Self-Transcendent Perceptual Dynamics and the Effects of Dispositional Mindfulness on Altered States of Consciousness: A Prospective Longitudinal Observational Study of a Naturalistic Psychedelic Retreat

Psychedelic substances reliably occasion transient self-transcendent states, including mystical-type experiences, which are theorized to support salutogenic psychological change and long-term well-being. Despite growing interest in these phenomena, little is known about how acute self-transcendent states translate into enduring trait-level changes, or whether individual differences such as baseline mindfulness shape these effects in real-world psychedelic settings. This naturalistic longitudinal study examined changes in mindfulness and multiple dimensions of self-transcendence during and following a medically supervised psychedelic retreat involving sequential psilocybin and dimethyltryptamine (DMT) administration. Fifty-four participants completed validated self-report measures of dispositional mindfulness, non-dual awareness (NDA), perceived body boundaries, spatial frame of reference, and acute psychedelic experiences at baseline, post retreat, and 1- and 2-month follow-ups. Linear mixed-effects models assessed longitudinal change, and regression analyses tested whether baseline mindfulness predicted acute psychedelic experiences or sustained self-transcendence. Results revealed sustained increases in mindfulness and NDA through the 2-month follow-up. Participants also reported increased bodily boundary transparency following the retreat and at the 1-month follow-up, as well as shifts toward a more allocentric spatial frame of reference that persisted across both follow-up assessments. Contrary to expectations, baseline mindfulness did not predict acute psychedelic experiences, nor self-transcendence outcomes at follow-up. Exploratory analyses revealed that acute mystical-type experiences were associated with greater bodily boundary transparency at both follow-ups and showed a trend-level association with NDA at 2 months. These findings suggest that brief, ecologically valid psychedelic retreat interventions can elicit transient selfless states that consolidate into enduring self-related trait changes, largely independent of baseline mindfulness.