Journal of Psychopharmacology
January 1, 2014
Peter S. Hendricks, Christopher Clark, Matthew W. Johnson et al.
88 citations
Hallucinogen use among individuals under community corrections supervision with a history of substance involvement was associated with a reduced likelihood of supervision failure, such as noncompliance with legal requirements including alcohol and other drug use. In a longitudinal study of 25,622 people, those who used hallucinogens had 40% lower odds of supervision failure after controlling for confounding factors. The findings suggest hallucinogens may promote abstinence and prosocial behavior in a population with high rates of recidivism.
Journal of Psychopharmacology
November 1, 2005
Kim P. C. Kuypers, Jan Ramaekers
88 citations
A single dose of MDMA (75 mg) transiently impairs immediate and delayed verbal recall during the intoxication phase (1.5–2 hours after dosing), but no residual memory impairment is present during the withdrawal phase (25.5–26 hours after dosing). In a double-blind, placebo-controlled crossover trial with 18 recreational MDMA users, methylphenidate (20 mg) showed no effect on memory or mood at any time point. During MDMA withdrawal, participants reported more fatigue and less vigor but no depressive symptoms. The findings indicate that MDMA directly causes short-term memory deficits, but these effects are not long-lasting.
Journal of Psychopharmacology
May 29, 2021
Pedro J. Teixeira, Matthew W. Johnson, Christopher Timmermann et al.
87 citations
Healthy behaviors like diet, exercise, and not smoking greatly reduce risks for cancer, diabetes, and cardiovascular disease, but lifestyle diseases remain a major burden. Psychedelic substances, particularly psilocybin, are being explored as tools to promote positive lifestyle change. Psilocybin has low toxicity, is non-addictive, and has shown favorable changes in patients with depression, anxiety, and substance misuse. The article describes proposed mechanisms of action and research linking psychedelics to health behavior change, suggesting that combining psychedelic experiences with methods like Cognitive Behaviour Therapy and Motivational Interviewing may help improve diet, exercise, nature exposure, and mindfulness.
Journal of Psychopharmacology
March 4, 2015
Matthew G. Kirkpatrick, Andrew W. Delton, Theresa E. Robertson et al.
86 citations
MDMA increases generosity, but the effect depends on the recipient's social closeness. In two studies, participants decided whether they or another person would receive money. Without MDMA, people were more generous toward close friends than acquaintances or strangers; generosity was linked to household income and the personality trait Agreeableness. After a high dose of MDMA (1.0 mg/kg), generosity increased only toward a friend. A lower dose (0.5 mg/kg) slightly increased generosity toward a stranger, especially among women. The findings suggest MDMA's prosocial effects are selective, similar to oxytocin, and depend on relationship proximity.
Journal of Psychopharmacology
September 5, 2018
James B. Leonard, Bruce D. Anderson, Wendy Klein‐schwartz
85 citations
Lysergic acid diethylamide (LSD) and psilocybin-containing mushrooms (PcMs) are serotonergic hallucinogens used recreationally. A retrospective analysis of 5,883 PcM and 3,554 LSD exposures reported to U.S. poison centers from 2000 to 2016 found that users are primarily male adolescents and young adults (13–29 years). The most common clinical effects were hallucinations (45.8% PcM, 37.4% LSD), agitation (24.1% PcM, 42.4% LSD), and tachycardia (18.0% PcM, 38.6% LSD). Serious effects such as hyperthermia, seizures, coma, increased serum creatinine, and cardiac arrest were infrequent. Most patients were treated and released from the emergency department; LSD use more often required medical admission. Moderate effect was the most frequent outcome.
Journal of Psychopharmacology
June 27, 2018
Christopher R. Nicholas, Kelsey M. Henriquez, Michele Gassman et al.
85 citations
Healthy participants given escalating doses of psilocybin (0.3, 0.45, and 0.6 mg/kg) showed a significant linear dose-related increase in Mystical Experience Questionnaire total score and the transcendence of time and space subscale, but not in the rate of complete mystical experiences. Dose 3 produced significantly higher transcendence of time and space scores than dose 1, while no dose-related differences emerged for total scores or mystical experience rate. Positive persisting effects 30 days after the last dose were significantly higher than negative ones, and a moderate increase in well-being or life satisfaction was associated with the maximum mystical experience score. Pharmacokinetic measures correlated with dose but not with mystical experience scores or rate, indicating that a complete mystical experience was not necessary for positive outcomes.
Journal of Psychopharmacology
March 1, 2006
Liesbeth Reneman, Maartje M. L. de Win, Wim van den Brink et al.
85 citations
Heavy ecstasy (MDMA) use may cause injury to the brain's serotonin system. Neuroimaging techniques like SPECT, PET, and proton magnetic resonance spectroscopy have been used to study this potential neurotoxicity in living humans. The few available studies suggest that heavy users risk reductions in serotonin transporter (SERT) densities in subcortical and possibly cortical brain regions, a marker of serotonin neurotoxicity. These reductions appear dose-dependent and transient, with females possibly more vulnerable than males. Proton magnetic resonance spectroscopy seems less sensitive for detecting ecstasy's neurotoxic effects. Whether lower exposure also leads to SERT loss remains unknown. Most studies are retrospective, providing indirect evidence, so longitudinal studies are needed for definitive conclusions.
Journal of Psychopharmacology
October 8, 2020
Yasmin Schmid, Peter Gasser, Peter Oehen et al.
82 citations
Lysergic acid diethylamide (LSD) and 3,4-methylenedioxymethamphetamine (MDMA) are being reinvestigated as treatments for psychiatric disorders. In Switzerland, a compassionate use program allowed 18 patients (12 women, 6 men, aged 29–77) with posttraumatic stress disorder and major depression to receive LSD (100–200 µg) or MDMA (100–175 mg) in group settings from 2014–2018. Drug-assisted sessions occurred about every 3.5 months after 3–10 psychotherapy sessions. LSD produced pronounced alterations of consciousness and mystical-type experiences, with effects largely comparable to those in patients or healthy subjects treated alone in research settings. The data may inform further controlled studies of substance-assisted psychotherapy.
Journal of Psychopharmacology
October 8, 2020
Dea Siggaard Stenbæk, M. Madsen, Brice Ozenne et al.
81 citations
People with higher levels of serotonin 2A receptor (5-HT2AR) binding in the neocortex before taking psilocybin experienced shorter peak psychedelic intensity and a longer time to return to normal consciousness. Higher pre-drug 5-HT2AR binding also predicted lower scores on a measure of mystical-type experiences. The findings reinforce that individual differences in brain 5-HT2AR levels shape the temporal and subjective features of the psilocybin experience.
Journal of Psychopharmacology
November 25, 2009
Celia J. A. Morgan, Leslie Muetzelfeldt, Mark Muetzelfeldt et al.
80 citations
A survey of 1501 UK residents with direct experience of 20 psychoactive substances asked them to rate each drug's physical, dependence-related, and social harms as well as benefits using the same scale previously used by experts. Users' harm rankings correlated very highly with expert rankings (r = 0.896). Alcohol, solvents, and tobacco were rated among the top ten most harmful drugs despite being unclassified under the Misuse of Drugs Act. No correlation existed between the legal classification of drugs and users' harm rankings. Ecstasy, cannabis, and LSD were rated highest by users for both acute and chronic benefits, suggesting users are relatively well informed and that the current legal classification does not inform users about harms.
Journal of Psychopharmacology
June 30, 2021
Drummond E-Wen Mcculloch, Martin Bruun Madsen, Dea Siggaard Stenbæk et al.
79 citations
A single dose of psilocybin in 10 healthy volunteers who had never used psychedelics produced a significant decrease in resting-state functional connectivity within the executive control network (ECN) one week later, an effect that was no longer present at three months. No other changes in brain connectivity were observed at either time point. Exploratory analyses suggested that the decreased ECN connectivity at one week predicted increased mindfulness at three months. The findings point to modulation of the ECN during the psychedelic 'afterglow' period as a possible neural pathway for lasting positive effects on well-being, though the neural basis of personality changes seen at three months remains unknown.
Journal of Psychopharmacology
December 14, 2022
Emma Morton, Kimberly Sakai, Amir Ashtari et al.
75 citations
A web-based survey of 541 people with bipolar disorder who had used psilocybin found that one-third reported new or worsening symptoms afterward, especially manic symptoms, insomnia, and anxiety. No difference in adverse event rates emerged between bipolar I and bipolar II. Emergency medical care was rare (3.3%). Despite adverse effects, respondents rated psilocybin use as more helpful than harmful. The findings suggest psilocybin may offer subjective mental health benefits for some people with bipolar disorder, but clinical trials should closely monitor symptoms because they may emerge or intensify.
Journal of Psychopharmacology
March 9, 2021
Otto Simonsson, James Sexton, Peter S. Hendricks
75 citations
People who have used a classic psychedelic at least once in their lifetime report better overall health and are less likely to be overweight or obese, based on data from over 171,000 U.S. adults. The study also found a trend toward lower odds of having a heart condition or cancer in the past year among those who had used a classic psychedelic. The findings suggest that classic psychedelics may be linked to better physical health, but the authors note that further research is needed to determine whether the relationship is causal and to explore possible mechanisms.
Journal of Psychopharmacology
February 28, 2020
Daniel Rosenbaum, Cory R. Weissman, Thomas Anderson et al.
75 citations
People who microdose psychedelics—taking small, non-hallucinogenic amounts of LSD or psilocybin—are less likely to report a history of substance use disorders or anxiety disorders than non-microdosers, but more likely to report recent recreational substance use. Among 909 participants recruited from Reddit, most microdosers used LSD (59.3%) or psilocybin (25.9%) on a one-day-on, two-days-off schedule. The findings suggest that microdosers differ from non-microdosers in psychiatric and substance-use profiles, and well-designed randomized controlled trials are needed to evaluate safety and potential benefits in clinical populations.
Journal of Psychopharmacology
April 30, 2014
T. Buchborn, H. Schröder, V. Höllt et al.
71 citations
Repeated low doses of lysergic acid diethylamide (LSD) reverse depression-like behavioral deficits in bulbectomised rats, an animal model of depression that responds only to antidepressants. Bulbectomised rats showed marked impairments in active avoidance learning, which were largely reversed by 11 days of LSD treatment (0.13 mg/kg/day). LSD also normalized a specific hippocampal decrease in 5-HT2 receptor signaling, but did not improve behavior in sham-operated rats and instead reduced their hippocampal 5-HT2 signaling. The findings suggest LSD may have antidepressant-like effects through re-balancing hippocampal 5-HT2 and 5-HT1A receptor signaling.
Journal of Psychopharmacology
December 17, 2021
Josephine Marschall, George Fejer, Pascal Lempe et al.
69 citations
In a double-blind, placebo-controlled, within-subject crossover study, psilocybin microdosing (a sub-hallucinogenic dose taken every third day) did not alter emotion processing, symptoms of anxiety or depression, or self-reported interoceptive awareness compared with placebo. Exploratory analyses showed that symptoms of depression and stress were significantly reduced in the first block compared with baseline, but participants broke blind in the second block, and there was no effect of expectations. The authors call for further research in a substance-naïve population with clinical-range anxiety and depressive symptoms to substantiate potential beneficial effects.
Journal of Psychopharmacology
April 29, 2015
Matthew J. Baggott, Matthew G. Kirkpatrick, Gillinder Bedi et al.
69 citations
MDMA increases the use of social, sexual, and emotional words during conversation. In a double-blind, within-subjects study, 35 healthy volunteers who had previously used MDMA received either 1.5 mg/kg oral MDMA or a placebo and then discussed a close personal relationship for five minutes. Both a standard dictionary method and a machine learning analysis showed that MDMA altered speech content: it boosted social and sexual words, and also increased words related to both positive and negative emotions. These changes in speech content may help explain how MDMA enhances sociability and emotional connection during social interactions.
Journal of Psychopharmacology
January 1, 2018
David E Nichols
68 citations
The pineal gland has been mythologized across cultures as the seat of the soul or third eye, with modern claims that it secretes the psychedelic compound N,N-dimethyltryptamine (DMT) during birth, dreaming, and near death to cause out-of-body experiences. Scientific evidence contradicts these ideas. The adult pineal gland weighs less than 0.2 g and primarily produces about 30 µg per day of melatonin, a hormone regulating circadian rhythm. Minute concentrations of DMT have been detected in the brain, but they are insufficient for psychoactive effects. Alternative explanations are offered for how stress and near-death states produce altered consciousness without DMT.
Journal of Psychopharmacology
September 1, 2004
Verónica Sánchez, Esther O’shea, Kathryn S. Saadat et al.
66 citations
Repeated doses of MDMA (ecstasy) given to rats in a single session cause a dose-dependent increase in body temperature and long-term damage to serotonin neurons in the brain, but not to dopamine neurons. A dosing schedule of three injections of 4 mg/kg led to about a 50% loss of serotonin in the hippocampus, cortex, and striatum, while three injections of 6 mg/kg led to about a 65% loss. When rats were housed in a hot environment (30 °C), the same dose produced a larger temperature increase (up to 2.6 °C) and a 65% loss of serotonin in the cortex and hippocampus, with no loss of dopamine in the striatum.
Journal of Psychopharmacology
April 7, 2022
Emma I Kopra, Jason Ferris, Adam Winstock et al.
65 citations
Among 9,233 people who used magic mushrooms in the past year, only 19 (0.2%) sought emergency medical treatment, corresponding to a per-event risk of 0.06%. Younger age was the only factor linked to a higher chance of needing emergency care. The most common symptoms were psychological—anxiety, panic, paranoia, and suspiciousness. Poor mindset, poor setting, and mixing substances were the most frequently cited reasons for the incidents. All but one person returned to normal within 24 hours. The findings confirm that psilocybin mushrooms are relatively safe, with serious adverse reactions being rare and short-lived.
Journal of Psychopharmacology
March 30, 2006
Kirstie Soar, John Turner, A. C. Parrott
65 citations
People who report problems from their ecstasy use show higher levels of psychiatric symptoms such as depression, anxiety, and somatization compared to those who use ecstasy without problems, polydrug users, and people who have never used illegal drugs. In contrast, non-problematic ecstasy users do not differ from controls on these measures. Problematic users also report greater lifetime consumption, average dosage, and binge use, and are more likely to have personal and family psychiatric histories. The findings suggest that ecstasy-related psychological problems are linked to dosage and pre-existing mental health vulnerabilities, not ecstasy use alone.
Journal of Psychopharmacology
April 19, 2016
Zach Walsh, Peter S. Hendricks, Stephanie D. Smith et al.
63 citations
Hallucinogen use among inmates at a US county jail was associated with a reduced likelihood of arrest for intimate partner violence (IPV). In a prospective study of 302 inmates, those who used hallucinogens were about 40% less likely to be arrested for IPV, both before and after accounting for other factors. The findings add to evidence that hallucinogens may help reduce problematic behaviors linked to externalizing psychopathology, such as substance misuse and criminality.
Journal of Psychopharmacology
March 6, 2023
Emma I Kopra, Jason Ferris, Adam Winstock et al.
62 citations
A large international survey of 3364 people who used LSD or psilocybin mushrooms for self-treatment of mental health conditions or life worries found positive changes across all 17 measured outcomes, with the strongest benefits for insight and mood. However, 22.5% of respondents reported negative effects. Higher intensity of the psychedelic experience, seeking advice beforehand, using psilocybin mushrooms, and treating post-traumatic stress disorder were linked to better outcomes. Younger age, high experience intensity, and using LSD were associated with more negative effects. The findings suggest self-treatment outcomes are generally favorable but carry more frequent negative effects than clinical settings.
Journal of Psychopharmacology
September 2, 2011
Paul Stokes, Alice Egerton, Ben Watson et al.
62 citations
Cannabis use during adolescence is considered a risk factor for psychosis, and animal studies indicate that THC, the psychoactive component, alters striatal dopamine transmission. This study compared striatal dopamine D2/D3 receptor availability in ten volunteers with a history of cannabis use and ten controls using PET scans. No significant differences in receptor availability were found between groups, nor any correlation with lifetime cannabis use frequency. However, limbic striatal receptor availability was ten percent lower in current nicotine smokers. These results suggest that, unlike other drugs of abuse, a history of cannabis use is not associated with changes in striatal dopamine D2/D3 receptor availability.
Journal of Psychopharmacology
June 8, 2023
Natalie Gukasyan, Roland R. Griffiths, David B. Yaden et al.
60 citations
Psilocybin-containing mushrooms produce weaker drug effects in people taking SSRI or SNRI antidepressants, with a 47% probability of weaker-than-expected effects for SSRIs and 55% for SNRIs, compared to 29% for bupropion, a non-serotonergic antidepressant. This dampening effect persists for up to three months after discontinuing the antidepressant, based on retrospective survey data from over 2,000 reports. Removing responses involving fluoxetine, which has a long half-life, did not change the result. The findings suggest that serotonergic antidepressants may reduce psilocybin's effects both during use and for a period after stopping.