Psilocybin: The Scientific View

Image: (left) brain on a placebo, (right) brain on psilocybin. Each colour represents a different cortical region, and the lines indicate functional connectivity between the regions.

I work with psilocybin for three main reasons: it’s legal in Holland, where I facilitate the experience itself (preparation and integration can be done in the UK/on Zoom); it’s easily grown locally and therefore is non-extractive from indigenous cultures; and most modern research on psychedelics has focused on psilocybin. Plus, you know, it has a fancy name. So three and half reasons, then.

But what is it? Well, psilocybin is a tryptamine, which is a monoamine alkaloid (monoamines are neurotransmitters. Other monoamines are serotonin and dopamine; and alkaloids are naturally occurring compounds). More than 200 species of mushrooms produce psilocybin. Once consumed, psilocybin swiftly metabolises into psilocin, which acts by stimulating the brain’s 5-HT2A receptors, among others. One reason why these receptors have evolved is to produce serotonin, which makes the brain more adaptable (or ‘plastic’) in times of distress.

By stimulating these receptors, activity is reduced in a brain region called the Default Mode Network (DMN). The DMN is often associated with activities such as self-reflection; complex mental imagery; mental time-travel, such as ruminating about the past and worrying about the future; theory of mind - the ability to attribute mental states such as beliefs, desires, emotions, and knowledge to oneself and others; and metacognition - being aware of one’s own awareness. It’s said that if the ego had an address, it would be the DMN. Because it’s where the mind goes to ruminate, an overactive DMN is linked to having wide-ranging consequences, from mental health issues to stunted creativity.

As the psilocin reduces activity in the DMN and other systems, normal signals within the brain are not able to run along the same neural pathways. Neuroplasticity increases as a result, as the brain automatically creates new pathways and alternative ways to exchange information, thereby increasing connectivity between brain regions that don't usually communicate (see the image above). This increased connectivity can enhance creative thinking and break unhelpful patterns, helping to establish fresher behaviours and beliefs. Brighter Pathways, if you will.

A commonly-used metaphor compares the brain to a snow-covered hill, with thoughts like sleds travelling down the hill. Every time we have the same thought, it creates deeper trails in the snow on the hill, until the sled becomes locked into them when it travels down. Those main trails represent the most well-travelled neural connections in the brain, including our ruminations, or our incessant inner critic. Over time, it becomes increasingly difficult to glide down the hill on a different path, or in a different direction. The psilocybin experience can be like a fresh fall of snow. The old trails become covered, allowing our thoughts to glide in other directions, exploring new landscapes. This ‘resnowing’ effect is thought to be one of several mechanisms behind a wide range of positive outcomes, as old pathways are replaced with fresh ones, helping us to move beyond our limitations.

Now, this is a very brain-centric view, because that's what the science has focused on to date. But we also need to incorporate the body, too. Where some say the body has a brain, it’s more accurate to say the body is a brain. Decades of research show us that our bodies store memories, emotions, blocks, and trauma. And trauma here can be defined as the consequence of anything that overwhelms the psyche and nervous system - which means that many of us may have trauma stored in the body, on a continuum, whether from an overwhelming event or period of time, including accidents or surgery. Even the process of birth can be traumatic. And with the emerging science of epigenetics, it’s possible that we have inherited trauma, too.

Hence why we need to learn how to tune in to, and release from, the body, while also understanding our processes and reframing our life scripts in the mind. And since the state of our nervous system informs, and often even creates, our mental and emotional states (including depression and anxiety), it has become clear to me that we must see working somatically as being foundational.

"Where some say the body has a brain, it’s more accurate to say the body is a brain. Decades of research show us that our bodies store memories, emotions, blocks, and trauma. And trauma here can be defined as the consequence of anything that overwhelms the psyche and nervous system - which means that many of us may have trauma stored in the body, on a continuum, whether from an overwhelming event or period of time, including accidents or surgery. Even the process of birth can be traumatic. And with the emerging science of epigenetics, it’s possible that we have inherited trauma, too."