Assessment of the acute effects of 2C-B vs psilocybin on subjective experience, mood and cognition
In a within‑subjects, double‑blind, placebo‑controlled study (n=22) of psychedelic‑experienced volunteers, 20 mg 2C‑B produced acute psychedelic alterations of moderate experiential depth but elicited less dysphoria, subjective impairment, auditory changes and ego‑dissolution than 15 mg psilocybin. Both drugs produced comparable psychomotor slowing, spatial memory impairments and transient pressor effects, while 2C‑B’s subjective effects were shorter in duration (largely resolving within ~6 hours).
Authors
- Kim Kuypers
- Johannes Ramaekers
- Nathalie Mason
Published
Abstract
2,5‐dimethoxy‐4‐bromophenethylamine (2C‐B) is a hallucinogenic phenethylamine derived from mescaline. Observational and preclinical data have suggested it to be capable of producing both subjective and emotional effects on par with other classical psychedelics and entactogens. Whereas it is the most prevalently used novel serotonergic hallucinogen to date, it's acute effects and distinctions from classical progenitors have yet to be characterized in a controlled study. We assessed for the first time the immediate acute subjective, cognitive, and cardiovascular effects of 2C‐B (20 mg) in comparison to psilocybin (15 mg) and placebo in a within‐subjects, double‐blind, placebo‐controlled study of 22 healthy psychedelic‐experienced participants. 2C‐B elicited alterations of waking consciousness of a psychedelic nature, with dysphoria, subjective impairment, auditory alterations, and affective elements of ego dissolution largest under psilocybin. Participants demonstrated equivalent psychomotor slowing and spatial memory impairments under either compound compared with placebo, as indexed by the Digit Symbol Substitution Test, Tower of London, and Spatial Memory Task. Neither compound produced empathogenic effects on the Multifaceted Empathy Test. 2C‐B induced transient pressor effects to a similar degree as psilocybin. The duration of self‐reported effects of 2C‐B was shorter than that of psilocybin, largely resolving within 6 hours. Present findings support the categorization of 2C‐B as a psychedelic of moderate experiential depth at doses given. Tailored dose‐effect studies are needed to discern the pharmacokinetic dependency of 2C‐B's experiential overlaps.
Research Summary of 'Assessment of the acute effects of 2C-B vs psilocybin on subjective experience, mood and cognition'
Blossom's Take
This is one of four studies that report on a study at Maastricht University that reported on the acute effects of 2C-B and psilocybin (versus placebo). As one of the few experiments (in healthy volunteers) it provides great insights into the effects of how these compounds work.
Introduction
Classical psychedelics produce profound alterations in waking consciousness, affecting mood, cognition, and self-referential awareness via serotonergic mechanisms, principally 5-HT2A receptor agonism. Previous research has characterised psilocybin's acute subjective, cognitive, and autonomic effects and has suggested inter-drug differences may arise from variations in receptor binding profiles beyond 5-HT2A. 2,5-dimethoxy-4-bromophenethylamine (2C-B) is a phenethylamine analogue of mescaline that has gained popularity recreationally and shows 5-HT2A/2C selectivity plus secondary activity at other monoaminergic and trace amine receptors; observational data and surveys describe a blend of psychedelic and entactogenic effects but controlled human data are lacking. Mallaroni and colleagues set out to provide the first double-blind, placebo-controlled, within-subject comparison of the immediate acute subjective, cognitive, cardiovascular, and pharmacokinetic effects of oral 20 mg 2C-B versus 15 mg psilocybin in healthy, psychedelic-experienced volunteers. The study aimed to characterise similarities and differences in phenomenology, cognitive impact, autonomic changes, and serum concentrations, with the hypothesis that 2C-B would produce distinct emotional effects relative to psilocybin.
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Study Details
- Study Typeindividual
- Journal
- Compounds
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- APA Citation
Mallaroni, P., Mason, N. L., Reckweg, J. T., Paci, R., Ritscher, S., Toennes, S. W., Theunissen, E. L., Kuypers, K. P., & Ramaekers, J. G. (2023). Assessment of the acute effects of 2C-B vs psilocybin on subjective experience, mood and cognition. Clinical Pharmacology & Therapeutics, 114(2), 423-433. https://doi.org/10.1002/cpt.2958
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