Luigi Espasiano
Boundaries of the Ego and the process of belief change in psychedelic-assisted therapy
Updated: Jan 16
Psilocybin and psychedelic substances in general, produce a wide spectrum of acute effects affecting the perceptual, emotional and cognitive spheres. The detected effects also include the phenomenon described as "Ego dissolution." It is known that this experience can have important philosophical and therapeutic implications as much for the "healthy" subject as in some psychopathologies such as major depression or pathological addictions. The following talk aims to illustrate the available hypotheses on how psychedelics would affect our sense of self and the relevance of this phenomenon in catalysing positive change in the individual.
One of my main ares of interests is that of "addictions". One can seemingly develop an addiction to many things; one can become addicted to video games, pornography, anti-anxiety drugs, the search for rare vinyls, the list is endless. What caught my attention is the role of the spiritual experience in the resolution of addictions. For example note that in AA (alcoholics anonymous), founded by Bill Wilson, a well-known proponent of LSD therapy, they speak of "awakening" to refer to the healing process.
In my own journey of learning about psychedelics and their healing potential, it became clear how the spiritual experience plays a key therapeutic role. In the psychedelic literature, the term "mystical experience" is used. This is a problematic term and one that I use with caution because of the many associations it has with the supernatural and in general with various constructs of religious ideologies. This religious connotation is certainly one of the factors that stigmatises its systematic and scientific study.
In this first reflective essay, therefore, I want to explore with you the nature of mystical experience, setting aside metaphysical or religious associations; I will then list some clinical studies that suggest the importance of this experience in the healing process. We will conclude with some suggestions based on recent available evidence on how to avoid difficult experiences.
Walter Stace and the study of Mystical experiences
One of the leading scholars to take an interest in the phenomenology of mystical experience is Walter Stace, an English philosopher, member of Princeton's dpt. of Philosophy, whose treatise Mysticism and Philosophy, is considered among the major works on the subject. Before Stace, William James was interested in the phenomena of "religious conversion" in his well-known essay entitled "The variety of religious experiences." For the purpose of this presentation we will refer to Stace, since his work is the key reference for the bulk of scholarly research of mystical experiences.
Studying numerous sources of religious literature from different cultures, Stace asserts that at the root of every spontaneous mystical experience it is possible to recognise a common core; what varies is the interpretation that the cultural context makes of it (1). The core that unites these accounts examined by Stace is the experience of becoming one with existence. In this state the dual aspect that accompanies our ordinary perception of reality is diminished or absent altogether. It is the experience of becoming one with existence itself.
Mystical experiences are those peculiar states of consciousness in which the individual discovers himself to be one continuous process with God, with the Universe, with the Ground of Being, or whatever name he may use by cultural conditioning or personal preference for the ultimate reality (Alan Watts, psychedelic and religious experience - 1968)
Continuing with Stace, he makes an initial qualitative distinction: introverted and extroverted mystical experience, believing that only the introverted variety can be considered "complete." The extroverted experience consists of a feeling of union with the world around us. The perception that at the bottom of everything there is a common reality. In the introverted experience, any boundary that ordinarily exists between the perceiver and the perceived is completely broken(2).
Stace further identifies 6 dimensions of mystical experience:
- Sacredness: feeling that what is encountered is sacred
- Meaningfulness: the experience we are having is dense with meaning and that the reality we are experiencing is truer than ordinary reality
- Deep joy
- Ineffability: difficult to find the right words to describe what we are experiencing - Paradox: to explain the experience we find ourselves having to admit the coexistence of mutually exclusive states/concepts
- Transcendence of time and space: especially in introverted experience, time and space as ordinarily understood have no meaning.
Before outlining some studies supporting the importance of mystical experience in psychedelic therapy, I would like to bring attention to the temporal dynamics of a session with psilocybin and the related psychological stages gone through by the subject.

The organic and gradual nature of the psychedelic experience is highlighted here (3). Characterised by the progressive attenuation of "ego boundaries" until the dissolution (more or less complete) of all duality and the experiencing of peaks of transcendence. "Ego" in this context means the subject's internal representation of himself as agent and identity or narrative. There is heated debate on this point, but I find interesting Thomas Metzinger's (4) hypothesis that the ego is a dynamic internal representation that the brain generates by integrating multisensory stimuli and whose function is to enable us to interact with the inner and outer worlds. This view is in agreement with predictive processing, the dominant model in the cognitive sciences, which basically postulates that the brain continuously generates probabilistic models of external reality and thus likely of internal reality as well.
CLINICAL STUDIES
We now have a clearer idea of the definition of mystical experience and the dynamics of the process that takes place in psychedelic therapy.
Returning to the premise made at the beginning, namely that this experience plays a central role in facilitating the treatment of the individual, in the second part of this report I briefly describe some of the most important studies supporting this hypothesis.
The first such study is the Good Friday Experiment, the subject of Walter Pankhe's doctoral dissertation (click on image below to access full thesis on maps.org), which using Stace's criteria for defining mystical experience as a reference, notes that it is impossible to distinguish psilocybin-induced mystical experiences from the spontaneous experiences studied by Stace. This significant study, however, is not without weaknesses (5).
The Johns Hopkins group concludes two important studies (6,7) that confirm Pankhe's hypothesis, confirming the potential of psilocybin to induce mystical experiences indistinguishable from the spontaneous experiences found by Stace, they also find a significant correlation between the dosage used and the probability of experiencing mystical states (8).
The first contemporary study with psilocybin in alcoholics (9,10) specifically studies the role of mystical experience in the healing process. After only one session with Psilocybin, patients achieved significant improvements understood as abstinence from drinking and decreased need to drink.
The last trial that i will mention in this essay enrolled patients suffering nicotine addiction (11). The authors find that there is a correlation between the probability of quitting the tobacco habit and the mystical quality of the psychedelic experience.
Many find it surprising and almost magical how one session of psychedelic therapy can have such profound effects. Few, however, are surprised to learn how much a single traumatic event, see post-traumatic stress disorder, can completely change an individual's destiny by affecting his or her life in a catastrophic way.
There are numerous questions that deserve close attention, to name just a few, why do some of the participants in the mentioned studies fail to reach the mystical state? What factors create the right conditions for a positive experience? (12,13)
References and interesting reads
(1) This hypothesis is known as "Perennialism" referred to in Huxley's beautiful essay "The Perennial Philosophy."
(2) This particular aspect is described in great detail in the chapter devoted to the study of Samadhi in "Science of Yoga," I.K. Taimni's commentaries on Patanjali's Yoga Sutras.
(3) Illustration taken from: Behavioural neurobiology of Psychedelic Drugs (Vollenweider et al) (4) See "The Ego Tunnel" and "Being No-one." These ideas are not new; in many sutras the Buddha talks about how the idea of an individual Self represents an illusory concept.
(5) Good Friday Experiment: a long-term follow-up and methodological critique (Rick Doblin 1991) 6 Psilocybin can occasion mystical-type experiences having substantial and sustained personal meaning and spiritual significance (Griffiths et al. 2006)
(7) Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later (Griffiths et al. 2008)
(8) Psilocybin occasioned mystical-type experiences: Immediate and persisting dose - related effects (Griffiths et al. 2011)
(9) Psilocybin-assisted treatment for alcohol dependence: a proof-of-concept study (Bogenschutz et al 2015)
(10) As I mentioned at the beginning, Bill Wilson, founder of Alcoholics Anonymous was an advocate of LSD therapy and in fact in the 1950s-70s there are several very encouraging studies that I will not mention here in which large improvements were reported after just one session with high-dose LSD (>250mcg). The said articles can be found on the MAPS website.
(11) Psilocybin-occasioned Mystical Experiences in the Treatment of Tobacco Addiction (Albert Garcia-Romeu et al 2018)
(12) Psychedelics and the essential importance of context (Robin Carhart-Harris et al. 2018)
(13) The wording "bad trip" needs to be revised since a difficult experience is not necessarily "bad," assuming the subject is well prepared prior to the session, assisted by competent staff during the experience, and follows a therapeutic path of integration.