One Dose of Psilocybin. A Month of Altered Brain Activity.

About this work

A single dose of psilocybin produced measurable shifts in brain activity — and possible structural changes — that persisted for up to a month, according to a study led by Robin Carhart-Harris with teams at UC San Francisco and Imperial College London. The key finding isn't just that the brain changed, but that the degree of change tracked directly with clinical outcome: participants whose brain networks became most flexible and varied after dosing reported the strongest, most durable mood improvements. The article breaks down what this means for how psychedelic therapy is usually explained — as a single cathartic event — versus a more mechanical picture, where the trip opens a temporary window of heightened neuroplasticity, and what happens in the weeks after may matter as much as the session itself. It also lays out the honest limits of the finding: this isn't a case for unsupervised use, and the described changes were tracked over roughly a month, not confirmed as permanent. Source: Carhart-Harris, R. et al., Nature Communications, UCSF and Imperial College London, July 2026.