In the last post we saw that there are some significant, lasting changes in personality traits and values that come as a result of psychedelic experience. It appears that the catalyst for these changes is something called mystical experience.
What is mystical experience, and why is it so powerful?
A mystical experience, as we will see, is one of the most profound and meaningful things a human being can undergo, if not the most. What’s more, it imparts lasting, positive changes on a person, not only subjectively but also in their observable behaviour.
This post explores mystical experience particularly as it pertains to psychedelics, as psychedelics are the only way we know to reliably bring it about. I mostly draw on recent psychedelic research, including published studies as well as the first chapter of Current Topics in Behavioural Neurosciences by Frederick S. Barrett and Roland R. Griffiths, entitled “Classic Hallucinogens and Mystical Experience: Phenomenology and Neural Correlates”. If you want to dive even deeper into this topic than we will in this post, I’d recommend reading that chapter.
This post is divided into 5 sections: a brief history of mystical experience, phenomenology of mystical experience, scientific measurement of mystical experience, brain activity during mystical experience, and observable outcomes of mystical experience.
Personally I find this to be probably the most interesting topic in existence. We are talking about the highest subjective conscious states human beings can reach, with lasting and meaningful implications. It is truly fascinating stuff, and for credibility’s sake I will mostly refrain from inserting my own commentary and let the research speak for itself. Let’s get into it.
Mystical Experience: A (Very) Brief History
For centuries mystics in various religious traditions have reported experiences of an extraordinary character. These involve feelings of direct connection with the divine; a sense of total cosmic unity; a sense of timelessness; pure bliss, joy, or gratitude; a sense of holiness or sacredness about the nature of reality; and a sense that the experience cannot be fully or properly described in words (ineffability).
These experiences can come about spontaneously, or as a result of practices like meditation or fasting. We have accounts of such experiences from historical figures like Plotinus, Meister Eckhart, Rumi and more.
Historically and in cases like these, the mystical experience was generally interpreted through the particular religious or philosophical framework of the individual. It was not clear how alike these experiences were in their subjectivity.
In his 1902 book The Varieties of Religious Experience, the American philosopher William James popularized the term “religious experience”, which is synonymous with mystical experience (and “visionary experience”). James suggested there was a common core to these experiences, regardless of difference in existing belief structure.
In mystic states we both become one with the Absolute and we become aware of our oneness. This is the everlasting and triumphant mystical tradition, hardly altered by differences of clime or creed. In Hinduism, in Neoplatonism, in Sufism, in Christian mysticism, in Whitmanism, we find the same recurring note, so that there is about mystical utterances an eternal unanimity which ought to make a critic stop and think, and which bring it about that the mystical classics have, as been said, neither birthday nor native land.1
In 1960, a British philosopher named Walter Stace published Mysticism and philosophy, in which he analyzed firsthand accounts of mystical experience from a wide range of religious texts. Stace, like James, concluded that there was in fact a common set of qualities that defined the mystical experience, independent of culture or origin. Modern research has confirmed this theory, now known as the “common core thesis”.234
Phenomenology of Mystical Experience
In Mysticism and philosophy, Stace describes the subjective qualities that define a mystical experience. He categorized two types of mystical experience – introvertive and extrovertive – distinguished by either an internally or externally-focused sense of unity. His definition included six other dimensions which are, with the exception of “paradoxicality”, still used to measure mystical experience today. Barrett and Griffiths explain:
In addition to the experience of introvertive or extrovertive types of unity, Stace described six other dimensions of mystical experience: (1) sacredness: a sense that what is encountered is holy or sacred; (2) noetic quality: the experience is imbued with an aspect of meaning and a sense of encountering ultimate reality that is more real than usual everyday reality; (3) deeply felt positive mood: joy, ecstasy, blessedness, peace, tenderness, gentleness, tranquility, awe; (4) ineffability: the experience is difficult to put into words; (5) paradoxicality: to explain the experience, one seems to have to describe the coexistence of mutually exclusive states or concepts; (6) transcendence of time and space: Introvertive mystical experiences may have a nonspatial and nontemporal aspect, such that the traditional notions of time and space have no meaning5
The current standard for measuring mystical experience is a test called the Revised 30-Item Mystical Experience Questionnaire (MEQ30), which is explained in more detail in the next section. For you just need to know that “mystical experience” in this post means a complete mystical experience as codified in the MEQ30. Barrett and Griffiths explain:
A complete mystical experience, as described by Stace (1960a), which is codified in the MEQ30, includes not only just ego dissolution… unity… or positive mood… but also transcendence of space and time, ineffability, noetic quality, and reverence or sacredness.6
Are psychedelic-induced mystical experiences “real” and “authentic”?
Some express doubts over the authenticity of mystical experiences induced by psychedelics as compared to mystical experience brought about by other means. They suggest the value of the experience might be diminished because it is brought about by ingesting a substance, rather than it happening spontaneously (“naturally”) or as a result of disciplined contemplative practice.
Concerns about authenticity are somewhat misguided and tend to reflect an incomplete understanding of history. Psychoactive plant substances have been used as sacraments in shamanic rituals and ceremonies in cultures around the world for thousands of years.7 And, as we will see later on, brain activity during psychedelic-induced mystical experience is the same as brain activity during mystical experience occasioned through meditation.
Furthermore, recent research shows that psychedelic-induced mystical experiences are qualitatively no different from those that come about in other ways. In fact, “experiences induced by psychedelic substances were rated as more intensely mystical, resulted in a reduced fear of death, increased sense of purpose, and increased spirituality as compared with nonpsychedelically triggered RSMEs [religious, spiritual, or mystical experiences].”8
Firsthand accounts of mystical experience from psychedelic research
The following are short descriptions from participants in studies with psilocybin at Johns Hopkins University (discussed further below). Participants who had a mystical experience describe them thus:
Feelings of gratefulness, a great (powerful) remembrance of humility… of my experience of being, the experience of my being in and within the infinite.
Rich joy and awe. My body melting and becoming one with the universe felt both painless and profound… Feeling complete as a person and physically a part of all things.
There is a meaningful presence that humbles any human heart.
Simultaneously being aware and saturated in the majesty of existence.
Seeing God speaks for itself; seeing and feeling forever was like traveling through space-time.9
Freedom from every conceivable thing including time, space, relationships, self, etc… It was as if the embodied “me” experienced ultimate transcendence – even of myself.
The ‘knowing’ was so powerful and yet personal. Experiencing the Beloved and falling in love.
The sense that all is One, that I experienced the essence of the Universe and the knowing that God asks nothing of us except to receive love.
[I experienced] a reality that was clear, beautiful, bright and joyful… In short, this experience opened me up (gave me a tangible vision) of what I think is attainable every day.
The complete and utter loss of self… The sense of unity was awesome… I now truly do believe in God as an ultimate reality.10
“The most personally meaningful and spiritually significant experience of my life”
Psychedelic-induced mystical experiences are widely rated as among the most meaningful and significant of a person’s life, if not the single most. The first modern study of this type was published in 2006, where participants were given high dose psilocybin in a controlled setting and 61% met criteria for a complete mystical experience.11 In a 14-month follow-up study, Griffiths et al. explain:
The most striking finding from this 14-month follow-up evaluation of the effects of psilocybin and methylphenidate [placebo] administered to hallucinogen-naïve volunteers is that a large proportion of volunteers rate their “psilocybin experience” as among the most personally meaningful and spiritually significant of their lives.12
It is remarkable that 67% of the volunteers rated the experience with psilocybin to be either the single most meaningful experience of his or her life or among the top five most meaningful experiences of his or her life. In written comments, the volunteers judged the meaningfulness of the experience to be similar, for example, to the birth of a first child or death of a parent.13
Scientific Measurement of Mystical Experience
A number of tests for measuring altered states of consciousness have been developed and used over the years. Here we focus mainly on those that are current and relevant to psychedelic-induced mystical experience.
Hood’s Mysticism Scale
One of the first formal measures of mystical experience was developed by Ralph Hood in the 1970’s. Hood drew from Stace’s conceptual categories to create an 8-item scale: ego quality, unifying quality, inner subjective quality, temporal/spatial quality, noetic quality, ineffability, positive aspect, and religious quality.14 The utility of Hood’s Mysticism Scale was confirmed in further studies and came to influence the measures used today.151617
Ego-Dissolution Inventory (EDI)
Ego-dissolution is a key facet of mystical experience, although importantly it does not constitute mystical experience in and of itself. Ego-dissolution “has been interpreted from a psychoanalytic perspective as a disruption of ego-boundaries, which results in a blurring of the distinction between self-representation and object-representation, and precludes the synthesis of self-representations into a coherent whole.”18 The Ego-Dissolution Inventory is a recently validated measure of this subjective experience.
In a 2016 paper published in Frontiers in Human Neuroscience, Nour et al. show that ego-dissolution correlates strongly with unitive (mystical) experience, and that “experiences of ego-dissolution, unity and dissolved ego-boundaries may be conceptually inseparable, occurring together during “peak” psychedelic experiences.19
Revised 30-item Mystical Experience Questionnaire (MEQ30)
In the early 1960’s, a 43-item Mystical Experience Questionnaire was developed and used by Walter Pahnke, the psychiatrist who ran the original Good Friday Experiment.
Later it was found that a 30-item questionnaire measures mystical experience just as well as the 43-item version. The Revised 30-item Mystical Experience Questionnaire (MEQ30) contains 30 descriptive statements divided into four categories: mystical, positive mood, transcendence of time and space, and ineffability.
Each item is rated on a 6-point scale, where 0=“none; not at all,” 1=“so slight cannot decide,” 2=“slight,” 3=“moderate,” 4=“strong (equivalent in degree to any previous strong experience or expectation of this description),” and 5=“extreme (more than ever before in my life and stronger than 4).
The MEQ30 is shown to be both reliable and valid, and is now the standard for measuring mystical experience.20 Barrett and Griffiths explain:
While other inventories have been used to measure and quantify important aspects of the subjective of psychedelics, such as experiences of unity and ego dissolution, none but the MEQ contains an array of items and subscales that adequately evaluates the construct of a complete mystical experience in relation to discrete psychedelic experiences.21
Brain Activity During Mystical Experience
In scientific terms, we do not fully understand the relationship between human consciousness and the biological brain. It’s not clear how subjective experience arises from the physical world, or whether it does at all.22
Because of the limitations on our understanding, most research in this area involves observing correlations between physical brain states and subjective conscious experiences. This is the study of what are called the neural correlates of consciousness.
Research on the neural correlates of psychedelic experience is quite recent, and is “insufficient to provide a complete model of the neural basis of mystical experiences.”23
Instead, Barrett and Griffiths combine the limited neuroimaging work on psychedelics with neuroimaging studies done on brain states during meditation. Brain activity and subjective experience during meditation and psychedelic experience are very similar.24
Since I am far from an expert on brain anatomy and functionality, this section keeps things fairly simple and relies heavily on quotes from the actual experts. If you want to go deeper, please see the references at the bottom of this post.
The Default Mode Network
During mystical experience, psychedelics seem to be acting primarily on a set of brain areas called the Default Mode Network (DMN). The DMN is a group of interconnected brain regions with activity that is highly correlated. It is responsible for, among other things, our sense of self in space and time, distinguishing between self and other, discursive thought (mind-wandering), remembering the past, and imagining the future.
Psychedelics (and meditation) appear to cause decreased activity in the DMN, and decreased connectivity between different areas of the DMN. Barrett and Griffiths explain:
The experience of unity that is central to mystical experiences involves a decrease in self-referential processing. There is compelling evidence for a network of brain areas (i.e., the nodes of the DMN) that are involved in self-referential processing and maintenance of a sense of the self in space and time. Decreased activity in these areas has been observed using multiple imaging modalities, both after administration of classic hallucinogens and during meditation practices.25
The medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC) are two regions that are part of the DMN.
The psychological processes ascribed to the MPFC and PCC include various types of self-referential processing including mentalizing (i.e., thinking about your own or others’ thoughts), internal dialog, self-related judgments, and autobiographical memory retrieval.
After intravenous administration of psilocybin or LSD, cerebral blood flow and BOLD activity in MPFC and PCC decreased substantially, as did effective connectivity between these areas. In the same studies, decreased cerebral blood flow correlated with increased intensity of drug effects and decreased sense of self (or increased “ego-dissolution”).
The PCC is implicated in “internally directed cognition”, “’getting caught up in’ one’s experience”, and “ego integrity”. One could argue that activity in the PCC may reflect self-referential processing (i.e., an internal dialog or chatter) that is quieted by meditation training. This is supported by research demonstrating that mind-wandering is associated with PCC activity.26
The parahippocampal cortex (PHC), another region of the DMN, is primarily responsible for encoding memory.
The PHC, and more broadly the hippocampal complex, has been implicated in supporting consciousness by supporting the moment-to-moment binding of sensory information into coherent memory representations, including those thought to be related to a sense of self. The PHC is involved in maintaining and recalling memories of self and self-relevant information.27
Another DMN region, the inferior parietal lobule (IPL), is responsible for our sense of self in time and space.
Decreased activity in the IPL (and specifically in the angular gyrus), and decreased communication between the IPL and other areas involved in maintaining a sense of self (such as the PCC) are observed both in studies of meditation and in studies of classic hallucinogens. These observations are consistent with the experience of altered sense of time and space that has been reported with both meditation and classic hallucinogens.
Considering the findings summarized above, it could be hypothesized that decreased activity and functional connectivity in the IPL (a lateral node of the DMN) mediates the experience of timelessness and spacelessness that accompanies introvertive mystical experience, be that occasioned by meditation or by classic hallucinogens.28
To sum up, during mystical experience induced by psychedelics or meditation, activity in various regions of the DMN is decreased, and connectivity between these regions is altered. This results in decreased self-referential processing, loss of sense of self, and the experience of timelessness and spacelessness that are characteristic of mystical experience.
This has been an overview of brain activity during mystical experience in particular. For more on brain activity during psychedelic experience in general, see Your Brain on Psychedelic Drugs.
Observable Outcomes of Mystical Experience
A wide range of therapeutic, behavioural and psychospiritual benefits come as a result of mystical experience. First let’s take a look at the outcomes in addiction treatment and mental health-related research.
In a 2014 study, the first of its kind, 15 participants received psilocybin along with cognitive behavioural therapy for cigarette smoking cessation. Six months after the study, 12 of 15 (80%) of participants were completely abstinent from smoking. Nine of these participants met criteria for a complete mystical experience, and there was significant correlation between mystical experience and smoking cessation.29 In a 12-month follow-up, 10 out of 15 participants (67%) were still completely abstinent.30 There is further data, gathered through a survey of over 350 people, showing that naturalistic psychedelic use is associated with quitting smoking.31
A 2015 study examined the effects of psilocybin combined with therapy to treat alcoholism in 10 volunteers. Self-reported alcohol use decreased significantly after the first psilocybin session, and remained lower than baseline at a 36-week follow up.32 Consistent with other studies in the field, “higher mystical type experience scores in the first psilocybin session were significantly related to greater reductions in alcohol consumption.” 33
Anxiety & Depression in Cancer Patients
Three studies have been conducted using psilocybin to treat end-of-life anxiety in patients with life-threatening cancer. To be clear, that means these people have late-stage cancer and know they are likely or definitely going to die.
The pilot study, published in 2011, administered psilocybin to 12 participants. Reduced anxiety was documented immediately after the session and at 1 and 3-month follow ups, and significant improvement in mood (reduced depression) was found after 6 months.34
Two further studies of this type were published in 2016, with larger samples sizes of 51 and 29.3536 Results were similar, with marked reductions in anxiety and depression in 60-80% of participants, and in some cases complete remission of symptoms.
These results are remarkable not only because they show persistent benefits for many months after a single medication administration, but also because of the large magnitude of clinical effects. Approximately 80% of participants at the 6-month follow-up continued to show clinically significant decreases in depressed mood and anxiety, and approximately 60% showed remission: in other words, symptom levels in the normal range.37
In both studies, the subjective intensity of mystical experience mediated clinical benefits.38
The significant association of mystical-type experience (MEQ30) during Session 1 with most of the enduring changes in therapeutic outcome measures 5 weeks later is consistent with previous findings showing that such experiences on session days predict long-term positive changes in attitudes, mood, behavior, and spirituality. For most measures, this relationship continued to be significant when the intensity of overall psilocybin effect was controlled in a partial correlation analysis. This suggests that mystical-type experience per se has an important role apart from overall intensity of drug effect. Finally, a mediation analysis further suggested that mystical-type experience has a mediating role in positive therapeutic response.39
A 2016 study examined the effects of psilocybin on treatment-resistant major depression in 12 volunteers.40 The participants had been suffering severe depression for years or decades, and had all tried other modalities including counselling, therapy, and multiple antidepressants with no success. Part of the inclusion criteria for the study was that a participant had to have tried at least one course each of two different antidepressants during the current depressed period.
Participants received two doses of psilocybin 7 days apart with psychological support before, during and after sessions. The results are remarkable:
…eight (67%) of the 12 patients achieved complete remission at 1 week and seven patients (58%) continued to meet criteria for response (50% reduction in BDI [Beck Depression Inventory] score relative to baseline) at 3 months, with five of these (42%) still in complete remission.41
Although this study did not explicitly measure mystical experience, the principle causal mechanism underlying the positive changes was found to be an increase in a general sense of “connectedness”. Connectedness is closely related to the mystical experience, and increases in connectedness correlate highly with ego-dissolution.42 Patients’ firsthand accounts of their experiences also include descriptions of oneness and direct connection with God and the divine, which are suggestive of mystical experience.43
What about the rest of us?
As you can see, there is good data supporting psychedelic-induced mystical experience for the treatment of various mental health and addiction issues. This work is extremely promising and there is much more to come. But as I said in the first post in this series, much of my interest here is in the “betterment of the well”. What effect does mystical experience have on otherwise healthy people who do not suffer from these ailments?
Increase in Positive Attitude, Mood, and Social Behaviour
In the 2006 Johns Hopkins study mentioned above, mystical experience had a lasting impact on the subjectivity of participants as well as their behaviour in the outside world.44 There were notable increases in mood, positive behaviour, and altruism (care for others) in social interaction. These changes were reported by the participants themselves, and corroborated by friends, family, and community members around them.45
Compared to methylphenidate [placebo], the psilocybin session experience produced significant increases in ratings of positive attitudes, mood, social effects, and behavior when rated retrospectively at both 2 months and at the 14-month follow-up46
Increased Wellbeing & Life Satisfaction
In this same study, 64% of the 36 participants reported that the psilocybin experience increased their sense of well-being or life satisfaction.47
the psilocybin session was associated with significant increases in ratings of the personal meaning of the experience, the spiritual significance of the experience, and well-being or life satisfaction due to the experience. No volunteer rated the experience as having decreased his or her sense of well-being or life satisfaction at either 2 months or the 14-month follow-up.48
This is in addition to, as mentioned before, many participants regarding the experience as among the most meaningful and significant of their lives. The lasting impact of the experience is supported by further population data showing that lifetime psychedelic use is associated with reduced psychological distress and reduced chance of suicide.4950
Mystical experience is among the most profound and meaningful experiences a person can have, if not the single most. The history of such experiences goes back thousands of years, and there is a common set of qualities that unites them. Mystical experience involves a sense of complete unity, bliss, direct connection with the divine, timelessness, awe, and self transcendence.
Mystical experience can come about spontaneously and through meditation or fasting, but this is rare. Classical psychedelics like LSD and psilocybin are the only way we know to reliably and safely bring it about. Psychedelics do this by acting on a set of brain regions called the Default Mode Network, which is responsible for our sense of self in space and time, self-referential memory, mind-wandering and more.
Research shows that psychedelic-induced mystical experience can successfully treat tobacco addiction, alcoholism, depression, and anxiety, often better than existing treatment modalities. Psychedelic-induced mystical experience also increases life satisfaction and wellbeing, and creates positive mood and behavioural changes that are observable in the outside world.
That’s pretty amazing, isn’t it?
If you made it all the way to the end, you’re probably wondering how you can have your own mystical experience. That is the subject of the next and final post in this series, which looks at how research methodology, physical setting, music choice, substance, dose and more contribute to increased likelihood of mystical experience.
- Harmless, William (2007), Mystics. p.14, Oxford University Press. ↵
- W. Hood Jr, Ralph & Paul Williamson, W. (2012). An empirical test of the unity thesis: The structure of mystical descriptors in various faith samples.. Journal of Psychology and Christianity. 19. 232-244. ↵
- Anthony, Francis-Vincent & A. M. Hermans, Chris & Sterkens, Carl. (2010). A Comparative Study of Mystical Experience Among Christian, Muslim, and Hindu Students in Tamil Nadu, India. Journal for the Scientific Study of Religion. 49. 264 – 277. 10.1111/j.1468-5906.2010.01508.x. ↵
- Chen, Zhuo & Qi, Wen & W. Hood, Ralph & Watson, Paul. (2011). Common Core Thesis and Qualitative and Quantitative Analysis of Mysticism in Chinese Buddhist Monks and Nuns. Journal for the Scientific Study of Religion. 50. . 10.1111/j.1468-5906.2011.01606.x. ↵
- Barrett, Frederick & Griffiths, Roland. (2017). Classic Hallucinogens and Mystical Experiences: Phenomenology and Neural Correlates. Current topics in behavioral neurosciences. . 10.1007/7854_2017_474. ↵
- Ibid. ↵
- Schultes RE, Hofmann A, Rätsch C (2001) Plants of the Gods: their sacred, healing, and Hallucinogenic powers. Healing Arts Press. ↵
- Yaden, David & Le Nguyen, Khoa & Kern, Margaret & B. Belser, Alexander & Eichstaedt, Johannes & Iwry, Jonathan & E. Smith, Mary & Wintering, Nancy & R.W., Jr, Hood, & Newberg, Andrew. (2016). Of Roots and Fruits: A Comparison of Psychedelic and Nonpsychedelic Mystical Experiences. Journal of Humanistic Psychology. 57. . 10.1177/0022167816674625. ↵
- Garcia-Romeu, Albert & Griffiths, Roland & Johnson, Matthew. (2015). Psilocybin-Occasioned Mystical Experiences in the Treatment of Tobacco Addiction. Current drug abuse reviews. 08. . 10.2174/1874473708666150107121331. ↵
- Griffiths, Roland & Richards, William & Johnson, Matthew & McCann, Ud & Jesse, Robert. (2008). Mystical-Type Experiences Occasioned by Psilocybin Mediate the Attribution of Personal Meaning and Spiritual Significance 14 Months Later. Journal of psychopharmacology (Oxford, England). 22. 621-32. 10.1177/0269881108094300. ↵
- Griffiths, Roland & Richards, William & Mccann, Una & Jesse, Robert. (2006). Psilocybin Can Occasion Mystical-Type Experiences Having Substantial and Sustained Personal Meaning and Spiritual Significance. Psychopharmacology. 187. 268-283. 10.1007/s00213-006-0457-5. ↵
- Griffiths et al. (2008) ↵
- Griffiths et al. (2006) ↵
- W. Jr Hood, Ralph. (1975). The Construction and Preliminary Validation of a Measure of Reported Mystical Experience. Journal for the Scientific Study of Religion. 14. 29. 10.2307/1384454. ↵
- Caird, Dale. (1988). The Structure of Hood’s Mysticism Scale: A Factor-Analytic Study. Journal for the Scientific Study of Religion. 27. 122. 10.2307/1387407. ↵
- F. Reinert, Duane & R. Stifler, Kenneth. (1993). Hood’s Mysticism Scale Revisited: A Factor-Analytic Replication. Journal for the Scientific Study of Religion. 32. 383. 10.2307/1387178. ↵
- W. Jr Hood, Ralph & J. Morris, Ronald & Watson, Paul. (1993). Further factor analysis of Hood’s Mysticism Scale. Psychological Reports. 73. . 10.2466/pr0.1993.73.3f.1176. ↵
- Nour, Matthew & Evans, Lisa & Nutt, David & Carhart-Harris, Robin. (2016). Ego-Dissolution and Psychedelics: Validation of the Ego-Dissolution Inventory (EDI). Frontiers in Human Neuroscience. 10. . 10.3389/fnhum.2016.00269. ↵
- Ibid ↵
- Barrett, Frederick & Johnson, Matthew & Griffiths, Roland. (2015). Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin. Journal of psychopharmacology (Oxford, England). 156. . 10.1177/0269881115609019. ↵
- Barrett & Griffiths (2017) ↵
- J. Chalmers, David. (2000). Facing Up to the Hard Problem of Consciousness. Journal of Consciousness Studies. 2. . 10.1093/acprof:oso/9780195311105.003.0001. ↵
- Barrett & Griffiths (2017) ↵
- Ibid. ↵
- Ibid. ↵
- Ibid. ↵
- Ibid. ↵
- Ibid. ↵
- Garcia-Romeu et al. (2015) ↵
- Johnson, Matthew & Garcia-Romeu, Albert & Griffiths, Roland. (2016). Long-term follow-up of psilocybin-facilitated smoking cessation. The American journal of drug and alcohol abuse. 43. 1-6. 10.3109/00952990.2016.1170135. ↵
- Johnson, Matthew & Garcia-Romeu, Albert & Johnson, Patrick & Griffiths, Roland. (2017). An online survey of tobacco smoking cessation associated with naturalistic psychedelic use. Journal of psychopharmacology (Oxford, England). 31. 269881116684335. 10.1177/0269881116684335. ↵
- Bogenschutz, Michael & Forcehimes, Alyssa & A Pommy, Jessica & Wilcox, Claire & Ribeiro Barbosa, Paulo Cesar & J Strassman, Rick. (2015). Psilocybin-assisted treatment for alcohol dependence: A proof-of-concept study. Journal of psychopharmacology (Oxford, England). 29. . 10.1177/0269881114565144. ↵
- Johnson, Matthew & Griffiths, Roland. (2017). Potential Therapeutic Effects of Psilocybin. Neurotherapeutics : the journal of the American Society for Experimental NeuroTherapeutics. 14. . 10.1007/s13311-017-0542-y. ↵
- Grob, Charles & Danforth, Alicia & S Chopra, Gurpreet & Hagerty, Marycie & Mckay, Charles & Halberstadt, Adam & Greer, George. (2011). Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer. Archives of general psychiatry. 68. 71-8. 10.1001/archgenpsychiatry.2010.116. ↵
- Griffiths, Roland & Johnson, Matthew & A Carducci, Michael & Umbricht, Annie & Richards, William & Richards, Brian & P Cosimano, Mary & Klinedinst, Margaret. (2016). Psilocybin produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial. Journal of Psychopharmacology. 30. 1181-1197. 10.1177/0269881116675513. ↵
- Ross, Stephen & Bossis, Anthony & Guss, Jeffrey & Agin-Liebes, Gabrielle & Malone, Tara & Cohen, Barry & Mennenga, Sarah & Belser, Alexander & Kalliontzi, Krystallia & Babb, James & Su, Zhe & Corby, Patricia & L Schmidt, Brian. (2016). Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: A randomized controlled trial. Journal of Psychopharmacology. 30. 1165-1180. 10.1177/0269881116675512. ↵
- Johnson & Griffiths (2017) ↵
- Ross et al. (2016) ↵
- Griffiths et al. (2016) ↵
- Carhart-Harris, Robin & Bolstridge, Mark & Rucker, James & Day, Camilla & Erritzoe, David & Kaelen, Mendel & Bloomfield, Michael & A Rickard, James & Forbes, Ben & Feilding, Amanda & Taylor, David & Pilling, Steve & H Curran, Valerie & Nutt, David. (2016). Psilocybin with psychological support for treatment-resistant depression: An open-label feasibility study. The Lancet Psychiatry. 3. . 10.1016/S2215-0366(16)30065-7. ↵
- R. Carhart-Harris et al. (2016) ↵
- Carhart-Harris, Robin & Erritzoe, David & Haijen, E & Kaelen, Mendel & Watts, R. (2017). Psychedelics and connectedness. Psychopharmacology. . 10.1007/s00213-017-4701-y. ↵
- Watts, Rosalind & Day, Camilla & Krzanowski, Jacob & Nutt, David & Carhart-Harris, Robin. (2017). Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression. Journal of Humanistic Psychology. 57. 002216781770958. 10.1177/0022167817709585. ↵
- Griffiths et al. (2006) ↵
- Griffiths et al. (2008) ↵
- Ibid. ↵
- Ibid. ↵
- Ibid. ↵
- Hendricks, Peter & Thorne, Christopher & Clark, Charles & Coombs, David & Johnson, Matthew. (2015). Classic psychedelic use is associated with reduced psychological distress and suicidality in the United States adult population. Journal of psychopharmacology (Oxford, England). 29. . 10.1177/0269881114565653. ↵
- S Krebs, Teri & Johansen, Pål-Ørjan. (2013). Psychedelics and Mental Health: A Population Study. PloS one. 8. e63972. 10.1371/journal.pone.0063972. ↵