Yasmin Schmid

Yasmin Schmid, MD

University of Basel

Acute effects of LSD and MDMA in patients during drug-assisted psychotherapy and in healthy subjects


Background: Lysergic acid diethylamide (LSD) and 3,4-methylenedioxymethamphetamine (MDMA) are re-investigated in the treatment of various psychiatric disorders. Several reports indicate that the acute effects are associated with the therapeutic efficacy. The aim of this study was therefore to characterize and compare the acute subjective effects of LSD and MDMA in patients and healthy subjects. Method: Acute effects of LSD (100-200 mcg) and MDMA (100-175 mg) were assessed in 11 patients with various psychiatric disorders. Acute effects of LSD (100 and 200 mcg) and MDMA (125 mg) were investigated in placebo-controlled studies in a total of 40 and 164 healthy subjects, respectively. Responses were evaluated using visual analogue scales (VASs), the 5 Dimensions of Altered States of Consciousness (5D-ASC) scale, and the Mystical Experience Questionnaire (MEQ). Results: In healthy subjects, LSD and MDMA both acutely increased ratings of feelings of openness, trust, and closeness to others on the VASs. LSD similarly induced pronounced alterations of consciousness on the 5D-ASC, and produced similar mystical-type experiences on the MEQ in patients and healthy volunteers. MDMA induced largely comparable effects in both groups. However, on the 5D-ASC, higher ratings for anxious ego dissolution, spiritual experience, insightfulness, and visionary restructuralization were observed in patients. In patients, MDMA produced higher ratings in most MEQ scores except for “positive mood”, and “internal unity”. Conclusions: LSD and MDMA both produced empathogenic effects that may be beneficial in drug-assisted psychotherapy. LSD and MDMA induced largely comparable acute alterations in consciousness and mystical-type experiences in patients and in healthy subjects.


I’m a medical doctor specialised in general medicine and clinical pharmacology and toxicology. I was working several years in the department of clinical pharmacology and toxicology at the University Hospital Basel and in the psychopharmacology research group of Prof. Matthias Liechti. At the moment, I’m working as a physician in the emergency department. I conducted several placebo-controlled, double-blind, cross-over studies concerning the effects of MDMA and LSD in healthy subjects, with special focus on the effects of these drugs on social cognition, but also acute and long-term effects. I’m planning a study in patients with LSD in patients suffering from cluster headache. The above mentioned results were obtained in collaboration with several psychiatrist working in private practice in Switzerland.



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