A single dose of psilocybin, the psychedelic substance in magic mushrooms, may produce physical changes in the brain that remain detectable for as long as a month, according to researchers at UC San Francisco and Imperial College London.
The study, published in Nature Communications, involved healthy adults who had never previously used a psychedelic. Although none of the participants had a diagnosed mental health condition, the findings may offer clues about why psilocybin has shown therapeutic potential for depression, anxiety, and addiction.
Researchers focused on temporary increases in brain "entropy," a term describing the variety and unpredictability of neural activity. Their results suggest that this more diverse pattern of brain activity may promote psychological insight and that the psychedelic experience itself could play an important role in psilocybin's longer-term effects.
A larger rise in entropy during the minutes and hours after a high dose was associated with greater emotional insight the following day. Participants who reported more insight were also more likely to describe improved well-being one month later.
"Psychedelic means 'psyche-revealing,' or making the psyche visible," said senior author Robin Carhart-Harris, PhD, the Ralph Metzner Distinguished Professor of Neurology at UCSF. "Our data shows that such experiences of psychological insight relate to an entropic quality of brain activity and how both are involved in causing subsequent improvements in mental health. It suggests that the trip -- and its correlates in the brain -- is a key component of how psychedelic therapy works."
