Matthias Liechti

Matthias Liechti, MD

University Hospital Basel

Clinical studies with LSD and MDMA in healthy subjects and patients: differential effects and dose considerations


There is medical use of LSD and MDMA in Switzerland to assist psychotherapy and clinical studies are being conducted using LSD and psilocybin in patients with anxiety or depression. Additionally, placebo-controlled studies are conducted in healthy subjects including dose-finding studies, pharmacokinetic studies, and comparisons of the acute effects of LSD, MDMA, and psilocybin. Specifically, placebo-controlled, double-blind, cross-over studies using oral administration of 0.1 and 0.2 mg LSD were conducted to better define the acute subjective, emotional, endocrine, and pharmacokinetic effects of LSD in healthy subjects. Additionally, acute responses and pharmacokinetics of different doses of LSD (0.025-0.2 mg) were investigated in a dose-response study in 16 healthy subjects. Furthermore, we compared the acute effects of LSD (0.1 mg), MDMA (125 mg), d-amphetamine (40 mg), and placebo in a randomized crossover study in 28 healthy subjects to explore differential effects of these prototypical substances. Finally, the pharmacokinetics and pharmacokinetic-pharmacodynamic relationsships of LSD and MDMA were investigated. The talk will summarize the findings and discuss their relevance for the therapeutic use of these substances and give an outlook on ongoing studies in patients.


Matthias Liechti is a professor for clinical pharmacology and internal medicine the University Hospital Basel. With his psychopharmacology research group, Matthias Liechti investigates the pharmacology of psychoactive substances both in vitro and in humans. The group is best known for the work on the acute effects of MDMA (ecstasy) and LSD in humans. The team also conducts Pharmaco-fMRI studies in collaboration with the Department of Psychiatry.



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