Alzheimer’s Disease (AD) is the most common form of dementia, a general term for memory loss and other cognitive abilities serious enough to interfere with daily life. AD accounts for 60% to 80% of dementia cases. According to a 2017 report, AD affects an estimated 6.08 million people in the United States. Although the disease is associated with old age, it could somewhat develop at any age (Bature, Guinn, Pang & Pappas, 2016). Approximately 200,000 people younger than 65 years with AD constitute the younger-onset US population with AD (Brookmeyer, Abdalla, Kawas & Corrada, 2017).
By definition, Alzheimer’s disease (AD) is a progressive neurodegenerative disease clinically characterized by impairment of cognitive and functional abilities as well as behavioral symptoms. It has been reported that individuals with AD experience a long asymptomatic (preclinical) phase in which neuropathological changes occur but cognitive ability is normal, followed by a symptomatic (prodromal or pre-dementia) phase of progressive cognitive decline before the onset of functional impairment and overt dementia. In addition, it has been discovered that cognitive impairment can be detected way before the onset of dementia symptoms (Dubois, Padovani, Scheltens, Rossi, Agnello & Saykin 2016).