A small group of healthy senior citizens is about to try psilocybin, the active ingredient in magic mushrooms, in a first-of-its-kind study exploring whether the psychedelic can help protect aging brains. While psilocybin has already shown promise treating depression and PTSD in younger patients, most research has focused on people with existing mental health conditions. Now, a team from the UC Berkeley Center for the Science of Psychedelics wants to know if it can also benefit healthy older adults, testing effects on perception, emotion, and memory in participants aged 60 to 85 through brain scans and detailed surveys.
This new trial, called PLASTICITY, builds on a growing body of psychedelic research. After decades of restriction, studies have shown psilocybin paired with therapy can ease depression, leading Oregon and Australia to approve supervised use for certain conditions, with more countries potentially following as late-stage trials report strong results. Scientists still don’t fully understand how the drug works, but evidence suggests it rapidly reorganizes connections between brain cells, especially in the hippocampus, a region central to learning and memory.
The science behind this hinges on plasticity, the brain’s ability to constantly rewire itself in response to experience. This flexibility is abundant in youth but tends to decline with age and in conditions like depression. Animal studies suggest psilocybin might help restore some of that youthful flexibility: in rodents, the drug has shifted depressive behavior toward more exploratory engagement, reopened developmental windows for learning, and even boosted sensitivity to oxytocin, the “love hormone,” suggesting it triggers a state where neurons become more receptive to rewiring.
Psilocybin’s effects may reach beyond the brain, too. Research has uncovered a link between the brain and the immune system’s response to stress, with the drug shown to reduce inflammation and calm anxiety-like behavior in stressed mice. Combined with its potential to boost plasticity, this dual action makes psilocybin an intriguing candidate for counteracting some of the physical and emotional changes that come with aging, particularly since traits linked to poor aging outcomes, like depression and stress, contrast sharply with traits linked to successful aging, like purpose and emotional regulation.
The PLASTICITY trial will use advanced MRI techniques to track structural and functional brain changes before and after dosing, along with surveys capturing shifts in mood, outlook, and social connection. Having begun enrollment in late 2025, the study aims to dose 20 participants by the end of 2026. Older adults have historically been underrepresented in psychedelic research, making up a tiny fraction of trial participants despite potentially having the most to gain. As the researchers note, whatever the results, the trial promises to shape how scientists think about intervening in the aging brain going forward.