MK-6240 PET Scans for Cognitive Health in Older Adults

Inclusion Criteria: 1. Aged 60 or older; 2. Speaks fluent English or Spanish; 3. Visual and auditory acuity adequate for neuropsychological and computerized testing; 4. Good general health with no disease(s) expected to interfere with the study; 5. Willing and able to participate for the duration of the study and in all study procedures including MRI and PET; 6. Normal cognition defined as a Clinical Dementia Rating of 0 and a Mini-Mental State Examination score of 25 or higher. FAST Stage 1 or 2. 7. Subjective memory or other cognitive complaints will be included. Exclusion Criteria: 1. Significant co-morbid neurologic disease such as Parkinson's disease, multiple sclerosis, brain cyst, tumor or aneurysm; 2. Major health conditions, except for Type II diabetes mellitus, hypercholesterolemia, and hypertension, which are NOT exclusionary for this study given their high prevalence in our target populations; 3. Significant psychiatric disorders such as schizophrenia, bipolar disorder, or attention-deficit hyperactivity disorder, except for depression and anxiety, which are NOT exclusionary for this study given their high prevalence in our target populations; 4. Existing diagnosis of dementia or mild cognitive impairment; 5. Alcohol or substance abuse or dependence within the past 2 years (DSM-IV criteria); 6. MRI contraindications, e.g. pacemakers, aneurysm clips, artificial heart valves, ear implants, metal fragments or foreign objects in the eyes, skin or body. Females who are pregnant or trying to get pregnant are also excluded; 7. PET contraindications, e.g. significant prior radiation exposure and pregnancy.