RCT · 2025
DMT plus harmine during a meditation retreat: brain connectivity changes two days later
- Original title
- Meditation, psychedelics, and brain connectivity: A randomized controlled resting-state fMRI study of N,N-dimethyltryptamine and harmine in a meditation retreat.
- Authors
- Egger K, Meling D, Polat F, et al.
- Journal
- Imaging neuroscience (Cambridge, Mass.), 2025
- Molecules
- DMT, Ayahuasca, Other
- Conditions
- Healthy volunteers
- Participants
- 40
- Evidence grade
- Moderate
- Source
- Read the original paper
The question
Does a single dose of an ayahuasca-inspired preparation (DMT combined with harmine) taken during a meditation retreat change how brain networks connect, compared with a placebo?
What they did
Forty meditation practitioners took part in a 3-day meditation retreat. They were randomly assigned, with neither they nor the researchers knowing who got what, to receive either a placebo or a buccal (absorbed in the cheek) preparation containing 120 mg of DMT and 120 mg of harmine. Everyone had resting-state functional MRI brain scans 2 days before and 2 days after the dose, and researchers compared several measures of how brain networks connect to each other.
What they found
Within the placebo group, meditators showed more separation between several resting-state brain networks after the retreat. The DMT-harmine group instead showed increased connectivity within the visual network and between the visual network and attention networks. Comparing the groups directly, the DMT-harmine group had greater connectivity between the visual network and the salience network after the retreat. The researchers found no lasting disruption of the large-scale cortical organization that is typically seen during the acute psychedelic experience, suggesting the brain returned to its usual pattern soon afterward.
The fine print
Only 40 people took part, and they were experienced meditators in a retreat setting, so results may not apply to patients or to other contexts. Scans were done just 2 days after dosing, so nothing is known about longer-term effects. The study measured brain connectivity, a surrogate marker, and the abstract reports no mental health or wellbeing outcomes, so it cannot show clinical benefit. This summary is based on the abstract alone.
What it means
Meditation alone and meditation combined with DMT-harmine appear to leave different short-term fingerprints on brain network connectivity, but this study does not tell us whether either approach improves mental health.
Evidence grade: Moderate. A randomized, double-blind, placebo-controlled trial, but with only 40 people, a short follow-up, and brain-imaging measures rather than health outcomes.
This summary is based on the study’s published abstract.