The government may never be able to “think rationally” about the therapeutic properties of hallucinogenic drugs, says Professor David Nutt. The top boffin was speaking on the publication of two new studies that show the anti-depressant qualities of magic mushrooms.
Prof Nutt, who was sacked from his role as Blighty's top drug adviser for questioning the law's classification of banned substances, said: “[The government's] attitude to these drugs is so utterly irrational that you kind of think, 'maybe that irrationality is so pervasive that they could never think rationally'.”
The pair of latest studies found that the effects of psilocybin, the active ingredient in magic mushrooms, may counter depression - and help sufferers relive happy moments.
Asked whether this would mean that the government would ever approve a drug based on psilocybin, Prof Nutt said: “Of course they'd have to. What's fascinating is that you could think they wouldn't, and of course you're right.”
Developing a product that uses psilocybin requires the thumbs-up from the Medicines and Healthcare Products Regulatory Agency (MHRA), which said in a statement: “The MHRA considers each individual product on its merits and any information which may have a bearing on the product's status, for example, the claims made for the product [and] the pharmacological properties of the ingredients.”
Psilocybin was classified as a Class-A drug under the Drugs Act 2005, placing it in the same category as cocaine, heroin and methadone.
MRI scans while trippin'
In one of the new studies, published in the journal Proceedings of the National Academy of Sciences, 30 healthy volunteers had their brains scanned by MRI while researchers infused their blood with psilocybin. The scans showed a decrease in activity in the brain's “hub” regions, areas that are especially well-connected to other areas.
The decreased oxygen and blood flow to these “hub” regions correlate with study participants' reports of unusual bodily sensations and an altered sense of space and time. One region affected was the medial prefrontal cortex (mPFC), which is known to be hyperactive during depression. The researchers believe that psilocybin's effects here could explain the antidepressant properties of magic mushrooms.
"Previous studies have suggested that psilocybin can improve people's sense of emotional wellbeing and even reduce depression in people with anxiety,” said Dr Robin Carhart-Harris, from the Department of Medicine at Imperial College London, who led the studies.
"This is consistent with our finding that psilocybin decreases mPFC activity, as many effective depression treatments do. The effects need to be investigated further, and ours was only a small study, but we are interested in exploring psilocybin's potential as a therapeutic tool."
In the second study, to be published on Thursday in the British Journal of Psychiatry, volunteers were prompted to think about positive memories while their brains were scanned. Volunteers' memories were more vivid after taking psilocybin compared with a placebo.
Two weeks after the experience, participants' ratings of memory vividness under the drug showed a positive correlation with their wellbeing. The drug also increased activity in the regions of the brain that process sensory information such as vision.
Prof Nutt confirmed that since news of the findings broke yesterday, he has received emails from patients asking to be recruited into a trial. “These people are desperate and it would be iniquitous for any government to deny them treatment,” said Prof Nutt. “It makes me choke.” ®