Participants in this study will undergo a series of non-invasive tests and activities designed to understand how a single dose of psilocybin might influence cognition and emotional well-being in healthy older adults. After providing written informed consent, eligible participants, aged between 60 and 85, will be randomly assigned to receive a dose of psilocybin ranging from a microdose to a moderate-to-high dose. Anatomical magnetic resonance imaging (MRI) and diffusion weighted imaging (DWI) will be used to assess changes in brain structure, while functional magnetic resonance imaging (fMRI) will be used to quantify changes in functional brain activity.
None
None
Single group
Psilocybin
DrugPsilocybin 1-30 mg
MRI measurements of brain structure
Diffusion-weighted MRI will be used to measure mean diffusivity in prefrontal cortex and hippocampus.
Amplitude and pattern of fMRI cortical responses
Functional magnetic resonance imaging (fMRI) responses to visual stimuli, diffusion-weighted MRI, and T1-weighted anatomical MRI will be used.
Vagus nerve reactivity
Change from baseline visit on peripheral psychophysiology will be recorded using a validated task to assess vagus nerve activation during a baseline measurement compared to activation measured while viewing emotionally evocative video clips.
Perceptual measurements
Perceptual measurements will be used to assess the effects of doses of psilocybin on participants' abilities to update visual prior expectations based on new information.
Penn Conditional Exclusion Test (PCET)
A validated set-shifting measure of cognitive flexibility.
Click on the lead sponsor to view all of their trials.
