A psychedelic revival: an antidote to the side effects of chemotherapy. In Science

In September, Science published the results of a study showing that the administration of psilocybin – the substance found in hallucinogenic mushrooms – could prevent damage to nerve fibres caused by chemotherapy drugs. The study combined experiments on mice with analyses of nerve cells and tissues, both human and animal. The discovery is significant because chemotherapy is a life-saving treatment which sometimes needs to be reduced or discontinued altogether as it can cause peripheral neuropathy – that is, pain and impaired tactile sensation in the limbs. It was observed that psilocybin acts on serotonin receptors, preserving the function of mitochondria (the cells’ powerhouses) and thus preventing the deterioration of nerve fibres and, ultimately, the symptoms of peripheral neuropathy.

Although this discovery has nothing to do with the psychedelic properties of psilocybin – and therefore with the hallucinatory effects experienced when taking hallucinogenic mushrooms – it nevertheless speaks to the rehabilitation that psychoactive substances have been undergoing for the past twenty years or so. That is, what is generally referred to as the ‘psychedelic renaissance’. It is no coincidence that, in Australia, since 2023, specifically authorised psychiatrists have been able to prescribe psilocybin to people diagnosed with treatment-resistant depression. But what happens to the brain when psilocybin is taken? This was the question posed in 2012 by a group of researchers led by Carhart-Harris, a professor at Imperial College London. In this study, the researchers used functional magnetic resonance imaging to observe how the brain responded to psilocybin. The results showed that levels of brain activation decreased significantly, even though it had previously been commonly assumed that psychedelic substances worked by increasing neural activity.

The fact that activity levels were reduced in the areas of the brain responsible for emotional regulation and decision-making, such as the anterior cingulate cortex, has led to the hypothesis that psilocybin acts as a sort of ‘relief valve’, as a means of deactivating the personal frameworks used to experience and interpret the world, ‘allowing for a state of uninhibited cognition’. It is as if to say: ‘Veil of Maya, adieu!’ Indeed, the authors emphasise that people suffering from depression exhibit excessive activity in the ventromedial prefrontal cortex, which manifests as rigidity and pessimism, as well as a tendency to slip into negative moods. According to the findings of their research, it is precisely this excess activity that psilocybin appears to dampen. While not all results are conclusive, studies conducted during these years of the ‘psychedelic renaissance’ appear encouraging.