Individual Differences in Placebo Analgesic Effects

Not Applicable

Not yet recruiting

• Conditions: Healthy
• Interventions: Behavioral: Placebo cream- "promotion" suggestion; Behavioral: Control cream; Behavioral: Placebo cream- "prevention" suggestion

• Registration Number: NCT04669093
• Lead Sponsor: Trustees of Dartmouth College

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2020-11-16
• Study First Submitted QC: 2020-12-10
• Study First Posted: 2020-12-16
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-15
• Last Update Posted: 2024-11-19
• Study Start: 2025-09-30
• Primary Completion: 2026-12-31
• Study Completion: 2026-12-31

Recruitment & Eligibility

• Status: NOT_YET_RECRUITING
• Sex: All
• Target Recruitment: 60

Inclusion Criteria

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

Exclusion Criteria

• 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Placebo cream- "prevention" suggestion	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.
Placebo	Placebo cream- "promotion" suggestion	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.
Control	Control cream	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.

Primary Outcome Measures

Name	Time	Method
Changes in subjective ratings of acute thermal pain	Measured repeatedly, immediately after thermal stimuli on the day of participation. Averaged and compared across interventions.	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.
Changes in subjective ratings of pain expectations	Measured repeatedly, immediately before thermal stimuli on the day of participation. Averaged and compared across interventions.	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.

Secondary Outcome Measures

Name	Time	Method
Facial expressions	Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.	We will obtain facial video recordings of participants with a video camera. We will analyze these data according to Facial Action Units (facial expressions) that are known to be related to pain, and compare them across interventions.
Thermal imaging of the face	Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.	We will obtain thermal recordings of participant's face with an infrared camera, and compare the heat signature of the face (the temperature in different parts of the face) 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.	Skin conductance will be measured. We will compare the skin conductance response to pain stimuli within participant 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.	Heart rate will be measured. We will compare the heart rate in response to pain stimuli within participant across interventions.

Trial Locations

Locations (1)

Dartmouth College; 🇺🇸 Hanover, New Hampshire, United States