Multimodal autonomic arousal tracks dose-dependent affective dynamics during the acute effects of DMT
Tomás Ariel D’amelio, Tomás Gil Garbagnoli, Jerónimo Rodríguez Cuello, Evan Lewis-Healey, Carla Pallavicini, Federico Cavanna, Nicolás Marcelo Bruno, Laura Alethia De la Fuente, Stephanie Müller, Debora Copa, Tristán Bekinschtein, Diego Vidaurre, Enzo Tagliazucchi
bioRxiv May 4, 2026 DOI: 10.64898/2026.04.30.721872
Summary
AI-generated from the abstractInhalation of DMT, a serotonergic psychedelic, produces a brief surge in sympathetic nervous system activity—heart rate, skin conductance, and respiration—that closely tracks the intensity of the emotional experience. Nineteen participants received 20 or 40 mg of DMT under a semi-naturalistic blinded design. Higher doses caused heart rate and breathing to increase within the first two minutes, while skin conductance rose only later, indicating a prolonged autonomic response. As the drug's effects waned, feelings of pleasantness and bliss emerged. Combining simple physiological measures with moment-by-moment self-reports offers a way to objectively characterize psychedelic-induced emotional states, which may aid future clinical biomarker research.
Study at a glance
| Characteristics | Semi-naturalistic blinded design Peer reviewed |
|---|---|
| Sample size | 19 |
| Population | Human participants |
| Interventions | N N-dimethyltryptamine (DMT) |
| Dose | 20 or 40 mg of freebase N,N-dimethyltryptamine (DMT) |
| Key finding | DMT induces a transient sympathetic activation that covaries with emotional arousal, followed by gradual disengagement accompanied by pleasantness and bliss. |
Abstract
ABSTRACT Serotonergic psychedelics induce altered states of consciousness characterised by profound changes in emotional experience. Although psychedelics modulate autonomic arousal, sympathetic engagement during their affective effects remains poorly characterised. We recorded cardiac, electrodermal, and respiratory activity in 19 participants following inhalation of 20 or 40 mg of freebase N,N-dimethyltryptamine (DMT) under a semi-naturalistic blinded design, alongside time-resolved retrospective phenomenological reports. DMT induced robust increases across all autonomic markers, integrated into a multimodal index that selectively tracked subjective emotional intensity. Dose-dependent divergence followed modality-specific profiles: heart rate and respiratory differences emerged within the first 2 min post-inhalation, whereas electrodermal activity diverged only during the later phase, with higher doses showing prolonged autonomic engagement. DMT thus produces a transient sympathetic activation co-varying with emotional arousal, followed by gradual disengagement accompanied by pleasantness and bliss. By combining time- and cost-effective peripheral physiological measures with time-resolved phenomenological reports, this work contributes to the objective characterisation of psychedelic-induced affective states and provides a methodological basis for future biomarker research in clinical applications.