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Does the Understanding of Placebo Mechanisms Compensate for the Loss of Efficacy Associated With Open Label Placebo

Does the Subject's Understanding of Underlying Placebo Mechanisms Compensate for the Loss of Efficacy Associated With the Disclosure of the Use of a Placebo

Status
UNKNOWN
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03934138
Acronym
PLACETHIC
Enrollment
126
Registered
2019-05-01
Start date
2019-05-03
Completion date
2020-09-01
Last updated
2019-05-16

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Acute Pain

Keywords

Placebo, Experimental pain

Brief summary

The investigators are investigating whether, when given detailed information about underlying placebo mechanisms and pain, subjects will have a response similar to that of those subjected to a procedure in which they receive a conventional placebo treatment (associated with deception). STUDY DESIGN: This is a non-inferior parallel, controlled and randomized, single blind trial. POPULATION: The investigators will include in the study 126 subjects without known pathology. Participants will then be divided into 2 groups on a randomized basis. METHODOLOGY: Each subject will undergo three sessions of Cold Pressure Test (CPT), a cold pain stimulation method: calibration, condition of interest (conventional placebo or educated placebo) and control. The investigators' main judgment criterion is be the difference in pain intensity experienced on the visual analog scale between the CPT control and the CPT under the condition of interest. This study will allow the investigators to rule on the non-inferiority of an educated open label placebo compared to a conventional placebo in the context of an acute painful stimulation.

Interventions

OTHEREducational movie on placebo mechanisms

Educational movie on placebo mechanisms : animated video, duration : 12 minutes. It will be followed by the CPTs : experimentally induced pain by keeping the non dominant hand in cold water (1° Celsius) for a limited time. The duration of immersion is personal and calibrated to be around to ensure that the intensity of pain will be homogeneous (around 7/10 on the visual analogue scale with no treatment)

OTHERInformative movie on hand washing

Animated video, duration : 11 minutes. It will be followed by the CPTs : experimentally induced pain by keeping the non dominant hand in cold water (1° Celsius) for a limited time. The duration of immersion is personal and calibrated to be around to ensure that the intensity of pain will be homogeneous (around 7/10 on the visual analogue scale with no treatment).

Sponsors

Laboratoire TIMC-IMAG
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)

Masking description

Only the subjects in the the conventional placebo group will be masked. In the educated open label placebo group, subjects will be aware that the cream is inert.

Intervention model description

2 groups : Educated open label placebo And Conventional placebo Each of the subjects will undergo the Cold Pressure text procedure under the condition of interest and a control.

Eligibility

Sex/Gender
ALL
Age
18 Years to 40 Years
Healthy volunteers
Yes

Inclusion criteria

* Person affiliated to Social Security * Informed consent, written and signed by the subject.

Exclusion criteria

* Persons referred to in Articles L1121-5 to L1121-8 of the Public Health Code (CSP), which corresponds to all protected persons: pregnant women, parturient women, nursing mothers, persons deprived of their liberty by judicial or administrative decision, persons subject to a legal protection measure, cannot be included in clinical trials. * Persons with a pathology against indicating the use of CPT experimentally induced pain : * Any pathologies affecting the venous, arterial or lymphatic system * Diabetes * Cardiac disorders * Asthma * Frostbite * Epilepsy * Arthritis * Lupus erythematosus * Allergy to Cremafluid® cream * Person with concomitant treatment that modifies sensitivity to pain, chronic or acute at the time of the experiment, such as analgesics, psychotropic drugs or anti-inflammatories.

Design outcomes

Primary

MeasureTime frameDescription
Pain intensity: Visual Analogue Scale (VAS)At the end of the CPT procedure, within 30 seconds after the removal of the hand from the CPT cold water tank.Evaluated with a Visual Analogue Scale (VAS) from 0 to 100 mm, with a non inferiority margin at 10 mm and a standard deviation at 22 mm.

Secondary

MeasureTime frameDescription
Anxiety respiratory frequency changeDuring the CPT procedureEvaluated thanks to the respiratory frequency collect with a PneumoTrace belt through LabChart software.
Anxiety blood pressure changeDuring the CPT procedureEvaluated thanks to the automatic blood pressure monitor (both systolic/diastolic blood pressure, heart rate)
Perception of the investigatorAt the end of the study, when all CPT procedures have been carried out, within 10 minutes after the last immersionThe perception of the investigator will be evaluated by a visual analogue scale perception of the investigator.
The Perceived Awareness of the Research Hypothesis Scale questionnaireAt the end of the study, when all CPT procedures have been carried out, within 10 minutes after the last immersionPerception of the research hypothesis with the Rubin Questionnaire. Perceived Awareness of the Research Hypothesis (PARH) wich is a scale of 4-item quantitative self-report method for measuring the potential influence of demand characteristics in research situations
Knowledge of placebo's mechanismsAt the beginning and end of the CPT proceduresEvaluated with a questionnaire made for this study with 17 questions about placebo mechanisms.

Other

MeasureTime frameDescription
Blood pressureAbout 1 minute before every CPT procedures and within 10 secondes after each CPT proceduresSafety measure to insure blood pressure does not exceed 150/90mmHg (both systolic/diastolic blood pressure, heart rate)

Countries

France

Contacts

Primary ContactNicolas PINSAULT
npinsault@chu-grenoble.fr04 76 76 52 56
Backup ContactCarole ROLLAND
carole.rolland@univ-grenoble-alpes.fr04 76 76 69 03

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 19, 2026