The Stages of
Alzheimer’s Disease

Alzheimer’s disease starts silently and progresses across several
stages. Each person moves through them differently.1

Today, we understand Alzheimer’s disease (AD) to be a continuum. By the time patients show symptoms, the underlying processes of the disease have been at work for up to 20 years.1-3

The AD Continuum

The progression of AD typically spans several stages, and the rate of disease progression varies from person to person. AD starts with a long asymptomatic stage, called preclinical AD, followed by a symptomatic stage before dementia, called mild cognitive impairment (MCI), which finally evolves to dementia, varying from mild to severe. 4-7

Preclinical AD

MCI due to AD

Mild Dementia

Moderate Dementia

Severe Dementia

Preclinical AD

duration: Up to 20 years

This is the stage of disease before symptoms become apparent but changes in the brain have occurred - like abnormal build-up of amyloid beta (a protein in the brain).1

brain
Elaborated from Kazim SF et. al. 201611

Mild cognitive impairment (MCI) due to AD

It occurs in people with evidence of brain changes and symptoms that may be visible to friends and family, but do not significantly interfere with daily life.1

Symptoms: A noticeable change in cognition, such as short-term memory loss, problems with wordfinding, or losing track of the day or date.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Mild AD dementia

People often function independently but need assistance with some activities.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Moderate AD dementia

Typically, the longest stage of the disease, when people may have difficulties communicating and experience increased confusion, making it difficult to perform everyday activities.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Severe AD dementia

Requires constant caregiving as people may lose awareness of their surroundings and experience loss of physical abilities.1

brain
Elaborated from Kazim SF et. al. 201611

Preclinical AD

MCI due to AD

Mild Dementia

Preclinical AD

duration: Up to 20 years

This is the stage of disease before symptoms become apparent but changes in the brain have occurred - like abnormal build-up of amyloid beta (a protein in the brain).1

brain
Elaborated from Kazim SF et. al. 201611

Mild cognitive impairment (MCI) due to AD

It occurs in people with evidence of brain changes and symptoms that may be visible to friends and family, but do not significantly interfere with daily life.1

Symptoms: A noticeable change in cognition, such as short-term memory loss, problems with wordfinding, or losing track of the day or date.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Mild AD dementia

People often function independently but need assistance with some activities.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Moderate AD dementia

Typically, the longest stage of the disease, when people may have difficulties communicating and experience increased confusion, making it difficult to perform everyday activities.1

brain
Elaborated from Kazim SF et. al. 201611

Dementia due to AD (mild, moderate, severe)

Includes three steps of disease progression characterised by Alzheimer’s-related brain changes and further decline, including worsening symptoms and functional impairment.1

Severe AD dementia

Requires constant caregiving as people may lose awareness of their surroundings and experience loss of physical abilities.1

brain
Elaborated from Kazim SF et. al. 201611

 

One of the challenges of AD is that today clinical practice limits the definition of the disease to people already suffering from mild, moderate or severe dementia.8

While it is recognized that a person with mild cognitive impairment (MCI) is at an increased risk of developing AD, MCI is not currently considered an AD stage. In other words, current clinical practice often does not recognize a person as having AD until the disease has progressed significantly and dementia is evident.8

Therefore, timely diagnosis of AD is an important first step and provides patients and caregivers with an opportunity to help manage the disease and plan for the future.8

Alzheimer’s disease is not part of normal ageing

While age is the strongest known risk factor for cognitive decline, Alzheimer’s disease is not a natural consequence of ageing.1,9

More than 60% of HCPs worldwide think dementia is part of normal ageing10

Dementia is NOT part of normal ageing but it refers to a particular group of symptoms caused by neurological disorders1

Alzheimer's disease is the most common cause of dementia
among older adults,
occurring in 60-80%
of cases1

Alzheimer’s disease symptoms often start subtly. People with early AD (and their families) may mistake early signs and symptoms for normal ageing and put off going to a doctor.1 Comorbid medical conditions, such as depression or stroke, can also impact cognitive and functional abilities, making an early diagnosis of AD challenging.1,8

 

As we get older, cognitive abilities start to decline, like nearly every part and function of the human body. However, early changes in cognition, such as an increased forgetfulness, thinking more slowly than usual or difficulty multi-tasking, may be caused by the underlying mechanisms of Alzheimer’s disease and not by normal ageing processes.1-3

WHAT'S NEXT

How Alzheimer's Disease Changes the Brain

Alzheimer’s disease operates out of sight – slowly developing over years to cause injury to the brain.