Individual Differences in Placebo Analgesic Effects

NCT04669093 | Not Yet Recruiting

• 1 other identifier: 230138
• Study Type: interventional
• Target: 60
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines the effects of placebo suggestions tailored to match or mismatch individual participants' motivational styles-an issue of person-situation 'fit' with important effects in public health settings, but which has been ignored in past research.

Conditions

Healthy

Outcome Measures

Primary Outcomes (2)

• Changes in subjective ratings of acute thermal pain

  Following each thermal stimulus, participants are asked to rate how painful it was, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher pain ratings. We will average and compare the pain ratings within participant across interventions.

  Measured repeatedly, immediately after thermal stimuli on the day of participation. Averaged and compared across interventions.

• Changes in subjective ratings of pain expectations

  Before each thermal stimulus, participants are asked to rate how painful they expect the next stimulus to be, on a semi-circular computerized scale. Ratings are based on the angle (0-180), with higher angle representing higher expectations ratings. We will average and compare the expectation ratings within participant across interventions.

  Measured repeatedly, immediately before thermal stimuli on the day of participation. Averaged and compared across interventions.

Secondary Outcomes (4)

• Facial expressions

  Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.

• Thermal imaging of the face

  Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.

• Changes in skin conductance response measured with a Biopac device

  Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.

• Changes in heart rate measured with a Biopac device

  Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.

Study Arms (2)

Placebo

EXPERIMENTAL

All participants will participate in two sessions, one with a placebo suggestion that matches the participant's motivational style, and one with placebo suggestion that does not match their motivational style, in a pseudo-random order.

Behavioral: Placebo cream- "promotion" suggestion; Behavioral: Placebo cream- "prevention" suggestion

Control

EXPERIMENTAL

Each session will also include a control phase, in which the same cream will be applied, and participants will be instructed that the cream has no analgesic effects.

Behavioral: Control cream

Interventions

Control cream BEHAVIORAL

In a control condition, with the same cream as in the placebo interventions, participants will be instructed that the cream is a control cream with no effects.

Control

Placebo cream- "promotion" suggestion BEHAVIORAL

Over-the-counter hand cream will be applied to participants' skin, but they will be told that they are given a highly efficient topical analgesic cream. The suggestion will be based on a "promotion" approach (promoting good feelings).

Placebo

Placebo cream- "prevention" suggestion BEHAVIORAL

Over-the-counter hand cream will be applied to participants' skin, but they will be told that they are given a highly efficient topical analgesic cream. The suggestion will be based on a "prevention" approach (preventing pain).

Placebo

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy participants
• Dominant promotion focus or dominant prevention focus (based on our screening)

You may not qualify if:

• Currently or recently suffered from chronic pain (based on screening)
• Cannot tolerate heat pain applied to the forearm, based on a calibration task at the beginning of the experiment

Sponsors & Collaborators

• Trustees of Dartmouth College: lead

Study Sites (1)

Dartmouth College

Hanover, New Hampshire, 03755, United States

Location

Study Officials

• Tor D Wager, PhD

  Dartmouth College

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Tor D Wager, PhD

CONTACT

(603)-646-2196; Tor.D.Wager@Dartmouth.edu

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants will not be aware of the type of suggestion (or the fact there are different types of suggestions) during the experiment. They will be debriefed upon the study's conclusion.
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Model Details: This is a within-participant design. Each participant will participate in two sessions. In both sessions, an over-the-counter hand cream will be applied to their skin, accompanied by a placebo suggestion that the cream is analgesic. In one session, the suggestion will match the participant's motivational style, and in the other session the suggestion will not match their motivational style. The order of sessions will be counterbalanced across participants. Each session will also include a control condition, in which participants will be told that the cream has no affect. The same over-the-counter hand cream will be used in all sessions.

Study Record Dates

• First Submitted: November 16, 2020
• First Posted: December 16, 2020
• Study Start (Estimated): September 30, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027
• Last Updated: December 9, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will share
• Time Frame: All data will be de-identified prior to sharing. Raw data will be submitted to NDA within one year from the end of data collection or 6 months from the acceptance date of the first primary study manuscript on the full dataset (excluding methods development papers), whichever is later. Analyzed data/maps of statistical results and models accompanying each paper will be submitted to NDA/OpenFMRI when the primary study manuscript is accepted.
• Access Criteria: These data would generally be made available to any qualified investigator for neuroimaging studies only including: i. Research on any brain phenomenon; ii. Neuroimaging research on non-disease traits (intelligence, behavioral traits); iii. Methods development research. The requesting investigator must provide documentation of local IRB approval. These data would not be made available to: i. Any criminal justice organization, because data may not be used for any criminal justice applications; ii. Any commercial entity, because use of the data is limited to not-for-profit organizations and data may not be used for any commercial purposes.

Locations

US (1)