Interest is growing in the use of the psychedelic drug LSD for psychiatric research and even potentially for treatment. But placebo-controlled studies conducted to date have used just one dose of the drug—none have investigated the impacts of a variety of dosages within the same subjects. In addition, past studies did not use pharmaceutically-defined dosages of LSD, which has made verifying the effects of a particular dose difficult. To address this gap, Matthias Liechti, professor in the department of clinical pharmacology and toxicology at the University of Basel in Switzerland, and his colleagues conducted a study.   See acast.com/privacy for privacy and opt-out information.