Scientific Reports
November 3, 2017
Will Lawn, Jaime E. C. Hallak, José Alexandre S. Crippa et al.
78 citations
Ayahuasca users reported greater well-being than both classic psychedelic users and non-psychedelic drug users, and less problematic drinking than classic psychedelic users, though both psychedelic groups reported more problematic drinking than non-psychedelic users. Ayahuasca's acute subjective effects typically lasted six hours, peaking one hour after consumption. These findings come from a large online survey of nearly 97,000 respondents, including 527 ayahuasca users. The authors call for longitudinal studies and randomized trials to further investigate ayahuasca's effects on well-being and alcohol use.
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 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
October 8, 2020
Rotem Petranker, Thomas Anderson, Larissa J. Maier et al.
57 citations
In a large online survey of 6,753 people who had microdosed psychedelics in the past year, most reported enhanced mood, creativity, focus, and sociability, and the most common challenge was 'None'. Contrary to expectations, having an approach-intention—microdosing to achieve a specific goal—predicted fewer rather than more benefits. Most participants did not test their substances. The perceived benefits greatly outweighed the challenges, but double-blind, placebo-controlled experiments are needed to confirm these self-reported effects.
The American Journal on Addictions
August 1, 2016
Joseph J Palamar, Monica J Barratt, Jason Ferris et al.
49 citations
Nearly half (46.4%) of a self-selected sample of US nightclub attendees reported lifetime use of at least one new psychoactive substance (NPS). Synthetic cannabinoids were the most common (24.8%), followed by tryptamines (23.0%), psychedelic phenethylamines (21.7%), euphoric stimulants (16.2%), and synthetic cathinones (10.5%). Females and older respondents (ages 22-60) had lower odds of any NPS use. Frequent nightclub attendance, especially weekly versus less than once a month, was linked to higher odds of NPS use overall. The authors suggest harm reduction initiatives are needed for this population, where environmental factors may amplify risks from lesser-known substances.
Translational Psychiatry
September 6, 2022
Tabea Schoeler, Jason Ferris, Adam Winstock
48 citations
About 1 in 200 people who use cannabis (0.47%) experience acute psychotic symptoms—hallucinations or paranoia—severe enough to require emergency medical treatment at some point in their lives, based on data from 233,475 users across multiple countries. Risk is higher among young individuals (2.66 times), those in Denmark (3.01 times), users of high-potency resin (2.11 times), those mixing cannabis with tobacco (2.15 times), and people with pre-existing mental health diagnoses: psychosis (14.01 times), bipolar disorder (4.30 times), anxiety (2.92 times), and depression (2.68 times). The findings suggest certain groups are especially vulnerable to cannabis-induced psychotic symptoms.
Journal of Psychopharmacology
June 7, 2022
Emma I Kopra, Jason Ferris, James Rucker et al.
42 citations
Among 10,293 people who used LSD in the past year, 1.0% sought emergency medical treatment, with a per-event risk of 0.2%. Younger age, mental health conditions, and more frequent use increased that risk. Most adverse reactions were psychological—anxiety, panic, confusion—often linked to poor setting or mindset. Symptoms usually resolved within 24 hours, though 11 people had issues lasting beyond 4 weeks. LSD appears relatively safe in recreational settings; adverse effects are typically short-lived and psychological. In clinical contexts, screening, preparation, and supervision should further reduce risks.
Drug and Alcohol Review
July 1, 2022
Monica J Barratt, Alexia Maddox, Naomi Smith et al.
19 citations
About 5.3% of respondents in a large international survey reported using binaural beats to experience altered states, with higher rates in the United States, Mexico, Brazil, Poland, Romania, and the United Kingdom. Younger age and non-male gender predicted use, as did recent use of cannabis, psychedelics, and novel drugs. Most users listened to relax or fall asleep (72.2%) or change their mood (34.7%), while 11.7% sought effects similar to those of other drugs—a motivation more common among classic psychedelic users (16.5% vs. 7.9%). Users primarily accessed binaural beats via video streaming sites on mobile phones.
Psychopharmacology
May 1, 2022
Sam Craft, Jason Ferris, Monica J Barratt et al.
19 citations
People who frequently use synthetic cannabinoid receptor agonists (SCRAs) experience a distinct withdrawal syndrome, with sleep problems, irritability, and low mood being the most common symptoms. Among 284 frequent users who had tried to quit, an average of 4.4 withdrawal symptoms occurred after just one day without use. Greater frequency and quantity of SCRA use were linked to more withdrawal symptoms. Compared to high-potency herbal cannabis, SCRAs were rated as having a faster onset, shorter duration of effects, faster tolerance development, and more severe withdrawal. The findings suggest that SCRAs carry a greater risk of problematic use and a more severe withdrawal syndrome than natural cannabis.
Human Psychopharmacology Clinical and Experimental
May 1, 2017
Leigh Coney, Larissa J. Maier, Jason Ferris et al.
18 citations
Most people who use LSD analogues (AL-LAD, 1P-LSD, ETH-LAD) have also tried LSD, and in the UK and US a higher proportion reported using analogues in the past year than LSD alone. Users described the effects as psychedelic, obtained the drugs online, and took them orally. The time to peak effect (2 hours) and duration (8 hours) were similar to LSD, but ratings for pleasurable high, strength, comedown, urge to use more drugs, value for money, and risk of harm were all significantly lower for the analogues compared with LSD. The authors suggest future studies should confirm these findings with chemical testing and dose measurement.
Journal of psychopharmacology (Oxford, England)
January 1, 2025
Karen P Barrios, Dean J Connolly, Jason Ferris et al.
17 citations
Ketamine use has increased globally, particularly among young men, yet emergency medical treatment for its toxicity is rare and often linked to other substance use. Analysis of over 130,000 Global Drug Survey responses found that 5.93% had used ketamine in their lifetime, with 57.70% using it in the past year. Past-year users were typically younger (average age 24.84 years), gay, students, and used other drugs. Among 4,477 past-year users, 120 adverse events occurred, with less than 0.10% requiring emergency medical treatment. The findings indicate frequent use but low harm, highlighting the need for tailored harm reduction and comprehensive screening for substance dependence.
April 12, 2020
Rotem Petranker, Thomas Anderson, Larissa J. Maier et al.
14 citations
preprint
A large survey of 6,753 people who microdosed LSD or psilocybin at least once in the past year found that the most commonly reported benefits were enhanced mood, creativity, focus, and sociability, partially replicating earlier findings. Most participants reported no challenges from microdosing, and the majority did not test their substances for purity. Contrary to expectations, microdosing with the intention of approaching a desired goal predicted fewer rather than more benefits. The authors conclude that the reported benefits outweigh the challenges, but emphasize that double-blind, placebo-controlled experiments are needed to confirm these self-reported effects.
Drug and Alcohol Review
November 5, 2024
Jordan J. Negrine, Cheneal Puljević, Jason Ferris et al.
8 citations
Australian psychologists generally hold positive attitudes toward psychedelic-assisted therapy (PAT) following the 2023 regulatory changes that permitted psilocybin and MDMA in clinical services. Most view PAT as promising for chronic mental health conditions like depression, but express concerns about limited evidence on efficacy, potential adverse experiences, and the complexity of individualized treatment protocols. Many psychologists lack detailed knowledge about the interventions. The findings emphasize the need for comprehensive education and training programs, including exposure to psychedelic experiences and credible higher education institutions, to ensure competent administration of PAT.
Journal of Psychedelic Studies
August 19, 2023
Liam Engel, Monica J Barratt, Jason Ferris et al.
7 citations
Among 284 people who used mescaline in the past year, 20% had consumed wild-harvested Peyote. Those who preferred Peyote most often cited indigenous cultural traditions (57.8%), availability (40.0%), and environmental sustainability (33.3%) as motivations. San Pedro was the most common mescaline source (56.1%), and those who preferred it cited availability (54.7%), potency (45.3%), and indigenous cultural traditions (44.2%). Price and potency were significantly more important for San Pedro preferrers. Fewer than 7% of San Pedro users had consumed it from native habitats. The findings suggest that promoting cultivated San Pedro could reduce unsustainable wild Peyote consumption.
J Psychopharmacol
July 29, 2024
Claire Walker, Timothy Piatkowski, Jason Ferris et al.
4 citations
People who use psychedelics outside of medical guidance to treat their own mental health conditions often report improvements in mental health and self-awareness, which may reduce their need for prescribed medications. An analysis of 2,552 respondents from the Global Drug Survey 2020 identified three key factors from self-reported psychedelic effects: Improved Mental Health, Improved Self-Awareness, and Neuro-Sensory Changes. Most respondents had a history of depression (80%) or anxiety (65.6%). The perceived benefits from psychedelic self-treatment were linked to a lower likelihood of currently using prescribed medication, especially for depression or combined depression and anxiety. These findings suggest that psychedelics could have therapeutic potential for mental health.
Journal of psychopharmacology (Oxford, England)
August 1, 2024
Luke Baxter, Cheneal Puljević, Tim Piatkowski et al.
3 citations
Among 3,340 first-time LSD users surveyed internationally, nearly all (97.7%) found the experience exciting, and adverse side effects were rare; only 17 individuals required emergency medical treatment. Although 64.1% reported feelings of fear, these were typically very mild and did not deter most from wanting to use LSD again. The authors conclude that while the recreational LSD experience is generally pleasurable and unwanted effects are uncommon, harm-reduction education remains important to prevent possible risks amid rising illicit use.
Scientific Reports
February 28, 2018
Will Lawn, Jaime E. C. Hallak, J.a.s. Crippa et al.
3 citations
A correction to this article has been published and is linked from the HTML and PDF versions. The error has not been fixed in the paper.
The International journal on drug policy
January 1, 2024
Leigh Coney, Amy Peacock, Aili Malm et al.
2 citations
People who buy MDMA, cocaine, or LSD from cryptomarkets are more likely to have no drug-using social network and to report adverse events requiring medical treatment. Among over 23,000 respondents from more than 70 countries in the 2018 Global Drug Survey, adverse events were low overall (5.2%). After controlling for age, gender, and frequency of use, recent cryptomarket use was associated with a higher likelihood of having no drug-using network for each drug. It was also linked to increased odds of adverse events for cocaine (adjusted odds ratio 1.70) and LSD (adjusted odds ratio 1.58). For those with a network larger than one person, cryptomarket use was still associated with more adverse LSD events. The findings suggest cryptomarket use may increase drug-related harm, but the complex mechanisms require further study.
Journal of psychopharmacology (Oxford, England)
June 1, 2026
Gabrielle Smith, Timothy Piatkowski, Jason Ferris et al.
1 citation
People who self-treat psychiatric conditions with unregulated drugs often use ketamine alongside other psychedelics. Among 5831 respondents to the 2020 Global Drug Survey who self-treated diagnosed psychiatric conditions, over 60% had prior psychiatric diagnoses, most commonly depression and anxiety. Those using both ketamine and other psychedelics attended festivals and clubs more often and used ketamine more frequently. Those using only non-ketamine psychedelics showed a significant reduction in ketamine use. Nearly half sought online advice before starting ketamine self-treatment, suggesting online platforms are key for harm reduction resources.
Journal of sex research
January 16, 2026
Mason Levey, Benjamin Bonenti, Timothy Piatkowski et al.
People who reported having used psychedelics to cope with or overcome sexual trauma were significantly less likely to say the drugs improved their sexual communication compared to those who had not used psychedelics for that purpose. No significant difference was found in emotional connection between the two groups. Among those who had used psychedelics for trauma, women were significantly more likely than men to report improvements in both communication and emotional connection. The findings suggest that gender plays a role in how psychedelics affect intimacy, and more research is needed to guide harm reduction and trauma-informed care.