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

Laboratoire TIMC-IMAG

Status: Unknown

Conditions: Acute Pain

Treatments: Other: Informative movie on hand washing; Other: Educational movie on placebo mechanisms

Study type: Interventional

Funder types: Other

Identifiers

NCT03934138

2017-A01643-50

Details and patient eligibility

About

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.

Enrollment: 126 estimated patients

Sex: All

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

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.

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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126 participants in 2 patient groups, including a placebo group

Educated open label placebo

Active Comparator group

Description:

These subjects will undergo all the same procedures as in the control group. But before the placebo CTP, they will watch a short movie explaining placebo mechanisms. While applying the placebo cream, they will be told that the cream is inert (placebo), efficient to decrease pain caused by cold and the mechanisms seen in the movie will take place.

Treatment:

Other: Educational movie on placebo mechanisms

Conventional placebo

Placebo Comparator group

Description:

These subjects will watch a video on hand washing. While applying the placebo cream, they will be told that this cream is effective to decreased pain caused by cold.

Treatment:

Other: Informative movie on hand washing