What happens to your brain when you take psilocybin?

This compound, found in hallucinogenic mushrooms, alters human brain activity for weeks, according to a new article published in Nature

For some years now, several research teams have been studying how psilocybin, the psychedelic substance from mushrooms, can rewire the brain to relieve anxiety depression, the anxiety and other disorders in humans. The finding improves understanding of the effects of psychedelic substances and helps reveal their therapeutic potential. However, there is still much skepticism about its safety and neurobiological mechanism.

Researchers at the University of Washington School of Medicine (USA) have monitored the Brain changes in seven healthy adults (ages 18 to 45) using MRI scans before, during, and three weeks after taking a high dose (25 mg) of psilocybin. The volunteers also received an additional amount 6 to 12 months later.

«In addition to providing information on the therapeutic component of psychedelics, our work provides a biomarker to test drugs currently being developed»

Joshua S. Siegel (Univ. of Washington)

“In addition to providing information on the therapeutic component of psychedelics, our work also provides a biomarker to test drugs that are currently being developed and that work in a similar way, including non-hallucinogenic psychedelic analogues,” he explains to SINC. Joshua S. Siegel, first author of this study published in Nature.

The experts discovered that psilocybin temporarily disrupts a critical network of brain areas involved in introspective thinking, such as daydream and remember. The results explain the drug's psychoactive effects on brain function, which could accelerate the development of drugs for various psychiatric diseases.

Psychedelics against depression

The researchers observed how the functional connectivity in the cortex and subcortex, and that these changes were due to the desynchronization of different brain regions.

The alterations caused by psilocybin were stronger in the so-called default mode network (DMN), which is connected to a region called the anterior hippocampus, involved in creating our sense of space, time, and self.

The alterations caused by psilocybin were strongest in the so-called default mode network, involved in creating our sense of space, time and self.

The substance caused a persistent decrease in functional connectivity between the anterior hippocampus and the DMN, which lasted for weeks. “The longer-term consequence is that it makes the brain is more flexible and potentially more able to enter a healthier state,” adds Siegel.

“At first there is an intense effect and, when it disappears, a punctual effect remains,” says the main co-author, Nico UF Dosenbach, professor of neurology. “That's exactly what we would like to see in a medicine. We wouldn't want people's brain networks to be wiped out for days, but we wouldn't want everything to go back to the way it was immediately. We want it to last long enough to make a difference.”

Possible side effects

Psilocybin showed promise as a treatment for depression in the 50s and 60s, but restrictive US federal drug policy in the following decades prevented almost all further research. In recent years, however, the regulations have been relaxed and interest in this field has been revived.

Psilocybin is not without adverse effects, especially in people with pre-existing mental disorders and especially when taken outside of a controlled environment.

Of course, it does not lack Adverse effects, especially in people with pre-existing mental disorders and especially when taken outside of a controlled environment and without a qualified healthcare professional.

“The biggest risk is that it can trigger psychosis, especially in people with a personal or family history of schizophrenia or bipolar disorders. This can last a long time after the drug has disappeared from the body,” says Siegel.

“There are also potential side effects immediately after taking the drug, such as nausea, anxiety and panic attacks, and paranoia. Buying magic mushrooms from unregulated and illegal sources is dangerous,” he continues.

Test its therapeutic efficacy

The authors stress that people should not interpret their study as a reason to self-medicate with psilocybin. The drug is not approved by the US Food and Drug Administration (FDA) as a treatment for depression or any other condition, and taking it without the supervision of trained mental health experts carries risks.

The authors stress that people should not interpret their study as a reason to self-medicate with psilocybin or take it without the supervision of mental health experts.

“This study was conducted in healthy adults, so we cannot be sure that the lasting effects are related to the therapeutic effects,” Siegel points out. "Are needed more research in participants with depression to verify the usefulness of psilocybin as an antidepressant or treatment of other mental disorders.”

Source: Travel SINC

Reference: Joshua S. Siegel et al. 'Psilocybin desynchronizes the human brain'. Nature (2024)