He is fast turning into a national treasure, is David Nutt, the UK government drugs advisor sacked for telling it like it is. Political controversy aside, Nutt is an active researcher into psychotropic drugs, and, television and press interviews aside, he occasionally does a spot of proper work. Which is just as well, in these publish or perish times.

Nutt and his colleagues have now published in peer-reviewed form the research which featured in the BBC documentary series, The Brain: A Secret History. Presenter Michael Mosley took part in Nutt’s trial of psilocybin, the hallucinogenic active ingredient of magic mushrooms. As indeed they are! From a short video clip posted on the BBC News website, you can see the effect that the drug had on Mosley. He wouldn’t stop rabbiting on about the experience.

This was a controlled scientific study, but we should not ignore the very real emotional and, dare I say it, spiritual effects that psychedelic drugs have on those who imbibe them. The effects of magic mushrooms, LSD, mescaline (peyote) and a whole number of other substances are similar, with the LSD trip being the most head-focused of all. With magic mushrooms one’s body is also affected by the drug, with the touch sensation, for example, being radically enhanced. We shall ignore the gurgling sensations in the lower regions.

Nutt’s research group has published two papers based on the psilocybin research. The first⁽¹⁾, in the Proceedings of the National Academy of Sciences, details a study in which healthy volunteers with previous positive experience of psychedelic drugs took psilocybin while inside magnetic resonance imaging (MRI) scanners, which measure changes in brain activity. The scans of the volunteers showed decreased activity in so-called “hub” regions of the brain, which are especially well-connected with other areas. This may be counter-intuitive to those used to the idea that psychedelic drugs are mind-expanding, which might imply that they increase mental activity. What psilocybin does is suppress hub activity which constrains and orders our experience of the world as experienced through the physical senses.

The MRI study revealed a decrease in oxygen supply and blood flow to the medial prefrontal cortex (mPFC) and posterior cingulate cortex (PCC) of the brain. The PCC is understood to play a role in consciousness and self-identity, while the mPFC is known to be overactive in those suffering from clinical depression. This could explain some of the antidepressant effects that have been reported for psychedelic drugs.

Nutt’s second study⁽²⁾, published in the British Journal of Psychiatry, focused on memory and positive emotions experienced while under the influence of psilocybin. The researchers found a positive correlation between memory vividness under the drug and longer-term wellbeing, with the effect lasting for weeks if not months following its consumption. If psilocybin facilitates access to memories and emotions, this has clear implications for its use as a psychotherapeutic agent.

According to Robin Carhart-Harris, first author of both papers,…

“Previous studies have suggested that psilocybin can improve people’s sense of emotional wellbeing and even reduce depression in people with anxiety. 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.”

This research is fascinating, and the results do indeed show the potential of psychedelic drugs in the treatment of depression and other disorders. But one should be very careful when it comes to public reporting of scientific research into psychedelics, owing to the dangers associated with self-medication. I say this as someone with extensive personal experience of psychedelic drugs. Positive experience, by and large.

What worries me particularly is any suggestion without caveat that hallucinogenic drugs may be beneficial to those suffering from anxiety. In the right conditions they could well be. That is, taken under controlled conditions, with the subject in the care of a qualified and sensitive therapist.

A depressed and anxious person taking such drugs outwith a controlled therapeutic environment runs the risk of inducing and exacerbating a serious panic attack, leading to a bad trip that could do significant emotional damage. Psychedelic drugs are useful tools for those engaged in a voyage of self-discovery, and they can be great fun. But they should not be played with lightly.

(1) Carhart-Harris et al., “Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin”, PNAS (2012)

(2) Carhart-Harris et al., “Implications for psychedelic-assisted psychotherapy: a functional magnetic resonance imaging study”, Brit. J. Psychiatry (2012)