In previous editions, we explored the effects of plant medicine during the experience itself, as well as the impact it can have on individuals. While these accounts may seem mystical or subjective, a growing body of scientific research is now lending support to what people report.

Progress is also being made on the legal front. For example, a significant majority in the Czech Chamber of Deputies approved the use of psilocybin for mental health treatment, targeting conditions such as severe depression, addiction, and existential distress [1]. If the proposal were adopted by the Senate, it could open access to treatment for hundreds of thousands of Czech patients — and potentially inspire other European countries to follow suit.

Editorial update: since this article was written, the Czech Senate has passed the law and the President has signed it; it is expected to come into force in early 2026.

In Switzerland, compassionate-use exemptions allow the therapeutic application of psilocybin under special authorization, while plants containing natural DMT — the active ingredient in ayahuasca — are not explicitly listed under federal narcotics schedules. This absence creates a degree of legal ambiguity, and their use continues to be assessed case by case at the cantonal level [2].

Research has shown that plant medicines such as ayahuasca and psilocybin exert their main pharmacological effects by activating serotonin 5-HT2A receptors. This activation leads to a downstream modulation of large-scale brain networks — in particular the Default Mode Network (DMN). More specifically, compounds like psilocybin and DMT bind to 5-HT2A receptors in cortical regions of the brain. The resulting neurophysiological effect is a disruption of the DMN's coherence and connectivity, accompanied by increased communication between other brain networks.

The DMN, located primarily along the brain's midline — across frontal, parietal, and temporal regions — plays a central role in self-referential mental activity. It underlies introspection, self-awareness, and autobiographical memory — what is often called "mental time travel." The DMN is also involved in future projection, daydreaming, spontaneous thought, and mind-wandering. Crucially, it supports our capacity for social cognition (understanding others), moral reasoning, and the construction of a coherent sense of self — the ongoing story we tell ourselves about who we are.

With plant medicines, the DMN becomes less dominant. This weakening often manifests as a softening of the self's rigid boundaries — a sense of unity or interconnection, in which individuals feel less isolated and more attuned to the world around them. Habitual thought patterns can be disrupted, leading to a reduction in rumination and self-criticism, and opening the way to greater mental flexibility. At the same time, increased connectivity between brain networks fosters a richer exchange of information. This reorganization often gives rise to spontaneous realizations, in which individuals connect past experiences — such as childhood memories — to present-day behaviors. Emotional processing tends to become more vivid and immersive.

Many report the surfacing and release of long suppressed emotions, accompanied by feelings of clarity, catharsis, and emotional relief. Taken together, these temporary shifts in brain activity open the door to new patterns of perception, thought, and self-experience. Many people who have had an experience with plant medicine will recognize this: the moment when fragmented pieces of a problem suddenly come together in a deeply meaningful way — whereas before, despite intense reflection, no line of thought seemed capable of reaching that level of understanding. Often, this "eureka moment" feels less like a discovery and more like a return — a return to something known but forgotten