The Impact of Psilocybin on Pain in Fibromyalgia Patients

Overview

Rationale: Recent evidence shows that Lysergic Acid Diethylamide (LSD), even when administered in low, non-hallucinogenic doses, can produce analgesic effects and improve pain tolerance in a sample of healthy volunteers. Such results complement what was already observed with other serotonergic psychedelics such as psilocybin: survey studies and case series indicate that its use may lead to improvements in chronic pain conditions such as migraines, cluster headaches and phantom limb pain even at low, non-psychedelic doses. These effects have however not yet been investigated and confirmed in clinical populations under controlled experimental conditions. Fibromyalgia (FM) is a chronic condition characterised by widespread pain, hyperalgesia, anxiety, disturbed sleep patterns, impaired cognitive functioning and comorbid mood disorders. Most suggested therapies are only associated with small improvements in pain ratings and quality of life. Currently, there is no data concerning the effectiveness of serotonergic psychedelics in improving pain ratings in fibromyalgia patients. Objective: The present study will explore the effects that the administration of a placebo and 2 low psilocybin doses (5 mg or 10 mg) will have on pain perception in a group of fibromyalgia patients. Study design: The present study uses a double-blind, randomized, placebo-controlled design. All participants will receive a placebo and 2 doses of psilocybin (5 mg or 10 mg) and will undergo the Cold Pressor Test (CPT) and the Pain Pressure Threshold Task (PPT) o test its analgesic effects.

Rationale: Recent evidence shows that Lysergic Acid Diethylamide (LSD), even when administered in low, non-hallucinogenic doses, can produce analgesic effects and improve pain tolerance in a sample of healthy volunteers. Such results complement what was already observed with other serotonergic psychedelics such as psilocybin: survey studies and case series indicate that its use may lead to improvements in chronic pain conditions such as migraines, cluster headaches and phantom limb pain even at low, non-psychedelic doses. These effects have however not yet been investigated and confirmed in clinical populations under controlled experimental conditions. Fibromyalgia (FM) is a chronic condition characterised by widespread pain, hyperalgesia, anxiety, disturbed sleep patterns, impaired cognitive functioning and comorbid mood disorders. It has high direct and indirect costs and it is considered challenging to treat. Most suggested therapies, in fact, are only associated with small improvements in pain ratings and quality of life. Currently, there is no data concerning the effectiveness of serotonergic psychedelics in improving pain ratings in fibromyalgia patients. Objective: The present study will explore the effects that the administration of a placebo and 2 low psilocybin doses (5 mg or 10 mg) will have on pain perception in a group of fibromyalgia patients. Study design: The present study uses a double-blind, randomized, placebo-controlled design. All participants will receive a placebo and 2 doses of psilocybin (5 mg or 10 mg) and will undergo the Cold Pressor Test (CPT) and the Pain Pressure Threshold Task (PPT) o test its analgesic effects. Study population: 35 fibromyalgia patients aged 18 to 65 years. Intervention: Placebo, 5 mg or 10 mg of psilocybin in randomized order. Main study parameters/endpoints: Primary outcomes will be subjective and objective measures of pain perception. Secondary measures will assess the effects that placebo and psilocybin will have on mood, cognition and psychedelic experience. Finally, participants will take part to an additional CPT after receiving hypnotic suggestions of analgesia to test whether such intervention may moderate pain ratings of individuals who took small doses of psilocybin. Nature and extent of the burden and risks associated with participation, benefit and group relatedness: Participants will visit the research lab 5 times during 5 weeks. Before the first study day, subjects will come for a screening visit during which they will also be familiarized with tests and study procedures. This includes a medical screening by a licensed physician (medical history review, laboratory screening, electrocardiogram recording). The study visits will consist of taking the study treatment (5 mg or 10 mg of psilocybin or placebo), taking part to the experimental tasks, taking blood samples, completing computer tasks and filling out questionnaires. Finally, participants will take part to a final online visit to administer post-study questionnaires.