Healthy VolunteersNeuroimaging & Brain MeasuresDepressive DisordersPsilocybin

The phenomenology of psilocybin's experience mediates subsequent persistent psychological effects independently of sex, previous experience, or setting

Repeated administration of psilocybin in healthy adults produced persistent positive psychological effects, and the acute phenomenology—particularly Oceanic Boundlessness, Visionary Restructuralization and peak experiences ending in a positive mood—predicted these long-term benefits independently of sex, prior psychedelic experience, setting or repeat dosing. Challenging or mixed acute experiences in the controlled laboratory did not produce lasting negative outcomes, supporting psilocybin’s psychological safety for repeated use in clinical trials.

Authors

  • Tomáš Páleníček
  • František Tylš
  • Martin Brunovský

Published

Pharmacological Reports
individual Study

Abstract

Background

Recent studies intensively explore psilocybin’s antidepressant potential, but variables like previous experience, repeated use, setting, and sex remain underexplored. This study examines acute and long-term effects of psilocybin in healthy individuals.

Methods

A double-blind, placebo-controlled, cross-over study included 40 healthy participants (20 females, mean age 38). Each received two doses of psilocybin (0.26 mg/kg) at least 56 days apart (mean 488) in two neuroimaging study arms. Nearly half had previous psychedelic experience. Acute effects were measured using the Altered States of Consciousness Scales (ASCs) and a Visual Analogue Scale (VAS) for emotional valence. The Persisting Effects Questionnaire (PEQ) assessed long-term effects.

Results

All results were independent of observed variables such as previous psychedelic experience, repeated use, setting, sex and occupation. Acute effects were moderate on the ASCs, with VAS ratings showing mostly pleasant or fluctuating experiences and only one unpleasant session. All experiences resolved in a positive or neutral state by the session’s end. Psilocybin produced lasting positive effects across all PEQ domains, with negligible negative effects. Oceanic Boundlessness (OBN) and Visionary Restructuralization (VRS) correlated with positive outcomes, while Dread of Ego Dissolution (DED), typically associated with fear, did not predict negative effects. The nature of the acute experience (pleasant or mixed) was not linked to the direction or intensity of long-term outcomes. Peak experiences ending in a positive mood were strongly associated with favourable long-term effects.

Conclusion

Repeated psilocybin administration in healthy individuals induces positive, lasting effects, with challenging experiences in controlled settings not causing adverse outcomes. These findings support psilocybin’s psychological safety and its repeated use in clinical trials.

Available with Blossom Pro

Research Summary of 'The phenomenology of psilocybin's experience mediates subsequent persistent psychological effects independently of sex, previous experience, or setting'

Introduction

Psilocybin, a serotonergic tryptamine psychedelic, has accumulating evidence for rapid antidepressant and enduring positive effects on well-being and attitudes in healthy and clinical populations. A central question addressed in recent research is the extent to which the subjective psychedelic experience — particularly peak or mystical-type states and features such as ego dissolution — mediates longer-term psychological benefits. At the same time, uncertainty remains about whether factors such as previous psychedelic experience, repeated dosing, sex, and the specific testing environment (for example EEG versus fMRI settings) influence either the acute phenomenology or the persistent outcomes. This study set out to test whether the acute phenomenological features of a psilocybin session predict persistent changes in mood, well-being and spirituality in healthy volunteers, while accounting for previous psychedelic experience, repeated administration, sex, and experimental setting. Tylš and colleagues used validated instruments for acute states (the Altered States of Consciousness scales, ASCs, and a time-course Visual Analogue Scale, VAS) and for persisting outcomes (the Persisting Effects Questionnaire, PEQ) to examine these relationships in a controlled, double-blind, placebo-controlled, crossover design embedded within a larger neuroimaging project. The investigators hypothesised that characteristics of the acute experience would drive long-term positive outcomes and treated the other variables as exploratory moderators.

Expert Research Summaries

Go Pro to access AI-powered section-by-section summaries, editorial takes, and the full research toolkit.

Full Text PDF

Full Paper PDF

Pro members can view the original manuscript directly in the browser.

Study Details

References (37)

Papers cited by this study that are also in Blossom

Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression

Goodwin, G. M., Aaronson, S. T., Alvarez, O. et al. · New England Journal of Medicine (2022)

656 cited
Trial of Psilocybin versus Escitalopram for Depression

Carhart-Harris, R. L., Giribaldi, B., Watts, R. et al. · New England Journal of Medicine (2021)

927 cited
Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms

Carhart-Harris, R. L., Roseman, L., Bolstridge, M. et al. · Scientific Reports (2017)

Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects

Griffiths, R. R., Johnson, M. W., Richards, W. A. et al. · Psychopharmacology (2011)

Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance

Griffiths, R. R., Richards, W. A., Mccann, U. et al. · Journal of Psychopharmacology (2006)

High dose psilocybin is associated with positive subjective effects in healthy volunteers

Nicholas, C. R., Henriquez, K. M., Gassman, M. C. et al. · Journal of Psychopharmacology (2018)

61 cited
Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern-era clinical studies

Andersen, K. A. A., Carhart-Harris, R. L., Nutt, D. J. et al. · Acta Psychiatrica Scandinavica (2020)

The clinical pharmacology and potential therapeutic applications of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT)

Reckweg, J., Uthaug, M. V., Szabo, A. et al. · Journal of Neurochemistry (2022)

Show all 37 references
Development of the Psychological Insight Questionnaire among a sample of people who have consumed psilocybin or LSD

Davis, A. K., Streeter Barrett, F., Griffiths, R. R. et al. · Journal of Psychopharmacology (2021)

108 cited
Psychedelics, Mystical Experience, and Therapeutic Efficacy: A Systematic Review

Knight, G., Rucker, J., Cleare, A. J. et al. · Frontiers in Psychiatry (2022)

Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin

Carhart-Harris, R. L., Erritzoe, D., Williams, T. et al. · PNAS (2012)

Ayahuasca enhances creative divergent thinking while decreasing conventional convergent thinking

Kuypers, K. P. C., Riba, &. J., De La Fuente Revenga, &. M. et al. · Psychopharmacology (2016)

Psychological flexibility mediates the relations between acute psychedelic effects and subjective decreases in depression and anxiety

Davis, A. K., Barrett, F. S., Griffiths, R. R. · Journal of Contextual Behavioral Science (2020)

143 cited
The entropic brain: a theory of conscious states informed by neuroimaging research with psychedelic drugs

Carhart-Harris, R. L., Leech, R., Shanahan, M. et al. · Frontiers in Human Neuroscience (2014)

The entropic brain - revisited

Carhart-Harris, R. L. · Neuropharmacology (2018)

Prediction of psilocybin response in healthy volunteers

Studerus, E., Gamma, A., Kometer, M. et al. · PLOS ONE (2012)

Predicting responses to psychedelics: a prospective study

Haijen, E. C. H. M., Kaelen, M., Roseman, L. et al. · Frontiers in Pharmacology (2018)

339 cited
Sex differences and serotonergic mechanisms in the behavioural effects of psilocin

Tylš, F., Páleníček, T., Kadeřábek, L. et al. · Behavioural Pharmacology (2016)

The peak experience variable in DPT-assisted psychotherapy with cancer patients

Richards, W. A., Rhead, J. C., Dileo, F. B. et al. · Journal of Psychedelic Drugs (2012)

Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness

Maclean, K. A., Johnson, M. W., Griffiths, R. R. · Journal of Psychopharmacology (2011)

Psilocybin-assisted treatment for alcohol dependence: a proof-of-concept study

Bogenschutz, M. P., Forcehimes, A. A., Pommy, J. A. et al. · Journal of Psychopharmacology (2015)

Quality of acute psychedelic experience predicts therapeutic efficacy of psilocybin for treatment-resistant depression

Roseman, L., Nutt, D. J., Carhart-Harris, R. L. · Frontiers in Pharmacology (2018)

Relationship of ketamine’s antidepressant and psychotomimetic effects in unipolar depression

Sos, P., Klirova, M., Novák, T. et al. · Neuropsychiatric Disease And Treatment (2013)

Esketamine Nasal Spray versus Quetiapine for Treatment-Resistant Depression

Reif, A., Bitter, I., Buyze, J. et al. · New England Journal of Medicine (2023)

98 cited
Therapeutic use of psilocybin: Practical considerations for dosing and administration

MacCallum, C. A., Pistawka, C. A., Deol, J. K. et al. · Frontiers in Psychiatry (2022)

Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study

Cavanna, F., Muller, S., de la Fuente, L. A. et al. · Translational Psychiatry (2022)

90 cited
Effects of Setting on Psychedelic Experiences, Therapies, and Outcomes: A Rapid Scoping Review of the Literature

Golden, T. L., Magsamen, S., Sandu, C. C. et al. · Current Topics in Behavioral Neurosciences (2022)

Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences

Carbonaro, T. M., Bradstreet, M. P., Barrett, F. S. et al. · Journal of Psychopharmacology (2016)

Case analysis of long-term negative psychological responses to psychedelics

Bremler, R., Katati, N., Shergill, P. et al. · Scientific Reports (2023)

Pharmacokinetics of Escalating Doses of Oral Psilocybin in Healthy Adults

Brown, R. T., Nicholas, C. R., Cozzi, N. V. et al. · Clinical Pharmacokinetics (2017)

Cited By (2)

Papers in Blossom that reference this study

Your Personal Research Library

Go Pro to save papers, add notes, rate studies, and organize your research into custom shelves.

The phenomenology of psilocybin's experience... — Research Summary & Context | Blossom