Meditation, Psychedelics, and Brain Connectivity: A Randomised Controlled Resting-State fMRI Study of N,N -Dimethyltryptamine and Harmine in a Meditation Retreat
medRxiv Klemens Egger, Daniel Meling, Firuze Polat et al. preprint
In a double-blind, placebo-controlled pharmaco-fMRI study, 40 meditation practitioners on a three-day retreat received either placebo or buccal DMT-harmine (120 mg each). Meditation alone increased network segregation across several resting-state networks, while DMT-harmine increased functional connectivity within the visual network and between visual and attention networks. Between-group differences showed increased connectivity between visual and salience networks in the DMT-harmine group. No prolonged cortical gradient disruption was observed, indicating a return to typical brain organization shortly after the experience. Meditation reduced connectivity between networks, whereas DMT-harmine increased within- and between-network connectivity, revealing distinct neural mechanisms.