Defining Alzheimer’s Disease

How science is evolving towards a better understanding of Alzheimer’s disease and its early detection.1

Alzheimer’s disease (AD) is a progressive neurological condition that impairs thinking, memory and independence, representing the most common cause of dementia.1,2

Alzheimer’s disease operates out of sight – slowly developing over years to cause injury to the brain.3,4 Short-term memory loss, difficulty finding words, and/or losing track of the day or date are typically the first signs of the disease. Other early symptoms include confusion, such as getting lost in familiar places, or changes in mood and personality, for instance becoming more irritable or anxious.1,5 As the disease progresses, people living with AD are slowly being robbed of their memories and the ability to perform everyday activities independently, like cooking, dressing or bathing.1,2

Today, we understand Alzheimer’s disease to be a continuum, as it can be present for decades before it is even suspected. The changes in the brain causing the disease can begin up to 20 years before the first symptoms appear.1-4 Even then, it often goes undetected for far too long. People with AD and their loved ones either overlook early signs of the disease or see them as ‘senior moments’ - just part of getting older.5,6


The Stages of Alzheimer's Disease

Alzheimer’s disease starts silently and progresses across several stages. Each person moves through them differently.



1. Alzheimer’s Association. Alzheimer’s Association Report: 2020 Alzheimer’s disease facts and figures. Alzheimer’s Dement. 2020;16(3):391-460.

2. Masters CL, Bateman R, Blennow K, et al. Alzheimer’s disease. Nat Rev Dis Primers. 2015;1:15056.

3. Jack CR, Bennet DA, Blennow K, et al. NIA-AA Research Framework: Toward a biological definition of Alzheimer’s disease. Alzheimers Dement 2018;14:535–562.

4. Bateman RJ, Xiong C, Benzinger TLS, et al. Clinical and Biomarker Changes in Dominantly Inherited Alzheimer’s Disease. N Engl J Med 2012;367:795–804.

5. Alzheimer’s Association: Mild Cognitive Impairment, Accessed December 11, 2020.

6. Wilcox J, Duffy PR. Is it a ‘senior moment’ or early dementia? Addressing memory concerns in older patients. Current Psychiatry, 2016 May: 15(5): 28-30, 32-34, 40.