To develop a model to predict disease progression in a large cohort of patients across a variety of neurodegenerative diseases, including Mild Cognitive Impairment (MCI) and dementia due to any neurodegenerative disease, including Alzheimer's Disease (AD), Lewy Body Disease (LBD), Vascular Disease (VaD) and Frontotemporal lobar degeneration (FTLD).

The goal of this study is to create a model to predict disease progression in patients with mild cognitive impairments and forms of dementia. To accomplish this, the current study will evaluate different tests including: brain imaging (MRI), body fluid samples (blood and cerebrospinal fluid), skin biopsy, cognitive ability, and behavioural questionnaires. The study team hopes that this information can be used to guide diagnosis and better predict disease progression in patients with mild cognitive impairment and and early dementia.

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.

Individuals who have been diagnosed with a mild cognitive impairment or early stage dementia that are between the ages of 30-95 can participate in the study as long as they have a study partner who can answer questionnaires at their 3 study visits and can complete a majority of assessments.

Individual participant data will not be available to other researchers. Only anonymized responses to the cognitive assessment, clinical assessment, behavioural questionnaires and biofluid protein levels will be shared.