Evaluation of the Efficacy of a Single Brief Intervention of Mindfulness to Reduce Stress Response in a Social Stress Task Paradigm

Inclusion Criteria:

• We plan to recruit adult female patients (>18 years old) suffering from fibromyalgia (FMS), with chronic pain (more than 6 months), willing and able to give informedconsent. Specifically, patients must fulfil the criteria of the American College ofRheumatology (2010) by having the following combination of scores at the widespreadpain index (WPI) and the severity score (SS) :

• WPI score is ≥7 and the SS score is ≥ 5 OR

• WPI score is comprised between 3 to 6 and the SS score ≥9

• And no other condition explaining the painful syndrome

Exclusion Criteria:

• Insufficient French language skills

• Unstable psychiatric co-morbidity: major depression with current suicidal risk,unstable psychotic disorder, unstable psychotropic medication (stable=more than 3month under the same dose).

• Somatic co-morbidity that could interfere with physiological monitoring/stresstolerance: such as cardiac malformation, recent myocardial dysfunction, cardiactransplantation, or cardiac treatment (pacemaker, antiarrhythmic drugs, muscarinicreceptor blockers, ACE inhibitors or any that would induce a modification in HR)

• Contraindication to sensors positioning (local skin damage or allergies)

• Substance use disorder (alcohol, drugs).

• Refusal to listen to an audio recording of mindfulness