September 13, 2024
Chris Letheby, Philip Gerrans
6 citations
Abstract A recent wave of research in psychiatry and neuroscience has re-examined the properties of ‘classic’ psychedelic substances—also known as serotonergic hallucinogens—such as psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT). Evidence to date suggests that psychedelics can be given safely in controlled conditions, at moderate to high doses, and may have...
Philosophical Perspectives on Psychedelic Psychiatry
September 13, 2024
Chris Letheby, Philip Gerrans
1 citation
Abstract The chapter undertakes three main tasks. The first is to review, briefly, the history of psychedelics in psychiatry, including the phenomenological and behavioural effects that first led to their being studied for therapeutic purposes. The second is to give an overview of recent research into the safety, efficacy, and therapeutic mechanisms of psychedelic-assisted psychotherapy. The...
Philosophical Perspectives on Psychedelic Psychiatry
September 13, 2024
Samir Chopra, Chris Letheby
Abstract Several authors have recently suggested that classic psychedelics might be safe and effective agents of moral enhancement. This raises the question: can we learn anything interesting about the nature of moral experience from a close examination of transformative psychedelic experiences? The interdisciplinary enterprise of philosophical psychopathology attempts to learn about the...
Neuroethics
May 17, 2024
Chris Letheby
14 citations
Increasing evidence suggests that psychedelic experiences, undergone in controlled conditions, can have various durable psychological benefits. One such benefit is reductions in fear of death, which have been attested in both psychiatric patients and healthy people. This paper addresses the question: how, exactly, do psychedelic experiences reduce fear of death? It argues, against some...
2024
Chris Letheby, Jaipreet Mattu, Eric Hochstein
4 citations
Hochstein try to put an end to the “mysticism wars,” by which they mean the battle between psychedelic researchers who hold that mystical concepts ought to be employed in attempts to describe and understand psychedelic experiences and those who do not hold this. Letheby, Mattu, and Hochstein side with the former and do so on the grounds that (as they put it), “there are no good reasons to...
Journal of Consciousness Studies
July 14, 2022
Chris Letheby
2 citations
An emerging body of research suggests that psychedelic experiences can change users' religious or metaphysical beliefs. Here I explore issues concerning psychedelic-induced belief change via a critique of some recent arguments by Wayne Glausser. Two scientific studies seem to show that psychedelic experiences can convert atheists to belief in God, but Glausser holds that academic and popular...
Journal of Psychedelic Studies
June 23, 2022
Shevaugn Johnson, Chris Letheby
1 citation
Abstract In this opinion piece we propose the investigation of psychedelic-assisted psychotherapy for the treatment of body dysmorphic disorder (BDD). BDD is a psychiatric disorder characterised by appearance-based preoccupations and accompanying compulsions. While safe and effective treatments for BDD exist, non-response and relapse rates remain high. Therefore, there is a need to investigate...
Philosophy and the Mind Sciences
April 19, 2022
Chris Letheby
6 citations
Much of my book Philosophy of Psychedelics is devoted to elaborating and defending two basic claims: that psychedelic therapy works mainly by changing mental representations of the self, and that it has many epistemic benefits consistent with a naturalistic worldview. The commentaries in this symposium generally focus on one or the other of these claims. On the mechanistic front, the...
Philosophy and the Mind Sciences
April 19, 2022
Chris Letheby
3 citations
In this précis I summarise the main ideas of my book Philosophy of Psychedelics. The book discusses philosophical issues arising from the therapeutic use of “classic” (serotonergic) psychedelic drugs such as psilocybin and LSD. The book is organised around what I call the Comforting Delusion Objection to psychedelic therapy: the concern that this novel and promising treatment relies essentially...
Philosophical Psychology
March 29, 2022
Nin Kirkham, Chris Letheby
15 citations
The urgent need for solutions to critical environmental challenges is well attested, but often environmental problems are understood as fundamentally collective action problems. However, to solve these problems, there is also a need to change individual behavior. Hence, there is a pressing need to inculcate in individuals the environmental virtues – virtues of character that relate to our...
Journal of Psychedelic Studies
January 21, 2022
Chris Letheby, Jaipreet Mattu
19 citations
Abstract Serotonergic (or “ classic” ) psychedelics have struck many researchers as raising significant philosophical questions that, until recently, were largely unexplored by academic philosophers. This paper provides an overview of four emerging lines of research at the intersection of academic philosophy and psychedelic science that have gained considerable traction in the last decade:...
Routledge Handbook on the Philosophy of Meditation
2022
Chris Letheby
2 citations
Psychedelic ingestion and meditative practice are both ancient methods for altering consciousness that became widely known in Western society in the second half of the 20th century. Do the similarities begin and end there, or do these methods – as many have claimed over the years – share some deeper common elements? In this chapter I take a neurophilosophical approach to this question and argue...
Scientific Reports
November 23, 2021
Christopher Timmermann, Hannes Kettner, Chris Letheby et al.
208 citations
Can the use of psychedelic drugs induce lasting changes in metaphysical beliefs? While it is popularly believed that they can, this question has never been formally 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...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
2 citations
‘The mechanisms of psychedelic therapy’ presents arguments against three theories of psychedelic therapy. The Molecular Neuroplasticity Theory ascribes therapeutic benefits to an experience-independent molecular mechanism. This theory is undermined by the correlation between ‘mystical-type experiences’ and beneficial outcomes, which suggests that genuinely psychological mechanisms are involved....
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
1 citation
‘The phenomenology of psychedelic therapy’ provides a selective overview of experiences commonly reported by those who take psychedelics in controlled and structured settings, such as clinical trials and religious rituals. The first half of this chapter reviews a variety of typical changes to perception and the sense of self. The second half reviews qualitative evidence concerning patients’...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
1 citation
‘Spirituality’ examines the import of psychedelic evidence for the philosophical project of naturalising spirituality. This chapter argues that psychedelic research vindicates the claim that there are transformative experiences and practices that can legitimately be called ‘spiritual’ and are compatible with adherence to a naturalistic worldview. The existential transformation afforded by some...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
1 citation
‘On the need for a natural philosophy of psychedelics’ provides a brief overview of the history of psychedelics in science and psychiatry, and a detailed review of recent evidence for their therapeutic and transformative efficacy. The chapter reviews clinical trials showing that one or two controlled psychedelic experiences can durably reduce symptoms of anxiety, depression, and addiction, and...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
The ‘Conclusion’ summarises the main ideas of Philosophy of Psychedelics and makes some suggestions for future research. The first part of the chapter provides a chapter-by-chapter summary of the arguments of the book, and lists the various testable predictions that follow from these arguments. The second part suggests some other directions for future research, pointing to outstanding questions...
Oxford University Press eBooks
August 1, 2021
Chris Letheby
Philosophy of Psychedelics is the first scholarly monograph in English devoted to the philosophical analysis of psychedelic drugs. Its central focus is the apparent conflict between the growing use of psychedelics in psychiatry and the philosophical worldview of naturalism, which holds that the natural world is all that exists. The book reviews scientific evidence that psychedelics such as...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
‘Epistemology’ argues that controlled psychedelic administration can have significant epistemic benefits consistent with a naturalistic worldview. The most obvious candidate for propositional knowledge, or knowledge that, is psychodynamic insight into one’s previously unknown mental states. This chapter argues that such insights are probably often accurate, but cannot be trusted uncritically:...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
‘Resetting the brain’ examines the hypothesis that (i) large-scale neural networks become stuck in dysfunctional configurations in pathology, and (ii) psychedelics cause therapeutic benefits by disrupting these configurations, providing an opportunity to ‘reset’ the relevant networks into a healthier state. This chapter argues that this view is correct but limited; per Chapter 5, it needs to be...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
‘Unbinding the self’ outlines the predictive self-binding account of psychedelic therapy introduced by Letheby and Gerrans (2017). On this account, the networks targeted by psychedelics integrate or ‘bind’ information from multiple sources into a hierarchical predictive model of the self. In pathological conditions, detrimental forms of self-modelling can become rigidly entrenched. By...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
‘The role of self-representation’ presents three lines of evidence in support of a simple hypothesis: the central mechanism of psychedelic therapy is the disruption and revision of mental representations of the self. One line of evidence connects experiences of ‘psychological insight’ to positive clinical outcomes, and the insights in question are often autobiographical in character. A second...
Philosophy of Psychedelics
August 1, 2021
Chris Letheby
This Introduction outlines the central focus of Philosophy of Psychedelics: the therapeutic use of psychedelics in psychiatry and its apparent conflict with philosophical naturalism. The chapter briefly describes recent findings that controlled psychedelic administration can have lasting psychological benefits for healthy subjects and for psychiatric patients. It then cites evidence that these...
PsyArXiv
July 8, 2021
Chris Letheby
preprint
In this précis I summarise the main ideas of my book Philosophy of Psychedelics . The book discusses philosophical issues arising from the therapeutic use of classic psychedelic drugs such as psilocybin and LSD. The book is organised around what I call the Comforting Delusion Objection to psychedelic therapy: the concern that this novel and promising treatment relies essentially on the...