The behavioral scheme developed by Reisberg, Ferris, de Leon, and Crook, known as the Global Deterioration Scale, is a seven-point rating scale that assesses the cognitive and functional capacity of the elderly and provides a staging scale from normal aging to severe Alzheimer's disease. A person at stage 1 has no subjective memory complaints and upon clinical interview shows no memory impairment. In stage 2,subjective memory complaints without objective evidence of memory impairment on clinical interview are noted. Stages 1 and 2 are considered within the limits of normal aging. Patients in Stage 3 are considered to have a mild cognitive impairment. Their behavior is characterized by deficits including getting lost traveling to an unfamiliar location, performance changes at work, decreased memory for names of people, and concentration difficulties during formal testing. It is only upon extensive interviewing that objective evidence for performance problems is seen. Stage 4 is considered to be the first stage of Alzheimer's disease in which problems during a clinical interview are noted. Deficits in knowledge of current and recent events, memory of ones personal history, concentrating, ability to travel and handle finances, orientation to time and person, and performing complex tasks, are characteristic of this stage. With progression to stage 5 , the patient needs assistance with activities of daily living. During an interview, patients in stage 5 typically are unable to recall their address, telephone number, or the names of close family members, although they may remember their own name and their spouse's name. Disorientation to time or place is often noted at this stage.