Beyond dose. Perceived group support as a person-level predictor of emotional breakthrough and psychological insight during DMT–harmine administration

Abstract Dose-escalation studies with dimethyltryptamine (DMT) show robust increases in emotional breakthrough, mystical experience, and psychological insight at higher doses, but with substantial inter-individual variability, suggesting factors beyond pharmacology shape response profiles. Growing evidence points to the clinical relevance of social factors, especially in group-based psychedelic therapy. Using data from a randomized-controlled trial, we investigated oromucosal DMT-harmine administration in a group setting and identified a three-layer architecture of acute psychedelic experience. First, dose scaled all three primary subjective outcomes. Second, perceived group support, reflecting stable between-person differences rather than session-to-session fluctuations, accounted for a substantial share of dose-independent between-subject variance in emotional breakthrough and psychological insight, though not in mystical-type experience. Third, pre-session affective personality, indexed by an approach-withdrawal composite, predicted group appraisal, with more approach-oriented profiles linked to more favorable perceptions of the group context. We situate these findings within the current research landscape and discuss the clinical implications of this three-layer framework for acute psychedelic experience.