Psilocybin-occasioned mystical-type experience in combination with meditation and other spiritual practices produces enduring positive changes in psychological functioning and in trait measures of prosocial attitudes and behaviors

Abstract

Psilocybin can occasion mystical-type experiences with participant-attributed increases in well-being. However, little research has examined enduring changes in traits. This study administered psilocybin to participants who undertook a program of meditation/spiritual practices. Healthy participants were randomized to three groups (25 each): (1) very low-dose (1 mg/70 kg on sessions 1 and 2) with moderate-level ("standard") support for spiritual-practice (LD-SS); (2) high-dose (20 and 30 mg/70 kg on sessions 1 and 2, respectively) with standard support (HD-SS); and (3) high-dose (20 and 30 mg/70kg on sessions 1 and 2, respectively) with high support for spiritual practice (HD-HS). Psilocybin was administered double-blind and instructions to participants/staff minimized expectancy confounds. Psilocybin was administered 1 and 2 months after spiritual-practice initiation. Outcomes at 6 months included rates of spiritual practice and persisting effects of psilocybin. Compared with low-dose, high-dose psilocybin produced greater acute and persisting effects. At 6 months, compared with LD-SS, both high-dose groups showed large significant positive changes on longitudinal measures of interpersonal closeness, gratitude, life meaning/purpose, forgiveness, death transcendence, daily spiritual experiences, religious faith and coping, and community observer ratings. Determinants of enduring effects were psilocybin-occasioned mystical-type experience and rates of meditation/spiritual practices. Psilocybin can occasion enduring trait-level increases in prosocial attitudes/behaviors and in healthy psychological functioning. Trial Registration ClinicalTrials.gov Identifier NCT00802282.

Keywords: Psilocybin; entheogen; meditation; mystical experience; psychedelic; traits.

Figure 1.

Within-session time-course of guide ratings of overall psilocybin effect during the sessions. Data points are means; brackets show ± 1 SEM (n=25); time 0=before capsule administration). The High-Dose High-Support and the High-Dose Standard-Support groups were significantly different from the Low-Dose Standard-Support group at all post-capsule time-points. The two high-dose groups were not significantly different at any time-points except for 60 and 90 minutes in Session 2.

Figure 2.

Guide ratings of volunteer behavior and mood assessed throughout the psilocybin sessions (Illustrative results from Table 2). Data are means of the peak response in each of the two psilocybin sessions in each participant. Bars show group means; brackets show 1 SEM; * indicates a significant difference from Low-Dose Standard-Support (Planned comparisons, p<.05); there were no significant differences between the High-Dose High-Support and High-Dose Standard-Support groups.

Figure 3.

Participant ratings on mystical experience questionnaires completed 7 hours after psilocybin administration (Illustrative results from Table 3). Data for the Mystical Experience Questionnaire (MEQ30) are percentages of the maximum possible score; data for the Mysticism Scale are total scores. Bars show group means; brackets show 1 SEM; * indicates a significant difference from the Low-Dose Standard-Support group; + indicates a significant difference between the High-Dose High-Support and the High-Dose Standard-Support groups (Planned comparisons, p<0.05).

Figure 4.

Spiritual practices at 6 months (from Table 4). Data, which were obtained at the 6-month follow-up, show retrospective ratings for the past 4 months. Bars displaying rate data show means; brackets show 1 SEM (n=25). Meditation rate data are minutes per day for all days. Bars displaying proportion data show the percentage of the group (n=25) reporting the practice during the indicated time interval. * indicates a significant difference from the Low-Dose Standard-Support group; + indicates a significant difference between the High-Dose High-Support group and the High-Dose Standard-Support group (Planned comparisons, p<0.05).

Figure 5.

Participant ratings of effects attributed to psilocybin session experiences at the 6-month follow-up (Illustrative results from Table 5). Data on altruistic/social effects, behavior changes, and spirituality are expressed as percentage of maximum possible score (bars show means, brackets show 1 SEM, n=25). Data for the questions about spiritual significance and change in well-being or life satisfaction are either raw scores (bars show means, brackets show 1 SEM, n=25) or percentages of the group (n=25). * indicates a significant difference from the Low-Dose Standard-Support group; + indicates a significant difference between the High-Dose High-Support group and the High-Dose Standard-Support group (Planned comparisons, p<0.05).

Figure 6.

Longitudinal measures assessed at the 6-month follow-up (Illustrative results from Table 6). Bars show means; brackets show 1 SEM (n=25); ★ indicates a significant difference between baseline and 6 months; * indicates a significant difference from the Low-Dose Standard-Support group; + indicates a significant difference between the High-Dose High-Support group and the High-Dose Standard-Support group (Planned comparisons, p<0.05). For comparison, dotted lines show mean scores from previous studies for each measure: Mysticism Scale (college students, Hood et al., 2001; Ralph W. Hood Jr, personal communication); Faith Maturity Scale (university students, Loma Linda University, 2007), Daily Spiritual Experience Scale (general population survey data, Underwood, 2006); Gratitude Questionnaire-6 (adults, McCullough et al., 2002); Life Meaning (college and community sample, Reker, 2007); Trait Forgiveness Scale (college students, Berry et al., 2005); Forgiveness Benevolence Motivation (college students, Tsang et al., 2006); Sanctification of Strivings (adults, Mahoney et al., 2005).

Figure 7.

Two observer-rated measures of participant attitudes and behavior assessed at the 6-month follow-up (from Table 6). Bars show means; brackets show 1 SEM (n=25); for both measures, * indicates a significant difference from the Low-Dose Standard-Support group; + indicates a significant difference between the High-Dose High-Support group and the High-Dose Standard-Support group (Planned comparisons, p<0.05). For the ASPIRES, which was assessed both at baseline and the 6-month follow-up, ★ indicates a significant difference between baseline and 6 months (Planned comparisons, p<0.05). Also for the ASPIRES, dotted line shows mean norm score (Piedmont, 2010).