Psilocybin and the Treatment of Anxiety and Depression

Over the last several years, a number of academic institutions have been researching the impact that the psilocybin molecule has on treating a variety of mental health conditions, including anxiety and depression. Psilocybin is the active psychedelic compound that naturally occurs in over 200 species of fungi. When humans ingest psilocybin, the body quickly converts it to psilocin, and this results in mind-altering effects such as euphoria, visual hallucinations, and distortions of space and time that are commonly reported by those who ingest these fungi or so-called “magic mushrooms.”

As it happens, the mind-altering effects caused by the ingestion of psilocybin may serve to be extremely useful in treating symptoms in those that suffer from anxiety and depression. This article will discuss some of the research that has been done on the treatment of depression and anxiety with psilocybin and why it is becoming increasingly important to find safe and effective treatments for these mental health conditions.

In 2016 at Imperial College London, Robin Carhart-Harris and his research team carried out an experiment to research the effects of psilocybin in patients with moderate to severe treatment-resistant depression. In the experiment, 12 patients (six men and six women) were given two doses of psilocybin (10mg and 25mg, 7 days apart). Before, during, and after each psilocybin treatment, patients were provided with psychological support. Treatments also took place in a comfortable, living room like setting. Patients’ depressive symptoms were then evaluated 1 week and 3 months following treatment. The researchers found that depressive symptoms were significantly reduced both 1 week and 3 months after treatment. Furthermore, none of the patients experienced serious adverse effects during their treatment with psilocybin.

This study highlights the fact that it does not take many doses of psilocybin (2 in this case) to allow for patients to experience sustained decreases in depressive symptoms. This study also highlights the importance of set (one’s mindset before using psilocybin) and setting (one’s physical environment while using psilocybin) as patients were supported psychologically and were in a comfortable setting throughout their entire treatment with psilocybin. This could be a significant reason as to why this experiment was as successful as it was. In fact, Carhart-Harris and 2 of his colleagues conducted an experiment in 2018 specifically to investigate how the quality of experience of a psilocybin treatment influences the beneficial impacts associated with the treatment. In that study, the authors found that the quality of experience (or set and setting) had a significant impact on whether the patients experienced reductions in depressive and anxious symptoms after their treatments.

Meanwhile at the Center for Psychedelic and Consciousness Research at Johns Hopkins University, Roland Griffiths and his research team were also conducting studies on psilocybin and its potential for the treatment of mental health conditions. In 2016, this team carried out a study to investigate the effects of psilocybin on patients with life-threatening cancer and depression/anxiety. The 51 patients that took part in the study were divided into 2 groups. One group took a very small dose of psilocybin (1mg or 3mg per 70kg of body weight, 5 weeks apart) and one group took a higher dose (22mg or 30mg per 70kg of body weight, 5 weeks apart). The researchers found that the patients that had received a higher dose of psilocybin experienced decreases in clinician and self-rated depressive and anxious symptoms. Furthermore, when the researchers followed up with the patients 6 months later, 80% of the patients in the high-dose group continued to display sustained significant decreases in their depressive and anxious symptoms.

A similar 2010 study by Charles Grob and colleagues at the UCLA School of Medicine gave moderate doses of psilocybin (0.2mg per kilogram of body weight) to 12 patients with advanced-stage cancer and anxiety. When the researchers followed up with patients 1 and 3 months after treatment, they found that the patients had experienced significant reductions in their anxiety symptoms. In both this study and Griffiths’ 2016 study, none of the patients who participated in the studies experienced adverse negative psychological impacts during or after their treatments with psilocybin. These studies highlight that psilocybin can be both safe and effective in reducing anxiety symptoms - even in a population (cancer-patients) that typically develops severe and significant depressive and anxious symptoms.

The reason why psilocybin is so successful at treating symptoms of depression and anxiety is not entirely known, but the answer might have something to do with the interaction between psilocybin and the “Default Mode Network” (DMN). The DMN consists of an interacting group of brain regions that correlate with one another. These brain regions include the Posterior cingulate cortex which is responsible for our “perception of self” or ego, the Medial prefrontal cortex which is responsible for the processing of personal information, the Angular gyrus which is responsible for spatial awareness and perception, the Dorsal medial subsystem which allows us to determine or infer the actions of others, and the Medial temporal subsystem which is responsible for the perception of time. An overactive DMN is associated with behaviours such as excessive self-criticism, negative filtering (when one only focuses on negative aspects of a situation), catastrophizing, and mind reading (when one assumes to know what others are thinking). Since many people with anxiety and depression are also prone to these types of behaviours, it has been hypothesized that an overactive DMN is highly common in people with these conditions. However, when one takes a dose of psilocybin the DMN is dampened. This dampening of the DMN may help individuals to break their negative thought patterns and thus reduce their anxious and depressive symptoms.

So why is this relevant? Well, anxiety disorders are the most common psychological disorders in the US, and their rates have been skyrocketing over the last decade. Nearly 1 in 5 US adults have an anxiety disorder, and nearly ⅓ of US adults will have an anxiety disorder at some point in their lives. Rates of major depression are on the rise as well, both in the US and worldwide. It is estimated that nearly 7% of US adults experience at least one significant episode of depression in any given year. What is causing this rise in anxiety and depression in the US and in other western countries? The answer to that question is likely a complex set of factors and each individual person who suffers from these disorders is likely influenced by some factors, and not others. Regardless of the cause for an individual’s anxiety or depression, treatment with psilocybin may be able to significantly reduce symptoms associated with these conditions and provide relief for many.

In conclusion, while anxiety disorders and depression are becoming more common, especially in the US and in other western countries, psilocybin might be able to help. The aforementioned studies described in this article showed promising results when patients with significant depressive and anxious symptoms were treated with a dose of psilocybin. Even minimal doses of psilocybin were shown to have lasting psychological benefits in these patients. Moreover, not a single patient in any of these studies experienced lasting adverse negative psychological effects as a result of their treatments with psilocybin. It is clear that psilocybin has the potential to be a safe and effective way to treat anxiety and depression and it would be wise to continue to study the beneficial impacts of psilocybin on those that suffer from these psychological disorders, with the hope that this treatment method may soon become more widely available.