Early last year, Australian researchers travelled to a two-day psychedelics retreat in the Netherlands to ask attendees if they would like to take part in a study.
Many said they'd give it a go. They consumed the psilocybin (found in magic mushrooms) they'd been planning to take, and then, hours later, as the effects were waning, they put on VR headsets.
Now they were immersed in a soothing outdoor environment hung with stars like giant fireflies.
In this VR world, they could grab a star and use it as an audio recording device, to speak to themselves about what had happened over the past few hours, during the peak of their trip.
The audio recordings they made formed a twinkling constellation representing their experience.
The following day, they returned to this VR world, and accessed their recordings to unpack and make sense of their experience. Within this virtual world, the participants could choose to nourish certain stars (and the associated thoughts and emotions) while symbolically letting go of others.
Some stars might be planted to grow into trees, while others could be burned in a virtual bonfire.
In recent years, two separate trends — improvements in headset technology and the growing use of psychedelic drugs in therapy — have intertwined.
From July, approved psychiatrists in Australia will be able to prescribe MDMA for post-traumatic stress disorder and psilocybin for treatment-resistant depression.
With MDMA (ecstasy) and ketamine also increasingly being trialled as mental health treatments, researchers are experimenting with the use of VR as a tool for psychedelic therapy.
Much of the work in this field is being done in Australia, where a small number of researchers are developing the world's first VR-assisted treatment protocols.
Can a headset help capture the fleeting insights generated while being high?
How psychedelic treatment works
The psychedelic therapy process generally has three phases: preparation, dosing and integration.
In the "preparation" phase, the therapist explains to the patient how psychedelics work, what kind of experiences might come up and how to process them as they happen.
Together they decide on an "intention" — an emotion or problem that they want to focus on during the experience.
During the "dosing" phase, the patient takes the psychedelics and is generally left alone as much as possible, with the therapist present to support them if they need help.
The final 'integration" phase typically begins the following day, then continues indefinitely, with repeat follow-up sessions between therapist and patient.
The role of the therapist is to initially learn what kind of insights and emotions emerged during the dosing session, and then unpack and identify the underlying themes.
But this can be difficult to achieve, said Agnieszka Sekula, a PhD candidate at Swinburne University.
"The main problem that we see with this approach is that the psychedelic experience is typically an emotional, embodied, experiential type of session.
"Whereas the psychedelic psychotherapy framework is still based to a large degree on talk therapy, which is a far more cognitive and analytical process."
About four years ago, Ms Sekula wondered if VR might be the solution.
Could it bridge the gap between dosing and integration phases by helping the patient recall what they had experienced?
"Integration initially is based on trying to remember, trying to reconnect to that experience and then process it," Ms Sekula said.
"We try to make that first component of it as easy and as rich as possible so that as much of this material is recorded as possible.
"And then it's easier for the patient and therapist to dive deeper into this and build as much on it as possible."
A 'multi-sensory canvas' that belongs to the patient
In 2020, she and a medical doctor, Prash Puspanathan, founded a start-up called Enosis Therapeutics.
The company would explore the use of VR as a tool within psychedelic therapy. In March 2022, with Luke Downey, a professor of neurocognition at Swinburne, they co-authored a paper describing some of their ideas, published in the journal Frontiers in Psychology.
That led to the recent pilot study in the Netherlands, where these ideas and theories were put in practice.
By that point, they had designed, built and tested the virtual world with bonfire, rolling surf and low-hanging stars for recording audio.
Under the VR-assisted treatment protocols, the world was designed to be an environment that patients shaped for themselves, a "mind map" of their psychedelic experience.
A therapist could "see" into this world, but they could not enter it. On a computer screen, they could watch the patient and listen to their recordings, but they had no avatar.
The recordings and other data were owned by the patient and stored on the laptop running the VR program.
The patient could return to the world through their treatment and keep shaping its "multi-sensory canvas".
Voice recordings proved to be powerful tools of recall, Ms Sekula said.
"They're reminded of what the experience was like by hearing the account of that experience in their own voice, with all those expressions and the emotional load that is attached to their voice."
Taking it to the Netherlands
One of the first questions that would be answered by the Netherlands study was: would anyone want to experiment with VR during a psychedelic experience?
Some in the psychedelic therapy community have been sceptical of VR, said Professor Downey, who was involved in the Netherlands pilot study.
"They suggested it was maybe interrupting the genuine mystical experiences among other people," he said.
But it turned out participation wasn't a problem.
"About 50 per cent of people who were at the retreat at the time said, 'Yes, I'll try that out,'" he said.
Afterwards, they were asked if they would do it again.
"About 90 per cent said they thought it was appropriate, they enjoyed it, and they would do it again as part of the psychedelic experience."
Participants were also interviewed about what it was like using the technology.
Ms Sekula said the results had not yet been published, but the people who had used VR in the dosing phase had better recall of their psychedelic experience.
She shared quotes from unnamed participants in the study:
"There were more memories than I thought. I thought I didn’t need the star to record this but then I actually said more than I remember."
"VR helped me to reflect on the experience, it kept the marvel; you're not tripping anymore but you are reminded by this magic vision."
"The stars fuelled with memories were helpful in structuring the mind."
A larger trial is now in the works. Late last year, Enosis announced it had partnered with Berlin-based Ovid Clinics, which uses ketamine to treat depression, anxiety, trauma and OCD.
Patients at the clinics will have the option of experiencing psychedelics in combination with the VR-assisted treatment protocols developed by Enosis.
It will be the world's first in-clinic trial of psychedelic therapy in conjunction with VR.
"They're offering it at the moment to the clients that are starting their ketamine treatments," Ms Sekula said, adding that some psychiatric clinics in Melbourne are also looking to partner with Enosis.
"[The clinics] are still learning and we're in the very early days with them."
Selling shovels in a gold rush
Professor Downey, who's not associated with Enosis, said he started out sceptical of VR's role in psychedelic treatment, but now thinks it has a future.
"We've got a lot of a lot of interest and it's definitely got people out there thinking, 'What can we do in VR? What would be our treatment protocol that makes a difference?'"
Investors were looking to make money from the emerging market of psychedelic treatments, he said.
"You can't patent the cannabis plants or LSD.
"You've got to have something else. What's going to be patentable and what's going to be the efficacy?"
Just down the road from Swinburne in Melbourne, researchers at Monash University have developed an exposure-therapy-based treatment for anxiety that combines VR and psychedelics.
The treatment has already been licensed by the Australian pharmaceutical company Icannex.
Some longstanding advocates for psychedelic therapy are wary of the new interest in VR.
Rick Doblin, who founded the Multidisciplinary Association for Psychedelic Studies (MAPS) in California in 1986, was critical of the use of what he called "guided imagery".
"You're having a VR program that's supposed to somehow remind you of your own inner imagery, so it will be not as precise as your own imagination," he said.
In other words, VR was solving a problem that did not exist.
Plus, he added, numerous clinical trials show that psychedelic treatment works fine without VR assistance.
He pointed to a recent MAPS trial of MDMA as a treatment for PTSD. Eighty-eight per cent of participants either had no PTSD or experienced "significant reductions" of PTSD symptoms.
"So the question is, what are we trying to fix?" he said.
"There are 12 per cent non-responders. Would VR help them?"
Transcendent experiences in a headset
Meanwhile, on the distant frontiers of psychedelic research, a bold idea has taken shape: is there a way to skip the drugs altogether?
Could VR on its own achieve the states of altered consciousness that are usually associated with a psychedelic trip?
In August 2022, in a study published in the journal Nature Scientific Reports, a team of researchers from the UK and Spain described their attempts to produce in virtual reality something that psychedelics reliably elicit: a "self-transcendent experience".
That is, the expansion of personal boundaries, including, potentially, a feeling of unity with other people or your surroundings.
To do this, the researchers developed a VR model called Isness-D, where each user is represented as a diffuse cloud of smoke, with a ball of light about where their heart would be.
If they choose to, participants in groups of four or five can gather in the same spot in the VR landscape to overlap their diffuse bodies, to create a sense of deep connectedness and "ego attenuation".
For their paper, the researchers measured the emotional response Isness-D elicited in 75 participants, basing their measurements on metrics already used in psychedelic research, such as experiences of ego dissolution and of intense shared humanity that transcends social structure.
On four key indicators, the program showed the same effect as a medium dose of LSD or psilocybin, according to the study.
This may seem abstract research, but communal VR meditation apps that use methods like the ones described in the study are already becoming available.
And they're attracting interested investors.
The CEO of the makers of one of these apps, Tripp, calls this industry "digital therapeutics" and has identified the metaverse as an opportunity for growth.
In a funding round last year it raised millions from companies like Amazon and Pokemon Go developer Niantic.
It's a scary idea: big business meddling in the realm of the spiritual, offering up mystical communion and shared humanity.
Think of mass transcendent experiences. Think of millions of glowing orbs.