The Effect of Hypnosis on Blood Concentrations of Endocannabinoids
Status:
Completed
Trial end date:
2018-09-01
Target enrollment:
Participant gender:
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.