The DOI matches its Crossref record; 56 of the 56 references it cites were found in a registry or an index.
Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness
Open accessAbstract
A large body of evidence, including longitudinal analyses of personality change, suggests that core personality traits are predominantly stable after age 30. To our knowledge, no study has demonstrated changes in personality in healthy adults after an experimentally manipulated discrete event. Intriguingly, double-blind controlled studies have shown that the classic hallucinogen psilocybin occasions personally and spiritually significant mystical experiences that predict long-term changes in behaviors, attitudes and values. In the present report we assessed the effect of psilocybin on changes in the five broad domains of personality - Neuroticism, Extroversion, Openness, Agreeableness, and Conscientiousness. Consistent with participant claims of hallucinogen-occasioned increases in aesthetic appreciation, imagination, and creativity, we found significant increases in Openness following a high-dose psilocybin session. In participants who had mystical experiences during their psilocybin session, Openness remained significantly higher than baseline more than 1 year after the session. The findings suggest a specific role for psilocybin and mystical-type experiences in adult personality change.
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“A unique and fascinating feature of psychedelics is that intake of one or a few doses is associated with long-lasting effects on behaviors, attitudes, mood, and personality in humans”
From Psychedelics and Neural Plasticity: Therapeutic Implications (2022) · cites this paper as MacLean et al., 2011
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
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“In the few recent studies that measured personality traits, psychedelics were linked to reductions in neuroticism and increases in openness and extraversion across both non-clinical and clinical populations (33, 34).”
From Psychoanalytically informed MDMA-assisted therapy for pathological narcissism: a novel theoretical approach (2025) · cites this paper as [34]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
In the citing paper
“Post-psychedelic decreases in neuroticism and increases in extroversion, and openness to experience have also been reported [60, 61]; however, these findings have been inconsistent across studies.”
From The psychological processes of classic psychedelics in the treatment of depression: a systematic review protocol (2022) · cites this paper as [61]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
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“Post-psychedelic decreases in neuroticism and increases in extroversion, and openness to experience have also been reported [60, 61]; however, these findings have been inconsistent across studies.”
From The psychological processes of classic psychedelics in the treatment of depression: a systematic review protocol (2022) · cites this paper as [61]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
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“It has been suggested by some studies that the intensity or quality of the psychedelic experience determines the treatment outcome (52–54).”
From Decreases in State and Trait Anxiety Post-psilocybin: A Naturalistic, Observational Study Among Retreat Attendees (2022) · cites this paper as [53]
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“it has been repeatedly found that psychedelic-induced mystical-type experiences and ego dissolution, the latter a phenomenon characterized by the reduction in self-referential awareness, disruption self-world boundaries, and increased feelings of unity with one’s surroundings (55), correlates with long-term (positive) outcomes (23, 52–54, 56–58).”
From Decreases in State and Trait Anxiety Post-psilocybin: A Naturalistic, Observational Study Among Retreat Attendees (2022) · cites this paper as [53]
Experimental — accuracy not yet measuredThe source backs part of the claim, not all of it — or backs it for a different population, condition or comparison.
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“Another potential selection bias remains, as studies including treatments with psychedelic substances require a rather high degree of motivation and openness to experience (82) by the participants because of the time-demanding study procedure and the phenomenologically rich nature of psychedelic experiences. This might have contributed to a ceiling effect regarding potential changes in trait”
From Potential therapeutic effects of an ayahuasca-inspired N,N-DMT and harmine formulation: a controlled trial in healthy subjects (2024) · cites this paper as [82]
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“Supporting the view that the psychedelic experience is required for their therapeutic effects, participants who have so-called mystical experiences during psilocybin sessions score significantly higher compared with baseline on the personality trait Openness, and the change is correlated to the intensity of the experience (MacLean et al., 2011).”
From Psychedelics and Neural Plasticity: Therapeutic Implications (2022) · cites this paper as MacLean et al., 2011
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“Studies using the five-factor model of personality suggest that psilocybin increases openness in healthy participants (34)”
From Psychoanalytically informed MDMA-assisted therapy for pathological narcissism: a novel theoretical approach (2025) · cites this paper as [34]
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“Mindfulness meditation has been generally deemed safe, but numerous reports exist of acute and long-term negative effects associated with the practise (74, 165–167).”
From Examining the Potential Synergistic Effects Between Mindfulness Training and Psychedelic-Assisted Therapy (2021) · cites this paper as [74]
Experimental — accuracy not yet measuredIn the citing paper
“While it has repeatedly been shown that hallucinogens increase the personality trait openness (85, 86), experimental studies investigating the long-term effects of entactogens and hallucinogens on social cognition and behavior remain scarce.”
From Modulation of Social Cognition via Hallucinogens and “Entactogens” (2019) · cites this paper as [85]
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Citations
Cites
Personality Structure: Emergence Of The 5-Factor Model
Digman, J. M. (1990) · Annual Review of Psychology · doi:10.1146/annurev.ps.41.020190.002221 · Cited by 6,731
Personality trait structure as a human universal.
McCrae, R. R., & Costa, P. T. (1997) · American Psychologist · doi:10.1037/0003-066x.52.5.509 · Cited by 4,234
On the practice of dichotomization of quantitative variables.
MacCallum, R. C., Zhang, S., Preacher, K. J., & Rucker, D. D. (2002) · Psychological Methods · doi:10.1037/1082-989x.7.1.19 · Cited by 3,538 · cited 1×
“First, median split analyses have been associated with reductions of power and effect size (MacCallum et al., 2002).”
Griffiths, R. R., Richards, W. A., McCann, U., & Jesse, R. (2006) · Psychopharmacology · doi:10.1007/s00213-006-0457-5 · Cited by 1,684 · cited 9×
“Finally, designating participants who met the criteria for a complete mystical experience allowed a comparison with previous studies (Griffiths et al., 2008; Griffiths et al., 2006; Pahnke, 1963; Richards et al., 1977; Griffiths et al., 2011).”
InfluentialSelf-citationSources of human psychological differences: the Minnesota Study of Twins Reared Apart
Bouchard, T. J., Lykken, D. T., McGue, M., Segal, N. L., & Tellegen, A. (1990) · Science · doi:10.1126/science.2218526 · Cited by 1,373 · cited 1×
“Many studies have confirmed that these personality factors are heritable (Bouchard et al., 1990) and reliable across cultures, suggesting a universal human personality structure that is rooted in biology (McCrae and Costa, 1997).”
What Do We Know When We Know a Person?
McAdams, D. P. (1995) · Journal of Personality · doi:10.1111/j.1467-6494.1995.tb00500.x · Cited by 1,235
Personality Trait Change in Adulthood
Roberts, B. W., & Mroczek, D. (2008) · Current Directions in Psychological Science · doi:10.1111/j.1467-8721.2008.00543.x · Cited by 1,222
Nichols, D. E. (2004) · Pharmacology & Therapeutics · doi:10.1016/j.pharmthera.2003.11.002 · Cited by 1,211
Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer
Grob, C. S., Danforth, A. L., Chopra, G. S., Hagerty, M., McKay, C. R., Halberstadt, A. L., & Greer, G. R. (2011) · Archives of General Psychiatry · doi:10.1001/archgenpsychiatry.2010.116 · Cited by 1,206
Human hallucinogen research: guidelines for safety
Johnson, M., Richards, W., & Griffiths, R. (2008) · Journal of Psychopharmacology · doi:10.1177/0269881108093587 · Cited by 1,203
Self-citationPsilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects
Griffiths, R. R., Johnson, M. W., Richards, W. A., Richards, B. D., McCann, U., & Jesse, R. (2011) · Psychopharmacology · doi:10.1007/s00213-011-2358-5 · Cited by 932
Self-citationGriffiths, R., Richards, W., Johnson, M., McCann, U., & Jesse, R. (2008) · Journal of Psychopharmacology · doi:10.1177/0269881108094300 · Cited by 905
Self-citationThe Construction and Preliminary Validation of a Measure of Reported Mystical Experience
Hood, R. W. (1975) · Journal for the Scientific Study of Religion · doi:10.2307/1384454 · Cited by 736
The neurobiology of psychedelic drugs: implications for the treatment of mood disorders
Vollenweider, F. X., & Kometer, M. (2010) · Nature Reviews Neuroscience · doi:10.1038/nrn2884 · Cited by 723
Cloninger, C. R. (1994) · Current Opinion in Neurobiology · doi:10.1016/0959-4388(94)90083-3 · Cited by 657
Evidence for 5-HT2 involvement in the mechanism of action of hallucinogenic agents
Glennon, R. A., Titeler, M., & MCKENNEY, J. D. J. (1984) · Life Sciences · doi:10.1016/0024-3205(84)90436-3 · Cited by 635
The Standardized Psychometric Assessment of Altered States of Consciousness (ASCs) in Humans
Dittrich, A. (1998) · Pharmacopsychiatry · doi:10.1055/s-2007-979351 · Cited by 577
DeYoung, C. G., Peterson, J. B., & Higgins, D. M. (2005) · Journal of Personality · doi:10.1111/j.1467-6494.2005.00330.x · Cited by 557
Studerus, E., Kometer, M., Hasler, F., & Vollenweider, F. X. (2011) · Journal of Psychopharmacology · doi:10.1177/0269881110382466 · Cited by 532 · cited 1×
“The subjective claims of hallucinogen-occasioned long-term changes (McGlothlin and Arnold, 1971; McGlothlin et al., 1967; Metzner and Editors, 1963; Studerus et al., 2011) appear to align with the modern personality construct of Openness, which encompasses aesthetic appreciation and sensitivity, imagination and fantas…”
Terracciano, A., McCrae, R., Brant, L., & Costa, P. (2005) · Psychology and Aging · doi:10.1037/0882-7974.20.3.493 · Cited by 529
(2024) · University of Notre Dame Press eBooks · doi:10.2307/jj.21341683.19 · Cited by 513
Silvia, P. J., Nusbaum, E. C., Berg, C., Martin, C. L., & O’Connor, A. (2009) · Journal of Research in Personality · doi:10.1016/j.jrp.2009.04.015 · Cited by 451
Modeling Intraindividual Change in Personality Traits: Findings From the Normative Aging Study
Mroczek, D. K., & Spiro, A. (2003) · The Journals of Gerontology Series B: Psychological Sciences and Social Sciences · doi:10.1093/geronb/58.3.p153 · Cited by 393
Personality at Midlife: Stability, Intrinsic Maturation, and Response to Life Events
Costa, P. T., Herbst, J. H., McCrae, R. R., & Siegler, I. C. (2000) · Assessment · doi:10.1177/107319110000700405 · Cited by 381
The Cambridge Handbook of Personality Psychology
Corr, P. J., Matthews, G., Ackerman, P. L., Anderson, N. R., Asendorpf, J. B., Bagby, R. M., Bond, M. H., Boyle, G. J., Briggs, A. L., Burch, G. S. J., et al. (2009) · Cambridge University Press eBooks · doi:10.1017/cbo9780511596544 · Cited by 359
Gale, R. M. (1960) · The Journal of Philosophy · doi:10.2307/2023665 · Cited by 353
Human psychopharmacology of hoasca, a plant hallucinogen used in ritual context in Brazil.
GROB, C. S., McKENNA, D. J., CALLAWAY, J. C., BRITO, G. S., NEVES, E. S., OBERLAENDER, G., SAIDE, O. L., LABIGALINI, E., TACLA, C., MIRANDA, C. T., et al. (1996) · The Journal of Nervous and Mental Disease · doi:10.1097/00005053-199602000-00004 · Cited by 338
Religious Conversion and Personality Change
Paloutzian, R. F., Richardson, J. T., & Rambo, L. R. (1999) · Journal of Personality · doi:10.1111/1467-6494.00082 · Cited by 307
The phenomenon of quantum change
Miller, W. R. (2004) · Journal of Clinical Psychology · doi:10.1002/jclp.20000 · Cited by 275
Intellect as distinct from openness: Differences revealed by fMRI of working memory.
DeYoung, C. G., Shamosh, N. A., Green, A. E., Braver, T. S., & Gray, J. R. (2009) · Journal of Personality and Social Psychology · doi:10.1037/a0016615 · Cited by 261
Hood, Jr., Ghorbani, N., Watson, P. J., Ghramaleki, A. F., Bing, M. N., Davison, H. K., Morris, R. J., & Williamson, W. P. (2001) · Journal for the Scientific Study of Religion · doi:10.1111/0021-8294.00085 · Cited by 225
Personality self-reports are concurrently reliable and valid during acute depressive episodes
Costa, P. T., Bagby, R. M., Herbst, J. H., & McCrae, R. R. (2005) · Journal of Affective Disorders · doi:10.1016/j.jad.2005.06.010 · Cited by 218
Sahdra, B. K., MacLean, K. A., Ferrer, E., Shaver, P. R., Rosenberg, E. L., Jacobs, T. L., Zanesco, A. P., King, B. G., Aichele, S. R., Bridwell, D. A., et al. (2011) · Emotion · doi:10.1037/a0022764 · Cited by 197
Self-citationMcCoubrie, R., & Davies, A. N. (2005) · Supportive Care in Cancer · doi:10.1007/s00520-005-0892-6 · Cited by 191
The Five-Factor Model of personality traits: consensus and controversy
McCrae, R. R. (2012) · Cambridge University Press eBooks · doi:10.1017/cbo9780511596544.012 · Cited by 190
Kelly, J. F., Stout, R., Magill, M., Tonigan, J., & Pagano, M. E. (2010) · Alcoholism: Clinical and Experimental Research · doi:10.1111/j.1530-0277.2010.01362.x · Cited by 181
PAHNKE'S "GOOD FRIDAY EXPERIMENT' A LONG-TERM FOLLOW-UP AND METHODOLOGICAL CRITIQUE
Doblin, R. (1991) · Cited by 163
Comparison of the reactions induced by psilocybin and LSD-25 in man
Isbell, H. (1959) · Psychopharmacology · doi:10.1007/bf00408109 · Cited by 140
Cracking the Plaster Cast: Big Five Personality Change during Intensive Outpatient Counseling
Piedmont, R. L. (2001) · Journal of Research in Personality · doi:10.1006/jrpe.2001.2326 · Cited by 129
Comparison of psilocin with psilocybin, mescaline and LSD-25
Wolbach, A. B., Miner, E. J., & Isbell, H. (1962) · Psychopharmacology · doi:10.1007/bf00412109 · Cited by 123
Long Lasting Effects of LSD on Normals
McGlothlin, W. H. (1967) · Archives of General Psychiatry · doi:10.1001/archpsyc.1967.01730290009002 · Cited by 119
McGlothlin, W. H. (1971) · Archives of General Psychiatry · doi:10.1001/archpsyc.1971.01750070037005 · Cited by 117
Treatment of alcoholism using psychedelic drugs: a review of the program of research.
Mangini, M. (1998) · Journal of Psychoactive Drugs · doi:10.1080/02791072.1998.10399714 · Cited by 114
Values and Beliefs of Psychedelic Drug Users: A Cross-Cultural Study
Lerner, M., & Lyvers, M. (2006) · Journal of Psychoactive Drugs · doi:10.1080/02791072.2006.10399838 · Cited by 98
The Peak Experience Variable in DPT-Assisted Psychotherapy with Cancer Patients
Richards, W. A., Rhead, J., Dileo, F., Yensen, R., & Kurland, A. (1977) · Journal of Psychedelic Drugs · doi:10.1080/02791072.1977.10472020 · Cited by 97
Attenuation of anticipation: A therapeutic use of lysergic acid diethylamide
Kast, E. (1967) · The Psychiatric Quarterly · doi:10.1007/bf01575629 · Cited by 94
Personality and Temperament: Genetics, Evolution, and Structure.
Riemann, R., Spinath, F. M., & Ostendorf, F. (2002) · Cited by 91
The Use of Hallucinogens in the Treatment of Addiction
Halpern, J. H. (1996) · Addiction Research & Theory · doi:10.3109/16066359609010756 · Cited by 63
The effect of N,N-dimethyltryptamine in human subjects tolerant to lysergic acid diethylamide
Rosenberg, D. E., Isbell, H., Miner, E. J., & Logan, C. R. (1964) · Psychopharmacology · doi:10.1007/bf00413244 · Cited by 61
Mescaline, LSD, Psilocybin, and Personality Change a Review†
Unger, S. M. (1963) · Psychiatry · doi:10.1080/00332747.1963.11023344 · Cited by 60
Methylenedioxyamphetamine (MDA)–Subjective Effects
Turek, I., Soskin, R. A., & Kurland, A. A. (1974) · Journal of Psychedelic Drugs · doi:10.1080/02791072.1974.10471499 · Cited by 59
LSD THE CONSCIOUSNESS EXPANDING DRUG
SOLOMON, D. (1965) · The American Journal of the Medical Sciences · doi:10.1097/00000441-196504000-00017 · Cited by 57
Griffiths, R. R., & Grob, C. S. (2010) · Scientific American · doi:10.1038/scientificamerican1210-76 · Cited by 46
Self-citationBelzen, J. A., & Geels, A. (2003) · BRILL eBooks · doi:10.1163/9789004494725 · Cited by 16
LSD, TRANSCENDENCE, AND THE NEW BEGINNING
Terrill, J., Savage, C. C., & Jackson, D. D. (2010) · Cited by 11
Conceptual and Empirical Consequences of the Unity Thesis
Hood, R. W. (2003) · BRILL eBooks · doi:10.1163/9789004494725_003 · Cited by 9
Research works printed but not linked: 5
- Costa PT, 1992, Revised NEO Personality Inventory (NEO-PI-R) and NEO Five Factor Inventory (NEO-FFI) Professional Manual
- Doblin R, 1991, J Transpers Psychol, 23, 1
- Metzner R, 1963, Psychedel Rev, 1, 18
- Pahnke WN (1963) Drugs and mysticism: an analysis of the relationship between psychedelic drugs and the mystical consciousness. Thesis. Harvard University, Boston.
- Unger SM, 1964, LSD: The Consciousness-expanding Drug, 200
Cited by
Sorted by citations
Nichols, D. E. (2016) · Pharmacological Reviews · doi:10.1124/pr.115.011478 · Cited by 1,762
Carhart-Harris, R. L., Leech, R., Hellyer, P. J., Shanahan, M., Feilding, A., Tagliazucchi, E., Chialvo, D. R., & Nutt, D. (2014) · Frontiers in Human Neuroscience · doi:10.3389/fnhum.2014.00020 · Cited by 1,252
REBUS and the anarchic brain: Toward a unified model of the brain action of psychedelics
Carhart-Harris, R. L., & Friston, K. J. (2019) · Pharmacological Reviews · doi:10.1124/pr.118.017160 · Cited by 1,180
Psilocybin-assisted treatment for alcohol dependence: A proof-of-concept study
Bogenschutz, M. P., Forcehimes, A. A., Pommy, J. A., Wilcox, C. E., Barbosa, P., & Strassman, R. J. (2015) · Journal of Psychopharmacology · doi:10.1177/0269881114565144 · Cited by 1,151
Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin
Carhart-Harris, R. L., Erritzoe, D., Williams, T., Stone, J. M., Reed, L. J., Colasanti, A., Tyacke, R. J., Leech, R., Malizia, A. L., Murphy, K., et al. (2012) · Proceedings of the National Academy of Sciences · doi:10.1073/pnas.1119598109 · Cited by 1,172
Metadata
- Authors
- MacLean, K. A., Johnson, M. W., & Griffiths, R. R.
- Affiliations
- Johns Hopkins University (US)
- Corresponding author
- MacLean, Katherine A
- Venue
- Journal of Psychopharmacology
- Publisher
- SAGE Publications
- Published
- 2011-09-28
- Volume
- 25
- Issue
- 11
- Pages
- 1453-1461
- ISSN
- 0269-8811 (ISSN-L)
- 1461-7285
- PMC
- PMC3537171
- OpenAlex
- W2118739111
- Cited by
- 895
- References
- 56
- Citations by year
- 2026: 48 · 2025: 80 · 2024: 92 · 2023: 87 · 2022: 93 · 2021: 100 · 2020: 100 · 2019: 63 · 2018: 56 · 2017: 50 · 2016: 46 · 2015: 23 · 2014: 22 · 2013: 15 · 2012: 17
- FWCI
- 18.60
- Type
- journal article
- Language
- en
- Open access
- green
- www.ncbi.nlm.nih.gov
- Locations
- Journal of Psychopharmacology (publishedVersion)
- PubMed (publishedVersion)
- Europe PMC (PubMed Central) (acceptedVersion)
- PubMed Central (acceptedVersion)
- Funders
- National Institute on Drug Abuse (R01DA003889, T32DA007209, R01DA03889)
- Topics
- Social Sciences › Psychology › Clinical Psychology › Psychedelics and Drug Studies
- Social Sciences › Psychology › Social Psychology › Paranormal Experiences and Beliefs
- Social Sciences › Health › Religion, Spirituality, and Psychology
- Keywords
- psilocybin, mystical experience, personality change, openness to experience, personality traits, hallucinogens, Big Five personality traits, aesthetic appreciation
- MeSH terms
- Adult, Attitude, Behavior, Double-Blind Method, Extraversion, Psychological, Female, Follow-Up Studies, Hallucinogens, Humans, Longitudinal Studies, Male, Middle Aged, Mysticism, Personality, Psilocybin, Randomized Controlled Trials as Topic, Young Adult
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