Improving Prognostic Confidence in Neurodegenerative Diseases Causing Dementia Using Peripheral Biomarkers and Integrative Modeling

Inclusion Criteria: * Possible or probable diagnosis of MCI or early dementia * Age 30-95 * Study partner who has some weekly contact with patient. Some of the neuropsychological assessment require collateral from close contacts to assess cognition and functioning. Since neurodegenerative diseases can be associated with reduced cognition, including reduced awareness of one's own impairments, participants will be assessed for their capacity to consent at all study visits. * Must, in the opinion of the site investigator, be able to complete most study procedures. Exclusion Criteria: * Participants who are not able to complete the majority of assessments in the opinion of the PI are excluded from the study. Exclusion criteria are evaluated at the site investigator's discretion; if the site investigator believes that the participant's symptoms are due to causes other than neurodegeneration, despite the presence of an exclusionary condition, the investigator may overrule the exclusion.