Individual Differences in Placebo Analgesic Effects
ConditionHealthy
Trial statusNot yet recruiting
Trial phaseNot applicable
Trial typeInterventional
Biological sexAll
Age18-55
SponsorTrustees of Dartmouth College
About this trial
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.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Healthy participants
Dominant promotion focus or dominant prevention focus (based on our screening)
Disqualifiers
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
Trial design
Design model
Crossover
Treatments tested in this trial
Placebo cream- "promotion" suggestion
BehavioralOver-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 cream- "prevention" suggestion
BehavioralOver-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).
Control cream
BehavioralIn 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.
Treatment groups
60 Participants
are divided into 2 treatment groupsGroup A: PlaceboExperimental treatment 2 interventions
Group B: ControlExperimental treatment 1 intervention
Trial outcomes
Primary outcomes
1
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.
Time frame
Measured repeatedly, immediately after thermal stimuli on the day of participation. Averaged and compared across interventions.2
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.
Time frame
Measured repeatedly, immediately before thermal stimuli on the day of participation. Averaged and compared across interventions.Secondary outcomes
1
Facial expressions
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.
Time frame
Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.2
Thermal imaging of the face
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.
Time frame
Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.3
Changes in skin conductance response measured with a Biopac device
Skin conductance will be measured. We will compare the skin conductance response to pain stimuli within participant across interventions.
Time frame
Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.4
Changes in heart rate measured with a Biopac device
Heart rate will be measured. We will compare the heart rate in response to pain stimuli within participant across interventions.
Time frame
Immediate response measured during painful stimulation on the day of participation. Averaged and compared across interventions.Sponsors and contacts
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Source ClinicalTrials.gov
This trial is not recruiting at the moment. You can still explore other options: