A clinic in Bristol has become the first in the UK to use ketamine-assisted therapy to treat patients with mental health issues.
The Awakn Clinic, which has just opened its doors, says its drug-assisted therapy aims to help treatment-resistant people who suffer from addiction or other mental health conditions.
The treatment offers involves a low dose of ketamine alongside talking therapy, and will cost £6,000 per patient.
What is ketamine?
Ketamine is an illegal class B drug in the UK but is often used recreationally by younger populations. In medical settings, the drug is used as an anaesthetic.
The clinic has opened following growing evidence from trials around the world, showing that psychedelics can be highly effective in treating all manner of mental health conditions, from PTSD to addiction and depression.
In the UK, ketamine has been trialled as a treatment for depression since 2011. Historically, it has not been accompanied by talking therapy in the manner Awakn is offering.
Some experts have criticised the cost of treatment and questioned whether there is enough research to support the use of ketamine in the clinic setting.
Professor David Nutt, scientific advisor to the clinic told the BBC, however: "Psychedelics are ushering a whole new paradigm for psychiatry with other countries moving very fast and we don't want to be left behind.
"Current psychiatric treatments are not adequate for a significant proportion of patients."
But, Bristol Psychedelic society coordinator Rhodri Karim warned, meanwhile that a medical setting like the clinic might not be an ideal place for a patient to "achieve healing" while using a psychedelic substance.
They told the BBC: "The medical context shouldn't be assumed as the best.
"There are plenty of contexts in other cultures where psychoactive medicines are used that are not medical and it begs the question as to whether medicine is the best places to be administering these treatments."
The clinic will treat people with a number of disorders, including OCD, anxiety, PTSD and depression. It has said that the therapy is intended for people who have tried a number of different avenues for their mental health problems but seen little progress or improvement.