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.
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 meditationspiritual practices. Healthy participants were randomized to three groups (25 each) (1) very low-dose (1 mg70 kg on sessions 1 and 2) with moderate-level (standard) support for spiritual-practice (LD-SS) (2) high-dose (20 and 30 mg70 kg on sessions 1 and 2, respectively) with standard support (HD-SS) and (3) high-dose (20 and 30 mg70kg on sessions 1 and 2, respectively) with high support for spiritual practice (HD-HS). Psilocybin was administered double-blind and instructions to participantsstaff 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 meaningpurpose, 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 meditationspiritual practices. Psilocybin can occasion enduring trait-level increases in prosocial attitudesbehaviors and in healthy psychological functioning. Trial Registration ClinicalTrials.gov Identifier NCT00802282.