The brain on DMT: mapping the psychedelic drug's effects

“Perhaps [entity encounters] relate to the fact that, certainly throughout our lives, but especially early on in our lives, we’re surrounded by entities – as in people,” says Carhart-Harris, who has a background in psychoanalytic and psychodynamic psychology.

“The first thing that we manage to focus our gaze on are people, and their eyes, usually. So it just follows that this will be a major part of the human psyche, and likely a major part of the unconscious.”

Carhart-Harris hopes to show that an encounter with an entity may show a similar pattern of brain activity to an encounter with a person.

“It’s not a bulletproof approach,” he says. “But we’re working on the hypothesis that the experience of entity encounters rests on brain activity. And if it does, then why don’t we look at the neural correlates of some elements of encounters [with] entities off the drug, and get a sense of where people’s brains are sensitive.”

The researchers will also be paying close attention to the transcendental qualities of the DMT experience. By asking participants to rate the intensity of experience, they hope “to capture, potentially, that leap” into another world which characterises a trip.

The experiment is the latest from Imperial College’s neuropsychopharmacology unit as part of the Beckley/Imperial Research Programme. Professor David Nutt is overseeing the study, Carhart-Harris and Timmermann designed it, and Timmermann is carrying it out.

They have a formidable record of safe experimentation with psychedelics, thanks to previous high-profile work with LSD and psilocybin. So securing permission to do the study was “quite a smooth process,” according to Carhart-Harris. Particularly when it came to the Ethics Review Committee.

“They were quite warm really to us. We even had someone on the panel whose eyes were really lighting up, basically volunteering to be part of the study,” he said. (The unnamed panel member was sadly not eligible to participate).

To make sure they get it right, the team has also called on the godfather of DMT research: Rick Strassman, clinical associate professor of psychiatry at the University of New Mexico School of Medicine.

Strassman gave advice on dosage and administration. He gave several hundred doses of the drug to volunteers between 1990-95, famously coining DMT “the spirit molecule” because of the wide range of mystical experiences participants reported.

Carhart-Harris is less enamoured by the use of non-secular, unscientific language to describe the DMT experience.

“It’s quite easy to hear a lot of pseudo-scientific musings and this idea of the ‘spirit molecule’ is in that space,” he said, later adding that psychedelics researchers “worry that they, as individuals, will be stigmatised and thought of as not serious scientists”.

DMT is best understood as “a tool that can be used to understand consciousness,” says Timmermann.

“It’s hard to find other tools out there that can alter consciousness so dramatically and so reliably,” says Carhart-Harris.

The dosage the researchers have settled on is 20mg – a quantity that is significantly more potent than it would be if smoked (the usual route of administration) due to its intravenous administration.

“I would characterise it as a moderate-high dose of DMT,” says Timmermann.

Participants will lie in the fMRI with an EEG cap on and their eyes closed. The whole experiment takes 20-30 minutes (the duration of a DMT trip), with researchers interjecting regularly to ask them to rate the intensity of the experience.

“We’re mostly looking at spontaneous brain activity, or ‘resting’ brain activity,” says Carhart-Harris. “Because resting, especially under DMT – you wouldn’t really call it rest.”

“People are not able to do a task or engage with the external world in that state,” agrees Timmermann.

researchers will record the experience and how it unfolded over time from the participant in very fine detail – a kind of peer-reviewed trip report.

12 people have already gone through the pilot, which involved just an EEG scan. A further 20 will go through the full EEG and fMRI scan.

One question that they do not expect to answer is why DMT exists in nature. “The DMT question is more for DMT enthusiasts, perhaps,” says Carhart-Harris.

But the question of why humans possess a specific serotonin receptor that DMT binds to is a big one, he says.

“As far as we know it’s one particular serotonin receptor that’s key to how these drugs work in the brain. It’s a big curiosity and a question that is unanswered in science. What are these receptors for, and what do they do?”

The answer may provide clues to the ability of psychedelic drugs to facilitate behavioural change. Studies have shown that they can be useful in the treatment of addictive or compulsive behaviours.

Finding a clinical application for DMT is “not the primary outcome,” however, says Timmermann. “These are all completely healthy people. So it’s hard to draw a direct inference on mental health, because they’re all well."

But preliminary results from the pilot suggest that DMT improves mood. “There is a significant drop in the depression scores,” says Timmermann.

And ultimately the team at Imperial, like scientists from all over the world making discoveries in the so-called psychedelic renaissance, envision a future when psychedelics can be prescribed by doctors and made available in a therapeutic setting.

“In many ways that’s the ultimate aim,” says Carhart-Harris.

If Imperial’s research already has the drug prohibitionists hyperventilating, the model Carhart-Harris proposes for the NHS will send them into an altered state of consciousness. It is the administration of psilocybin and DMT (not, it should be stated, at the same time) in a series of therapeutic treatments, for those conditions where they are shown to be effective.

“People will realise that it’s quite expensive to develop this kind of treatment,” he says. “Because it’s a treatment model that requires some psychological preparation, quite a few hours of staff time to look after this patient, and ward space.

“And how is this possible in the shell of the National Health Service that we have?”

The advantage of DMT is its short acting time. Several short DMT treatments, which last under an hour, could be used to supplement psilocybin treatments, which would have effects that last for several hours.

Carhart-Harris and the rest of the team may be calling out the falsehoods people project onto the DMT experience. But they are not the only myths to ruin. He is just as comfortable providing the science that underpins the advocacy of psychedelic drugs in a therapeutic context.

“Done right, with all the appropriate caveats and safeguards, it could be a revolution in psychiatry,” he says. “It’s quite a reasonable thing to say.”

Updated 06.07.17: A reference to a specific aspect of the experiment has been removed at the request of Imperial College. The full name of the research programme carrying out the work has also been added.