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Speech markers of psychedelic-induced psychological change

Joanna Kuć, Rosalind McAlpine, Amelia Sellers, George Blackburne, Daniel R Lametti, Jeremy I Skipper

bioRxiv April 21, 2025 preprint DOI: 10.1101/2025.04.16.649217 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Longitudinal observational study
Sample size 29
Population Adults participating in a 5-MeO-DMT retreat
Intervention 5-MeO-DMT
Dose 1×12 mg
Duration Two weeks before and two weeks after the 5-MeO-DMT session
Keywords Psychedelics Mental health Linguistics Cognitive science Communication patterns
Key findings Speech markers shifted toward increased cognitive language and decreased social words, and voice quality changed, with baseline features predicting psychological outcomes after 5-MeO-DMT.

Abstract

Abstract 5-MeO-DMT, a potent, short-acting psychedelic, induces profound shifts in cognition, affect, and self-awareness. Because language explicitly expresses these domains and voice implicitly conveys them, both may serve as potential ‘biomarkers’ of behavioural change. This study introduces a novel framework for analysing baseline language and vocal features, pre- to post-psychedelic changes, assessing their potential to predict subjective experiences and psychological outcomes. Daily voice journals from 29 participants were collected via ‘RetreatBot’ for two weeks before and after 5-MeO-DMT (1×12 mg). Transcripts were analysed using NLP (bag-of-words for vocabulary; transformer model for textual affect), and acoustic features (e.g., pitch, jitter, shimmer) were extracted to assess vocal dynamics. Following 5-MeO-DMT, speech markers revealed increased cognitive language, decreased social words, and altered voice quality (increased jitter/shimmer). Baseline speech patterns predicted psychological preparedness, ego dissolution anxiety, emotional breakthrough, and post-experience well-being. This first longitudinal analysis of speech markers following psychedelic use demonstrates a shift from external focus to introspection. Speech markers predicted and tracked psychological transformation, establishing vocal journaling as a valuable framework for monitoring psychedelic-induced changes and facilitating integration.