Early onset Alzheimer’s disease is when someone develops the condition before the age of 65 years old. Late onset involves the disease occurring from the age of 65.
Alzheimer’s disease is the most common cause of dementia, and its prevalence increases with age.
Doctors often categorize Alzheimer’s disease into early onset or late onset. Typically, the age cut-off for these types is 65. However, some experts use 60 years old as the cut-off for early or late onset.
In a clinical setting, a healthcare professional may not describe Alzheimer’s disease as late onset. However, they may use it to refer to a delayed onset of the condition.
Early onset is also known as younger onset Alzheimer’s disease. This type of condition affects individuals below the age of 65.
Many individuals with early onset Alzheimer’s disease are in their 40s and 50s. The exact cause of the disease at these younger ages is unknown.
However, experts have found that there may be a connection between early onset Alzheimer’s disease and certain genes. Those with a genetic form of early onset Alzheimer’s disease may be more likely to begin experiencing symptoms in their 30s or 40s.
Read about early onset Alzheimer’s disease.
Late onset Alzheimer’s disease is when the condition develops after the age of 65. This type of disease is more common than early onset.
According to 2020 research, early onset Alzheimer’s disease accounts for only around 5% to 10% of all cases of the condition. However, the research authors also note that the rates of early onset derive from significantly less data, so the prevalence may be higher.
The authors add that around 1 in 9 people ages 65 years and older have Alzheimer’s disease, while 1 in 3 who are over the age of 85 years old have the condition.
Learn more about late onset Alzheimer’s disease.
Besides the age of onset, the initial symptoms of early and late onset Alzheimer’s disease can also vary.
A 2018 review notes that early onset Alzheimer’s disease is more likely to present with atypical symptoms.
The Alzheimer’s Society in the United Kingdom also states that the symptoms of early onset Alzheimer’s disease are less likely to be memory loss and more commonly involve changes in:
- personality
- behavior
- language
- vision
However, an earlier age of onset does not necessarily mean it is a different type of Alzheimer’s disease.
Genetics can play a role in early onset Alzheimer’s disease. Underlying health conditions and lifestyle factors can also cause the development of symptoms at an earlier age. These include:
- smoking
- drinking excess alcohol
- stroke
- heart disease
- head trauma
- age-related hearing loss
- depression
- diabetes
Common signs of Alzheimer’s disease
Early signs of Alzheimer’s disease
- memory loss that often disrupts daily life
- losing track of dates
- loss of spontaneity
- forgetting recently learned information or repeating questions
- taking longer to complete daily tasks
- getting lost or wandering
- difficulty solving problems or planning
- misplacing items in odd places or losing them
- difficulty paying bills or handling money
What are the seven stages of early onset Alzheimer’s?
The seven stages of Alzheimer’s disease are:
- before symptoms appear
- basic forgetfulness
- noticeable memory issues
- more than memory loss, including confusion
- decreased independence
- severe symptoms
- lack of physical control
What is the life expectancy of someone with early Alzheimer’s?
On average, people with Alzheimer’s disease live between 4 to 8 years following diagnosis. However, they can live as long as 20 years.
Alzheimer’s and dementia resources
To discover more evidence-based information and resources for Alzheimer’s and dementia, visit our dedicated hub.
Early onset Alzheimer’s disease involves the condition developing before the age of 65 years old. Late onset is when it occurs from the age of 65 years old.
Age is the key difference between the two categorizations of Alzheimer’s disease. However, the way symptoms appear may also differ. For example, early onset may not always involve memory loss at first. Instead, a person may experience personality changes and behavioral changes.
If individuals notice they or a loved one are experiencing changes in memory, difficulty completing daily tasks, or changes in personality or behavior, they need to contact a healthcare professional.