Early onset Alzheimer’s disease is a variant of Alzheimer’s disease that begins to cause symptoms when people are in their 40s and 50s. Symptoms include memory loss, difficulty completing familiar tasks, and personality changes.

Alzheimer’s disease is a type of dementia that affects nearly 6 million people in the United States and over 50 million people worldwide.

Although it’s commonly known to affect adults 65 years and older, about 5% of those with the diagnosis have early onset Alzheimer’s disease, sometimes called “younger onset.” This generally means that the person with the diagnosis is in their 40s or 50s.

The diagnosis of early onset Alzheimer’s disease can be delayed because people at this age might not seek medical attention, discounting their own symptoms as stress-induced.

Additionally, other conditions that more commonly affect this age group (such as multiple sclerosis) need to be ruled out before Alzheimer’s disease is diagnosed in middle age.

As the disease affects the brain, it can cause a decline in memory, reasoning, and thinking abilities. The decline is typically slow, but this can vary on a case-by-case basis.

This article reviews the symptoms, risk factors, diagnosis, and treatment of early onset Alzheimer’s disease.

Alzheimer’s disease is the most common form of dementia. Dementia is a general term for the loss of memory functions or other mental abilities that affect your daily life.

You or a loved one may be developing early onset Alzheimer’s disease if you experience any of the following:

Memory loss

You or a loved one may begin to appear more forgetful than usual. Forgetting important dates or events can occur.

If questions become repetitive and frequent reminders are required, you should contact your doctor.

Difficulty planning and problem-solving

Alzheimer’s disease may become more apparent if you or a loved one has difficulty developing and following a plan of action. Working with numbers may also become difficult.

This can often be seen when you or a family member begins to demonstrate problems maintaining monthly bills or a checkbook.

Difficulty completing familiar tasks

Some people may experience a problem with concentration. Routine day-to-day tasks requiring critical thought may take longer as the disease progresses.

The ability to drive safely may also be called into question. If you or a loved one gets lost while driving a commonly traveled route, this may be a symptom of Alzheimer’s disease.

Difficulty determining time or place

Losing track of dates and miscalculating the passage of time as it occurs are also two common symptoms. Planning for future events can be impaired as it becomes difficult to keep track of details.

As symptoms progress, people with Alzheimer’s disease can become increasingly forgetful about where they are, how they got there, or why they’re there.

Vision loss

Vision problems can also occur. This can cause difficulty in reading.

You or a loved one may also begin to have problems judging distance and determining contrast or color when driving.

Difficulty finding the right words

Initiating or joining in on conversations may appear difficult. Conversations may randomly be paused in the middle, as you or a loved one may forget how to finish a sentence.

Because memory is impaired, repetitive conversations can occur. You may have difficulty finding the right words for specific items.

Misplacing items often

You or a loved one may begin putting items in unusual places. It may become more difficult to retrace your steps to find any lost items.

Forgetting where objects are placed combined with mistrusting others (another symptom of Alzheimer’s disease) can make people suspicious that others are stealing.

Difficulty making decisions

Financial choices may demonstrate troubles with judgment. An example of this is donating large amounts of money to telemarketers.

This symptom can lead to financial loss if trusted loved ones don’t step in.

Physical hygiene also becomes less of a concern. You or a loved one may experience a rapid decline in bathing frequency and a lack of willingness to change clothing on a daily basis.

Withdrawing from work and social events

As symptoms appear, you may notice that you or a loved one becomes increasingly withdrawn from common social events, work projects, or hobbies that were previously important. Avoidance can increase as symptoms worsen.

Experiencing personality and mood changes

Extreme swings in mood and personality may occur. A noticeable change in moods may include:

You may notice that you or your loved one is increasingly irritated when something outside a typical routine takes place.

Although Alzheimer’s disease isn’t an expected part of advancing age, you’re at increased risk as you get older. More than 32% of people over age 85 have Alzheimer’s disease.

You may also have an increased risk of developing Alzheimer’s disease if a parent, sibling, or child has the disease. If more than one family member has Alzheimer’s disease, your risk increases.

A 2016 study showed that African Americans, Native Americans, and Native Alaskans are at higher risk for developing early onset Alzheimer’s disease compared to white people.

Prevalence of early onset Alzheimer’s disease

Early onset Alzheimer’s disease affects approximately 220,000 to 640,000 people in the United States, according to estimates from 2006.

The exact cause of early onset Alzheimer’s disease hasn’t been fully determined. Many researchers believe that this disease develops as the result of multiple factors rather than one specific cause.

Researchers have discovered rare genes that may directly cause or contribute to Alzheimer’s disease. These “deterministic genes” are:

  • amyloid precursor protein (APP) on chromosome 21
  • presenilin-1 (PS1) on chromosome 14
  • presenilin-2 (PS2) on chromosome 1

These genes may be carried from one generation to the next within a family. Carrying these genes can result in adults younger than age 65 developing symptoms earlier than expected.

Mutations in these genes account for only 5% to 10% of all Alzheimer’s cases, but they are risk factors for a majority of early onset Alzheimer’s disease cases.

Apolipoprotein E (APOE-e4) is another gene associated with Alzheimer’s disease. It’s more commonly a factor in people who develop Alzheimer’s disease after age 65.

Early onset Alzheimer’s disease cannot be prevented, but you can reduce your risk. People who take steps to reduce their risk of early onset Alzheimer’s disease can still develop the disease.

Lifestyle changes that help reduce risk include:

Talk with a doctor if you or a loved one is finding it increasingly difficult to perform day-to-day tasks or if you or a loved one is experiencing increased memory loss. They may refer you to a doctor who specializes in Alzheimer’s disease.

Especially in the case of early onset Alzheimer’s disease, symptoms may seem to be related to other causes, like stress.

There’s no one test to diagnose Alzheimer’s disease. Your doctor may use many different tools to arrive at a diagnosis. These include:

Recent research has focused on blood tests that can identify proteins associated with Alzheimer’s disease in the blood. While these show promise, more research is needed.

There’s no cure for Alzheimer’s disease at this time. Detecting the disease early on can help with treatment options and managing symptoms.

Symptoms of Alzheimer’s disease can sometimes be treated with medications meant to help improve memory loss or decrease sleeping difficulties. These medications include

Research is still being done on possible alternative treatments.

Some activities and habits can help both the person with Alzheimer’s disease and their caregiver to manage symptoms and behavioral problems. These include:

  • maintaining a familiar environment
  • getting exposure to sunlight
  • eating a nutritious diet
  • reducing or eliminating alcohol consumption
  • doing relaxation techniques to reduce stress
  • doing aerobic exercises

Since early onset Alzheimer’s disease can affect people in their 40s and 50s, symptoms can sometimes be more disruptive to work, social, and family life. Managing symptoms of early onset Alzheimer’s disease often focuses on more age-appropriate support.

Specific support may include:

  • occupational therapy
  • speech therapy
  • vision therapy

Receiving an early onset Alzheimer’s disease diagnosis can be worrying. However, it gives you time to put together a plan so that you have peace of mind for the future when symptoms appear or intensify.

Try creating a plan together with your family, friends, and medical team. It can also be beneficial to meet with a financial planner and a lawyer.

Here are some key things to consider:

  • Education: You may find it helpful to learn more about Alzheimer’s disease and how it progresses. Talk with your doctor and learn about what your care plan could look like in the future.
  • Health insurance: Find out which medications and treatments are covered by your plan.
  • Future care costs: What will your medical and care expenses be? This may include professional home care of safety equipment for the home.
  • Disability insurance: What is covered by your employer? What documentation is needed?
  • Loss of income: Will you be able to keep working? If so, for how long? Will someone in your family need to stop working in order to become a caregiver?
  • Power of attorney: Who will have the authority to make health, financial, and legal decisions for you when you can’t anymore?
  • Support: Try finding a support group specifically for people with early onset Alzheimer’s disease and their caregivers. Their life situations are likely to be similar to yours.

It’s important to have a detailed, realistic plan for your future care. This will allow you to be more confident as you navigate through the stages of Alzheimer’s disease.

The symptoms of Alzheimer’s disease may worsen over time. For many people, a period of 2 to 4 years will pass between the onset of symptoms and receiving an official diagnosis from their doctor. This is considered to be the first stage.

After receiving a diagnosis, you or a loved one may begin to show signs of the second and later stages of the disease. This period of mild cognitive impairment can last anywhere from 2 to 10 years.

During the final stage of Alzheimer’s dementia, people lose independence. This is the most severe form of the disease. You or a loved one may be unable to remember the names of loved ones and will definitely need help with tasks such as financial management, self-care, and driving.

Support options for early onset Alzheimer’s disease

If you or a loved one has Alzheimer’s disease, there are many resources available that can provide you with more information or connect you with face-to-face support services.

The National Institute on Aging offers an extensive literature database and has information about the most current research.

The Alzheimer’s Association also provides valuable information for caregivers about what to expect at each stage of the disease.