Brain waves predict the intensity of magic mushroom trips

Psilocybin-related trip intensity may be predictable from a person's baseline resting brain activity. A double-blind, placebo-controlled crossover study in healthy adults found that psilocybin shifted EEG activity away from slow rhythms and toward faster high-frequency activity. Participants received either measured psilocybin capsules or placebo, with resting EEG recorded before dosing and again 60 minutes after ingestion, around the peak effects. Under psilocybin, power of slow-frequency waves decreased while beta and gamma power increased across the cortex. Stronger high-frequency activity correlated with more intense subjective effects on the Altered States of Consciousness Questionnaire. Cosmic unity and positive mood tracked increases in high-frequency activity in memory and emotion-related regions, while anxiety and fear of ego loss tracked greater changes in visual processing areas. The study also reported increased default mode network connectivity, and higher baseline fast-wave activity in the frontal cortex predicted more intense later psychological experiences. Limitations include a small sample (25) and testing only healthy volunteers, so clinical prediction for depression or trauma remains to be confirmed.