potential downsides of treatment may cause those negative effects to happen or make them worse, but not telling people about these effects would violate rules about informed consent.

Informed consentrequires that doctors and researchers inform patients and subjects of any possible adverse side effects when taking a medication or undergoing treatment. Researchers suggest, however, that presenting people with a list of potential side effects can increase the likelihood of a nocebo response.In other words, describing what might happen actually has the effect of changing what people experience—our ability tomanifestcan be a positive and negative.

Treatment Adherence

The fact that the nocebo effect causes negative outcomes can also have an effect on treatment compliance andresearch dropout rates. People may be less likely to continue taking treatment if they are having unpleasant side effects, regardless of the fact that those side effects are actually related to expectations and not to the effects of the treatment itself. Participants in research studies may also be more likely to drop out of the study if they experience nocebo effects.

Worsening of Negative Side Effects

Hearing that we may experience side effects from a particular treatment may actually lead to nocebo responses that make these negative outcomes worse. In one study, for example, some participants were told that a flexibility test might cause pain while others were not told this. After the test, those who had been told that the test might be painful reported experiencing significantly higher levels of pain than those in the other group.

Because of this, researchers caution that doctors and therapists should consider the powerful impact that cognitive processes and expectations can have on the experience of pain. People who fear that treatment will cause pain may end up avoiding treatment.

The nocebo effect can have a serious impact on how people feel after a treatment, so healthcare professionals should use caution when presenting treatment options. This phenomenon is also a powerful example of hownegative thinkingcan influence your health and well-being. When you are undergoing treatment or taking a medication, it may be more helpful to focus on the potential positive benefits rather than worrying about the possible negative side effects.

8 SourcesVerywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Planès S, Villier C, Mallaret M.The nocebo effect of drugs.Pharmacol Res Perspect. 2016;4(2):e00208. doi:10.1002/prp2.208Mitsikostas DD, Mantonakis LI, Chalarakis NG.Nocebo is the enemy, not placebo. A meta-analysis of reported side effects after placebo treatment in headaches.Cephalalgia. 2011;31(5):550-61. doi:10.1177/0333102410391485Cepeda MS, Lobanov V, Berlin JA.Use of ClinicalTrials.gov to estimate condition-specific nocebo effects and other factors affecting outcomes of analgesic trials. J Pain. 2013;14(4):405-11. doi:10.1016/j.jpain.2012.12.011Faasse K, Petrie KJ.The nocebo effect: patient expectations and medication side effects.Postgrad Med J. 2013;89(1055):540-6. doi:10.1136/postgradmedj-2012-131730Häuser W, Hansen E, Enck P.Nocebo phenomena in medicine: their relevance in everyday clinical practice.Dtsch Arztebl Int. 2012;109(26):459-65. doi:10.3238/arztebl.2012.0459Tinnermann A, Geuter S, Sprenger C, Finsterbusch J, Büchel C. Interactions between brain and spinal cord mediate value effects in nocebo hyperalgesia.Science. 2017;358(6359):105-108. doi:10.1126/science.aan1221Wells RE, Kaptchuk TJ.To tell the truth, the whole truth, may do patients harm: the problem of the nocebo effect for informed consent.Am J Bioeth. 2012;12(3):22-9. doi:10.1080/15265161.2011.652798Pfingsten M, Leibing E, Harter W, et al.Fear-avoidance behavior and anticipation of pain in patients with chronic low back pain: a randomized controlled study.Pain Med. 2001;2(4):259-66. doi:10.1046/j.1526-4637.2001.01044.x

8 Sources

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Planès S, Villier C, Mallaret M.The nocebo effect of drugs.Pharmacol Res Perspect. 2016;4(2):e00208. doi:10.1002/prp2.208Mitsikostas DD, Mantonakis LI, Chalarakis NG.Nocebo is the enemy, not placebo. A meta-analysis of reported side effects after placebo treatment in headaches.Cephalalgia. 2011;31(5):550-61. doi:10.1177/0333102410391485Cepeda MS, Lobanov V, Berlin JA.Use of ClinicalTrials.gov to estimate condition-specific nocebo effects and other factors affecting outcomes of analgesic trials. J Pain. 2013;14(4):405-11. doi:10.1016/j.jpain.2012.12.011Faasse K, Petrie KJ.The nocebo effect: patient expectations and medication side effects.Postgrad Med J. 2013;89(1055):540-6. doi:10.1136/postgradmedj-2012-131730Häuser W, Hansen E, Enck P.Nocebo phenomena in medicine: their relevance in everyday clinical practice.Dtsch Arztebl Int. 2012;109(26):459-65. doi:10.3238/arztebl.2012.0459Tinnermann A, Geuter S, Sprenger C, Finsterbusch J, Büchel C. Interactions between brain and spinal cord mediate value effects in nocebo hyperalgesia.Science. 2017;358(6359):105-108. doi:10.1126/science.aan1221Wells RE, Kaptchuk TJ.To tell the truth, the whole truth, may do patients harm: the problem of the nocebo effect for informed consent.Am J Bioeth. 2012;12(3):22-9. doi:10.1080/15265161.2011.652798Pfingsten M, Leibing E, Harter W, et al.Fear-avoidance behavior and anticipation of pain in patients with chronic low back pain: a randomized controlled study.Pain Med. 2001;2(4):259-66. doi:10.1046/j.1526-4637.2001.01044.x

Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Planès S, Villier C, Mallaret M.The nocebo effect of drugs.Pharmacol Res Perspect. 2016;4(2):e00208. doi:10.1002/prp2.208Mitsikostas DD, Mantonakis LI, Chalarakis NG.Nocebo is the enemy, not placebo. A meta-analysis of reported side effects after placebo treatment in headaches.Cephalalgia. 2011;31(5):550-61. doi:10.1177/0333102410391485Cepeda MS, Lobanov V, Berlin JA.Use of ClinicalTrials.gov to estimate condition-specific nocebo effects and other factors affecting outcomes of analgesic trials. J Pain. 2013;14(4):405-11. doi:10.1016/j.jpain.2012.12.011Faasse K, Petrie KJ.The nocebo effect: patient expectations and medication side effects.Postgrad Med J. 2013;89(1055):540-6. doi:10.1136/postgradmedj-2012-131730Häuser W, Hansen E, Enck P.Nocebo phenomena in medicine: their relevance in everyday clinical practice.Dtsch Arztebl Int. 2012;109(26):459-65. doi:10.3238/arztebl.2012.0459Tinnermann A, Geuter S, Sprenger C, Finsterbusch J, Büchel C. Interactions between brain and spinal cord mediate value effects in nocebo hyperalgesia.Science. 2017;358(6359):105-108. doi:10.1126/science.aan1221Wells RE, Kaptchuk TJ.To tell the truth, the whole truth, may do patients harm: the problem of the nocebo effect for informed consent.Am J Bioeth. 2012;12(3):22-9. doi:10.1080/15265161.2011.652798Pfingsten M, Leibing E, Harter W, et al.Fear-avoidance behavior and anticipation of pain in patients with chronic low back pain: a randomized controlled study.Pain Med. 2001;2(4):259-66. doi:10.1046/j.1526-4637.2001.01044.x

Planès S, Villier C, Mallaret M.The nocebo effect of drugs.Pharmacol Res Perspect. 2016;4(2):e00208. doi:10.1002/prp2.208

Mitsikostas DD, Mantonakis LI, Chalarakis NG.Nocebo is the enemy, not placebo. A meta-analysis of reported side effects after placebo treatment in headaches.Cephalalgia. 2011;31(5):550-61. doi:10.1177/0333102410391485

Cepeda MS, Lobanov V, Berlin JA.Use of ClinicalTrials.gov to estimate condition-specific nocebo effects and other factors affecting outcomes of analgesic trials. J Pain. 2013;14(4):405-11. doi:10.1016/j.jpain.2012.12.011

Faasse K, Petrie KJ.The nocebo effect: patient expectations and medication side effects.Postgrad Med J. 2013;89(1055):540-6. doi:10.1136/postgradmedj-2012-131730

Häuser W, Hansen E, Enck P.Nocebo phenomena in medicine: their relevance in everyday clinical practice.Dtsch Arztebl Int. 2012;109(26):459-65. doi:10.3238/arztebl.2012.0459

Tinnermann A, Geuter S, Sprenger C, Finsterbusch J, Büchel C. Interactions between brain and spinal cord mediate value effects in nocebo hyperalgesia.Science. 2017;358(6359):105-108. doi:10.1126/science.aan1221

Wells RE, Kaptchuk TJ.To tell the truth, the whole truth, may do patients harm: the problem of the nocebo effect for informed consent.Am J Bioeth. 2012;12(3):22-9. doi:10.1080/15265161.2011.652798

Pfingsten M, Leibing E, Harter W, et al.Fear-avoidance behavior and anticipation of pain in patients with chronic low back pain: a randomized controlled study.Pain Med. 2001;2(4):259-66. doi:10.1046/j.1526-4637.2001.01044.x

Meet Our Review Board

Share Feedback

Was this page helpful?Thanks for your feedback!What is your feedback?HelpfulReport an ErrorOtherSubmit

Was this page helpful?

Thanks for your feedback!

What is your feedback?HelpfulReport an ErrorOtherSubmit

What is your feedback?