European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
May 1, 2022
Isabel Wießner, Rodolfo Olivieri, Marcelo Falchi et al.
42 citations
A low dose of LSD (50 μg) produces both beneficial and detrimental cognitive effects 24 hours after administration. Compared to placebo, LSD sub-acutely improved visuospatial memory and phonological verbal fluency but impaired cognitive flexibility, as measured by fewer categories achieved and more perseveration on the Wisconsin Card Sorting Test. The findings suggest that LSD-assisted therapy might be explored for conditions involving memory and language decline, such as brain injury, stroke, or dementia, while also indicating a mixed 'afterglow and hangover' profile.
Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology
May 1, 2025
Marcelo Falchi-Carvalho, Fernanda Palhano-Fontes, Isabel Wießner et al.
35 citations
Vaporized DMT, a short-acting psychedelic, rapidly reduced depression symptoms in patients with treatment-resistant depression. In an open-label trial, 14 patients received inhaled DMT at 15 mg and then 60 mg. The treatment was safe and well-tolerated, with no serious adverse events. By day 7, depression scores on the Montgomery-Asberg Depression Rating Scale dropped by an average of 21.14 points. The response rate was 85.71%, and the remission rate was 57.14%, with effects lasting up to 3 months. Suicidal ideation also decreased significantly, with no severe ideation the day after dosing. Vaporized DMT offers a non-invasive, time-efficient alternative to longer-acting psychedelics and traditional antidepressants.
European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology
March 1, 2023
Isabel Wießner, Marcelo Falchi, Dimitri Daldegan-Bueno et al.
6 citations
Low to moderate doses of LSD alter language structure, semantics, and vocabulary over time. In a double-blind, placebo-controlled crossover study, 24 healthy volunteers (age 35±11, 33% women) received 50 μg LSD or placebo. LSD reduced verbosity, lexicon, and connectivity in speech networks from 1.5 to 4 hours, decreased semantic distances between words from 2 to 24 hours, and shifted vocabulary related to grammar, persons, time, space, and biological processes from 1.5 to 24 hours. Simpler, disconnected structure and increased semantic similarity may reflect cognitive impairments, while vocabulary changes may indicate subjective perceptual shifts. Automated language analysis could offer unconstrained insights into psychedelic cognition.