Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness

Abstract

A large body of evidence, including longitudinal analyses of personality change, suggests that core personality traits are predominantly stable after age 30. To our knowledge, no study has demonstrated changes in personality in healthy adults after an experimentally manipulated discrete event. Intriguingly, double-blind controlled studies have shown that the classic hallucinogen psilocybin occasions personally and spiritually significant mystical experiences that predict long-term changes in behaviors, attitudes and values. In the present report we assessed the effect of psilocybin on changes in the five broad domains of personality - Neuroticism, Extroversion, Openness, Agreeableness, and Conscientiousness. Consistent with participant claims of hallucinogen-occasioned increases in aesthetic appreciation, imagination, and creativity, we found significant increases in Openness following a high-dose psilocybin session. In participants who had mystical experiences during their psilocybin session, Openness remained significantly higher than baseline more than 1 year after the session. The findings suggest a specific role for psilocybin and mystical-type experiences in adult personality change.

Figure 1

Change in Openness from screening to post-test as a function of mystical experience during the high-dose psilocybin session (N = 52). Data points show individual experimental data; a linear regression line has been fit to those data.

Figure 2

Changes in Openness after psilocybin in participants who did and did not have mystical experiences. Figure shows Openness T scores at screening (Pre) and post-test (Post) in participants who had a complete mystical experience (n = 30; filled symbols) and those who had an incomplete or no mystical experience (n = 22; open symbols). Data points are means; bars show ± 1 SEM; asterisk indicates a significant difference (p < .001) at the post-psilocybin assessment. Screening levels of Openness and its facets did not differ between participants who met the criteria for having had a complete mystical experience and those who did not (ps > .10).

Figure 3

Changes in five facets of Openness after psilocybin in participants who did and did not have mystical experiences. Figure shows facet T scores (Fantasy, Aesthetics, Feelings, Ideas and Values) at screening (Pre) and post-test (Post) in participants who had complete mystical experiences (black bars) and those who did not (grey bars). Bars show means; brackets indicate statistical differences (*p < .05, **p < .01).