Journal of psychopharmacology (Oxford, England)
April 1, 2016
Matthew W Johnson, Katherine A Maclean, Michael J Caspers et al.
11 citations
Salvinorin A is a kappa opioid agonist and the principal psychoactive constituent of the Salvia divinorum plant, which has been used for hallucinogenic effects. Previous research on salvinorin A pharmacokinetics likely underestimated plasma levels typically resulting from the doses administered due to inefficient vaporization and not collecting samples during peak drug effects. Six healthy...
The International Journal of Neuropsychopharmacology
February 12, 2016
Marta Valle, Montserrat Puntes, Jimena Coimbra et al.
31 citations
BACKGROUND: Salvinorin-A is a terpene found in the leaves of the plant Salvia divinorum. When administered to humans, salvinorin-A induces an intense but short-lasting modified state of awareness, sharing features with those induced by the classical serotonin-2A receptor agonist psychedelics. However, unlike substances such as psilocybin or mescaline, salvinorin-A shows agonist activity at the...
Drug and Alcohol Dependence
November 1, 2015
Albert Garcia‐romeu, Tehseen Noorani, Roland R. Griffiths et al.
6 citations
Aims: We assessed long-term (>12 months) outcomes of psilocybin-facilitated smoking cessation, and qualitatively analyzed participants’ accounts to inform potential psychological mechanisms of treatment efficacy. Methods: Fifteen individuals who completed a pilot study of psilocybin-facilitated smoking cessation were invited for a long-term follow-up. Eleven (73%) returned and were interviewed...
Journal of Psychopharmacology
October 6, 2015
Frederick S. Barrett, Matthew W Johnson, Roland R. Griffiths
634 citations
The 30-item revised Mystical Experience Questionnaire (MEQ30) was previously developed within an online survey of mystical-type experiences occasioned by psilocybin-containing mushrooms. The rated experiences occurred on average eight years before completion of the questionnaire. The current paper validates the MEQ30 using data from experimental studies with controlled doses of psilocybin. Data...
Journal of Psychopharmacology
September 1, 2015
Peter S. Hendricks, Matthew W Johnson, Roland R. Griffiths
107 citations
Hendricks et al. (2015) found that having ever used any classic psychedelic substance—namely, dimethyltryptamine (DMT), ayahuasca, lysergic acid diethylamide (LSD), mescaline, peyote or San Pedro, or psilocybin—was associated with a significantly reduced likelihood of past month psychological distress (weighted OR = .81 (.72–.91)), past year suicidal thinking (weighted OR = .86 (.78–.94)), past...
The International Journal of Neuropsychopharmacology
June 5, 2015
Marta Valle, Montserrat Puntes, Jimena Coimbra et al.
75 citations
BACKGROUND: Salvinorin-A is a terpene with agonist properties at the kappa-opioid receptor, the binding site of endogenous dynorphins. Salvinorin-A is found in Salvia divinorum, a psychoactive plant traditionally used by the Mazatec people of Oaxaca, Mexico, for medicinal and spiritual purposes. Previous studies with the plant and salvinorin-A have reported psychedelic-like changes in...
Current Drug Abuse Reviews
January 9, 2015
Albert Garcia‐romeu, Roland R. Griffiths, Matthew W. Johnson
480 citations
Psilocybin-occasioned mystical experiences have been linked to persisting effects in healthy volunteers including positive changes in behavior, attitudes, and values, and increases in the personality domain of openness. In an open-label pilot-study of psilocybin-facilitated smoking addiction treatment, 15 smokers received 2 or 3 doses of psilocybin in the context of cognitive behavioral therapy...
Journal of Psychopharmacology
September 11, 2014
Mary P Cosimano, Matthew W. Johnson, Albert Garcia‐romeu et al.
910 citations
Despite suggestive early findings on the therapeutic use of hallucinogens in the treatment of substance use disorders, rigorous follow-up has not been conducted. To determine the safety and feasibility of psilocybin as an adjunct to tobacco smoking cessation treatment we conducted an open-label pilot study administering moderate (20 mg/70 kg) and high (30 mg/70 kg) doses of psilocybin within a...
Psychopharmacology
March 1, 2013
Katherine A Maclean, Matthew W Johnson, Chad J Reissig et al.
134 citations
Salvinorin A is a kappa opioid agonist and the principal psychoactive constituent of the plant Salvia divinorum, which has increased in popularity as a recreational drug over the past decade. Few human studies have examined salvinorin A. This double-blind, placebo-controlled study evaluated the dose-related effects of inhaled salvinorin A in individuals with histories of hallucinogen use. Eight...
Drug and Alcohol Dependence
March 1, 2013
Lawrence P Carter, Chad J Reissig, Matthew W Johnson et al.
28 citations
Although concerns surrounding high-dose dextromethorphan (DXM) abuse have recently increased, few studies have examined the acute cognitive effects of high doses of DXM. The aim of this study was to compare the cognitive effects of DXM with those of triazolam and placebo. Single, acute, oral doses of DXM (100, 200, 300, 400, 500, 600, 700, 800 mg/70 kg), triazolam (0.25, 0.5mg/70 kg), and...
Psychopharmacology
March 1, 2013
Lawrence P Carter, Bethea A Kleykamp, Roland R. Griffiths et al.
19 citations
Several studies have documented impairments in memory processes as a result of ketamine administration; however, few studies have compared the profile of cognitive effects of ketamine to other drugs. The aim of this study was to compare the cognitive effects of ketamine with those of triazolam in healthy volunteers. Doses of ketamine (0.2, 0.4 mg/kg intramuscular (i.m.)), triazolam (0.2, 0.4...
Journal for the Scientific Study of Religion
December 1, 2012
Katherine A Maclean, Jeannie‐marie Leoutsakos, Matthew W. Johnson et al.
412 citations
A large body of historical evidence describes the use of hallucinogenic compounds, such as psilocybin mushrooms, for religious purposes. But few scientific studies have attempted to measure or characterize hallucinogen‐occasioned spiritual experiences. The present study examined the factor structure of the Mystical Experience Questionnaire (MEQ), a self‐report measure that has been used to...
Psychopharmacology
September 1, 2012
Chad J Reissig, Lawrence P Carter, Matthew W Johnson et al.
89 citations
Although reports of dextromethorphan (DXM) abuse have increased recently, few studies have examined the effects of high doses of DXM. This study in humans evaluated the effects of supratherapeutic doses of DXM and triazolam. Single, acute oral doses of DXM (100, 200, 300, 400, 500, 600, 700, and 800 mg/70 kg), triazolam (0.25 and 0.5 mg/70 kg), and placebo were administered to 12 healthy...
Drug and Alcohol Dependence
June 1, 2012
Matthew W Johnson, R Andrew Sewell, Roland R. Griffiths
121 citations
Psilocybin is a well-characterized classic hallucinogen (psychedelic) with a long history of religious use by indigenous cultures, and nonmedical use in modern societies. Although psilocybin is structurally related to migraine medications, and case studies suggest that psilocybin may be efficacious in treatment of cluster headache, little is known about the relationship between psilocybin and...
Psychopharmacology
December 1, 2011
Roland R. Griffiths, Matthew W Johnson, William A Richards et al.
938 citations
This dose-effect study extends previous observations showing that psilocybin can occasion mystical-type experiences having persisting positive effects on attitudes, mood, and behavior. This double-blind study evaluated psilocybin (0, 5, 10, 20, 30 mg/70 kg, p.o.) administered under supportive conditions. Participants were 18 adults (17 hallucinogen-naïve). Five 8-h sessions were conducted...
Journal of Psychopharmacology
September 28, 2011
Katherine A Maclean, Matthew W Johnson, Roland R. Griffiths
907 citations
A large body of evidence, including longitudinal analyses of personality change, suggests that core personality traits are predominantly stable after age 30. To our knowledge, no study has demonstrated changes in personality in healthy adults after an experimentally manipulated discrete event. Intriguingly, double-blind controlled studies have shown that the classic hallucinogen psilocybin...
Drug and Alcohol Dependence
May 1, 2011
Matthew W Johnson, Katherine A Maclean, Chad J Reissig et al.
134 citations
Salvinorin A is a potent, selective nonnitrogenous kappa opioid agonist and the known psychoactive constituent of Salvia divinorum, a member of the mint family that has been used for centuries by Mazatec shamans of Mexico for divination and spiritual healing. S. divinorum has over the last several years gained increased popularity as a recreational drug. This is a double-blind, placebo...
Sci Am
December 1, 2010
Roland R. Griffiths, Charles S. Grob
46 citations
Hallucinogens as medicine.
Journal of Psychopharmacology
May 30, 2008
Roland R. Griffiths, Wa Richards, Mw Johnson et al.
883 citations
Psilocybin has been used for centuries for religious purposes; however, little is known scientifically about its long-term effects. We previously reported the effects of a double-blind study evaluating the psychological effects of a high psilocybin dose. This report presents the 14-month follow-up and examines the relationship of the follow-up results to data obtained at screening and on drug...
Experimental and Clinical Psychopharmacology
November 1, 2006
Michelle R Lofwall, Roland R. Griffiths, Miriam Z Mintzer
57 citations
Ketamine is a noncompetitive N-methyl-D-aspartate (NMDA) antagonist. Given the purported role of the NMDA receptor in long-term potentiation, the primary purpose of the present study was to further understand the dose-related effects of ketamine on memory. The study was also designed to provide information about the relative effects of ketamine on memory versus nonmemory effects and to more...
Psychopharmacology
July 7, 2006
Roland R. Griffiths, William A. Richards, U. Mccann et al.
1,684 citations
RationaleAlthough psilocybin has been used for centuries for religious purposes, little is known scientifically about its acute and persisting effects.ObjectivesThis double-blind study evaluated the acute and longer-term psychological effects of a high dose of psilocybin relative to a comparison compound administered under comfortable, supportive conditions.Materials and methodsThe participants...
Behavioural Pharmacology
August 1, 1996
Christine A. Sannerud, B. Kaminski, Roland R. Griffiths
9 citations
The present study evaluated the intravenous self-administration of four substituted phenethylamines, using a substitution procedure in baboons. Baboons were trained to self-inject 0.32mg/kg/injection cocaine under a fixed-ration (FR) schedule, with a 3h timeout following each injection. Doses of (+/-)-N-ethyl-3, 4-methylenedioxyamphetamine HCI (MDE), (+/-)-N-hydroxy-3,...
Psychopharmacology
1987
R J Lamb, R R Griffiths
MDMA (d,1-3,4-Methylenedioxymethamphetamine HCl; "ecstasy") self-injection (0.1-3.2 mg/kg/injection) was examined in baboons under conditions in which baseline responding was maintained by intravenous injections of cocaine HCl (0.32 mg/kg/injection). Drug was available under a FR 160-response schedule of intravenous injection. Each drug injection was followed by a 3-h time out allowing a...
Pharmacology, biochemistry, and behavior
September 1986
R Nemeth-Coslett, J E Henningfield, M K O'Keeffe et al.
Multiple measures of tobacco cigarette smoking and subjective and physiological effect were collected during 90 minute test sessions in volunteer cigarette smokers who also had histories of recreational marijuana use. Before sessions, subjects smoked one marijuana cigarette (placebo or 1.29%, 2.84%, 4.00%) using a standardized puffing procedure. Each dose and placebo was given four times to...