Psilocybin Reorganizes the Brain Into Structured Patterns, Five-Year Monash Study Finds

A five-year brain-imaging study at Monash University in Australia has found that psilocybin — the chemical that makes some mushrooms 'magic' — does not simply plunge the brain into chaos, but reorganizes its activity into structured patterns aligned with what a person is doing and experiencing. The study, published in the journal Nature, produced the largest single-site psychedelic neuroimaging dataset to date.

The researchers compared electroencephalography (EEG) readings of brain waves and functional MRI scans of 62 healthy adults, none of whom had taken psychedelics before, recorded before and after a dose of psilocybin. Shortly after dosing, participants were scanned as they rested with eyes closed for five minutes, followed an audio-guided meditation, listened to music, and then opened their eyes to watch a short movie; a similar sequence was repeated during the EEG sessions.

Tracking brain activity moment by moment with a machine-learning method, the team found that what looked like disorder contained pathways whose structure closely matched each context. The order was strongest in participants who reported a profound, positive experience marked by a reduced sense of separation between self and world — the self-dissolving experiences sometimes called 'ego death', which the researchers suggest could be key to psychedelic treatments' benefits.

First author and neuroscientist Devon Stoliker told New Atlas that the boundary between self and world may not be fixed: the findings suggest brain systems actively maintain this distinction, and psilocybin can temporarily dissolve it. Senior author and computational neuroscientist Adeel Razi said the important question is not whether psychedelics replace existing treatments, but which patients benefit, under what conditions, and how reliably.

Like most psychedelics, psilocybin acts on a specific type of serotonin receptor in the brain, triggering its characteristic hallucinations and inducing neural plasticity — making it a candidate therapy for depression, PTSD and anxiety. The team's next step is to determine whether the individual brain signatures can be generalized enough to predict meaningful therapeutic change.