Learning Mechanisms for Placebo and Nocebo Studies on Somatosensory Sensations: a Systematic Review and Meta-analysis.

NCT04387851 | Completed DMC

• 1 other identifier: META-BLOM-DD-2022
• Study Type: observational
• Target: 130
• Locations: 1 country
• Sites: 1

Brief Summary

Placebo and nocebo effects are defined as the positive and negative effects occurring after the (supposed) administration of an inert treatment, which, through a given learning process, is believed to have positive or negative effects. The objective of this study is to summarize the available knowledge on experimental inductions of placebo and nocebo effects on somatosensory sensations, specifically pain and itch. The aim isto investigate the extent to which learning processes (such as conditioning and verbal suggestions) induce placebo and nocebo effects on pain and itch in healthy humans. The researchers intent to examine expectancy induction methods for placebo and nocebo effects on somatosensory sensations, describe methodological attributes of the research and propose practical and theoretical implications as well as future directions for research investigating placebo and nocebo effects on somatosensory sensations.

Conditions

Pain; Itch

Keywords

Placebo; Nocebo; Pain; Itch; Somatosensory; Learning

Outcome Measures

Primary Outcomes (2)

• Placebo magnitude

  The magnitude of induced placebo effects, by measures including, but not limited to, self-report measures of perceived sensation intensity or unpleasantness (e.g., as rated on a visual analogue scale or numerical rating scale).

  Through study completion, an average of 1 month

• Nocebo magnitude

  The magnitude of induced nocebo effects, by measures including, but not limited to, self-report measures of perceived sensation intensity or unpleasantness (e.g., as rated on a visual analogue scale or numerical rating scale).

  Through study completion, an average of 1 month

Study Arms (2)

Placebo

Placebo effects are defined as the positive effects occurring after the (supposed) administration of an inert treatment, which, through a given learning process, is believed to have positive effects.

Behavioral: Placebo induction; Behavioral: Control

Nocebo

Nocebo effects are defined as the negative effects occurring after the (supposed) administration of an inert treatment, which, through a given learning process, is believed to have negative effects.

Behavioral: Control; Behavioral: Nocebo

Interventions

Placebo induction BEHAVIORAL

The placebo interventions of interest are experimental learning methods (e.g. verbal suggestion, conditioning), used to induce placebo effects on somatosensory sensations.

Placebo

Control BEHAVIORAL

Placebo and nocebo effects should be measured relative to a control group (between-subjects design). In the case of within-subjects designs, these will be included to the extent possible (in a separate analysis or descriptively depending on the number of results).

Nocebo; Placebo

Nocebo BEHAVIORAL

The nocebo interventions of interest are experimental learning methods (e.g. verbal suggestion, conditioning), used to induce nocebo effects on somatosensory sensations.

Nocebo

Eligibility Criteria

• Sex: all
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Healthy, adult human volunteers. Patient samples will not be included to improve homogeneity of the results.

You may qualify if:

• Studies using experimental induction of placebo and/or nocebo effects on somatosensory sensations (i.e., pain and/or itch), which necessitates the (supposed) administration of an inert treatment, which, through a given learning process, is believed to have positive or negative effects.
• This review will include original, controlled experimental studies on healthy participants that employed learning-based inductions of placebo and/or nocebo effects on somatosensory sensations. The studies should be written in English, German or Dutch, available full-text, and published in a peer-reviewed journal. No year restrictions on publication date will be imposed.

Sponsors & Collaborators

• Leiden University Medical Center: lead
• Universiteit Leiden: collaborator

Study Sites (1)

Leiden University

Leiden, South Holland, 2333 AK, Netherlands

Location

Related Publications (2)

• Thomaidou MA, Blythe JS, Peerdeman KJ, van Laarhoven AIM, Van Schothorst MME, Veldhuijzen DS, Evers AWM. Learned Nocebo Effects on Cutaneous Sensations of Pain and Itch: A Systematic Review and Meta-analysis of Experimental Behavioral Studies on Healthy Humans. Psychosom Med. 2023 May 1;85(4):308-321. doi: 10.1097/PSY.0000000000001194. Epub 2023 Mar 23.

  PMID: 36961347 DERIVED

• Blythe JS, Thomaidou MA, Peerdeman KJ, van Laarhoven AIM, van Schothorst MME, Veldhuijzen DS, Evers AWM. Placebo effects on cutaneous pain and itch: a systematic review and meta-analysis of experimental results and methodology. Pain. 2023 Jun 1;164(6):1181-1199. doi: 10.1097/j.pain.0000000000002820. Epub 2022 Nov 16.

  PMID: 36718994 DERIVED

MeSH Terms

Conditions

Pain; Pruritus

Interventions

Nocebo Effect

Condition Hierarchy (Ancestors)

Neurologic Manifestations; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Skin Diseases; Skin and Connective Tissue Diseases; Skin Manifestations

Intervention Hierarchy (Ancestors)

Placebo Effect; Effect Modifier, Epidemiologic; Epidemiologic Factors; Quality of Health Care; Health Care Quality, Access, and Evaluation; Public Health; Environment and Public Health

Study Officials

• Andrea WM Evers, Prof. Dr.

  Leiden University Medical Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: May 11, 2020
• First Posted: May 14, 2020
• Study Start: March 1, 2019
• Primary Completion: December 1, 2021
• Study Completion: December 1, 2021
• Last Updated: January 11, 2022

Record last verified: 2022-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP
• Time Frame: Immediately after publication of the study. Data will be retained for 15 years.
• Access Criteria: Data can be shared with scientists in relevant fields for the purpose of future studies such as replication or meta-analysis (or with designated persons for monitoring purposes).

Locations

NL (1)