Journal of substance abuse treatment
December 1, 2002
Evgeny Krupitsky, Andrey Burakov, Tatyana Romanova et al.
240 citations
In a double-blind randomized clinical trial, seventy detoxified heroin-addicted patients received either a high psychedelic dose (2.0 mg/kg) or a low non-psychedelic dose (0.2 mg/kg) of ketamine combined with existentially oriented psychotherapy. The high dose produced a full psychedelic experience and led to significantly greater abstinence rates over two years, a greater and longer-lasting reduction in heroin craving, and more positive change in unconscious emotional attitudes compared to the low dose. Both patients and therapists were unaware of the dose given.
Drug testing and analysis
January 1, 2012
Steven A Barker, Ethan H Mcilhenny, Rick Strassman
143 citations
Three indole alkaloids with varying psychedelic activity—DMT, bufotenine, and 5-MeO-DMT—have been reported as naturally occurring in humans. A critical review of 69 studies from 1955 to 2010 examined their detection in blood, urine, and cerebrospinal fluid. The review evaluates the methods and criteria used, highlighting strengths and weaknesses of past approaches. It notes shortcomings in existing data given recent findings and suggests future directions for research on these endogenous psychedelics.
Journal of psychoactive drugs
September 1, 2009
Paulo Cesar Ribeiro Barbosa, Irene Maurício Cazorla, Joel Sales Giglio et al.
113 citations
Twenty-three people were assessed just before and six months after their first ayahuasca experience in two Brazilian religious groups. In the Santo Daime group, minor psychiatric symptoms decreased, mental health improved, and attitudes shifted toward greater confidence and optimism. In the União do Vegetal group, physical pain decreased and attitudes shifted toward greater independence. More frequent ayahuasca use was linked to more independence, while a longer period without ayahuasca was linked to less independence. The authors discuss possible mechanisms behind these changes and suggest areas for future research.
Biomedical chromatography : BMC
December 1, 2013
Steven A Barker, Jimo Borjigin, Izabela Lomnicka et al.
73 citations
A qualitative liquid chromatography-tandem mass spectrometry method was developed to simultaneously analyze three known N,N-dimethyltryptamine endogenous hallucinogens, their precursors and metabolites, as well as melatonin and its metabolic precursors. The method was characterized using artificial cerebrospinal fluid and applied to rat brain pineal gland microdialysate. It allows direct injection of 23 chemically diverse compounds plus a deuterated internal standard without dilution or extraction. The approach is simple, sensitive, specific, and uses stringent MS confirmatory criteria including exact mass measurements. For the first time, N,N-dimethyltryptamine was detected in pineal gland microdialysate from the rat.
Journal of chromatography. A
December 18, 2009
Ethan H Mcilhenny, Kelly E Pipkin, Leanna J Standish et al.
58 citations
A new analytical method using direct injection and liquid chromatography-tandem mass spectrometry can simultaneously measure 11 psychoactive compounds in ayahuasca, a plant-based Amazonian beverage used in traditional medicine and religious ceremonies. The technique uses a deuterated internal standard for accurate quantitation and requires only simple dilution of samples up to 200-fold, avoiding complex extraction steps. It shows high specificity, low detection and quantitation limits, and appears to eliminate matrix effects. The method was tested on three different ayahuasca preparations and is expected to aid clinical, ethnobotanical, and forensic studies.
Biomedical chromatography : BMC
March 1, 2012
Ethan H Mcilhenny, Jordi Riba, Manel J Barbanoj et al.
57 citations
A new single analytical method can directly measure 14 major alkaloid components of ayahuasca, including known and potential metabolites of N,N-dimethyltryptamine and harmala alkaloids, in human blood plasma. The method uses 96-well plate protein precipitation and filtration followed by HPLC-ion trap-ion trap-mass spectrometry with heated electrospray ionization to reduce matrix effects. It provides adequate sensitivity, specificity, and reproducibility for clinical research, expanding the list of compounds that can be monitored after ayahuasca administration while simplifying the analysis compared to previous combined techniques.
Biomedical chromatography : BMC
September 1, 2011
Ethan H Mcilhenny, Jordi Riba, Manel J Barbanoj et al.
51 citations
The primary metabolite of N,N-dimethyltryptamine (DMT) in humans after ayahuasca ingestion is the corresponding N-oxide, the first time this metabolite has been described in in vivo human studies. Very little DMT was detected in urine, despite monoamine oxidase inhibition by harmala alkaloids. The major harmala alkaloid excreted was tetrahydroharmine. A rapid, sensitive method using HPLC-electrospray ionization-selected reaction monitoring-tandem mass spectrometry was developed and applied to urine samples from three individuals administered ayahuasca, identifying and quantifying major constituents and metabolites. The protocol is suitable for toxicological and clinical research on ayahuasca.
Biological psychiatry global open science
March 1, 2025
Abigail E Calder, Clifford Qualls, Gregor Hasler et al.
5 citations
The Hallucinogen Rating Scale (HRS) is a widely used questionnaire for measuring subjective effects of psychedelics and other psychoactive drugs. By analyzing 991 questionnaires from 18 studies involving 13 substances, researchers identified 8 factors with good internal consistency that map onto psychedelic effects. The factor model fit the data better than previous models and showed dose responses for most drugs. Patterns on the 8 factors clearly distinguished classic psychedelics (psilocybin, DMT) from dissociatives (ketamine, salvinorin A), empathogens (MDMA), stimulants (methylphenidate, amphetamine), and THC. The meaningfulness factor uniquely differentiated psychedelics from all other substances, supporting the HRS as a psychometrically sound tool for measuring drug-induced altered states.