What is the nocebo effect and does it apply to dentistry?—A narrative review

Abstract

Background Evidence for the nocebo effect, a phenomenon characterised by suboptimal treatment efficacy, worsening of symptoms, or the occurrence of adverse events caused by an individual’s negative treatment expectations, is growing across a multitude of medical fields. However, little attention has been paid to patients’ negative expectations and the nocebo effect within dentistry. Aim This review summarises essential evidence of the nocebo phenomenon especially in relation to pain and drug administration. Subsequently, an overview of the current evidence of the nocebo phenomenon in the dental field is presented. Methods A PubMed search was performed using keywords related to “nocebo,” “placebo,” “expectations,” and “dentistry.” In addition to the articles selected from the search, placebo/nocebo researchers and dental researchers added important references from their respective fields. Results Although research on the nocebo effect in dentistry is limited, available current evidence suggests that the factors, which is related to the nocebo effect are likely to play a role in dental practice. Conclusion Preliminary evidence from the review warrants further investigation into the nocebo effect in dentistry. Finally, based on the general knowledge of the nocebo effect, the review indicates fruitful arrays of research into the nocebo effect in dentistry.

Procedural Aspects of Epidural Catheter Placement: A Prospective Observational Study of 173 Epidural Catheter Insertions

“…Furthermore, the nocebo effects of expectations are well known and can be related to patients' prior experiences based on verbal instructions received or on patients' social observations 11 . However, no previous study has examined nocebo effects in relation to the epidural catheter insertion procedure, and only limited evidence for these effects exists for most medical procedures in general 11,12 . We used a regression model to examine whether these patient-specific factors influenced pain related to the epidural procedure and added physician-specific factors based on perceived clinical relevance, considering the absence of prior studies.…”

Nocebo response in dentistry: A systematic review and meta‐analysis of adverse events in analgesic trials of third molar removal

“…Although the nocebo phenomenon and role of non‐specific factors have been investigated and identified across a wide range of medical conditions and treatments, 1 there is a dearth of knowledge about these factors within the field of dentistry. The latter despite an increase in papers highlighting the importance of recognising the possible nocebo phenomenon within this field 7–11 . As experimental research inducing nocebo effects is often complicated by ethics, 12 systematically assessing the nocebo response in placebo arms of RCTs provides a good platform to understand the influence of non‐specific factors.…”

“…The latter despite an increase in papers highlighting the importance of recognising the possible nocebo phenomenon within this field. [7][8][9][10][11] As experimental research inducing nocebo effects is often complicated by ethics, 12 systematically assessing the nocebo response in placebo arms of RCTs provides a good platform to understand the influence of non-specific factors. The third molar (M3) extraction model has been used to investigate the efficacy and safety of analgesics 13 and, therefore, provides a good model to explore the nocebo response within the field of dentistry.…”

Nocebo response intensity and influencing factors in the randomized clinical trials of functional dyspepsia: A systematic review and meta‐analysis

“…The placebo effect is the phenomenon in which patients experience symptomatic improvement as a result of positive psychological expectations or beliefs about treatment efficacy rather than as a direct outcome of the treatment itself. While the nocebo effect refers to the harmful effects of a pharmacological or nonpharmacological treatment caused by negative expectations of patients and is not directly related to their physiological effects 4,5 . The nocebo effect is mostly noticed due to the occurrence of adverse reactions or events in the placebo group during RCTs.…”

“…While the nocebo effect refers to the harmful effects of a pharmacological or nonpharmacological treatment caused by negative expectations of patients and is not directly related to their physiological effects. 4,5 The nocebo effect is mostly noticed due to the occurrence of adverse reactions or events in the placebo group during RCTs. Unfavorable side effects reported by the participants who are given placebo in double-blinded placebo-controlled trials to evaluate the efficacy and safety of new drugs are considered as nocebo responders.…”