Studies have consistently shown associations of elevated blood pressure in mid-life and the later likelihood of developing impaired functioning due to dementia. However, the question remains about treatment of older persons (i.e. >65 years of age) who may have elevated blood pressure identified at a visit to a physician. Studies about the benefits of treating older persons have been inconsistent so there is no consensus on the question of treating older persons to reduce the risk of cognitive decline or dementia. Part of the reason for the inconsistency may be due to the variability in how blood pressure levels change over time. Some factors that cause this variability are history of hypertension and treatment, vascular lesion load in the brain, and genetic susceptibility. This study aims to identify patient characteristics, in addition to current blood pressure and age, which if known will ultimately improve the clinical decision-making about treating elevated blood pressure to reduce the risk for cognitive decline or dementia.In addition, this study aims to compare the benefits of different anti-hypertensive treatment strategies in lowering the risk for cognitive impairment and dementia. This includes any treatment that lowers blood pressure and specific anti-hypertensive drugs that may independently affect processes lead to cognitive decline or dementia.