The Effect of Hypnosis on Blood Concentrations of Endocannabinoids

Summary

Introduction: Many interventions such as hypnosis, mindfulness meditation, conditioned pain modulation and placebos have been shown to effectively reduce pain both in the laboratory and in clinical settings. However, little is known about their neurophysiological mechanisms of action. Analgesia induced by these techniques is thought to be based on opioidergic and non-opioidergic mechanisms (potentially endocannabinoid mechanisms). Objective: Our main objective is to evaluate the effect of hypnosis, meditation, conditioned pain modulation and placebo on blood concentrations of endocannabinoids (anandamide, 2-arachidonylglycerol, N-palmitoyl-ethanolamine, N-oleoylethanolamide), endogenous opioids (β-endorphins, met / leu-enkephalins, and dynorphins) and norepinephrine in healthy adults. Methods: This study is based on a single-group pre-experimental research design in which two experimental sessions including hypnosis or meditation, conditioned pain modulation and placebo interventions will be completed by all participants. In order to have a better description of the sociodemographic and clinical characteristics of the sample, information will be collected by questionnaires or tests filled by participants at baseline, including: age, sex, language, culture, religion, salary, menstrual cycle of women, medication (if any), mood, anxiety, pain catastrophizing, mindfulness, hypnotic susceptibility, and DNA information. Outcome measures will be collected before, during and after each intervention. The primary outcome is plasma concentrations of endocannabinoids. Secondary measurements include plasma concentrations of endogenous opioids and norepinephrine; change in pain intensity during the thermal noxious stimuli; and autonomic nervous system variability (as measured by heart rate variability). Anticipated results: The investigators expect a positive relationship between the change in pain intensity (analgesia) induced by the interventions (hypnosis, meditation, conditioned pain modulation, and placebo) and the change (increase) in plasma concentrations of endocannabinoids, opioids, and norepinephrine in healthy adults. It is also believed that the interventions will influence heart rate variability. Moreover, it is expected that there will be a relationship between the efficiency of the analgesic intervention and some gene polymorphisms associated to pain modulation and endocannabinoids, opioids or norepinephrine in healthy individuals.

Conditions

• Hypnosis
• Endocannabinoids
• Analgesia

Interventions

BEHAVIORAL

Hypnosis

Hypnosis is a therapeutic method in which the experimenter or therapist make suggestions to individuals after they have undergone a hypnotic induction. This induction is a relaxation procedure designed to focus one's mind and to induce a hypnotic trance in individuals. The hypnotic trance consists in a state of deep absorption, concentration and altered sensations, cognitions and behaviors. Hypnosis can be used for pain control in experimental and clinical settings. In this study, standardized hypnosis including a relaxation technique for the hypnotic induction and a direct hypnotic analgesia technique for the hypnotic suggestions will be used.

BEHAVIORAL

Meditation

Meditation is a relaxation method that can be used to reduce pain symptoms and pain perception in clinical and experimental situations. In this study, a standardized mindfulness meditation session of 20 minutes will be used to induce a relaxation and an analgesic effect in participants. Mindfulness meditation is a practice intended to increase mindfulness and awareness of the self and the environment by techniques of controlled breathing, focus on neutral elements, and observation of one's thoughts and emotions without judgment.

OTHER

Conditioned pain modulation

Conditioned pain modulation (CPM) is a pain inhibition mechanism that is used to assess endogenous analgesia capacity. The method to evaluate CPM in healthy individuals and patients with pain includes both a conditioning stimulus (a noxious stimulus that induces CPM) and a test stimulus (a noxious stimulus used to evaluate the analgesic response to the conditioning stimulus). In this study, the conditioning stimulus will be a cold pressor test (two-minutes immersion of one hand in ice water) and the test stimulus will be a two-minutes thermal noxious stimulus delivered by a contact thermode.

DRUG

Placebo Oral Tablet

A placebo is a substance (or treatment) with no active therapeutic effect. The placebo effect (analgesia) in this study will be induced by the oral administration of one inert tablet (sugar pill). The tablet is a round, hard, white, flat-faced tablet with no active ingredient. The participant is told that the tablet is an active drug, more specifically an analgesic or a painkiller, that is used to achieve analgesia, relief from pain. This placebo condition is used to induce a diffuse analgesic effect in participants.

Sponsors & Collaborators

• Université de Sherbrooke

  lead OTHER

Principal Investigators

• Serge Marchand, Ph.D. · Université de Sherbrooke

• Guillaume Leonard, Ph.D. · Université de Sherbrooke

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2017-11-14

Primary Completion

2018-09-01

Completion

2018-09-01

Countries

• Canada

Study Locations