Science of Inner Healing


Psilocybin mushrooms played an important role in Aztec rituals and were often referred to as Teonanactal (“flesh of the gods”).


Distribution of the serotonin 2A receptor in the human brain. Source: Saulin et al., 2011

What are psychedelics and how do they work?
What is psilocybin? 

Psilocybin and modern scientific research

Psilocybin is a classical psychedelic and an active component of psychoactive fungi (aka “magic mushrooms/truffles”) with a long history of ceremonial use dating back to prehistoric times (1). However, it was only in the first half of the 20th century when it became the focus of biomedical and clinical research. Despite promising preliminary results and an acceptable risk profile (2, 3), a series of reforms in the 1960s-1970s effectively shut down this vein of research for several decades (4). Only relatively recently, modern science started to revisit the medical value of classical psychedelics and psilocybin, in particular.

By the moment of writing, there are dozens of modern (completed or ongoing) small-scale clinical trials investigating the medical value of psychedelics (incl. psilocybin) for the treatment of depression, anxiety and addictions (5–7). Yet, it is important to recognise, that even despite preliminary evidence for their efficacy and safety (8), psychedelic-assisted treatment remains experimental and more large-scale studies are needed in this vein for them to be recognised by mainstream psychiatry as an officially viable treatment option.

Mechanism of action

Psilocybin acts on a variety of receptors in the brain, however, as a classical psychedelic, its characteristic psychological effects are mediated via its action on serotonin 2a receptors located in the deep layers of the neocortex (most advanced and recently developed part of the neural system). They play an important role in orchestrating interactions of high-order cognitive functions and perceptions, and are believed to be particularly important for active stress-coping behaviors (9) and neurobiological plasticity (10), or brain’s capacity for change.

On a system level, psychedelics appear to promote more flexible patterns of neural activity, widening the repertoire of the functional states that the brain can be in over a fixed amount of time (11). This is physiologically the opposite to what we typically observe in patients suffering from some psychiatric disorders like depression, which is associated with neurophysiological (12) and cognitive (13) inflexibility, allowing for rigid mental states of rumination and self-defeating thoughts. Ultimately, the ability of psychedelics to promote neural and behavioral plasticity, provides scientific justification for using these substances as catalysts and/or adjuncts to various forms of behavioral interventions and psychotherapy in particular, by creating a shift in perception and aiding in development of new mental models.

Psilocybin’s effects have been demonstrated even in otherwise difficult to treat psychiatric conditions, such as, for example, treatment resistant depression (TRD). In a small-scale trial, 9 out of 12 TRD patients did not meet criteria on the week following a high-dose session and 5 of them remained depression-free at 3-month follow-up (6).


Acute effects of psilocybin on brain connectivity.

Source: Petri et al., 2014

Changes in symptom severity in patients with treatment resistant depression following a high-dose psilocybin session.

BDI - Beck's Depression Inventory.

Source: Carhart-Harris et al., 2016

The process of change

There are dozens of psychological models of psychedelic’s action stemming from various schools of psychology. Some link their effects to the lowering of psychological resistances thereby providing more direct access to the unconscious and facilitating a discharge of emotionally charged tensions, while others emphasise the importance of the so-called mystical-type experiences, characterised by the profound ineffable experience of owe, interconnectedness with the Universe (14)

At Katharsis, we implement a holistic approach to psychedelic therapy, aligning with state-of-the-art biomedical research and medical-grade professionalism and safety, whilst paying respect to ceremonial use of these powerful substances and recognising limitations of the scientific method. Here, we establish a mutually supportive dialogue between modern medicine, academic science and spirituality to assist you on your journey toward self-discovery and healing.


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2. T. S. Krebs, P.-Ø. Johansen, Lysergic acid diethylamide (LSD) for alcoholism: meta-analysis of randomized controlled trials. J. Psychopharmacol. (Oxf.). 26, 994–1002 (2012).

3. J. J. Rucker, L. A. Jelen, S. Flynn, K. D. Frowde, A. H. Young, Psychedelics in the treatment of unipolar mood disorders: a systematic review. J. Psychopharmacol. (Oxf.). 30, 1220–1229 (2016).

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