Psychedelics, Mystical Experience, and Therapeutic Efficacy: A Systematic Review

Abstract

The mystical experience is a potential psychological mechanism to influence outcome in psychedelic therapy. It includes features such as oceanic boundlessness, ego dissolution, and universal interconnectedness, which have been closely linked to both symptom reduction and improved quality of life. In this review, 12 studies of psychedelic therapy utilizing psilocybin, ayahuasca, or ketamine were analyzed for association between mystical experience and symptom reduction, in areas as diverse as cancer-related distress, substance use disorder, and depressive disorders to include treatment-resistant. Ten of the twelve established a significant association of correlation, mediation, and/or prediction. A majority of the studies are limited, however, by their small sample size and lack of diversity (gender, ethnic, racial, educational, and socioeconomic), common in this newly re-emerging field. Further, 6 out of 12 studies were open-label in design and therefore susceptible to bias. Future studies of this nature should consider a larger sample size with greater diversity and thus representation by use of randomized design. More in-depth exploration into the nature of mystical experience is needed, including predictors of intensity, in order to maximize its positive effects on treatment outcome benefits and minimize concomitant anxiety.Systematic Review Registration: PROSPERO, identifier CRD42021261752.

Association between mystical-type experiences under psychedelics and improvements in well-being or mental health – A comprehensive review of the evidence

“…The review did find several dozen studies that have assessed this association, with most reporting positive associations between mysticaltype experience and medium-to-long term improvement in well-being or mental health. This concurs with the findings of Ko et al (2022) limited to clinical studies and changes in symptoms of psychiatric disorders. However, the current level of evidence for such positive links appeared different for changes in different aspects of well-being or mental health.…”

“…Many recent studies have explored this association, but to my knowledge, the evidence on this question has not been comprehensively synthesized. Recently, Ko, Knight, Rucker, and Cleare (2022) did specifically and systematically review the evidence for mystical experiences under psychedelics associating with reduction in symptoms of mental health disorders in clinical studies of psychedelic-assisted therapy. Including, besides classic psychedelics, studies on ketamine, they found twelve such studies and noted that ten out of them provide evidence for such an association.…”

“…Including, besides classic psychedelics, studies on ketamine, they found twelve such studies and noted that ten out of them provide evidence for such an association. My review here differs from that of Ko et al (2022) in that all types of quantitative studies in all kinds of populations are included and in that it is limited to classic psychedelics only.…”

On the need for metaphysics in psychedelic therapy and research

“…In turn, it is conjectured that such additional metaphysical sense-making will increase the long-term benefits of psychedelicassisted psychotherapy. This conjecture stems from two main seeds: First, there is compelling evidence that psychedelic-induced metaphysical experiences per se are a mechanism of positive psychological benefit (Roseman et al, 2018;Mollaahmetoglu et al, 2021;Rothberg et al, 2021;Yaden and Griffiths, 2021;Ko et al, 2022;McCulloch et al, 2022). Second is the thought that there may be less reason for the individual to come to reject the significance of such experiences as delusional once they realise that there may be more reason to bestow potential veridicality to the experience.…”

Acute effects of subanesthetic ketamine on cerebrovascular hemodynamics in humans: A TD-fNIRS neuroimaging study

“…It is argued that one of the predictors of outcome measures in psychedelic therapy is the intensity of mystical experiences reported by the participants 62 . As such, exploring parameters capable of such predictive power can pave the way for treatment optimization.…”