Michael Pollan was at a dinner party when he overheard a prominent psychologist talking about her recent acid trip, and the insight it gave her.

It got him thinking.

Pollan, a US author and journalism professor at Harvard and Berkeley universities, became "intensely curious" about psychedelic drugs.

He spoke to people participating in clinical trials who were being treated for anxiety or alcohol addiction with psilocybin, the active ingredient in magic mushrooms.

Pollan says he was "so struck" by their transformations "after a single psychedelic experience".

Sorry, this audio has expired Hear more from Michael Pollan about trying psychedelic drugs in the name of science.

"In many cases they acquired a new perspective on their life," he tells RN's Life Matters.

"They said things like, 'It was like the camera had been pulled back further on the scene of my life than it ever had and I saw myself from a distance in a whole new way'.

"Their sense of themselves as an individual became much less separate from nature, from other people, from the universe.

"It made me very curious as to whether I could do a similar reset myself."

Pollan, who also read research on the topic, then undertook a "reset" of his own.

His "liberating" experiment involved taking hallucinogenic drugs like LSD, mushrooms and ayahuasca — which all have potentially dangerous side-effects.

The risks of psychedelic drugs Frightening and disturbing hallucinations

Frightening and disturbing hallucinations Panic and unpredictable behaviour that can be dangerous

Panic and unpredictable behaviour that can be dangerous Confusion

Confusion Fast or irregular heartbeat

Fast or irregular heartbeat Vomiting, sweating or chills

Vomiting, sweating or chills A 'flashback' experience days, weeks, months and even years after use Source: Alcohol and Drug Foundation

Pollan, who was initially sceptical about the therapeutic use of psychedelics, is now convinced of its value.

'You're the astronaut' — but there are risks

Pollan first experimented with psychedelic drugs in his 20s.

Now in his early 60s, he says this time it was about more than getting high — he had something to learn.

"Psychedelics may be wasted on the young," says Pollan, who has written about his experience and research in How To Change Your Mind.

"I think that there is something about what they do to the mind that is particularly valuable when you get older."

Ahead of his "reset", Pollan took steps to decrease the potential risks associated with his drug use.

He sought a thorough health-check from his doctor before embarking on his psychedelic experiments. His drug use often involved a supervisory "guide" who stayed with him during the experience.

"They hold your hand if you are getting upset, they help you get up and go to the bathroom, and they are with you, which gives you a sense of safety," he explains.

"They'll tell you sometimes: 'We're mission control and you're the astronaut, and you should feel free to go as far out into space as you want and we are here watching you and we'll take care of your body'."

Pollan notes that a "bad trip" is a distinct possibility — it may feel like "you're going crazy or melting or dying", or you may feel anxious, or "that you are being pursued".

The guide, he says, can help get past that feeling.

"If you're willing to relax your mind and let it float downstream, as John Lennon famously put it, you will pass through that scary place into often quite an ecstatic place," Pollan says.

Former Beatle John Lennon was known to experiment with drugs. ( Getty: Michael Putland )

Experts are quick to point out the high risks associated with taking psychedelics — guide or no guide.

Dr Stephen Bright, senior lecturer in addiction at Edith Cowan University, says recreational users have no control over the quality or dose of what they're taking.

"You can't have a quality control in a black market," he says.

He says participants in controlled clinical or research environments are heavily screened.

"There's a range of mental health disorders that contraindicate psychedelic drugs," he says, including "psychotic mental illness, bipolar disorder [and] borderline personality disorder".

"If somebody isn't screened appropriately it could exacerbate a mental illness."

He says the psychedelic experience "can be quite intense, psychologically".

"If there's not good integration that takes place afterwards people may find it difficult reintegrating back into their day-to-day role afterwards," he says.

That's accounted for in a medical setting, where someone usually stays overnight in the hospital so that the next morning hours can be devoted to "integration work": discussing "the experience they had, and what that means to them", and how to "implement what they've learned in their day-to-day life".

"And in doing so they're not discharged from the hospital until it's determined that they're psychologically well enough to go home," Dr Bright says.

A 'temporary rewiring of the brain'

Pollan says by experimenting with psychedelic drugs he learned a lot about himself — and also about why psychedelics "in carefully calibrated doses" could be a useful tool in treating mental illness.

He says they appear to achieve a "temporary rewiring of the brain".

In some US clinical trials, he says, scientists imaging the brains of people on psilocybin "are discovering some very interesting things".

"When you have a high-dose trip on psilocybin or LSD, you would expect the brain to kind of erupt in a lot of excitation because that's how the experience feels, there are all these visual fireworks," he says.

"But in fact, what happens is that one particular network in the brain, something called the default mode network, is deactivated, it kind of goes offline."

That part of the brain, he says, is involved in generating a sense of being a self, and self-criticism.

Disrupting that, Pollan says, "appears to be the therapeutic mechanism by which [psychedelic drug-taking] helps people".

Dr Bright says it's important the clinical trials Pollan references are approached with caution.

"I would say that the trials occurring overseas demonstrate a good evidence that psychedelic assisted psychotherapy is a useful tool in treating depression; anxiety associated with end of life, so people with terminal cancer; addiction to tobacco as well as alcohol," he says.

However, he's concerned that with increased media attention in Australia about such trials — undertaken in places like the US, UK and New Zealand — "more and more people are looking to the underground to access these treatments".

"With that comes a range of problems because it's not regulated," he says.

'A really difficult topic'

There are potential benefits, Dr Bright says, but they exist alongside potential serious risks.

"It's a really difficult topic," he says.

Pollan is a firm believer in the value of psychedelics.

He says their use also offers a chance to understand "the greatest mystery we face" — consciousness.

"Nobody understands consciousness or how brains produce an interior life," he says.

"The fact that it means something to be you, it feels like something to be you and you have experience from a subjective point of view, that's a great mystery.

"By disturbing that consciousness you can understand it better."

Pollan believes his experience has helped him better understand what it is we're made of — and made him feel more tightly tethered to the world around him.

"One of the really striking things about psychedelics is that they make you feel very interconnected with other things," he says.