Psychedelics alter metaphysical beliefs

Abstract

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 significant shifts away from 'physicalist' or 'materialist' views, and towards panpsychism and fatalism, post use. With the exception of fatalism, these changes endured for at least 6 months, and were positively correlated with the extent of past psychedelic-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 consolidated by data from an independent controlled clinical trial. Together, these findings imply that psychedelic-use may causally influence metaphysical beliefs-shifting them away from 'hard materialism'. We discuss whether these apparent effects are contextually independent.

Figure 1

Psychedelic use is associated with shifts in metaphysical beliefs away from hard physicalism or materialism. Attending a psychedelic ceremony was associated with shifts away from hard-materialistic views (a-left), and items associated with transcendentalism, non-naturalism, panpsychism, primacy of other realms, dualism and solipsism/idealism (b-left), with some changes enduring up to 6 months (Bonferroni-corrected). Additionally, significant positive relationships were observed between lifetime psychedelic use and baseline scores on metaphysical beliefs (a-right), and items referring to transcendentalism, non-naturalism, and panpsychism, while a negative relationship was found with materialism (b-right). (b-left: mean values and standard errors displayed. *Significant change at 4 weeks; **significant change at 6 months, Bonferroni-corrected; b-right: * p < 0.0001, Bonferroni-corrected).

Figure 2

The nature of belief-shifts post-psychedelic-use. Matrices displaying the rate of belief-shift from and towards different ‘hard’ metaphysical positions are displayed at 4 weeks (a-above) and 6 months (b-above) following the ceremony. Significant rates of change were found only for respondents’ endorsing materialism at 4 weeks (a-below) and 6 months (b-below), with most of these ‘hard materialists’ leaning towards dualism or equanimity (or reduced hard materialism) post-ceremony. Significant rates of belief-shift were also found for respondents with non-committal views on panpsychism at baseline, who then shifted towards a panpsychist ‘believer’ stance at 4 weeks (c) and 6 months (d) post-ceremony. (e) Lifetime psychedelic use was positively correlated with panpsychist views and negatively correlated with hard materialistic views measured at baseline. (*p < 0.05, **p < 0.01, ***p < 0.001).

Figure 3

Shifts away from hard materialistic beliefs are associated with increases in well-being. A positive correlation was observed for shifts away from hard materialism versus changes in well-being at both (a) 4 weeks and (b) 6 months.

Figure 4

Changes in non-physicalist beliefs are moderated by baseline variables and pre-state identify fusion and mediated by acute emotional synchrony during the psychedelic session. Path model showing changes in Non-physicalist Beliefs to be affected by several demographic and trait characteristics including absorption, gender and age, mediated through perceived emotional synchrony during the psychedelic group session. The effect of synchrony on non-physicalist beliefs was conditional on respondents’ baseline scores of peer conformity. Standardized β-coefficients are shown for significant (p < 0.05) regression paths (not shown are additional significant correlations between non-physicalist beliefs at baseline and absorption with gender, r = 0.19 and r = 0.16, respectively, as well as a significant effect between beliefs at baseline and at 4 weeks post-session; β = 0.75.

Figure 5

Consistent shifts away from physicalism after psilocybin therapy for depression: (a) significant shifts away from hard physicalism were only seen for psilocybin and not the escitalopram condition at the 6 week endpoint versus baseline (Bonferroni-corrected; p values and Cohen’s d effect sizes shown). (b) Greater belief-shifts in the predicted direction were found for treatment responders in the psilocybin condition versus responders in the escitalopram group (p value and Hedges’ g effect size shown). (c) Shift in non-physicalist beliefs were significantly associated with increases in ‘Spiritual Universality’ (STS scale) at the 6-week endpoint versus baseline, and this was specific for the psilocybin group (i.e., it was not seen in the escitalopram group).