Journal of Psychopharmacology
September 11, 2014
Mary P Cosimano, Matthew W. Johnson, Albert Garcia‐romeu et al.
910 citations
In an open-label pilot study, 15 nicotine-dependent smokers received moderate (20 mg/70 kg) and high (30 mg/70 kg) doses of psilocybin as part of a structured 15-week smoking cessation program. At 6-month follow-up, 12 of 15 participants (80%) showed seven-day point prevalence abstinence, a rate substantially exceeding the typical 35% or less reported for other behavioral or pharmacological therapies. The authors note the open-label design prevents definitive conclusions about efficacy, but the findings suggest psilocybin may be a potentially useful adjunct to smoking cessation treatment.
The American Journal of Drug and Alcohol Abuse
July 21, 2016
Matthew W. Johnson, Albert Garcia‐romeu, Roland R. Griffiths
702 citations
In a structured treatment program, psilocybin shows considerable promise for promoting long-term smoking abstinence. This work adds to recent and historical evidence of high success rates when using classic psychedelics to treat addiction. Further research into psilocybin-facilitated treatment of substance use disorders is warranted.
Current Drug Abuse Reviews
January 9, 2015
Albert Garcia‐romeu, Roland R. Griffiths, Matthew W. Johnson
480 citations
In an open-label pilot study, 15 smokers received 2 or 3 doses of psilocybin alongside cognitive behavioral therapy for smoking cessation. Twelve of 15 participants (80%) had biologically verified smoking abstinence at 6-month follow-up. Those who quit scored significantly higher on a measure of psilocybin-occasioned mystical experience than those who relapsed, while general drug intensity did not differ between groups. Nine of 15 participants (60%) met criteria for a complete mystical experience. Smoking cessation outcomes correlated with measures of mystical experience on session days and with retrospective ratings of personal meaning and spiritual significance. The results suggest mystical experience may mediate psychedelic-facilitated addiction treatment.
Journal of Psychopharmacology
June 25, 2018
Tehseen Noorani, Albert Garcia‐romeu, Thomas Cody Swift et al.
285 citations
In a follow-up study of a psilocybin-facilitated smoking cessation pilot, 12 of 15 original participants were interviewed about 30 months after their psilocybin sessions. Participants described gaining vivid insights into their self-identity and reasons for smoking, and reported that experiences of interconnectedness, awe, and curiosity persisted long after the drug's acute effects. The content of the psilocybin experience overshadowed short-term withdrawal symptoms. Participants also emphasized the importance of preparatory counseling, strong rapport with the study team, and a sense of momentum from being engaged in the treatment. Beyond quitting smoking, many reported lasting positive changes such as increased aesthetic appreciation, altruism, and pro-social behavior.
Frontiers in Psychiatry
January 22, 2020
Earth Erowid, Fire Erowid, Albert Garcia‐romeu et al.
155 citations
A cross-sectional, self-report survey found that people who use psychedelics reported reductions in problematic substance use, including alcohol, opioids, and stimulants. The authors note that because the study is cross-sectional and relies on self-reports, it cannot determine whether psychedelics caused these changes. However, the results suggest a potential for psychedelics to reduce problematic substance use and support further clinical research into psychedelic-assisted treatment for substance use disorders.
Journal of Psychopharmacology
January 18, 2017
Matthew W. Johnson, Albert Garcia‐romeu, Patrick S. Johnson et al.
129 citations
A survey of 358 people who quit or reduced smoking after using a psychedelic (like psilocybin or LSD) in a non-laboratory setting at least one year earlier found that 38% reported continuous smoking cessation, with 74% of those abstinent for over two years. Another 28% reported a lasting reduction in smoking, from a median of 300 cigarettes per month before to 1 per month after. The remaining 34% temporarily reduced smoking but relapsed, typically within 3–6 months. Those who relapsed rated their psychedelic experience as less personally meaningful and spiritually significant than the other groups. Across all groups, participants reported less severe withdrawal symptoms like depression and craving after psychedelic use compared with past quit attempts. Changes in life priorities and values were cited as the most important psychological factor.
Journal of Psychopharmacology
February 20, 2021
Albert Garcia‐romeu, Frederick S. Barrett, Theresa M. Carbonaro et al.
101 citations
Psilocybin, a naturally occurring psychedelic, shows promise for treating mood and substance use disorders when given in structured settings. Most trials have adjusted the dose by body weight, but fixed dosing is simpler and cheaper. Analyzing data from ten previous studies (total 288 participants) that used weight-adjusted doses of 20 or 30 mg per 70 kg, or a fixed dose approximating 25 mg, no significant associations emerged between body weight or sex and the subjective effects (mystical, challenging, or intensity). Across body weights from 49 to 113 kg, body weight did not affect psilocybin's subjective effects, suggesting fixed dosing is as effective and more practical than weight-adjusted dosing.
ACS Pharmacology & Translational Science
December 29, 2020
Justin C. Strickland, Albert Garcia‐romeu, Matthew W. Johnson
89 citations
The musical genre played during psilocybin sessions may influence mystical experiences and smoking cessation outcomes. In a small study of ten participants receiving psilocybin for tobacco smoking cessation, overtone-based music led to higher mystical experience scores than Western classical music. Six of ten participants chose overtone-based music for a third session. Biologically confirmed smoking abstinence was 66.7% for those choosing overtone-based playlists versus 50% for Western classical. These results question the assumed unique benefit of Western classical music typically used in psychedelic therapy and support further experimental examination of session components.
Frontiers in Psychiatry
September 19, 2023
Hillary Jackson, Sara So, Abigail Yaffe et al.
87 citations
A large prospective survey of adults planning to take psilocybin outside clinical settings found that, on average, participants reported lasting reductions in anxiety, depression, and alcohol misuse, along with improvements in cognitive flexibility, emotion regulation, spiritual wellbeing, and extraversion, and decreases in neuroticism and burnout after use. However, a minority reported persisting negative effects: 11% at 2–4 weeks and 7% at 2–3 months after use, including mood fluctuations and depressive symptoms. The study included 2,833 respondents at baseline, 1,182 at 2–4 weeks, and 657 at 2–3 months post-use. Participants were primarily college-educated White men in the United States, mean age 40, who used dried psilocybin mushrooms (mean dose 3.1 grams) for self-exploration.
Drugs Education Prevention and Policy
April 30, 2021
Johannes Thrul, Albert Garcia‐romeu
78 citations
Research into the therapeutic potential of highly restricted Schedule I hallucinogens, such as the classic psychedelic psilocybin and the entactogen MDMA, is expanding. These substances, long prohibited under federal law, are now being studied for possible benefits in mental health treatment, though their legal status limits investigation.
The International Journal of Neuropsychopharmacology
May 10, 2021
Natalie Gukasyan, David B. Yaden, Matthew W. Johnson et al.
56 citations
Psychedelic substances produce unusual changes in conscious experience, leading some to propose they offer unique insights into consciousness. However, psychedelics are unlikely to provide information relevant to the "hard problem of consciousness," which involves explaining how first-person experience emerges. Instead, they bear on multiple "easy problems of consciousness," involving relations between subjectivity, brain function, and behavior. This review discusses common meanings of "consciousness" regarding psychedelics and considers models of their effects on the brain linked to explanatory claims about consciousness. It calls for epistemic humility about psychedelic research's potential to explain the hard problem while noting ways psychedelics may advance study of specific aspects of consciousness.
Frontiers in Psychology
March 25, 2022
David S. Mathai, Victoria Mora, Albert Garcia‐romeu
51 citations
Ketamine, a dissociative drug used as an anesthetic since the 1970s, also shows promise for psychiatric applications, especially when combined with psychological interventions. A review of historical and modern approaches discusses the clinical relevance of ketamine's acute psychoactive effects and proposes a unique model for using esketamine with Acceptance and Commitment Therapy (ACT). The authors suggest considerations for advancing medication-assisted psychotherapy as a field.
Kennedy Institute of Ethics journal
December 1, 2022
Neşe Devenot, Aidan Seale‐feldman, Elyse Smith et al.
50 citations
Psychedelic medicine relies on set and setting, but the specific therapeutic frameworks used alongside the drugs are rarely studied. Analyzing a treatment manual and post-session reports from a pilot psilocybin-assisted smoking cessation study, this article shows how therapeutic frameworks interact with psilocybin to rapidly reshape participants' identity and sense of self. Multiple domains of identity shift were identified that appear to serve as mechanisms for quitting smoking, each present in the manualized treatment. As psychedelic medicine becomes mainstream, consensual, evidence-based approaches to identity shift that respect patient autonomy and encourage empowerment should become key in psychedelic bioethics.
Journal of Psychopharmacology
July 1, 2023
Justin N Bonnieux, Baeleigh VanderZwaag, Zahra Premji et al.
29 citations
A scoping review of 42 studies on psilocybin's effects on cognition and creativity in adults found that macrodoses tended to impair cognitive performance and creativity during the acute phase (minutes to hours after intake), while microdoses tended toward creative enhancement. The few macrodosing studies that included post-acute measures (1–85 days) reported primarily null but some positive effects. Psilocybin was mostly administered orally (83%) in bodyweight-adjusted doses (74%) to healthy participants (90%). Only 26% of studies explicitly reported safety outcomes, and among those, only one reported serious adverse reactions. The findings are limited by methodological concerns and inadequate assessment of long-term effects.
Neuropharmacology
May 13, 2022
Cynthia E. Ortiz, Haley Maria Dourron, Noah W Sweat et al.
26 citations
Psilocybin-facilitated psychotherapy may be effective across many mental health conditions, but vulnerable populations, who carry a disproportionate mental health burden, have been largely excluded from clinical research. This report highlights the need to include these groups in studies, considering their problematic historical context and differential experiences with psychedelics. It offers actionable recommendations for future research, such as improved recruitment strategies, careful communication of subjective effects, building therapeutic alliance, multicultural competence, and flexible study designs. The authors call for expanded and improved research in this rapidly advancing field.
Journal of Psychoactive Drugs
February 7, 2025
Amy Lehrner, Heather Jackson, David S. Mathai et al.
11 citations
Among 679 adults using psilocybin in naturalistic settings, 68.2% reported acute feelings of shame or guilt during the experience, which were difficult to predict. The ability to constructively work through these feelings predicted wellbeing 2-4 weeks later. On average, psilocybin produced a small but significant decrease in trait shame maintained 2-3 months after use (Cohen's dz = 0.37), though trait shame increased in 29.8% of participants. The activation of self-conscious emotions with psychedelics warrants further attention as a challenging experience subcategory relevant to psychological outcomes, potentially creating a unique learning condition for shame-related memory reconsolidation.
Psychedelic Medicine
August 30, 2023
Samantha Hilbert, David S. Mathai, Nathan D. Sepeda et al.
10 citations
Dissociatives like dextromethorphan may have clinical applications when used in supportive settings similar to those in psychedelic research, which prioritize optimizing psychologically valuable drug experiences. The analysis suggests that such contexts could enhance therapeutic outcomes.
Psychedelic Medicine
January 20, 2025
Marianna Graziosi, Gabrielle Agin-Liebes, Mary P Cosimano et al.
9 citations
Psilocybin and other serotonergic psychedelics are used in research settings with safety measures including controlled environments, staff presence, screening, and psychoeducation. An analysis of study materials from psilocybin trials over the past two decades found that psychoeducation documents varied but commonly emphasized biological and physical safety, psychological safety and well-being, aspects of setting, and the potential for expectancies. The materials prioritized biological and psychological safety across all sites. The authors also identified elements unrelated to safety that may contribute to participant expectancies and suggest these extrapharmacological factors be studied systematically to maximize safety while minimizing extraneous expectancies.
Drug and Alcohol Dependence
November 1, 2015
Albert Garcia‐romeu, Tehseen Noorani, Roland R. Griffiths et al.
6 citations
In a long-term follow-up of a pilot study, 11 out of 15 original participants were interviewed an average of 30 months after receiving psilocybin as part of a smoking cessation treatment. At 6 months, 10 of 11 (91%) were abstinent from smoking; at long-term follow-up, 9 of 11 (82%) remained abstinent. Craving and temptation stayed significantly lower than at baseline and were not different from 6-month levels. Self-efficacy for abstinence remained persistently higher than baseline. Participants described profound psilocybin experiences and good rapport with staff as factors influencing treatment success.
July 26, 2024
C. J. Healy, Aaron Frazier, Stephen Kirsch et al.
5 citations
preprint
Adults with childhood maltreatment histories who used psychedelic drugs with therapeutic intent at ceremonies or raves showed significant improvements in PTSD symptoms, complex PTSD symptoms, trait shame, social connectedness, and general connectedness from before the experience to two months afterward, with effect sizes ranging from 0.73 to 1.12. The degree of improvement was linked to specific acute subjective effects of the psychedelic experience, suggesting that the psychosocial context of these group settings may contribute to therapeutic benefits.
Cancer
December 18, 2023
Johannes Thrul, Zofia Kozak, Michael A. Carducci et al.
5 citations
Psilocybin, when administered in a group-based, assisted intervention, shows promise for treating depression in cancer patients. Two articles in Cancer report that this approach leads to persistent improvements in mood, building on earlier work that found psilocybin reduces existential distress in this population. The editorial discusses these findings, noting the positive effects on mood without specifying effect sizes or sample details.
Biological Psychiatry
April 9, 2018
Michael C. Mckenna, John R. Fedota, Albert Garcia‐romeu et al.
3 citations
No Summary
June 9, 2023
Sandeep M. Nayak, Sydney White, Samantha Hilbert et al.
1 citation
preprint
A longitudinal study of 657 people planning a psychedelic experience measured changes in beliefs about mind perception, metaphysical positions, and Atheist-Believer status before and after the experience. Replicating prior work, participants showed increased mind perception for living and non-living targets such as plants and animals. However, there was little to no change in metaphysical beliefs like dualism or in Atheist-Believer status. These results contrast with cross-sectional studies suggesting psychedelics alter non-naturalistic beliefs or religious identity, but they support the idea that psychedelics specifically affect how people perceive minds in various entities.
Scientific Reports
December 8, 2025
Amrit Baral, Yue Pan, Wayway M. Hlaing et al.
Among older U.S. men, those who reported lifetime use of classic psychedelics alone had more than two and a half times the odds of a prostate cancer diagnosis compared with non-users, after adjusting for demographic, behavioral, and clinical factors. In men aged 65 or older, the odds were more than three and a half times higher. The analysis used nationally representative survey data from 2015–2019, covering 19,460 men aged 50 and older. Cannabis-only use and co-use of cannabis and psychedelics did not show a significant association. The authors suggest further research is needed to understand possible reasons and biological mechanisms behind this link.
SLEEP
May 1, 2025
Denise C. Vidot, Amrit Baral, Bria-Necole Diggs et al.
Among 18-to-35-year-olds in the Herbal Heart Study, 39.5% reported lifetime psychedelic use and 32.8% reported psilocybin use. Overall, 54.5% were satisfied with sleep, 23.0% dissatisfied, and 22.5% neutral, with no differences in sleep satisfaction across the full sample. However, among Hispanic/Latino participants, 33.9% of psychedelic consumers reported sleep dissatisfaction versus 17.2% of non-consumers. Hispanic/Latino psychedelic consumers had 4.4 times higher odds of both sleep dissatisfaction and satisfaction compared to being neutral; psilocybin-alone consumers had 9.2 times higher odds of dissatisfaction. No associations appeared among non-Hispanic White, non-Hispanic Black, or other groups, suggesting a complex link specific to Hispanic/Latino individuals.