Inclusion Criteria:

• NIMH diagnostic criteria for Age Associated Memory Impairment (AAMI)
• Mini-Mental State Examination (MMSE) score between 26 and 30 (unless < 8 years of educational achievement)
• No significant cerebrovascular disease
• Estrogen replacement therapy and thyroid replacement therapy (if the participant is euthyroid) are permitted if the therapies are stable for > 1 month
• Memory and verbal fluency cut-off scores that increase the probability of incipient dementia (Buschke-Fuld: 34; verbal fluency: 46 for letters, 7 for categories; Benton Visual Retention: 5)
• Adequate visual and auditory acuity to allow neuropsychological testing
• Normal screening laboratory tests and electrocardiogram (ECG)

Exclusion Criteria:

• Possible or probable Alzheimer Disease (AD) or other dementia
• Neurologic or other physical illness that could produce cognitive deterioration
• History of transient ischemic attacks (TIAs), carotid bruits, or lacunes on an MRI scan
• History of myocardial infarction within the previous year or unstable cardiac disease
• Uncontrolled hypertension (systolic BP > 170 or diastolic BP > 100)
• History of significant liver disease, pulmonary disease, diabetes, or cancer
• DSM-IV criteria for major psychiatric disorders within the previous 2 years
• Past or present history of alcoholism or drug dependence
• Untreated depression as determined by a Hamilton Depression Rating Scale (HAM-D) score of 12 or more
• Drugs that may significantly affect psychometric test results
• Centrally active beta-blockers, narcotics, clonidine, anti-Parkinsonian medications, antipsychotics, benzodiazepines, systemic corticosteroids, medications with significant cholinergic or anticholinergic effects, anti-convulsants, warfarin, vitamins other than the standard multivitamin supplement, ginkgo biloba, and any nutraceuticals. Occasional chloral hydrate use will be allowed, but discouraged, for insomnia.
• Investigational drugs within the previous month or longer, depending on drug half-life
• Contraindication for MRI scan (e.g., metal in body, claustrophobia)