Psychedelics alter metaphysical beliefs

This study of prospective survey data (n=866) finds that psychedelics indeed alter metaphysical beliefs and shift them towards panpsychism and fatalism (away from physicalist/materialist). The level of impressionability, and the level of emotional synchrony mediated these effects.


“Are psychedelics able to induce lasting changes in metaphysical beliefs? While it is popularly believed that they can, this has never been systematically tested. Here we exploited a large sample derived from prospective online surveying to determine whether and how beliefs concerning the nature of reality, consciousness, and free-will, change after psychedelic use. Results revealed significant shifts away from ‘physicalist’ or ‘materialist’ views, and towards panpsychism and fatalism, post use. These changes remained detectable at 6 months, and were associated with the extent of past use and improved mental-health outcomes. Path modelling suggested that the belief-shifts were moderated by impressionability at baseline and mediated by perceived emotional synchrony with others during the psychedelic experience. The observed belief-shifts post psychedelic use were confirmed by data from an independent controlled clinical trial. Together, these findings imply that psychedelic use has a causal influence on metaphysical beliefs –shifting them away from ‘hard materialism’.”

Authors: Christopher Timmermann, Hannes Kettner, Chris Letheby, Leor Roseman, Fernando E. Rosas & Robin L. Carhart-Harris


Metaphysics as a topic of study is something most of us are completely unaware of. Yet, at the same time, we all engage in metaphysics in our daily lives. We hold implicit beliefs about the nature of reality. Some believe that there is no more to the world than just the matter it consists of (materialism) and others believe that a God or gods are the foundation that started it all. Still others, half-jokingly, say that it’s ‘turtles all the way down.’

Psychedelics reliably alter consciousness. A recent paper discussed that all that used DMT in a study had the lived experience of meeting other entities. So, the current paper, asks if psychedelics can causally change our beliefs about the nature of reality, consciousness, and free will? The researchers also wanted to know if there was a relationship with mental health. And finally, what the underlying psychological mechanisms are that underlie a belief shift.

The study found that people indeed changed their beliefs after the use of psychedelics. The 866 participants in the study were those participating in a prospective survey study, and the data was confirmed with data from the SSRI vs psilocybin for depression study participants.

Who changed their mind?

  • On average participants moved away from physicalism and towards mind-body dualism and panpsychism (all things have a mind)
  • This was most pronounced for those who were more impressionable and for whom it was their first psychedelic experience
  • Participants who felt emotional syncronicity with others during the experience also shifted their beliefs more

Further analyses of the data show that those who come from a ‘hard-materialistic’ view reliably shifted towards ‘hard-dualism.’ This also correlated with an improvement in well-being, answering the second question the researchers had. When they compared the data from this large survey with the clinical trial, they found similar results, confirming these findings.

What the study also found is that contextual factors (such as feeling emotionally close to others during the experience) can greatly influence the outcomes afterward. This doesn’t only apply to metaphysical beliefs, but also to mental health outcomes, personality, and political beliefs. If, in the near future, psychedelics become more widely available in medical (and recreational) use, it should be done so whilst keeping this in mind.

Study details

Topics studied

Study characteristics



Authors associated with this publication with profiles on Blossom

Chris Timmermann
Chris Timmerman is a postdoc at Imperial College London. His research is mostly focussed on DMT.

Chris Letheby
Chris Letheby is a philosopher that studies the therapeutic potential of psychedelics. He is currently a lecturer in philosophy and a postdoc at the University of Adelaide.

Leor Roseman
Leor Roseman is a researcher at the Centre for Psychedelic Research, Imperial College London. His work focussed on psilocybin for depression, but is now related to peace-building through psychedelics.

Robin Carhart-Harris
Dr. Robin Carhart-Harris is the Founding Director of the Neuroscape Psychedelics Division at UCSF. Previously he led the Psychedelic group at Imperial College London.

Linked Research Papers

Notable research papers that build on or are influenced by this paper

Psychedelic Experiences Increase Mind Perception but do not Change Atheist-Believer Status: A Prospective Longitudinal Study
This prospective longitudinal survey (n=657) finds that people who use psychedelics recreationally increase in prescribing 'mind perception' to living and non-living targets (e.g. plants and animals). However, unlike previous studies, they didn't find changes in metaphysical beliefs along the Atheist-Believer scale.

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