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Mental Health: Alzheimer's & Dementia

Alzheimer's

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Alzheimer's & Dementia (Merck Manual)

Alzheimer disease is a progressive loss of mental function, characterized by degeneration of brain tissue, including loss of nerve cells, the accumulation of an abnormal protein called beta-amyloid, and the development of neurofibrillary tangles.

  • Forgetting recent events is an early sign, followed by increasing confusion, impairment of other mental functions, and problems using and understanding language and doing daily tasks.
  • Symptoms progress so that people cannot function, causing them to become totally dependent on others.
  • Doctors base the diagnosis on symptoms and results of a physical examination, mental status tests, blood tests, and imaging tests.
  • Treatment involves strategies to prolong functioning as long as possible and may include drugs that may slow the progression of the disease.
  • How long people live cannot be predicted, but death occurs, on average, about 7 years after the diagnosis is made.

Alzheimer disease is a type of dementia, which is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn.

In 60 to 80% of older people with dementia, Alzheimer disease is the cause. It is rare among people younger than 65. It becomes more common with increasing age. About 11% of people aged 65 or older and about 32% of those aged 85 or older have Alzheimer disease. It affects more women than men, partly because women live longer. In 2015 in the United States, an estimated 5.3 million people had Alzheimer disease. The number of people with Alzheimer disease is expected to greatly increase as the proportion of older people increases.

Dementia is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn.

  • Typically, symptoms include memory loss, problems using language and doing activities, personality changes, disorientation, and disruptive or inappropriate behavior.
  • Symptoms progress so that people cannot function, causing them to become totally dependent on others.
  • Doctors base the diagnosis on symptoms and results of a physical examination and mental status tests.
  • Blood and imaging tests are used to determine the cause.
  • Treatment focuses on maintaining mental function as long as possible and providing support as the person declines.

Dementia occurs primarily in people older than 65. Dementia, particularly the disruptive behavior that often accompanies it, is the reason for more than 50% of admissions to nursing homes. However, dementia is a disorder and is not a part of normal aging. Many people over 100 do not have dementia.

Dementia differs from delirium, which is characterized by an inability to pay attention, disorientation, an inability to think clearly, and fluctuations in the level of alertness.

  • Dementia affects mainly memory, and delirium affects mainly attention.
  • Dementia typically begins gradually and has no definite beginning point. Delirium begins suddenly and often has a definite beginning point.

Juebin Huang, MD, PhD – Merck Maual – Consumer Version - http://www.merckmanuals.com