Can psychedelics help our minds and brains stay healthy as we grow older?
That’s the question posed by a new first-of-its-kind study launched earlier this year at the UC Berkeley Center for the Science of Psychedelics.
The study, known as PLASTICITY (Psychedelic Longitudinal Aging Study In Cognitively Healthy Older Adults), is the first psychedelic neuroimaging study specifically focused on older adults. The study will use MRI and other measures to investigate how psilocybin impacts memory, perception, emotion, and brain structure and function in healthy adults between the ages of 60 and 85.
The researchers will test whether psychedelics can enhance neuroplasticity in the brains of healthy older adults, help them regulate their emotions, feel more socially connected, and experience a sense of awe. Previous work has shown that psychedelics can reduce negative mental states like depression, anxiety, stress and rumination, and that these negative mental states may be linked with accelerated aging, said Tyler Toueg, a UC Berkeley doctoral student in neuroscience who co-led the project’s design.
“There’s a lot of overlap between the mental states that psychedelics influence and those associated with successful aging,” Toueg said.
As populations age worldwide, cognitive decline and neurodegenerative diseases such as Alzheimer’s disease are becoming increasingly common, with significant consequences for individuals, families, and health care systems. Given this demographic shift and the rising burden of neurodegenerative disease, there is an urgent need for new strategies to promote successful aging.
Previous studies in non-human animals have shown that psilocybin increases the number of synaptic connections in the hippocampus and the prefrontal cortex of the brain. If psilocybin has the same effect on the human brain, it could help counteract the structural brain changes associated with aging.
“One of the things that I am most interested in is seeing whether we can actually measure those potentially beneficial brain changes in older adults,” Toueg said.
While thousands of people have received psilocybin in controlled research settings over the past several decades, older adults have been largely absent from modern psychedelics studies. A 2024 review found that older adults represented only about 1.4% of all participants.
“Older adults have been almost entirely excluded from modern psychedelics research, yet they may stand to benefit significantly from compounds that promote brain plasticity,” said Michael Silver, a professor of optometry and vision science and neuroscience and the faculty director of the Berkeley Center for the Science of Psychedelics. “This study allows us to directly test whether the promising findings from animal models translate to older humans and to generate data that will inform future research on aging, cognition, and mental health.”
In the study, participants will take 1-30 mg of synthetic psilocybin, a compound found in psychedelic mushrooms. The researchers will collect a baseline assessment before each participant’s psychedelic experience. Then, they’ll repeat the assessment one week and one month after the experience to look for changes.
The assessments will include cognitive, perceptual, and emotion testing, as well as advanced brain imaging. The imaging includes diffusion MRI to measure the microstructure of the hippocampus — a part of the brain involved with memory and learning — and functional MRI to examine brain activity during memory encoding and retrieval. Participants will also undergo measures of visual perception and will complete surveys examining how subjective aspects of the experience relate to longer-term changes in well-being.
The study will also assess whether psilocybin can lead to sustained increases in vagus nerve activity when participants are experiencing positive emotions, like awe. Because vagus nerve activity is associated with better recovery from stress, it is a possible mechanism that could explain how psilocybin is related to mental health.
“One of the wonderful aspects of doing a study like this at UC Berkeley is that we are able to work with a broad array of experts — including emotion scientists and people who are experts in cognition and aging — to simultaneously study many facets of the enduring effects of the psychedelic experience,” Silver said.
The interdisciplinary project was designed by Toueg, a Ph.D. candidate in the neuroscience graduate program at Berkeley, along with faculty spanning neuroscience, psychology, and psychiatry: Silver, a leading neuroscientist in the study of the human visual system in the brain; William Jagust, a prominent neuroscientist studying brain aging and Alzheimer’s disease; Dacher Keltner, a renowned psychologist on emotion, awe and well-being; and Brian Anderson, a psychiatrist at both UCSF and Berkeley’s psychedelics center, who is also acting as the medical director for the study.
If you would like to learn more about potentially being a research participant in BCSP neuroscience studies of human subjects, please email BCSPresearchsubjects@berkeley.edu.
