Neuroplasticity Enhancement From Cognitive Training Reinforced by Psilocybin (NECTAR) in Aging and Alzheimer's Disease

Background: Normal aging, as well as dementias such as Alzheimer s disease, can cause changes in the brain that affect memory, attention, and thinking. Researchers want to know if regular mental tasks (cognitive training) can improve brain function in older adults. They also want to know if psilocybin, a compound found in certain mushrooms, can further support improved brain function. Objective: To learn how regular cognitive training, with or without psilocybin, can improve brain health in older adults. Eligibility: People aged 65 years and older with mild cognitive impairment or early-stage Alzheimer s disease. Healthy older adults with normal cognition are also needed. Design: Participants will be screened. They will have a test of their heart function and an imaging scan. They will have mental health screening and tests of their thinking and memory. They will practice brain-training tasks on a tablet. Participants will be divided into 2 groups: 1 will have cognitive training plus psilocybin; 1 will have cognitive training only. Those having cognitive training only will have 5 or 6 clinic visits. They will take the tablet home to practice brain training daily. They will wear a device to measure brain waves as they sleep; they may have 1 overnight stay in the clinic, or they may wear the device at home. Imaging scans and other tests will be repeated at each visit. Those taking psilocybin will have up to 9 clinic visits. In addition to the visits for cognitive training, they will take 1 psilocybin capsule by mouth 2 weeks apart (the second dose is optional). They will remain in the clinic for 24 hours after each dose.