For decades, psychedelics belonged more to the world of counterculture, magic mushrooms and the 1960s than serious medicine and now scientists are putting them inside brain scanners.
A major Australian study has produced one of the clearest pictures yet of what happens to the human brain under the influence of psilocybin, the psychedelic compound found in so-called magic mushrooms.
It comes as psychedelic-assisted therapy moves further into clinical medicine in Australia and overseas, raising a question few would have imagined being asked seriously a generation ago: why are scientists taking psychedelics so seriously?
Researchers from Monash University spent five years examining the effects of psilocybin on healthy adults in what they describe as the world’s largest single-site brain-imaging study of its kind.
Published in Nature, their findings challenge the idea that psychedelics simply send the brain into chaos. Instead, beneath the disruption, researchers found patterns of organisation influenced by what a person was experiencing at the time.
The research grew from Monash’s PsiConnect project and involved 62 healthy adults with no previous psychedelic experience.
Participants received 19mg of psilocybin and underwent brain monitoring using MRI and EEG. Their brains were studied while resting, meditating, listening to music and watching a movie.
Half had also completed an eight-week mindfulness course.
Scientists already knew psychedelics could disrupt the usual organisation of brain networks. Lead researcher Dr Devon Stoliker, from Monash’s Turner Institute for Brain and Mental Health, said his team found something else beneath that disruption.
“We uncovered hidden order within that disruption,” he said.
Under psilocybin, networks involved in processing our internal and external worlds became less distinct. But they also reorganised according to what participants were experiencing.
The effect was strongest among those who reported more positive experiences and a reduced sense of separation between themselves and the world around them — an experience the researchers called “embeddedness”.
Some of the most revealing results came from a very simple test. Normally, closing our eyes dramatically changes the visual information reaching the brain. Under psilocybin, people can continue experiencing vivid visual phenomena even with their eyes shut.
Researchers found the difference between eyes-open and eyes-closed brain activity shrank by 85 per cent in the visual network. Across all brain networks, it fell by more than two-thirds.
EEG measurements showed a similar effect, with the difference in a major brain rhythm between the two states falling by 48 per cent.
Psilocybin wasn’t simply shutting down normal brain activity. It was changing the boundaries between different brain states.
The brain’s response also depended on what participants were doing. Resting, meditating, listening to music and watching moving images produced different patterns of brain organisation.
“What a person is doing and focusing on shapes how their brain responds,” senior researcher Professor Adeel Razi said.
That finding is particularly relevant to psychedelic-assisted therapy, where considerable importance is placed on “set and setting” — broadly, a person’s state of mind and the environment in which the experience takes place.
Participants also rated music as substantially more meaningful and emotionally resonant after taking psilocybin.
Those who showed stronger brain reorganisation were more likely to report positive psychological changes the following day. Researchers also used machine learning to examine individual responses rather than relying solely on averages across the group.
Eventually, that may help scientists understand why people respond differently to psychedelic therapy and whether brain activity can tell clinicians something useful about those responses.
We’re not there yet.
Australia has already moved further down this road than many countries.
Since July 2023, authorised specialist psychiatrists have been able to prescribe psilocybin for treatment-resistant depression and MDMA for post-traumatic stress disorder under strict conditions.
Both remain unapproved medicines in Australia. They have not been evaluated by the Therapeutic Goods Administration for quality, safety and efficacy and included on the Australian Register of Therapeutic Goods.
Access is tightly controlled. Psychiatrists need approval from a human research ethics committee and specific TGA authorisation, while protocols allowing patients to take the medicines home are not accepted.
The international picture is changing as well.
On September 4, New Zealand’s medicines regulator approved two psychiatrists to prescribe pharmaceutical-grade MDMA as part of treatment programs for eligible adults with PTSD.
Then there is the money flowing into the field.
In July, pharmaceutical giant Eli Lilly agreed to acquire psychedelic medicine developer AtaiBeckley in a deal worth up to US$3.8 billion. That acquisition was completed on September 11.
AtaiBeckley’s lead investigational program is BPL-003, a psychedelic-based nasal spray being developed for treatment-resistant depression.
It is a remarkable change in status for substances that spent decades largely outside mainstream medicine.
But psychedelic-assisted therapy remains a highly controlled and developing field.
The Monash study doesn’t prove psilocybin will successfully treat depression or other mental health conditions.
Its 62 participants were healthy adults, not patients being treated for depression. They knew they had taken psilocybin and there was no placebo group.
Their responses also varied despite receiving the same dose.
Researchers don’t yet know whether particular surroundings, music or activities produce better therapeutic outcomes. Nor do they know whether the brain patterns they’ve identified can predict which patients will benefit.
That’s where some of the most interesting research may now lie.
Psychedelics have travelled an extraordinary distance from their counterculture reputation. Scientists can now watch, with increasing detail, what happens to the brain as perception changes — while psychiatrists, regulators and pharmaceutical companies investigate whether some of those effects can be put to medical use.
What once appeared to be chaos inside the brain is starting to look considerably more organised.
IMPORTANT LEGAL INFO This article is of a general nature and FYI only, because it doesn’t take into account your personal health requirements or existing medical conditions. That means it’s not personalised health advice and shouldn’t be relied upon as if it is. Before making a health-related decision, you should work out if the info is appropriate for your situation and get professional medical advice.
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