AD (the most common cause of dementia) is a progressive disease characterised by loss of function and death of nerve cells in several areas of the brain. The neurodegeneration leads to loss of cognitive functions such as memory and learning. The new Alzheimer’s Diagnostic Guidelines refer to the spectrum of AD in three stages; (1) preclinical AD, (2) mild cognitive impairment (MCI) due to AD, and (3) dementia due to AD.

Read more about the changing definition of AD