Magic mushrooms growing in the wild. Photo / NZ Herald

A hallucinogenic drug derived from magic mushrooms is being given to human guinea pigs in a controversial experiment aimed at curing schizophrenia.

Professor David Nutt, who was sacked as a Government adviser after a controversy about the dangers of drugs, is leading the study that is costing the taxpayer £250,000 (NZD$585,000).

Volunteers at King's College London will be given psilocybin - the naturally occurring psychedelic compound produced by more than 200 species of mushrooms - and placed inside an MRI scanner to monitor their brain activity.

They will experience a "high" for an hour and have been warned "the size and shape of things can appear distorted, walls may appear to move, shapes and colours may be seen on surfaces, the room may appear to get bigger or brighter, and time may appear to pass more slowly".

The scientists believe the hallucinations experienced by users of magic mushrooms are caused by the same part of the brain that is active during a schizophrenic episode.

After the 24 volunteers have had their dose, they will then be given an experimental drug called saracatinib. The hope is that if the saracatinib stops the hallucinations of the psilocybin, then it could also alleviate schizophrenia.

Using psilocybin has required special permission from the Home Office. The drug is being sent from Germany, at a cost of £1,000 a dose.

The participants will all be male, aged between 18 and 50, and have previously used hallucinogenic drugs. They are being paid £350 each for taking part. Prof Nutt claims the study, funded by the Medical Research Council and conducted in conjunction with Imperial College, could provide a huge leap forward in the treatment of schizophrenia. He said: "There have been no breakthroughs in the treatment of schizophrenia for 50 years because it is such a complicated illness. Because psilocybin is a controlled substance, we have had to jump through a lot of hoops - the study was delayed for a year while we got the Home Office licence.

"Magic mushrooms can be picked for free but we are having to pay £1,000 a dose. It's madness. Our volunteers will experience the effects of the psilocybin for about an hour and there will be some of the world's best psychiatrists on hand.

"If this is successful, it could pave the way for a much larger study of the drug on people with schizophrenia. We have decades to catch up on as many drugs such as psilocybin were made illegal, and that has made studying them very difficult."

Elizabeth Burton-Phillips, of charity DrugFAM, said: "Magic mushrooms are a powerful hallucinogen which can cause real harm to the brain. As with all hallucinogenic drugs, the impact on anyone's brain is a game of Russian roulette."

- Daily Mail