What is Alzheimer’s disease?

Alzheimer’s disease is a progressive degenerative disease that results in a loss of brain cells. It is the most common form of dementia, affecting 60-80 % of people with dementia above 65 years of age. The most common symptoms of Alzheimer’s dementia are memory impairment, confusion, disorientation in time and place, difficulties with communication and everyday tasks.

In people with Alzheimer’s disease, the brain undergoes changes, including the accumulation of proteins called ‘ß-amyloid’ and Tau in the brain. The accumulation of ß-amyloid and Tau can start more than a decade before clinical symptoms of dementia occur. Although there is no preventive or curative treatment for Alzheimer’s disease yet, researchers are investigating possible interventions to delay the onset of disease. These interventions would then be used by healthy persons during the long ‘preclinical’ period, that is: before any symptoms of Alzheimer’s disease occur.

During the last few years, new conceptual approaches and criteria to describe Alzheimer’s disease have been developed referring to the spectrum of Alzheimer’s disease in three stages: (1) preclinical Alzheimer’s disease, (2) mild cognitive impairment (MCI) due to Alzheimer’s disease, and (3) dementia due to Alzheimer’s disease.


Read more about the changing definition of Alzheimer’s disease