As more humans live longer, there’s a growing focus on aging well. In a new study at the BCSP, scientists are researching a promising potential use of psilocybin: to promote successful aging of healthy older adults.
We caught up with Tyler Toueg, a Ph.D. candidate in the neuroscience graduate program at UC Berkeley, and Michael Silver, neuroscientist and director of the BCSP, in a Q&A about psilocybin’s possible benefits for older adults, the brain mechanisms underlying cognitive decline, and how this study could open up further possibilities for psychedelics research.
BCSP:
Tell us about the aims of the BCSP’s PLASTICITY (Psychedelic Longitudinal Aging Study In Cognitively Healthy Older Adults) study.
Tyler Toueg:
There are many things that we’re testing in the study, but one of the most meaningful is seeing whether we can demonstrate changes in structural plasticity in the brain that could be helpful for older adults. We know that with age, we lose synaptic connections, especially in certain brain regions like the hippocampus and prefrontal cortex. It’s been shown in animal models that psychedelics increase the number of synaptic connections in these regions, so we’re using MRI to assess structural change after giving psilocybin to our participants.
The other aim I’m particularly interested in is that there are a variety of different behaviors that are associated with either more successful or worse aging. Things like depression, anxiety, stress and rumination are all associated with worse aging outcomes. Things like having purpose in life, emotional regulation, and awe are all associated with more successful aging. From what we’ve seen in other psychedelic studies that were not focused on older adults, psychedelics tend to promote changes in outcomes that have been associated with successful aging, and reduce outcomes that have been associated with worse aging. In this study, we’re interested in seeing if there is evidence of these changes in older adults one month after taking psilocybin.
BCSP:
Why do changes in structural plasticity matter as we age?
Michael Silver:
There are declines in structural plasticity associated with aging, which can represent a reduction in function and ability. There’s evidence that psychedelics cause structural brain changes in the opposite direction of those that often occur with aging.
BCSP:
Why is it meaningful to study psychedelics and older adults?
Tyler Toueg:
One of the reasons is that we don’t have a lot of tools available to help promote “successful aging.” Before coming to Berkeley, I studied the characterization of risk for Alzheimer’s disease, and I realized that even if we could predict a person’s trajectory earlier and more accurately than we are currently able to, what we could offer people often wouldn’t really change. The general advice would be to exercise, sleep, eat healthy, and engage in social connection. The tools around promoting successful aging are really under-explored.
Michael Silver:
It’s also worth mentioning that older subjects are extremely underrepresented in psychedelics research. Of those that have participated in psychedelics trials, less than 1.4 percent are in the age range we’re studying.
Tyler Toueg:
Yeah, we’re actually the first to do a psychedelic neuroimaging study in healthy older adults.
I’m very interested in psilocybin as a potential mental health treatment, but I’m also interested in it as a way to shed light on these central mysteries in neuroscience and psychology.
Michael Silver
BCSP:
This study is multidisciplinary, involving researchers across departments. Can you share more about how it came together?
Michael Silver:
In this study, we’re able to uniquely play to our strengths at UC Berkeley by working together with Dr. Dacher Keltner and Dr. Bill Jagust and the members of their labs. Berkeley has outstanding basic mechanistic research in both neuroscience and psychology. Within that area, Dacher’s work has been very influential in questioning the deficit model of well-being, where we wait for something to break, as opposed to promoting proactive approaches to human health and flourishing. Bill is one of the leading authorities in the world on aging and its biological mechanisms. Tyler brought us together to design the basic structure of the PLASTICITY study.
BCSP:
How does this study contribute to the broader field of psychedelics research?
Michael Silver:
Until recently, there had been almost no legal research with psychedelics in human subjects for nearly fifty years, which is really unprecedented. Even for very controversial topics like gun control or poverty research, the research has continued in some form at traditional research institutions, but that wasn’t the case for psychedelics for decades.
During the time when there was a desert of research in psychedelics, neuroscience advanced tremendously, and we now have these incredible tools for noninvasively measuring structural and functional changes in the brain. Normally, such scientific advances would go hand-in-hand with the research on a topic like psychedelics, but we have this real mismatch, with many fundamental questions about the effects and actions of psychedelics that have yet to be addressed.
Much of the resurgence of psychedelics research has been focused on development of new therapies for FDA approval for mental health treatments, so the studies have been on safety or efficacy of a particular treatment for a particular disorder. For that kind of work, you don’t necessarily need to understand the brain mechanisms; you just need to assess if it works and if it’s safe enough.
At the BCSP, we’re conducting some of the missing basic science research. We’re fortunate to have philanthropist funders who are interested in these basic questions, who see psychedelics as tools for deepening our understanding of the mind and brain and consciousness. It’s important for our work that our research subjects aren’t patients; we’re not treating them for a disorder. We are conducting foundational research which will provide important information for developing more precise and effective therapies.
BCSP:
Where are you in the study now?
Tyler Toueg:
We started enrollment last November and we now have two subjects that have gone through all the study visits, so we have two full data sets. Recruitment is ongoing, and our goal is to have twenty subjects dosed by the end of 2026.
BCSP:
This study has the potential to have wide-ranging implications for psychedelic science. What possible findings excite each of you the most?
Tyler Toueg:
What really excites me is that we’re focused on healthy older adults. Most clinical trials with older adults are focused on people who already have a diagnosis. We’re asking whether we can actually promote positive outcomes in older adults who are healthy. It has been exciting to see emerging interest in the potential of psychedelics to promote successful aging, and I’m thrilled to be part of one of the first studies to explore this. I think that no matter what we find, this study will have implications for how we think about intervening in the aging brain.
Michael Silver:
I’m most excited by the basic science possibilities. We have so much to learn about the relationships among the mind and brain and consciousness, and at this time, we don’t even know what the form of the answers is going to look like. In the type of pharmacology research that we are doing, we know what the drug is chemically, and we know the types of neurotransmitter receptors it interacts with, but we don’t know how this leads to psychedelic experiences and long-term changes to the brain. I’m very interested in psilocybin as a potential mental health treatment, but I’m also interested in it as a way to shed light on these central mysteries in neuroscience and psychology.
This interview was edited for length and clarity.
Interested in being part of the study?
The Berkeley Center for the Science of Psychedelics is recruiting older adult participants for an experiment studying the effects of psilocybin on neuroplasticity. Participants will be asked to take a 1-30 mg dose of psilocybin and undergo 3 MRI sessions (1 week before psilocybin, 1 week after psilocybin, and 1 month after psilocybin). There will be 5 in person visits and 6 remote visits (approximately 40 hours over 3 months). Participants will be compensated at a rate of $15/hour, with a cap of $550. The study will take place partially remote and partially in person at the Brain Imaging Center and at the UC Berkeley Center for the Science of Psychedelics, Telegraph office.
Eligibility:
1. Healthy participants
2. Must be 60 – 85 years of age
To participate or learn more, please contact BCSP Research Staff at (415) 874-1308 or BCSPresearchsubjects@berkeley.edu.