Alzheimer’s Disease (AD) is the most common form of dementia in the elderly. Dementia is considered a disorder of the brain that affects an individual’s ability to perform daily activities. AD is named after Dr. Alois Alzheimer, who, in 1906, noticed changes in the brain tissue of a woman who had died of an unusual mental illness. Her symptoms included memory loss, language problems, and unpredictable behavior. After the patient died, Dr. Alzheimer examined her brain and found many abnormal clumps, which we now call amyloid plaques and tangled bundles of fibers, now termed neurofibrillary, or tau tangles. These plaques and tangles in the brain are still considered important features of Alzheimer’s disease. (More discussion on these plaques and tangles is presented later in this course).
Alzheimer's disease (AD) is a global health problem and a significant cause of morbidity and mortality among elderly populations. The disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills. It eventually destroys the ability to perform the simplest of tasks. The first symptoms of AD typically appear in an individual’s mid-60s.
Although brain damage in AD is the main reason for the patient's decline and incapacitation, it is secondary illnesses and other conditions that are ultimately responsible for causing the patient's decline and death. In the final stages of AD, patients cannot perform the tasks necessary to keep the body alive and functioning. Neurologic damage and muscle weakness typically cause patients to lose the ability to coordinate such basic tasks as walking. Moreover, patients lose bladder and bowel control and have difficulty chewing and swallowing food. In fact, pneumonia is considered the most common cause of death in AD patients because of the impairment in swallowing food or beverage, which can enter the lungs and cause infection. Other common causes of death include dehydration, malnutrition, falls, and other infections.
In 2022, an estimated 6.5 million Americans, age 65 and older, are living with Alzheimer’s Disease (AD), and worldwide, over 35 million people are living with the disease. These numbers are expected to rise significantly in the future. AD is now considered the 6th leading cause of death in the U.S. It is estimated that every 65 seconds, someone in the U.S. develops the disease. About one in 10 people age 65 or older has AD, and almost two-thirds of Alzheimer’s patients in the U.S. are women. Moreover, older African-Americans are about twice as likely as older whites to have AD or other dementias. It is estimated that by 2050, the number of Alzheimer’s cases for people aged 65 and older may grow to a projected 12.7 million. It is estimated that 1 in 3 seniors die with AD or other dementia. At present, AD kills more people than breast cancer and prostate cancer combined.
The costs of healthcare and long-term care for individuals with AD or other dementias are considerable. In 2022, AD and other dementias cost the U.S. approximately $321 billion. By 2050, these costs are estimated to reach nearly $1 trillion.
