What is early-onset Alzheimer disease?

Alzheimer disease is the most common form of dementia. It affects your memory, thinking, and behavior. It often progresses to the point where it affects daily activities and functions.

Alzheimer disease most commonly affects older adults. But it can also affect people in their 30s or 40s. When Alzheimer disease happens in someone younger than age 65, it's known as early-onset (or younger-onset) Alzheimer disease.

A very small number of people with Alzheimer disease have the early-onset form. Many of them are in their 40s and 50s when the disease takes hold.

Most types of early-onset Alzheimer disease are the same. But there are a few small distinctions:

• Common Alzheimer disease. Most people with early-onset Alzheimer disease have the common form of the disease. The disease progresses in about the same way as it does in older people.

• Genetic (familial) Alzheimer disease. This form is very rare. A few hundred people have genes that directly contribute to Alzheimer disease. These people start showing symptoms of the disease in their 30s, 40s, or 50s. 

What causes early-onset Alzheimer disease?

Experts don't know what triggers the start of Alzheimer disease. They suspect that 2 proteins damage and kill nerve cells. Fragments of one protein, beta-amyloid, build up and are called plaques. Twisted fibers of another protein, tau, are called tangles. Almost everyone develops plaques and tangles as they age. But those with Alzheimer disease develop many, many more. These plaques and tangles first damage the memory areas of the brain. Over time, they affect more areas of the brain. Experts don't know why some people develop so many plaques and tangles or how they spread and damage the brain.

Who is at risk for early-onset Alzheimer disease?

Family history of the disease is the only known risk factor at this time.

What are the symptoms of early-onset Alzheimer disease?

For most people with early-onset Alzheimer disease, the symptoms closely mirror those of other forms of Alzheimer disease.

Early symptoms are:

• Forgetting important things, particularly newly learned information or important dates

• Asking for the same information again and again

• Trouble solving basic problems, such as keeping track of bills or following a favorite recipe

• Losing track of the date or time of year

• Losing track of where you are and how you got there

• Trouble with depth perception or other vision problems

• Trouble joining conversations or finding the right word for something

• Misplacing things and not being able to retrace your steps to find it

• Increasingly poor judgment

• Withdrawal from work and social situations

• Changes in mood and personality

Later symptoms are:

• Severe mood swings and behavior changes

• Deepening confusion about time, place, and life events

• Suspicions about friends, family, or caregivers

• Trouble speaking, swallowing, or walking

• Severe memory loss

How is early-onset Alzheimer disease diagnosed?

The current diagnosis of early-onset Alzheimer disease relies on finding the signs of mental decline noted above. Your healthcare provider can then diagnose Alzheimer disease with a few tests.

First, your healthcare provider asks about your health history. They also do cognitive tests of memory, problem solving, and other mental skills. Depending on the results of the office-based cognitive testing, your provider may also request that you have more detailed testing done with a neuropsychologist. Your provider might also test your blood, urine, and spinal fluid. You may also need certain imaging test such as CT and MRI scans of your brain. These give your provider a closer look at brain tissue to show how much damage there is.

In the future, researchers hope that studies on biomarkers will allow experts to diagnose the disease more quickly. Biomarkers are proteins in the body, or other types of markers, that reliably indicate the progress of a disease.

How is early-onset Alzheimer disease treated?

Early-onset Alzheimer disease currently has no cure. But healthcare providers have been successful in helping some people maintain their mental function, control behavior, and slow the progress of the disease.

Medicines are used to help people maintain mental function. They may include:

• Donepezil

• Rivastigmine

• Galantamine

• Memantine

• Lecanemab-irmb

Results have been mixed. But these medicines seem to help people with their symptoms for anywhere from a few months to a few years.

Other treatments that may play a role in slowing the progress of early-onset Alzheimer disease include physical activity, cardiovascular and diabetes treatments, antioxidants, and cognitive training. A number of studies are ongoing in this area, and researchers are learning new things about Alzheimer disease every day.

Can early-onset Alzheimer disease be prevented?

Experts don’t know how to prevent Alzheimer disease. Recently, some evidence showed that finding the disease early can lead to better treatment options. It’s best to look for any of the early warning signs mentioned above and see your healthcare provider right away if you notice any. Keeping active both physically and mentally, as well as socializing with others, seem to offer some protection.

Living with early-onset Alzheimer disease

Early-onset Alzheimer disease can be a hard disease to cope with. It helps to have a positive outlook and to stay as active and mentally engaged as possible.

It’s also important to realize that you are not alone. Rely on your friends and family as much as possible. Don’t be afraid to join a support group, if you feel that it might be helpful.

When the disease is still in its early stages, it's critical to think about the future. This can include financial planning, working with employers on current and potential job responsibilities, clarifying health insurance coverage, and getting all your important documents in order should your health take a turn for the worse. 

Alzheimer disease has no cure. But you can make the best of a bad situation by keeping your mind and your body as healthy as possible. This can include:

• Eating a healthy diet

• Getting regular exercise

• Cutting down on alcohol

• Using relaxation methods to reduce stress

When should I call my healthcare provider?

As with any disease, it's important to keep an eye on your condition. Call your healthcare provider if you notice any sudden changes in yourself, or in the person you care for, that make more help necessary. You can discuss the next steps with your provider.

Key points about early-onset Alzheimer disease

• Alzheimer disease commonly affects older people. But early-onset Alzheimer disease can affect people in their 30s or 40s.

• Alzheimer disease affects memory, thinking, and behavior.

• There is no known cure, but early diagnosis and treatment can lead to better quality of life.

• Stay healthy with a good diet and regular exercise.

• Stay away from alcohol and other substances that may affect memory, thinking, and behavior.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your provider tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your provider if you have questions, especially after office hours and on weekends and holidays.