Role of the Serotonin 5-HT2A Receptor in LSD-induced Altered States of Consciousness (LDR-Study)

The present study explores the role the 5-HT2A receptor in LSD-induced altered states of consciousness using escalating doses of LSD and the 5-HT2A receptor blocker ketanserin administered before a high dose of LSD.

Topic Healthy Subjects
Compound Placebo LSD
Country Switzerland
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Trial Details



Trial Number

Sponsors & Collaborators

University of Basel
The University of Basel Department of Biomedicine hosts the Liechti Lab research group, headed by Matthias Liechti.

Measures Used

5-Dimensional Altered States of Consciousness Questionnaire
The 5D-ASC scale measures altered states of consciousness and contains 94 items (visual analog scales).

Mystical Experience Questionnaire
The MEQ is a self-report measure that has been used to measure mystical-type experiences in laboratory studies of psychedelics. The scale was developed by Walter Pahnke in 1963 and covers the major dimensions of classic mystical experience: unity (internal and external), transcendence of time and space, noetic quality, sacredness, positive mood, and ineffability/paradoxicality. Variations of the MEQ exist; the MEQ-30 and the MEQ-43.

Data attribution

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