The healing properties of psilocybin mushrooms are being explored. Photo / Getty Images
Back in the 1960s, George Goldsmith's use of magic mushrooms was purely recreational. "It was... an exploration like many people do when they're younger. I found it really very interesting."
Now magic mushrooms have propelled Goldsmith higher than he could ever have possibly imagined - to the helm of a company worth US$1.99bn (NZ$2.81bn).
Indeed Compass Pathways, the London-based mental health start-up Goldsmith founded and runs with his wife, Ekaterina Malievskaia, has tripled in value since stocks launched on the Nasdaq on September 20th - tribute, Goldsmith says, to the "level of need that drives people to view us as that important".
Believers include Peter Thiel, co-founder of PayPal and celebrated investor, in Facebook among others.
Others are more sceptical, pointing out that Compass' single product, a synthetic version of psilocybin, the active ingredient in magic mushrooms, is still only in phase two trials (the result of which are expected next year) and probably three years from commercial therapeutic launch.
But either way, there is no doubting the extraordinary reversal of fortunes underway for drugs - like psilocybin, ketamine and cannabis - once viewed as criminal but now as medicinal - and potentially hugely profitable.
Psilocybin in particular, is aimed at patients - several million each in Europe and the US - with treatment-resistant depression.
"People get into a really rigid pattern of thinking and view of the world as not being a good place," says Goldsmith. Psilocybin, he says, breaks up those patterns, acting as "a critically important reset".
But there is no denying that the treatment, which patients would undergo with a trained therapist, is out of the ordinary. "It isn't as though people are experiencing Harvey the bunny rabbit or monsters… but it is a full-on psychedelic journey that has a profound impact."
So profound, in fact, that the beneficial effects of a single session might last weeks or even months, helping patients off the daily rounds of pills that most current treatments require, if they exist at all.
Goldsmith is quick to insist that this beneficial "journey" is not all about the trip - patients will undergo preparatory and post-session therapy. But he is evangelical about the possibilities which, he says, draw on "research and mental-health based innovation in the UK", yet could transform "global mental health".
The foundations were laid less than a decade ago, he says, by "the groundbreaking work" of two British researchers - David Nutt and Robin Carhart-Harris at Imperial College, which "really indicated the [negative] brain mechanisms" that psilocybin might be able to alleviate or improve.
Now, he says, Britain is still the heart of the magic mushroom revolution. The largest trial of psilocybin conducted so far, on89 healthy participants, took place at King's College London last year, and Compass is today conducting trials at NHS sites. Goldsmith says the health service is watching closely.
"Far too many people are suffering; the current tools don't work for enough; there is chronic medicine use with chronic side effects, so I think there's a great deal of interest in this."
Little, however, can happen before the trials results are in. Goldsmith fully admits that there is still a lot we don't know about psilocybin as a medicine: dosage, duration, even safety. "There are no significant concerns emerging yet [on safety] but again that's why we're doing the research." Quantifying and standardising such treatments is an expensive, time-consuming business, - as company accounts showing tens of millions of investment this year show.
In all it has been seven years since Goldsmith, an American who spent time in the free-thinking Pacific state of Oregon (which, coincidentally, voted last month to legalise psilocybin and decriminalise possession of heroin), turned his mind to magic mushrooms again for the first time in 30 years.
Then it was his wife who, looking for therapies to help her depressed son, came across an article about psilocybin. "She said, 'George, you were around in the 60s, what do you know about this stuff?'"
Their medical quest became desperate. "He was placed on so many of the traditional antidepressants and medicines on top of medicines, he became unrecognisable to us," Goldsmith, 65, recalls. "We nearly lost him three times in a year." The situation, happily, has improved now, notably after therapy with ketamine, a drug known on the street as "Special K", but now an approved and regulated treatment under the brand name Spravato.
Such is the journey to respectability that Goldsmith hopes psilocybin will emulate. For it is not, he says, merely depression that it can address. The ability to disrupt "rigid" mental patterns is applicable in a host of areas, from body dysmorphia to eating disorders. The original paper that Malievskaia was studying in 2013 addressed Obsessive Compulsive Disorder.
Compass is also on the lookout for new compounds too, he says, that might do the job of psilocybin but be faster acting.
In August the company teamed up with Jason Wallach, Assistant Professor of Pharmaceutical Sciences at the University of Philadelphia, to create a Drug Discovery Centre developing psychedelic compounds that target a brain receptor thought to be key to mental health.
Understanding such receptors are key to traditional biotech research. "And critical to our work [too]," says Goldsmith.
"But there's another layer above that, which is the mechanism of change from someone being deeply depressed and disconnected from every aspect of their life to being connected to their family."
Compass aims fundamentally to understand and improve both - "the mechanism of change in addition to the biological mechanism of action."
Easygoing, his crisp white hair thinning above tinted John Lennon shades and an equally crisp white shirt, looking every inch the teenage mushroom-sampler made good, it's easy to believe he will. Millions of lives, and billions of dollars, will rise or fall on the outcome.