TRC-PAD Program: In-Clinic Trial-Ready Cohort

Inclusion Criteria:

1. Provision of signed and dated informed consent form

2. Stated availability and willingness to comply with all study procedures untilreferred to a clinical trial

3. Age 50-85 (inclusive)

4. Global Clinical Dementia Rating (CDR) score of 0 or 0.5 and no diagnosis of dementia

5. Has a study partner that is willing to participate as a source of information andhas at least weekly contact with the participant (contact can be in-person, viatelephone or electronic communication). The study partner must have sufficientcontact such that the investigator feels the study partner can provide meaningfulinformation about the participant's daily function.

6. In good general health as evidenced by medical history

7. Adequate visual and auditory acuity to allow neuropsychological testing

8. Fluent in English or Spanish

9. For females who are not surgically sterile or post-menopausal by two years,receiving a Positron Emission Tomography (PET) scan for amyloid biomarkerconfirmation: negative pregnancy test prior to amyloid PET scan

10. Completed six grades of education or has a good work history

11. Evidence of elevated or intermediate (subthreshold) levels brain amyloid as assessedby central review of amyloid PET or cerebrospinal fluid (CSF) data. Prior amyloidtesting results may be used with approval from the Coordinating Center.

Exclusion Criteria:

1. Treatment with an another anti-amyloid investigational anti-amyloid drug or otherexperimental intervention within 12 months. Use of aducanumab or other approvedanti-amyloid treatments allowed if stable for at least 3 months.

2. Enrolled in another interventional clinical trial within the last 12 weeks

3. Any significant neurologic disease such as Alzheimer's disease dementia, Parkinson'sdisease, multi-infarct dementia, Huntington's disease, normal pressurehydrocephalus, brain tumor, progressive supranuclear palsy, seizure disorder,subdural hematoma, multiple sclerosis, or history of significant head traumafollowed by persistent neurologic deficits or known structural brain abnormalities.

4. Major depression, bipolar disorder as described in DSM-V within the past 1 year orpsychotic features, agitation or behavioral problems within 3 months, which couldlead to difficulty complying with the protocol

5. History of schizophrenia (DSM V criteria)

6. History of alcohol or substance abuse or dependence within the past 2 years (DSM Vcriteria)

7. Clinically significant or unstable medical condition, including uncontrolledhypertension, uncontrolled diabetes, or significant cardiac, pulmonary, renal,hepatic, endocrine, or other systemic disease in the opinion of the Investigator,may either put the participant at risk because of participation in the study, orinfluence the results, or the participant's ability to participate in the study.

8. History within the last 3 years of a primary or recurrent malignant disease with theexception of non-melanoma skin cancers, resected cutaneous squamous cell carcinomain situ, basal cell carcinoma, cervical carcinoma in situ, or in situ prostatecancer with normal prostate-specific antigen post-treatment

9. Clinically significant abnormalities in B12 or thyroid function tests (TFTs) thatmight interfere with the study. A low B12 is exclusionary, unless follow-up labs (homocysteine (HC) and methylmalonic acid (MMA)) indicate that it is notphysiologically significant.

10. Clinically significant abnormalities in screening laboratories or ECG.

11. For participants undergoing CSF collection: a current blood clotting or bleedingdisorder, or significantly abnormal PT or PTT at screening or if on anti-coagulation (e.g. warfarin)

12. Participants whom the Site PI deems to be otherwise ineligible.