“We have the chance to demonstrate the breadth and depth of experience and expertise that we have here,” Langmead said.

Professor Susan Rossell,the lead researcher on Australia’s largest trial examining psilocybin for treatment-resistant depression,which began on February 2,said the TGA’s approval had been rushed and the research was still in its infancy.

“I think they have succumbed to pressure by lobbyists,” said Rossell,a cognitive neuropsychologist and research fellow at Swinburne’s Centre for Mental Health.

“There is no long-term safety data,especially for psilocybin. It’s just super premature. There’s just no guidelines on a whole pile of things that people are going to need to know to do this safely.”

In amedia release earlier this month,the TGA said the decision was made after extensive public consultation,a report from an expert panel and advice from the Advisory Committee on Medicines Scheduling.

It said the decision acknowledges the current lack of options for patients with specific treatment-resistant mental illnesses and means psilocybin and MDMA can be used therapeutically in a controlled medical setting.

To prescribe,psychiatrists will need to be approved by a human research ethics committee and by the TGA under theAuthorised Prescriber Scheme.

“The Authorised Prescriber Scheme allows prescribing permissions to be granted under strict controls that ensure the safety of patients,” the TGA said.

Dr Daniel Perkins,an adjunct associate professor at the Centre for Mental Health at Swinburne University,said there is a need for caution but the way the TGA had allowed access was very controlled.

“It’s quite a good and pragmatic balance between enabling access to the medications,which could potentially provide a lot of benefit to patients with PTSD or treatment-resistant depression,who aren’t responding to existing treatments,while also minimising risk.”

Perkins is the co-executive director of Psychae Institute,a non-profit medicinal psychedelics research centre studying the use of the psychedelic drug Dimethyltryptamine (DMT) for treatment-resistant depression and alcoholism.

Perkins said the TGA was signalling that psychedelic compounds would be treated similarly to medicinal cannabis,which was approved for use as an unregistered medicine without phase three clinical trials.

“So it really means the pathway to market for psychedelic compounds could be much,much quicker,” Perkins said. “This really makes the area much more attractive for investors.”

Patrick McGorry,a psychiatrist and executive director of Orygen,the National Centre of Excellence in Youth Mental Health,said he was “absolutely stunned” by the approval of medicinal psilocybin.

“I’ve seen significant numbers of patients over the years become psychotic on that drug,and while they say in the clinical trial,so far,that hasn’t happened,you can’t really screen subjects for vulnerability to psychosis,” McGorry said.

“If people are being treated for treatment-resistant depression,that would be a higher risk group for having a psychotic reaction to the drug.”

Imperial College London professor David Nutt,a strong advocate for the use of psychedelic-assisted therapies to treat mental illness,said there had been no cases of psychosis in the thousands of people given psilocybin in modern clinical trials.

But he said these excluded people with a known family risk of schizophrenia and he agreed with McGorry there was a risk in the vulnerable,especially if taken outside a clinical setting.

Nutt,who is director of the university’s neuropsychopharmacology research unit,said he met with the TGA last year and presented them with new evidence into the current research into psilocybin and MDMA.

“In the last 10 years,there have been major expert groups reviewing the harms of a range of drugs,and they’ve all included psychedelics,” he said. “They all come to the same conclusion that these drugs are amongst the least harmful of all the drugs that are used,either recreationally or clinically,that come under some kind of control.”

Nutt said the TGA’s decision would mean that real-world evidence could be generated alongside the ongoing clinical trials.

“The information we’re going to generate through this Australian initiative is going to be produced at a cost that is a fraction of the cost of RCTs[randomised controlled trials],” he said.

Nutt believes that in five years,most Western countries will follow Australia’s lead and allow some psychedelic therapy for a number of disorders,which could include treatment-resistant PTSD,obsessive compulsive disorder,anorexia and pain syndrome.

“I think there will be a sea change,” he said. “And I think Britain is going to lag behind,which is one of the reasons I love working with you guys,because you’re so far ahead of the game.”

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