A single high dose of psilocybin produced measurable changes in both brain activity and brain structure that remained detectable up to one month later in healthy adults who had never used a psychedelic substance, according to a placebo-controlled study published in Nature Communications by researchers at UC San Francisco and Imperial College London.
The study, which was published in May 2026 and has received renewed attention this month, used a within-subjects design in 28 entirely psychedelic-naive healthy adults, meaning each participant served as their own comparison across both a placebo condition and a high-dose psilocybin condition. The research team used electroencephalography, functional MRI, and diffusion tensor imaging to track changes in brain function and structure before the dose and at multiple points up to one month afterward.
