Journal of Psychopharmacology
November 30, 2016
Stephen Ross, Anthony Bossis, Jeffrey Guss et al.
1,699 citations
A single moderate dose of psilocybin (0.3 mg/kg), combined with psychotherapy, produced immediate and sustained improvements in anxiety and depression among 29 patients with cancer-related psychological distress. At the 6.5-month follow-up, approximately 60–80% of participants continued to show clinically significant reductions in depression or anxiety. Psilocybin also decreased demoralization and hopelessness, improved spiritual wellbeing, quality of life, and attitudes toward death. The therapeutic effects on anxiety and depression were mediated by the psilocybin-induced mystical experience.
Journal of Psychopharmacology
January 9, 2020
Gabrielle Agin-Liebes, Tara C. Malone, Matthew M. Yalch et al.
353 citations
A long-term follow-up of a randomized trial found that psilocybin-assisted psychotherapy produced lasting reductions in anxiety, depression, hopelessness, demoralization, and death anxiety in people with cancer-related psychiatric distress. At an average of 3.2 and 4.5 years after psilocybin administration, 60–80% of participants still showed clinically significant antidepressant or anxiolytic responses. Most participants (71–100%) attributed positive life changes to the therapy and rated it among the most personally meaningful and spiritually significant experiences of their lives. The study's conclusions are limited by the crossover design of the original trial, but the results suggest psilocybin-assisted therapy may promote long-term relief from cancer-related distress.
Journal of Humanistic Psychology
April 28, 2017
Alexander Belser, Gabrielle Agin-Liebes, Thomas Cody Swift et al.
305 citations
In psilocybin-assisted psychotherapy for cancer patients with anxiety, participants commonly reported feelings of interconnectedness, emotional range, meaningful visual phenomena, and revised life priorities. Most described exalted joy, bliss, love, and transient distress, while some experienced lasting identity changes, synesthesia, catharsis, improved relationships, and forgiveness. The findings suggest psilocybin-assisted psychotherapy may effectively treat psychological distress in cancer patients.
EClinicalMedicine
September 24, 2020
B. Anderson, Alicia Danforth, Prof Robert Daroff et al.
271 citations
The text is a funding and support acknowledgments section listing various foundations, institutes, and government agencies that provided financial or material support for the work. It does not present any research findings, arguments, or study details.
Journal of Humanistic Psychology
June 14, 2017
Thomas Cody Swift, Alexander Belser, Gabrielle Agin-Liebes et al.
187 citations
In psilocybin-assisted psychotherapy for cancer patients with anxiety, participants described reconciling with death, acknowledging cancer's place in life, and emotionally uncoupling from the disease. The immersive and sometimes distressing psilocybin session led to spiritual or religious interpretations, a felt reconnection to life, reclaiming presence, and greater confidence about cancer recurrence. Patients also reported anxiety and trauma related to cancer and a perceived lack of emotional support. The findings suggest psychological mechanisms—such as emotional uncoupling and reconciliation with death—that may underlie large reductions in anxiety and depression observed in recent trials.
ACS Pharmacology & Translational Science
March 18, 2021
Stephen Ross, Gabrielle Agin-Liebes, Sharon L. Lo et al.
133 citations
People with advanced cancer face elevated risks of desire for hastened death, suicidal ideation, and completed suicide. Loss of meaning, a component of demoralization, predicts these outcomes. In a randomized controlled trial, psilocybin-assisted psychotherapy produced rapid and sustained improvements in depression, demoralization, and hopelessness. Secondary analyses showed that among participants with elevated suicidal ideation at baseline, reductions in suicidal ideation appeared as early as 8 hours and persisted for 6.5 months. Large reductions in loss of meaning emerged 2 weeks after treatment and remained significant at 6.5 months and at 3.2 and 4.5 year follow-ups. The findings suggest psilocybin-assisted psychotherapy may be an effective antisuicidal intervention for cancer patients due to its positive impact on hopelessness and meaning-making.
Frontiers in Pharmacology
April 3, 2018
Tara C. Malone, Sarah E. Mennenga, Jeffrey Guss et al.
128 citations
Cancer patients who receive psilocybin-assisted psychotherapy often have personalized experiences that extend beyond their diagnosis, centering on self-compassion, love, acceptance of death, and past trauma. In a double-blind trial, 29 patients with cancer-related anxiety and depression received either psilocybin or niacin with psychotherapy. Psilocybin produced rapid and lasting reductions in anxiety and depression. Detailed accounts of four participants show that while the content of each psilocybin session was unique, common themes emerged. The findings highlight how the subjective effects of psilocybin can address individual spiritual and psychological needs.
ACS pharmacology & translational science
April 9, 2021
Gabrielle Agin-Liebes, Trevor F Haas, Rafael Lancelotta et al.
121 citations
Most people who used mescaline in natural settings reported lasting improvements in depression, anxiety, PTSD, and substance use disorders, with 68–86% of those with a history of these conditions noting subjective improvement after their most memorable experience. Those who improved reported stronger acute mystical-type, psychological insight, and ego dissolution effects (Cohen's d 0.7–1.5). For 35–50% of respondents, the mescaline experience ranked among the top five most spiritually significant or meaningful events of their lives. Psychological insight during the experience was linked to higher odds of improvement in depression, anxiety, and alcohol and drug use disorders. The authors call for controlled clinical trials to confirm these preliminary findings.
Journal of Psychopharmacology
March 1, 2022
Gabrielle Agin-Liebes, Richard J. Zeifman, Jason B. Luoma et al.
51 citations
People who participated in ayahuasca retreats in Central and South America reported reduced negative mood and increased positive mood and psychological flexibility three months later. Acute experiences of cognitive reappraisal during the ceremony were the strongest predictor of improvements in positive mood and flexibility. Increases in psychological flexibility statistically accounted for the link between acute psychological factors, including reappraisal, and later mood improvements. The findings suggest that acute reappraisal and subsequent gains in psychological flexibility are key mechanisms behind psychedelic-assisted therapy's benefits, supporting the integration of mindfulness-based and third-wave therapy approaches with such interventions.
Journal of Humanistic Psychology
June 12, 2021
Gabrielle Agin-Liebes, Eve Ekman, B. Anderson et al.
47 citations
In a qualitative study of nine gay cisgender men diagnosed with HIV before 1996 and experiencing significant trauma symptoms, psilocybin-assisted group therapy helped participants shift from habitual, evaluative thinking to mindful, experiential awareness. During psilocybin sessions, individuals processed and released previously avoided feelings such as grief and shame, and accessed positive emotions including joy, gratitude, love, care, and compassion. The treatment also supported meaning-making and posttraumatic growth across psychological, relational, and spiritual dimensions, as participants integrated past traumas into their life narratives. These findings suggest that combining group therapy with psilocybin may enhance trauma processing by reinforcing social cohesion, safety, trust, and belonging.
Psychology of Addictive Behaviors
June 5, 2023
Gabrielle Agin-Liebes, Elizabeth M Nielson, Michael Zingman et al.
42 citations
Psilocybin increases the flexibility of self-related thinking, reduces shame and self-criticism, improves emotional regulation, and lowers alcohol cravings. Psychosocial treatments that combine self-compassion training with psychedelic therapy may improve psychological outcomes for alcohol use disorder.
Frontiers in Epidemiology
March 23, 2022
Alan K. Davis, Brooke J. Arterberry, Yitong Xin et al.
20 citations
Asian females had the highest prevalence of past-year hallucinogen use (35.06%), two or more times that of White males and females and Native American males. More than half of White males and females, Multiracial males, and Hispanic males had ever used psilocybin or LSD, while less than a quarter of Black males and females reported lifetime psilocybin use. Native American males had the lowest lifetime MDMA use (17.62–33.30%) but the highest lifetime peyote use (40.37–53.24%). Pacific Islander males had the highest lifetime mescaline use (28.27%), and Pacific Islander males and females had the highest lifetime DMT use (15.68–38.58%).
Current topics in behavioral neurosciences
January 1, 2022
Gabrielle Agin-Liebes, Alan K. Davis
16 citations
Depression is the leading cause of global disability and a major contributor to the global burden of disease. Early experimental trials suggest that psilocybin, a serotonergic psychedelic, combined with therapeutic support shows promise for treating depression, with large effect sizes. Neuroimaging reveals dynamic effects of psilocybin on brain functional activity. This chapter reviews methods and findings from three small clinical trials examining psilocybin therapy for major depressive disorder and treatment-resistant depression, presenting insights from functional magnetic resonance imaging and qualitative analyses, along with study limitations and future directions.
European journal of psychotraumatology
December 1, 2025
Gabrielle Agin-Liebes, Richard J Zeifman, Jennifer M Mitchell
11 citations
MDMA-assisted therapy (MDMA-AT) for severe posttraumatic stress disorder (PTSD) improves self-compassion, which may explain its therapeutic benefits. In a double-blind trial with 82 adults, MDMA-AT significantly increased compassionate self-responding (self-kindness, common humanity, mindfulness) and decreased uncompassionate self-responding (self-judgment, isolation, over-identification) compared to placebo plus therapy, with large effect sizes on most subscales. Changes in self-compassion fully mediated the reduction in PTSD severity and depressive symptoms, but not in alcohol or substance use. Self-compassion appears to be a key psychological mechanism in MDMA-AT, suggesting that targeting it could refine treatments for PTSD with co-occurring depression.
Nature Mental Health
October 7, 2024
Petros Petridis, Jack Grinband, Gabrielle Agin-Liebes et al.
10 citations
No Summary
Psychopharmacology
August 1, 2024
Kimberly Sakai, Ellen R Bradley, Joseph A Zamaria et al.
10 citations
People who take SSRIs and use psilocybin mushrooms together often report a less intense psychedelic experience, though many report no change in intensity. About 8% of Reddit posts describing coadministration mention negative physical or psychological effects, including a small number of reports that may indicate serotonin toxicity and one possible psychotic or manic episode. The interactions appear complex and likely depend on multiple factors. Prospective studies are needed to determine whether psilocybin treatments are safe and effective for people using SSRIs.
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.
Journal of psychoactive drugs
January 1, 2023
Anja Loizaga-Velder, Cecile Giovannetti, Ricardo Campoy Gomez et al.
9 citations
An outpatient therapeutic program run by Yaqui health professionals and traditional healers for Yaqui tribe members in Sonora, Mexico, combines traditional Indigenous healing practices—including sweatlodge (temazcal), medicinal plants, and ritual use of naturally derived psychedelics such as ayahuasca, peyote, and Incilius alvarius secretions—with culturally adapted group and individual psychotherapy, sports, meals, construction work, and cultural activities. Three case studies from an ongoing observational study show therapeutic progress and improved psychometric outcomes, suggesting this intercultural approach holds promise for addressing substance use disorders and mental health issues in Indigenous communities.
Journal of Psychedelic Studies
January 24, 2025
Cecile Giovannetti, Anja Loizaga-Velder, Ricardo Campoy Gomez et al.
5 citations
An outpatient clinic serving a Yaqui Indigenous community in Mexico integrated ayahuasca ceremonies with psychotherapeutic support to treat substance use and mental health disorders. In 37 patients with depression, anxiety, complicated grief, or substance use disorder, symptom scores dropped substantially after two ceremonies: depression scores fell from 15.7 to 5.1, anxiety from 16.6 to 6.3, and complicated grief from 39.6 to 10.7. Among eight patients with suicide risk, seven no longer showed risk after one ceremony. The ceremonies were well-tolerated. The findings suggest that culturally-attuned, community-based ayahuasca-assisted therapy may rapidly reduce mental health symptoms and warrants further study.
Research Square
August 22, 2025
Richard J. Zeifman, George Danias, Gabrielle Agin-Liebes et al.
2 citations
Psychedelics can acutely induce mystical experiences and elevated positive mood, which may contribute to the potential benefits of psychedelic therapy. However, there remains limited understanding of the occurrence and importance of specific positive emotional experiences within psychedelic therapy. Therefore, we examined the effects of psychedelics on positive emotional experiences and their association with improvements in mental health. Methods: Study 1 was an observational study of naturalistic psychedelic use. Study 2 used data from a clinical trial that compared psilocybin with escitalopram in individuals with major depressive disorder.
June 10, 2025
Gabrielle Agin-Liebes, Petros Petridis, Richard J. Zeifman et al.
1 citation
preprint
In a trial where adults with alcohol use disorder received either psilocybin or an active placebo alongside psychotherapy, psilocybin-assisted therapy robustly increased compassionate self-responding and decreased uncompassionate self-responding, with the largest effects on reducing self-judgment, isolation, and over-identification. Across all participants, small but significant correlations linked improvements in self-compassion to reduced drinking. However, in the psilocybin group alone, no significant association emerged between self-compassion gains and drinking reductions, while the control group showed moderate associations. These between-group differences were not statistically significant. Self-compassion appears clinically relevant for alcohol use disorder treatment but may not mediate outcomes when psilocybin is part of therapy.
Journal of Psychoactive Drugs
January 27, 2022
Ciarán Martin Fitzpatrick, B. Anderson, Gabrielle Agin-Liebes et al.
1 citation
A case report described a person with obsessive-compulsive disorder whose symptoms lessened after consuming psilocybin-containing mushrooms. The report prompted a letter arguing that psychedelic research has moved beyond case studies and that journals should prioritize publishing clinical trials over case reports.
February 11, 2026
Sarah Shnayder, Gabrielle Agin-Liebes, Troy Hubert et al.
preprint
In people with treatment-resistant obsessive-compulsive disorder (OCD), greater mystical-type experiences during psilocybin sessions—especially feelings of unity, sacredness, and transcendence—were linked to lower OCD symptom severity at 1-week and 12-week follow-ups, even after accounting for baseline severity and treatment condition. The Mystical subscale of the Mystical Experience Questionnaire showed the strongest and most consistent associations. The Space–Time subscale was related to lower OCD severity only at 12 weeks. Positive mood, ineffability, and challenging experiences were not significantly tied to post-treatment OCD severity. These results suggest that the quality of subjective experience during psilocybin sessions may help optimize treatment outcomes.
January 15, 2026
Benjamin Kelmendi, Thomas G. Adams, Terence H. W. Ching et al.
preprint
A single dose of psilocybin (0.25 mg/kg) produced rapid and sustained reductions in obsessive-compulsive disorder (OCD) symptoms among adults with treatment-resistant OCD. In a randomized, double-blind trial, 28 adults received either psilocybin or niacin (250 mg). At 48 hours, OCD severity scores dropped by about 10 points more in the psilocybin group than in the niacin group, a large effect. At one week, 69% of psilocybin participants achieved a clinically meaningful response, compared with none in the niacin group. Benefits lasted through 12 weeks. One serious adverse event occurred. Open-label psilocybin given later also reduced symptoms. The findings suggest psilocybin may offer a new treatment approach for treatment-resistant OCD, but larger confirmatory trials are needed.