Psilocybin therapy

Research in humans has shown with PET scans that psilocybin binds to 5-HT2A receptors in the brain. The degree of receptor occupancy is related to certain subjective effects of the psychedelic experience.

It is more accurate to speak of a change in serotonergic signaling than of a simple increase in the amount of serotonin in the synaptic cleft.

Preclinical research in particular shows indications of changes in neuroplasticity. Furthermore, research has shown that psilocybin can directly bind to TrkB, the receptor for BDNF.

In cell and animal models, this interaction was associated with processes that promote neuroplasticity. However, it has not yet been shown that every psychedelic experience in humans automatically leads to new neural connections.

fMRI research has shown that psilocybin can reduce the amygdala's response to negative emotional stimuli. In the same study, reduced amygdala reactivity was associated with a more positive mood.

This does not mean that psilocybin always reduces anxiety during an experience. Intense or challenging emotions can also occur.

fMRI research has found changes in areas that are part of the default mode network (DMN). The original idea that psilocybin simply causes more blood to flow to the brain is too simplistic.

Some studies, however, show regional decreases in cerebral blood flow.

Psilocybin alters the normal communication within the DMN and between different brain networks. Research shows that the normal synchronization between brain networks during the psychedelic state can be strongly altered.

This is associated with changes in the normal experience of the self and with the phenomenon of ego dissolution.

A recurring finding is a decrease in alpha activity, approximately 8 to 13 Hz. Additionally, changes have been found in other frequency bands, including theta, beta, and gamma.

Therefore, it is too simplistic to talk about a simple shift from alpha waves to theta waves.

In a controlled study in healthy volunteers, a rapid decrease in TNF-α was found. Seven days later, lower values of IL-6 and CRP were also measured.

These results are interesting, but do not prove that psilocybin is a general anti-inflammatory agent or treats inflammatory diseases.

In clinical research, reductions in depressive symptoms have been found after treatment with psilocybin in people with depression.

However, its action cannot be simply explained as a supplement to a serotonin deficiency. Psilocybin affects multiple neurobiological and psychological processes.

Researchers have now investigated connectedness through specific questionnaires. In prospective research, changes were found in feelings of connectedness with the self, others, and the world.

Neuroimaging research has linked ego dissolution with changes in the communication between brain regions involved in self-directed processing.

A changed self-perception can therefore provide space for a different way of looking at personal thoughts, emotions, and patterns. However, that does not mean that every thought or conclusion during an experience is automatically correct.

Research on the amygdala shows that psilocybin can alter the processing of negative emotional stimuli. However, during the psychedelic experience, temporary feelings of anxiety or tension can also arise.

Psychological insight is now also being scientifically studied. The Psychological Insight Questionnaire was developed to measure changes in insight during psychedelic experiences.

Research shows links between such experiences and later changes in psychological functioning.

Mystical experiences have been extensively studied within psychedelic research. In controlled studies, experiences were described that were considered personally and spiritually meaningful by the participants.

Observational research has described various changes in health behaviors following psychedelic experiences. Because these studies are largely based on self-reporting, it cannot be concluded that psilocybin directly causes these changes.