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n. pl. no·ce·bos or no·ce·boes
A substance that causes undesirable side effects as a result of a patient's perception that it is harmful rather than as a result of a causative ingredient.

[Latin nocēbō, I will harm, first person sing. future tense of nocēre, to harm (on the model of placebo); see nek- in Indo-European roots.]
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
References in periodicals archive ?
False medical information can also lead to patients' experiencing greater side effects through the "nocebo effect." Sometimes patients benefit from an intervention simply because they believe they will -- that's the placebo effect.
Expectation has other powerful effects, such as the placebo effect and the nocebo effect.
Non-medical switching from originator to biosimilar etanercept - no evidence for a relevant nocebo effect--a retrospective analysis of real-life data.
In that regard, experts from Aspetar agree with the authors of this study, who suggested that one of the contributing factors to this decline could be a phenomenon known as the Nocebo effect, or 'imaginary/anticipatory fatigue'.
Just as much as someone could get better with the placebo effect, the opposite can happen through what's called the nocebo effect, when someone believes that they will get worse or will die from a disease.
Because every product carries some risk, patients need good clinical data to separate a product's true effectiveness from its placebo and nocebo effects, to make well-informed decisions.
"However, the root cause of decline in performance, is not necessarily fasting," Chamari said."Researchers suggest that there could be a 'nocebo' effect in play.
Treatment may be further complicated by 'nocebo' effects, which are adverse effects based on the patient's conscious and unconscious expectations of harm.
Hall, "Placebo, nocebo, and neuropathic pain," Pain, vol.
It is also conceivable that the comprehensive multidisciplinary services provided by the CVHP may contribute in reducing patients negative expectations about therapies (the nocebo [30] effects that induce a reduction of their efficacy and or tolerance) and eventually lead to an improvement in compliance.
Furthermore, the study noted that an additional 8% of the 3D viewers expressed discomfort that arose either as a result of the 3D glasses or due to the nocebo effect in the form of negative presumptions regarding 3D viewing [4, 6].