Psilocybin in long-term meditators: Effects on default mode network functional connectivity and retrospective ratings of qualitative experience

In this randomized study (n=16) experienced meditators were given a placebo (n=8) or a high dose of psilocybin (n=8). Using fMRI, greater functional connectivity in the default mode network (DMN) was observed in those who received psilocybin. Changes in brain function were also observed one day after the high dose of psilocybin. Those who had received psilocybin reported significantly greater meaning, spiritual significance, psychological challenge, and psychological insight than those who had received the placebo.

Abstract

Aims: Descriptions of meditation experiences can bear striking similarity to descriptions of some experiences with classic (serotonergic) hallucinogens. Neuroimaging studies reveal striking overlap in the effects of psilocybin and the effects of meditation on functional connectivity of the default mode network (DMN). This ongoing study explored the effects of psilocybin on subjective experience and DMN connectivity in long-term meditators.

Methods: 16 meditators (mean lifetime meditation = 4206 h) received either a placebo (n = 8) or a high dose psilocybin (n = 8) capsule before a laboratory session. Retrospective self-report measures of subjective experience and resting-state fMRI data were collected the day after the session. Seed-based functional connectivity analyses were applied to fMRI data. Self-report measures and functional connectivity of the DMN were compared between placebo and psilocybin groups.

Results: Participants who received psilocybin attributed significantly greater meaning, spiritual significance, psychological challenge, and psychological insight to their session experiences than those who received placebo. 75% of participants in the psilocybin group rated the experience to be in the top 10 most meaningful experiences of their life. Participants who received psilocybin also showed lower functional connectivity between hippocampal and posterior DMN regions and greater functional connectivity among DMN regions than those who received placebo.

Conclusions: Participants attributed substantial meaning to their high-dose psilocybin experience, and showed changes in brain function the day after a high dose of psilocybin. Further research should explore the relationship of these enduring changes in brain function to abuse liability and therapeutic outcomes with psilocybin.”

Authors: Frederick S. Barrett, Matthew W. Johnson & Roland R. Griffiths

Study details

Compounds studied
Psilocybin

Topics studied
Neuroscience

Study characteristics
Randomized

Participants
16

Authors

Authors associated with this publication with profiles on Blossom

Frederick Barrett
Frederick Streeter Barrett is an Assistant Professor of Psychiatry and Behavioral Sciences and works at the Johns Hopkins University Center for Psychedelic and Consciousness Research.

Matthew Johnson
Matthew Johnson is an Associate Professor of Psychiatry and Behavioral Sciences at Johns Hopkins University. His research is concerned with addiction medicine, drug abuse, and drug dependence.

Roland Griffiths
Roland R. Griffiths is one of the strongest voices in psychedelics research. With over 400 journal articles under his belt and as one of the first researchers in the psychedelics renaissance, he has been a vital part of the research community.

Institutes

Institutes associated with this publication

Johns Hopkins University
Johns Hopkins University (Medicine) is host to the Center for Psychedelic and Consciousness Research, which is one of the leading research institutes into psychedelics. The center is led by Roland Griffiths and Matthew Johnson.