NCT04227756

Comparative Acute Effects of LSD, Psilocybin and Mescaline

Comparative Acute Effects of LSD, Psilocybin and Mescaline in a Random-Order Placebo-Controlled Cross-Over Study in Healthy Subjects

• Status: Completed
• Phase: Phase 1
• Study type: Interventional
• Enrollment: 32 (actual)
• Sponsor: University Hospital, Basel, Switzerland · Academic / Other
• Sex: All
• Age: 25 Years – 65 Years
• Healthy volunteers: Accepted

Summary

LSD, psilocybin and mescaline are widely used for recreational and ethnomedical purposes. All three substances are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in the substances' molecular structures and receptor activation profiles which may induce differential subjective effects. To date, there are no modern studies comparing LSD, psilocybin and mescaline directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo.

Detailed description

LSD (lysergic acid diethylamide), psilocybin (the active substance in "magic mushrooms") and mescaline (the active substance in Peyote and San Pedro cacti) are serotonergic hallucinogens widely used for recreational and/or ethnomedical purposes. LSD, psilocybin and mescaline are thought to induce prototypical psychedelic effects primarily via stimulation of the 5-HT2A receptor. However, there are differences in their molecular structures (LSD: ergoline, psilocybin: tryptamine; mescaline: phenethylamine)and receptor activation profiles which may induce different subjective effects. To date, there are no modern studies comparing these three substances directly within the same clinical study and research subjects using validated psychometric tools. Therefore, the LPM-Study compares the acute effects of LSD, psilocybin, mescaline and placebo in a double-blind, placebo-controlled, 4-period cross-over design with four treatment conditions: 1) 100 μg LSD, 2) 20 mg psilocybin, 3) 300 or 500 mg mescaline, and 4) placebo. The main objective of this study is to determine whether LSD, psilocybin and mescaline produce qualitatively similar subjective alterations of mind and associated brain activity patterns despite their unique receptor activation profiles. The study investigates psychological (psychometry), physiological and neuronal (magnetic resonance imaging) variables. The LPM-Study provides insight into the acute effects profiles of three serotonergic hallucinogens. It will enhance the understanding of psychedelic-induced altered states of consciousness in humans and will be relevant for the fields of psychiatry, psychology, and forensic toxicology.

Conditions

• Healthy

Interventions

Type	Name	Description
DRUG	LSD	LSD 0.1 mg per os, single dose OR Psilocybin 20 mg per os, single dose OR Mescaline 300 mg per os, single dose OR Placebo
DRUG	Psilocybin	Psilocybin 20 mg per os, single dose
DRUG	Mescaline	Mescaline 300 mg or 500 mg per os, single dose
OTHER	Placebo	Placebo (Mannitol)

Timeline

• Start date: 2020-05-19
• Primary completion: 2022-09-02
• Completion: 2022-09-02
• First posted: 2020-01-14
• Last updated: 2024-01-24

Locations

1 site across 1 country: Switzerland