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Matthias E. Liechti

University Hospital of Basel

79 papers in the library · 7,237 citations · publishing 2000-2026

Papers

The 4-alkyl chain length of 2,5-dimethoxyamphetamines differentially affects in vitro serotonin receptor actions versus in vivo psychedelic-like effects

Molecular Psychiatry November 5, 2025 Dino Luethi, Grant C. Glatfelter, Eline Pottie et al. 1 citation

Psychedelic-like effects of ring-substituted amphetamines are primarily mediated by 5-HT 2A receptors. Small lipophilic substituents at the 4-position of 2,5-dimethoxyamphetamine enhance clinical potency. This study examined 4-alkylated 2,5-dimethoxyamphetamines (methyl, ethyl, propyl, butyl, amyl) for in vitro receptor activity and in vivo effects in mice using the head-twitch response (HTR) assay. Increasing 4-alkyl chain length raised affinity at 5-HT 2A receptors. The 4-propyl analog showed the highest potencies for 5-HT 2A receptor activation (1–9 nM) in vitro; other chain lengths ranged from 2–56 nM. In mice, maximal HTR counts varied from 23 to 119, with potencies from 0.42 to 2.76 mg/kg.

Comparison of acute effects of 3,4-methylenedioxymethamphetamine (MDMA) with and without a supplemental booster dose in healthy participants: a double-blind, randomized, placebo-controlled, crossover study

Translational Psychiatry June 4, 2026 Mélusine Humbert‐droz, Anna M. Becker, Jan Valenta et al.

A booster dose of MDMA prolongs the acute subjective drug effects compared with a single dose, without increasing peak effects. In a double-blind, randomized, placebo-controlled crossover study with 23 healthy volunteers, a 120 mg dose of MDMA followed by a 60 mg booster after 2 hours extended the duration of subjective effects to an average of 5.6 hours, versus 4.6 hours with a single dose. Adverse effects were more common after both MDMA conditions than placebo. Whether the prolonged effect translates into clinical benefit for MDMA-assisted psychotherapy remains unknown.

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness—a psychometric analysis using the PES100 in controlled psychedelic studies

Religion Brain & Behavior March 31, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

After administration of LSD, psilocybin, mescaline, or DMT, mystical oneness—the core of mystical experience—showed dose-sensitive strong correlations with luminous light and renewal, and a moderate-to-strong correlation with ego disintegration. These findings from 386 healthy participants across 15 studies support a broader, dynamic model of mystical experience, where mystical oneness unfolds with ego disintegration, renewal, and luminous light. The results offer insights for psychedelic-assisted therapy.

Dose-dependent pharmacokinetics and acute effects of intravenous bolus N,N-dimethyltryptamine: double-blind, randomized versus open-label dose-escalation administration study in healthy participants

Translational Psychiatry March 27, 2026 Livio Erne, Lorenz Mueller, Isabelle Straumann et al.

Bolus injections of DMT produce very strong subjective effects that peak within 2 minutes and subside completely within 12–30 minutes, consistent with a short elimination half-life of about 6–7 minutes. A ceiling effect for peak subjective effects occurred at the 15 mg dose, and no tolerance developed to the acute effects. Tolerability markedly improved when doses were escalated openly rather than given double-blind, and at equivalent doses the subjective effects were rated as less intense. These results indicate that blinding and expectancy influence the subjective experience and that individual dose-escalation may improve tolerability and guide dose selection in future DMT studies.