A small study found that a single 25mg dose of psilocybin, the active ingredient in magic mushrooms, produced measurable brain changes that remained visible a month later, along with reported improvements in psychological insight, well-being, and mental flexibility.
According to The Guardian, researchers used specialized brain scans that tracked the diffusion of water along nerve bundles in the brain. The scans suggested that some nerve tracts became denser and more robust after participants took the drug.
The researchers noted that the opposite pattern is commonly associated with ageing and dementia.
Changes in Brain Entropy
Robin Carhart-Harris, a neurologist at the University of California, San Francisco, and senior author of the study, said the findings were significant because anatomical brain changes were still visible one month after a single dose.
Carhart-Harris said researchers do not yet fully understand what the changes mean, but participants generally reported positive psychological effects, including improved well-being and greater mental flexibility.
Writing in Nature Communications, the researchers also said participants who showed the largest increase in brain entropy after taking psilocybin were more likely to report stronger psychological insight and improved well-being one month later.
The study linked flexible thinking patterns with better mental health outcomes. Carhart-Harris said the findings suggest a possible “psychobiological therapeutic action” for psilocybin.
Experts Urge Caution Over Findings
Alex Kwan, a neuroscientist at Cornell University, said earlier studies in mice showed psychedelics can rewire nerve connections through a process known as plasticity, which may explain potential therapeutic effects.
Kwan said the new study comes closer than most human studies to addressing whether similar changes occur in people. However, he also noted that the findings should be treated cautiously because the study involved a small number of participants and diffusion tensor imaging provides only an indirect and limited view of brain connections.
