What is psilocybin used for in mental health?

Psilocybin is a compound found primarily in mushrooms, especially mushrooms from the Psilocybe family, the so-called magic mushrooms. When ingested, it transforms into another substance, psilocin, which has psychedelic properties. Psychedelics are compounds that are able to create altered states of consciousness. They allow us to perceive reality differently. Specifically, psilocybin, or psilocin, activates serotonin receptors in the brain. Serotonin is a neurotransmitter mainly related to mood and emotions. This activation produces an effect on the brain.

Psilocybin consumption first causes acute effects that last about six hours after ingestion. Our normal brain connections — which make us perceive what we perceive and feel we feel — change and tend to become disorganized, typically leading to hallucinogens in which reality is perceived differently. You may see different colors or have visual hallucinations, feel that you are not yourself, and that the concept of self and the perception of time are distorted. This is largely due to this disorganization of the brain’s connections.

There are other effects that are more persistent and can last up to 21 days. These effects have more to do with mental health research because they affect brain plasticity. Plasticity is the brain’s ability to transform, create new neurons, generate new connections, etc. It is believed that these substances are capable of expanding brain plasticity, the ability to learn. This leads, for example, to improved mood or a better response to psychotherapy, which is essential to ensuring that the positive effects caused by these substances continue. In other words, what these substances do is facilitate the recovery process from depression and other mental health issues.

They also cause persistent changes in brain connectivity. After the six hours I mentioned earlier, connectivity is restored, and you feel normal again, but there are still some more subtle effects on connectivity that have also been linked to improvements in symptoms of depression. After treatment, the person can experience a rapid improvement in mood and an attenuation of depressive symptoms, which can sometimes take several weeks with conventional antidepressants.

That’s the positive side of psilocybin, but there is also a negative side. Experiences with psychedelics such as psilocybin can be very intense and therefore very scary and even traumatic experience. This is colloquially known as a bad trip. In order to ingest these substances, which are not approved for medical use in any country — except Australia, which has allowed their administration in some cases since last year — you need to be prepared. In Spain and other countries, they are only used for research. In this context, a therapist prepares the participant by explaining what effects psilocybin may have, and the substance is always taken in company. Taking it alone and without experience can be dangerous.

From a safety perspective, the substance is very safe. It is unlikely that a patient will have serious physical effects, but it can cause nausea or vomiting, or an increase in blood pressure and heart rate, which makes it dangerous for people with heart problems or uncontrolled hypertension.

It is being investigated as treatment for depression, and there is also some evidence that it could address addictions, especially alcohol abuse; and anxiety problems, such as end-of-life anxiety, for example, in people with terminal illnesses who are afraid of death. These are the fields that have the most evidence. But the main area is depression resistant to conventional pharmacological treatment.

I am currently involved in two clinical trials studying the use of psilocybin and a psilocybin analogue in treating depression and in a clinical trial using 5-MeO-DMT, which is another hallucinogen that also contains the venom of the bufo toad. But the impact of psychedelics on mental health has been studied for a long time. In the 1960s, research with these compounds was already underway. But the hippie movement, excess consumption and the hardening of anti-drug policies, led to a complete ban on these investigations. At the beginning of this century, however, research resumed. And there are a growing number of clinical trials.

In my opinion, these substances have great potential if used properly. The fact is that there are many people with mental illness who do not respond to conventional treatments and who suffer greatly. I do not believe that they will be useful for treating all mental illnesses or that they will be useful for all people, but I do believe that they are another tool with a different mechanism that also increases the effect of psychotherapy. What we are seeking to implement is precisely psychedelic-assisted psychotherapy.

Adriana Fortea is a specialist in psychiatrist at the Hospital Clínic of Barcelona. She is a researcher in the Multimodal Neuroimaging group in recent-onset and high-risk psychoses, at IDIBAPS and CIBERSAM.

Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition