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Roland R. Griffiths

Johns Hopkins University, Johns Hopkins Medicine

69 papers in the library · 13,523 citations · publishing 1996-2025

Papers

Long-term follow-up of psilocybin-facilitated smoking cessation: Abstinence outcomes and qualitative analysis of participant accounts

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.

DOI: 10.1016/j.drugalcdep.2015.07.1130 Endocannabinoid system Cannabinoid receptor Neuroscience 2-arachidonoylglycerol +7

Belief change and agnostic frames in psychedelic research and clinical contexts

Philosophical Perspectives on Psychedelic Psychiatry September 13, 2024 David B. Yaden, Sandeep M. Nayak, Roland R. Griffiths 4 citations

The proportion of people who change their metaphysical beliefs after psychedelic experiences is not yet known precisely, but evidence suggests such changes can occur in some cases. This review examines the accruing evidence on the prevalence and magnitude of these belief changes and considers potential psychological mechanisms. It also briefly reviews relevant historical and contemporary philosophical work and describes clinical guidelines. Philosophically informed recommendations are offered for research and clinical contexts where psychedelic-induced metaphysical belief changes may arise.

DOI: 10.1093/oso/9780192898371.003.0008 Consciousness studies Psychedelic therapy Psychedelics Entheogens +20

Impact of Psilocybin on Peripheral Cytokine Production

Psychedelic Medicine February 28, 2024 Dana DiRenzo, Jamie Perin, Erika Darrah et al. 4 citations

A preliminary study suggests that psilocybin may cause a temporary increase in cytokine production within one week after administration, but this effect is not consistent across different patient populations. The findings indicate that peripheral cytokine production is possibly altered by psilocybin.

DOI: 10.1089/psymed.2023.0039 Full text Psilocybin Peripheral Production economics Cytokine

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

Spanish translations of three questionnaires measuring acute psychedelic effects—the Psychological Insight Questionnaire (PIQ), Challenging Experiences Questionnaire (CEQ), and Mystical Experiences Questionnaire (MEQ)—showed good psychometric properties in a sample of 442 native Spanish speakers. Confirmatory factor analysis confirmed that the factor structures matched the original English versions, and this consistency held across subgroups who had used LSD or psilocybin. Construct validity was supported by positive associations between the PIQ and MEQ and between these measures and changes in cognitive fusion, alongside negative associations with changes in prosocial behaviors. Predictive validity was indicated by strong relationships between persisting effects and scores on the MEQ and PIQ. The Spanish versions can be reliably used in research with Spanish-speaking populations.

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

Belief changes associated with psychedelic use

PsyArXiv June 30, 2022 Sandeep Manel Nayak, Manvir Singh, David Bryce Yaden et al. 4 citations preprint

A single psychedelic experience can increase non-physicalist beliefs, including dualism, paranormal/spiritual beliefs, and consciousness in both mammals and non-mammals, with medium to large effects. Belief in superstition changed negligibly. The percentage of participants identifying as a believer in a higher power or ultimate reality rose from 29% before the experience to 59% after. Greater mystical experience during the session was linked to larger belief changes. These shifts remained largely stable an average of 8.4 years later.

DOI: 10.31234/osf.io/rdzmy Psychedelics Core beliefs Fundamental worldviews Understanding of reality +13

Psilocybin induces spatially constrained alterations in thalamic functional organizaton and connectivity

bioRxiv (Cold Spring Harbor Laboratory) March 2, 2022 Andrew Gaddis, Daniel E. Lidstone, Mary Beth Nebel et al. 2 citations preprint

Psilocybin, a classic psychedelic, alters perception and cognition by affecting connectivity between the thalamus and cortex. Using a novel analysis of resting-state fMRI data, this study found that psilocybin changes the functional organization within specific thalamic nuclei—primarily the mediodorsal and pulvinar nuclei—and alters their connections with visual and default mode networks. These changes correlated with subjective drug effects. When the thalamus was treated as a single unit, a numerical but not statistically significant increase in thalamocortical connectivity was observed, suggesting that psilocybin causes widespread modest increases offset by strong focal decreases in relevant nuclei.

DOI: 10.1101/2022.02.28.482395 Full text Psilocybin Default mode network Thalamus Neuroscience +4

Naturalistic Psilocybin Use Increases Mind Perception but not Atheist-Believer status: A Prospective Longitudinal Study

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.

DOI: 10.31234/osf.io/auycp_v1 Psilocybin Naturalism Naturalistic observation Perception +2

Serotonergic antidepressant use is associated with weaker psilocybin effects

October 28, 2022 Natalie Gukasyan, Roland R. Griffiths, David B. Yaden et al. 1 citation preprint

Serotonergic antidepressants, such as SSRIs and SNRIs, weaken psilocybin's effects, while the non-serotonergic antidepressant bupropion has less of a dampening effect. In 595 reports of taking psilocybin with an antidepressant, the probability of weaker than expected effects was 0.48 for SSRIs, 0.56 for SNRIs, and 0.29 for bupropion. After discontinuing a serotonergic antidepressant, reduced psilocybin effects persisted for up to 3 months, with odds of reduced effects not significantly different from the first week until 3–6 months post-discontinuation. The findings suggest that serotonergic antidepressants diminish psilocybin's effects both concurrently and for months after stopping.

DOI: 10.31234/osf.io/2zys9 Full text Psilocybin Serotonergic Serotonin Antidepressant +6