Nathan D. Sepeda - The Consciousness Library

Safety, feasibility, and preliminary clinical outcomes of psilocybin-assisted therapy for veterans with severe, treatment-resistant PTSD: an open-label pilot clinical trial.

Communications medicine July 30, 2026 Stacey B Armstrong, Adam W Levin, Nathan D Sepeda et al.

Psilocybin-assisted therapy (PAT) shows promise for treating PTSD in adults but hasn't been studied in U.S. military Veterans, who face higher symptom severity and suicide risk. This open-label pilot trial evaluated the safety and feasibility of PAT in Veterans with severe, treatment-resistant PTSD. The clinical trial was pre-registered at ClinicalTrials.gov (NCT05554094). The eligibility...

DOI: 10.1038/s43856-026-01767-4 Full text

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings.

International Journal of Methods in Psychiatric Research June 1, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience and...

DOI: 10.1002/mpr.70073 Full text Mystical experience Psychedelic experience Psychometrics Setting

Integrating the Mystical Experience Questionnaire Into a Broader Psychometric Framework: English Validation of the Psychedelic Experience Scale and Comparison of Psilocybin and LSD Sessions Across Two Controlled Settings

Repository for Publications and Research Data (ETH Zurich) April 30, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Objectives: For English, the validated part of Psychedelic Experience Scale (PES48) is a four-factor structure called the Mystical Experience Questionnaire (MEQ30). The other validated part of the PES48 consists of four more factors: two more mystical factors (paradoxicality and connectedness, which together with the MEQ30 form the MEQ40), and two more non-mystical factors (visual experience...

DOI: 10.3929/ethz-c-000799490 Psilocybin Mysticism Scale ratio German +8

Acute Cardiovascular Effects of Psilocybin: A Pooled Analysis of 14 Studies with Safety Recommendations

medRxiv Preprint Server April 28, 2026 Sandeep M. Nayak, Nathan D. Sepeda, Matthew Nielsen Dick et al. preprint

Background Psilocybin has increasingly been studied as a therapeutic for psychiatric and neurologic conditions, yet comprehensive cardiovascular safety data are limited. Current trials often exclude individuals with blood pressure ≥140/90 mmHg, criteria established conservatively without robust empirical support.

DOI: 10.64898/2026.04.28.26351625 Full text

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness—a psychometric analysis using the PES100 in controlled psychedelic studies

Religion Brain & Behavior March 31, 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Mystical dynamics—the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light—has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...

DOI: 10.1080/2153599x.2026.2635353 Mysticism Psychometrics Key lock Psychometric testing +4

Trip sitting or just sitting? Session facilitators substantially influence psychedelic experiences in clinical trials but not in healthy ones

Psychiatry Research February 13, 2026 Sean P. Goldy, Nathan D. Sepeda, Samantha Hilbert et al. 1 citation

Psychedelics' characteristic acute subjective effects predict therapeutic benefits, such as decreases in depression and anxiety. Thus, optimizing treatment involves better understanding which factors shape subjective effects. Session facilitators, who support participants before, during, and after psychedelic administration sessions, form an important part of the setting of these experiences....

DOI: 10.1016/j.psychres.2026.117010 Psilocybin Clinical trial Multilevel model Sitting +10

Mystical dynamics: renewal, luminous light, and ego disintegration as key features associated with mystical oneness-a psychometric analysis using the PES100 in controlled psychedelic studies

Repository for Publications and Research Data (ETH Zurich) 2026 Kurt Stocker, Matthias Hartmann, Frederick S. Barrett et al.

Mystical dynamics-the notion that mystical oneness may unfold involving ego disintegration, renewal, and luminous light-has been discussed anecdotally by psychedelic researchers and therapists but has not yet been empirically examined in controlled settings. This study investigated the occurrence and dose-dependency of mystical dynamics in healthy participants after administration of...

DOI: 10.3929/ethz-c-000798382 Mysticism Experiential learning Religious experience Dynamics music +2

Five-year outcomes of psilocybin-assisted therapy for Major Depressive Disorder

Journal of Psychedelic Studies September 4, 2025 Alan K. Davis, Meghan DellaCrosse, Nathan D. Sepeda et al. 4 citations

Abstract Background Major Depressive Disorder (MDD) is a leading cause of disability and economic loss, with high recurrence and treatment resistance. Psilocybin-assisted therapy (PAT) shows promise in reducing depressive symptoms, but long-term effects are unknown. We aimed to determine the long-term safety and efficacy of PAT for MDD over a five-year follow-up period. Methods Individuals who...

DOI: 10.1556/2054.2025.00461 Psilocybin Major depressive disorder Psychotherapist Clinical psychology

Effects of Psilocybin on Religious and Spiritual Attitudes and Behaviors in Clergy from Various Major World Religions

Psychedelic Medicine May 16, 2025 Roland R. Griffiths, William A. Richards, Robert L. Jesse et al. 14 citations

Background: Although historical writings, anthropological accounts, and experimental studies document associations between psilocybin use and religion, no prospective experimental study has investigated how the effects of psilocybin are experienced and interpreted by religious clergy. This exploratory study evaluated the overall safety and the acute and enduring effects of psilocybin in clergy....

DOI: 10.1089/psymed.2023.0044 Psilocybin Hallucinogen Psychotherapist

Shame, Guilt and Psychedelic Experience: Results from a Prospective, Longitudinal Survey of Real-World Psilocybin Use

Journal of Psychoactive Drugs February 7, 2025 Amy Lehrner, Heather Jackson, David S. Mathai et al. 11 citations

The classic psychedelic psilocybin has attracted special interest across clinical and non-clinical settings as a potential tool for mental health. Despite increasing attention to challenging psychedelic experiences, few studies have explored the relevance of shame-related processes with psychedelic use. This prospective, longitudinal study involved sequential, automated, web-based surveys that...

DOI: 10.1080/02791072.2025.2461997 Psilocybin Shame Hallucinogen Clinical psychology

Examining differences in the effects and contexts of naturalistic psilocybin use for White participants vs. Participants of Color: A longitudinal online survey study.

Journal of Affective Disorders February 1, 2025 Grant Jones, Matthew X. Lowe, Sandeep M. Nayak et al. 12 citations

Psilocybin (a psychoactive compound found in "magic mushrooms" or "shrooms") has been gaining increased attention in research and popular culture as a number of clinical and observational studies have demonstrated that it may have potential for improving mental wellbeing. Relatedly, there has been a substantial uptick in naturalistic (e.g., real-world, non-clinical) psilocybin use in the United...

DOI: 10.1016/j.jad.2024.10.058 Full text Psilocybin Psychedelic medicine Hallucinogenic treatment Racial inequities +7

The Epidemiology of Psychedelic Use Among United States Military Veterans

Journal of Psychoactive Drugs September 12, 2024 Katinka Hooyer, Rachel Yehuda, Alan K. Davis et al. 4 citations

We sought to identify patterns of psychedelic use among United States military veterans, compare demographic variables and perspectives of those who did and did not report use, and characterize benefits and adverse outcomes associated with use. Respondents (N = 426) were recruited to complete an online cross-sectional survey. Approximately one-half (51%) reported using psychedelics. Most did so...

DOI: 10.1080/02791072.2024.2401977 Epidemiology Military personnel Gerontology

The therapeutic alliance between study participants and intervention facilitators is associated with acute effects and clinical outcomes in a psilocybin-assisted therapy trial for major depressive disorder

PLoS One March 14, 2024 Adam W. Levin, Rafaelle Lancelotta, Nathan D. Sepeda et al. 65 citations

We examined if the therapeutic alliance between study participants and intervention facilitators in a psilocybin-assisted therapy (PAT) trial changed over time and whether there were relationships between alliance, acute psilocybin experiences, and depression outcomes. In a randomized, waiting list-controlled clinical trial for major depressive disorder in adults ( N = 24), participants were...

DOI: 10.1371/journal.pone.0300501 Psychedelic therapy Psilocybin research Therapeutic relationships Mental health +1

Prospective associations of psychedelic treatment for co-occurring alcohol misuse and posttraumatic stress symptoms among United States Special Operations Forces Veterans.

Military psychology : the official journal of the Division of Military Psychology, American Psychological Association 2024 Stacey B. Armstrong, Yitong Xin, Nathan D. Sepeda et al. 19 citations

This study evaluated prospective associations of ibogaine and 5-MeO-DMT treatment for risky alcohol use and post-traumatic stress disorder (PTSD) symptoms among United States (US) Special Operations Forces Veterans (SOFV). Data were collected during standard clinical operations at pre-treatment and 1-month (1 m), 3-months (3 m), and 6-months (6 m) post-treatment in an ibogaine and 5-MeO-DMT...

DOI: 10.1080/08995605.2022.2156200 Full text Addiction treatment Psychedelic Special operations veterans Alcohol misuse +6

Naturalistic psilocybin use is associated with persisting improvements in mental health and wellbeing: results from a prospective, longitudinal survey

Frontiers in Psychiatry September 19, 2023 Hillary Jackson, Sara So, Abigail Yaffe et al. 87 citations

Introduction The classic psychedelic psilocybin, found in some mushroom species, has received renewed interest in clinical research, showing potential mental health benefits in preliminary trials. Naturalistic use of psilocybin outside of research settings has increased in recent years, though data on the public health impact of such use remain limited. Methods This prospective, longitudinal...

DOI: 10.3389/fpsyt.2023.1199642 Psilocybin Anxiety Hallucinogen Clinical psychology +1

Open-label study of consecutive ibogaine and 5-MeO-DMT assisted-therapy for trauma-exposed male Special Operations Forces Veterans: prospective data from a clinical program in Mexico.

The American Journal of Drug and Alcohol Abuse September 3, 2023 Alan Kooi Davis, Yitong Xin, Nathan D. Sepeda et al. 29 citations

Background: Research in psychedelic medicine has focused primarily on civilian populations. Further study is needed to understand whether these treatments are effective for Veteran populations.Objectives: Here, we examine the effectiveness of psychedelic-assisted therapy among trauma-exposed Special Operations Forces Veterans (SOFV) seeking treatment for cognitive and mental health problems in...

DOI: 10.1080/00952990.2023.2220874 Full text 5-MEO-DMT Ibogaine Psychedelic Special operations veterans +6

Double-Blind Comparison of the Two Hallucinogens Dextromethorphan and Psilocybin: Experience-Dependent and Enduring Psychological Effects in Healthy Volunteers

Psychedelic Medicine August 30, 2023 Samantha Hilbert, David S. Mathai, Nathan D. Sepeda et al. 10 citations

This analysis suggests the utility of exploring clinical applications of dissociatives that occur within the supportive contexts that are characteristic of psychedelic research and that prioritize the optimization of psychologically valuable drug experiences. This study was registered with ClinicalTrials.gov (NCT02033707).

DOI: 10.1089/psymed.2023.0035 Full text Psilocybin Dextromethorphan Hallucinogen Psychotherapist +1

Translation and Initial Psychometric Evaluation of Spanish Versions of Three Psychedelic Acute Effects Measures: Mystical, Challenging, and Insight Experiences

Journal of Psychoactive Drugs July 14, 2023 Christopher Timmermann, Aki Nikolaidis, Alan K. Davis et al. 4 citations

This study translated and tested the psychometric properties of acute psychedelic effects measures among Spanish-speaking people. The Psychological Insight Questionnaire (PIQ), Challenging Experiences Questionnaire (CEQ), and Mystical Experiences Questionnaire (MEQ) were translated before being incorporated into a web-based survey. We recruited native Spanish-speakers (N = 442; Mage = 30.8, SD...

DOI: 10.1080/02791072.2023.2232379 Psilocybin Confirmatory factor analysis Clinical psychology Prosocial behavior +4

Efficacy and safety of psilocybin-assisted treatment for major depressive disorder: Prospective 12-month follow-up

Journal of Psychopharmacology February 1, 2022 Natalie Gukasyan, Alan K. Davis, Frederick S. Barrett et al. 419 citations

Background: Preliminary data suggest that psilocybin-assisted treatment produces substantial and rapid antidepressant effects in patients with major depressive disorder (MDD), but little is known about long-term outcomes. Aims: This study sought to examine the efficacy and safety of psilocybin through 12 months in participants with moderate to severe MDD who received psilocybin. Methods: This...

DOI: 10.1177/02698811211073759 Psilocybin Major depressive disorder Anxiety Hamd +8

Psilocybin therapy increases cognitive and neural flexibility in patients with major depressive disorder.

Translational Psychiatry November 8, 2021 Manoj K. Doss, Michal Považan, Monica D Rosenberg et al. 343 citations

Psilocybin has shown promise for the treatment of mood disorders, which are often accompanied by cognitive dysfunction including cognitive rigidity. Recent studies have proposed neuropsychoplastogenic effects as mechanisms underlying the enduring therapeutic effects of psilocybin. In an open-label study of 24 patients with major depressive disorder, we tested the enduring effects of psilocybin...

DOI: 10.1038/s41398-021-01706-y Full text Psychedelic-assisted therapy Neuroplasticity Psilocybin therapy Psychedelic treatment +20

Increases in Psychological Flexibility Mediate Relationship Between Acute Psychedelic Effects and Decreases in Racial Trauma Symptoms Among People of Color

Chronic Stress 2021 Alan K. Davis, Yitong Xin, Nathan D. Sepeda et al. 66 citations

Background Previous research showed acute psychedelic effects were associated with decreases in racial trauma (RT) symptoms among black, indigenous, and people of color (BIPOC). Among samples comprised primarily of white participants, positive outcomes of psychedelic experiences have been mediated by increases in psychological flexibility. Therefore, we examined whether changes in psychological...

DOI: 10.1177/24705470211035607 Flexibility engineering Clinical psychology Association psychology Path analysis statistics +1

People of color in North America report improvements in racial trauma and mental health symptoms following psychedelic experiences

Drugs Education Prevention and Policy December 10, 2020 Monnica T. Williams, Alan K. Davis, Yitong Xin et al. 100 citations

This study examined how psychedelics reduced symptoms of racial trauma among black, indigenous, and people of color (BIPOC) subsequent to an experience of racism. A cross-sectional internet-based survey included questions about experiences with racism, mental health symptoms, and acute and enduring psychedelic effects. Changes in mental health were assessed by retrospective report of symptoms...

DOI: 10.1080/09687637.2020.1854688 Psilocybin Anxiety Mental health Clinical psychology +4

Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder

JAMA Psychiatry November 4, 2020 Mary P Cosimano, Alan K. Davis, Frederick S. Barrett et al. 1,269 citations

Importance: Major depressive disorder (MDD) is a substantial public health burden, but current treatments have limited effectiveness and adherence. Recent evidence suggests that 1 or 2 administrations of psilocybin with psychological support produces antidepressant effects in patients with cancer and in those with treatment-resistant depression. Objective: To investigate the effect of...

DOI: 10.1001/jamapsychiatry.2020.3285 Full text Psilocybin Major depressive disorder Randomized controlled trial Context archaeology +4

Psychedelic Treatment for Trauma-Related Psychological and Cognitive Impairment Among US Special Operations Forces Veterans

Chronic Stress August 12, 2020 Alan K. Davis, Lynnette A. Averill, Nathan D. Sepeda et al. 83 citations

Background U.S. Special Operations Forces Veterans are at increased risk for a variety of mental health problems and cognitive impairment associated with military service. Current treatments are lacking in effectiveness and adherence. Therefore, this study examined psychedelic treatment with ibogaine and 5-methoxy-N,N-dimethyltryptamine for trauma-related psychological and cognitive impairment...

DOI: 10.1177/2470547020939564 Full text Psychedelic therapy Veteran mental health Trauma recovery Cognitive improvement

Emotions and brain function are altered up to one month after a single high dose of psilocybin.

Scientific Reports February 10, 2020 Frederick S. Barrett, Manoj K. Doss, Nathan D. Sepeda et al. 375 citations

Psilocybin is a classic psychedelic compound that may have efficacy for the treatment of mood and substance use disorders. Acute psilocybin effects include reduced negative mood, increased positive mood, and reduced amygdala response to negative affective stimuli. However, no study has investigated the long-term, enduring impact of psilocybin on negative affect and associated brain function....

DOI: 10.1038/s41598-020-59282-y Full text Psilocybin Magic mushrooms Anxiety Neuroplasticity +14

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