Inclusion Criteria:

All ARMADA subjects must meet the following criteria:

• Either be an existing participant of a longitudinal study of cognitive changes in aging and dementia or be enrolled in the Alzheimer’s Disease Center (source study) prior to being offerd enrollment in the ARMADA study. The source study at Mayo Clinic in Florida is the Alzheimer Disease Center.
• Mayo Clinic Jacksonville is one of nine data collection sites in the ARMADA consortium. The Mayo Clinic ADC in Jacksonville focuses recruitment of older African American adults. Mayo Clinic will enroll the following types of participants:
  • African-American English speaking Cognitively Normal Control subjects ages 65-85 (NC)
  • African-American English speaking subjects with Mild Cognitive Impairement (MCI)
  • African-American English speaking Cognitively Normal aging subjects ages 85+
  • African-American English speaking subjects with a diagnosis of early stage dementia due to Alzheimer Disease
• Have the ability to speak and understand English.

Participants with no cognitive impairment recruited from the source study must be:

• Living independently in the community.
• Reporting no difficulties in daily living activities.
• Have a Clinical Dementia Rating Score of CDR=0 (no cognitive impairment).
• Between the ages 65-85 for the Normal Control subjects.
• Age 85+ for the healthy aging subjects.

Particiants with cognitive impairment recruited from the source study must:

• Carry a clinical diagnosis of amnestic mild cognitive impairment (aMCI, single domain or multidomain; Global CDR=0.5, plus Memory CDR=0.5 with or without additional domains of CDR 0.5) based on their participation in the source study for MCI subjects.
• A clinical diagnosis of dementia of the Alzheimer type, mild stage (Clinical Dementia Rating Scale Global score=1.0) based on their participation in the source study for subjects with dementia.

Exclusion Criteria:

Participants with no cognitive impairment:

• History of CNS disease.
• DSM criteria for any chronic major psychiatric disorder, or alcohol or substance abuse, serious medical illness (thyroid disorder, renal, hepatic, cardiac or pulmonary insufficiency, unstable diabetes, uncontrolled high blood pressure, cancer), or chronic use of neuroleptic or hypnotic medications.
• Inability to provide informed consent AND absence of a surrogate decision maker.
• Participants will not be excluded if they have conditions such as hypertension, hypercholesterolemia or diabetes that are well controlled with medications. Similarly, those taking antidepressants or anxiolytics for situational reactions will be included.

Participants with cognitive impairment:

• Exclusion criteria for these individuals have typically been applied at the source study but include the presence of disorders that, in and of themselves, could mimic dementia (viz., toxic/metabolic encephalopathy, normal pressure hydrocephalus, stroke, inflammatory process, brain tumor), a history of DSM criteria for any chronic major psychiatric disorder, alcohol or other substance abuse.
• Participants will not be excluded if they have conditions, such as hypertension, hypercholesterolemia or diabetes that are well controlled with medications. Similarly, those taking antidepressants or anxiolytics for situational reactions will be included.