Biological Psychiatry Cognitive Neuroscience and Neuroimaging
February 9, 2024
Yasmin Schmid, Anya K. Bershad
15 citations
MDMA and serotonergic psychedelics both produce prosocial effects, but they do so through different mechanisms that may influence which psychosocial interventions work best with each compound. This narrative overview compares evidence across four categories of prosocial effects: altered self-image, responses to social reward, responses to negative social input, and social neuroplasticity. MDMA alters self-perception in a way less tied to mystical-type states than serotonergic psychedelics. MDMA enhances responses to social reward, while serotonergic psychedelics may also do so but require more research. Both drug classes dampen reactivity to negative social stimuli and induce social neuroplasticity in preclinical evidence, promoting adaptive rewiring of neural circuits that may aid trauma processing.
JAMA psychiatry
June 1, 2025
Lorenz Mueller, Joyce Santos de Jesus, Yasmin Schmid et al.
14 citations
Repeated low doses of LSD (20 μg twice weekly for six weeks) did not reduce ADHD symptoms more than placebo in adults with moderate-to-severe ADHD. In a double-blind randomized trial with 53 participants, the LSD group showed an average 7.1-point improvement on the ADHD symptom scale, while the placebo group improved by 8.9 points—a difference that was not statistically significant. The treatment was physically safe and psychologically well tolerated. The findings suggest that microdosing LSD, despite popular interest, offers no advantage over placebo for ADHD symptom relief.
British journal of clinical pharmacology
November 25, 2024
Aaron Klaiber, Mélusine Humbert-Droz, Laura Ley et al.
6 citations
Mescaline doses up to 800 mg appear safe in controlled clinical settings for healthy individuals. In two double-blind, placebo-controlled studies with 48 participants and 96 administrations, positive subjective effects increased with dose and consistently outweighed negative effects. Autonomic effects rose moderately: systolic blood pressure exceeded 180 mmHg in 6% of administrations, heart rate above 100 beats/min occurred in 3%, and body temperature above 38 °C in 5%. Nausea limited higher doses. Kidney and liver function and blood cell counts remained normal. Flashbacks followed 2% of administrations. Adverse effects totaled 51 at 100 mg and 180 at 800 mg.
Drug testing and analysis
September 1, 2024
Verena Angerer, Yasmin Schmid, Florian Franz et al.
6 citations
In six healthy volunteers, the new psychoactive substance MDAI at 3.0 mg/kg produced subjective effects comparable to 125 mg of MDMA, including increased blood pressure, but did not raise heart rate or body temperature. MDAI increased cortisol and prolactin levels, appeared in serum about 20 minutes after ingestion, and remained detectable for at least 4 days in serum and 6 days in urine. The drug was well tolerated. Further research is needed to evaluate whether MDAI might have medicinal applications.
Journal of psychopharmacology (Oxford, England)
December 26, 2025
Kurt Stocker, Matthias Hartmann, Yasmin Schmid et al.
5 citations
A psychometric revalidation of the Altered States of Consciousness Scale (ASC) using data from 901 questionnaires across 16 psychedelic studies (with LSD, psilocybin, mescaline, and DMT) shows that ten of the eleven subscales can be grouped into three higher-order dimensions—Positive Effects, Distressing Effects, and Perceptual Effects—mirroring the original three-dimensional model but with improved statistical fit. The Anxiety subscale could not be integrated due to floor effects (low anxiety in the sample) but is retained for clinical relevance. The revised scale, 3D-ASCr, is recommended for use with classic serotonergic psychedelics.
Clinical pharmacokinetics
July 14, 2025
Lorenz Mueller, Aaron Klaiber, Laura Ley et al.
4 citations
Mescaline, a classic psychedelic, shows dose-proportional increases in blood concentration and effects after oral administration. Peak levels occur within about 2 hours, with a half-life of 3.5 hours. Effects begin around 1 hour after dosing, with intensity and duration increasing from 13% and 2.8 hours at 100 mg to 89% and 15 hours at 800 mg. About 53% of the dose is excreted unchanged in urine, and 31% as a main metabolite. Oral bioavailability is at least 53%, limited by first-pass metabolism, with renal elimination as the primary clearance route.
Swiss Medical Weekly
July 1, 2025
Samuel E Christen, Elias Bekka, Yasmin Schmid et al.
3 citations
Caffeine, nicotine, cannabis, and psilocybin are naturally occurring psychoactive substances that alter perception, consciousness, cognition, and emotions. Their natural origins have led to long histories of human use and cultural significance. Caffeine and nicotine are widely available as everyday stimulants, while psilocybin is strictly regulated and cannabis is legal in some regions. Their pharmacological and toxicological properties are well known, but ongoing research investigates therapeutic use for specific diseases and disorders. This narrative review provides an overview of these four substances, summarizing evidence on therapeutic potential, health benefits, and associated risks.
Psychopharmacology
March 26, 2025
Laura Ley, Matthias E Liechti, Anna M Becker et al.
3 citations
Healthy volunteers enroll in psychedelic trials primarily out of interest in the substances and the appeal of the study setting, hoping for personal development and transformative experiences. In a series of six double-blind, placebo-controlled trials involving 151 participants, positive experiences were promoted by music, access to nature, and a trusting relationship with the investigator. A sterile hospital environment, lack of investigator support, and investigator-induced discomfort were criticized. Most volunteers felt their expectations were exceeded and would take the substances again, ideally in a natural setting with friends. Four key factors for positive study experiences are a secure interpersonal relationship, an aesthetically pleasing environment, access to nature, and music.
Neuropharmacology
May 1, 2025
Michael Noback, Johnny A Kenton, Adam K Klein et al.
2 citations
A compound called 2,5-dimethoxy-4-propylamphetamine (DOPR), a psychedelic that activates 5-HT2A receptors, can increase motivation in mice with low baseline motivation without causing hallucinogenic-like effects. In a progressive ratio breakpoint task (PRBT) involving 80 mice, doses as low as 0.0106 mg/kg improved performance only in animals with low initial motivation; high-performing mice were unaffected. The head-twitch response (HTR) assay in 72 mice showed hallucinogenic-like effects only at doses of 0.1 mg/kg or higher. These results suggest that low doses of DOPR might treat amotivated states while avoiding hallucinogenic side effects, warranting further research in rodents with disease-relevant conditions.
BMJ open
May 11, 2026
Julia Colcott, Alexandre A Guerin, Olivia Carter et al.
A new tool, the MDMA-Assisted Psychotherapy Side Effects Tool (M-SET), was developed to systematically capture side effects during MDMA-assisted psychotherapy. Experts in MDMA-AP and neuropsychopharmacology participated in a two-round online Delphi process to refine a list of 165 items across four questionnaires covering screening, baseline, medication session days, and follow-up. The tool aims to improve safety monitoring and build a more robust evidence base on the tolerability of MDMA-AP for research and clinical use.