12 Signs You Could Have Early-Onset Alzheimer’s Disease

Updated: Oct. 10, 2022

Early-onset Alzheimer's disease starts before age 65, with symptoms like memory loss. Doctors reveal the other telltale signs to watch for.

Symptoms of early-onset Alzheimer’s disease

You’ve probably heard the terms “dementia” and “Alzheimer’s disease” used interchangeably. But, before you’re able to recognize the symptoms of early-onset Alzheimer’s, you need to be able to tell the difference between dementia vs. Alzheimer’s. Here’s a quick recap: Dementia is an overarching term for mental decline (including loss of memory, language skills, and thinking abilities) that could be caused by many diseases and conditions, whereas Alzheimer’s disease is the most common cause of dementia.

Often, Alzheimer’s disease is thought to be a condition that affects the elderly, but it can also impact people under age 65, which is known as early-onset. According to the Alzheimer’s Association, about 200,000 people have early-onset Alzheimer’s disease in the U.S. and it tends to occur to people in their 40s and 50s. Keep in mind that this condition is relatively rare and makes up only 5% of the 5 million people in the U.S. that have Alzheimer’s disease. That said, how can you tell if someone has simple forgetfulness or early-onset Alzheimer’s disease?

We spoke with medical experts who reveal the telltale signs and when they’re a cause for concern.

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You’re extremely forgetful

Memory loss is the most common symptom of early-onset Alzheimer’s disease (and late-onset as well). It’s typically one of the first signs that something is wrong. Symptoms of early-onset Alzheimer’s—which are similar to those that appear in other cases of the condition—usually start when people are in their 40s or 50s, but memory loss is also a normal part of aging.

“We don’t want to worry people that when they can’t remember a name or a word, that they’re on their way to Alzheimer’s,” says Rudolph Tanzi, PhD, vice-chair of neurology and the director of the Genetics and Aging Research Unit at Massachusetts General Hospital and a professor of neurology at Harvard Medical School. “As we get older, our brain isn’t as good. Wear and tear, and inflammation, affect the brain much like it affects our joints.”

According to the Alzheimer’s Association, memory issues that reflect normal aging include things like not being able to remember details of a conversation or event that took place a year ago, or not being able to remember the name of an acquaintance. But signs of a cognitive problem might be not being able to recall details of recent events or conversations, or not recognizing or knowing the names of family members. (Read about 10 early signs of Alzheimer’s, and why an early diagnosis is so important.)

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You’re misplacing things—all the time

Everyone misplaces things from time to time—cell phone, glasses, keys. The difference in people who might have early-onset Alzheimer’s or another cognitive problem is that these losses happen more frequently, and they’re unable to retrace their steps or think of where to look for the lost item. For example, if your car keys are in your other purse, it’s probably no big deal. But if they turn up in the refrigerator, it could be cause for concern. (Try these 15 memory exercises proven to keep your brain sharp.)

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Repeating yourself

People with early-onset Alzheimer’s (or late-onset) may repeat statements and questions over and over, not realizing that they’ve asked the same question before, according to the Alzheimer’s Association. “The time to get worried,” says Elise Caccappolo, PhD,  director of the neuropsychology service and associate professor of neuropsychology at Columbia University Medical Center, “is when people repeat themselves within a very short time span.” An example would be if someone asks when a friend is coming to visit, gets told the answer, and then asks the same question a few minutes later without remembering that he or she had already inquired. (Learn more about the stages of Alzheimer’s.)

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Your sleep habits change

Many people with Alzheimer’s have difficulty sleeping, waking up more often, and staying awake longer during the night. Changes in sleep that might indicate early-onset Alzheimer’s include daytime napping and/or feeling drowsy during the day but being unable to sleep at night. (Learn more about unexpected reasons for insomnia.)

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You have trouble completing everyday tasks

“As a general rule, what I tell people is that as we age, many of us will experience the phenomenon of slower processing speed,” explains Pierre Tariot, MD, director of the Banner Alzheimer’s Institute in Phoenix. “We can’t manage complex intellectual challenges as quickly as we did in our youth.” Multitasking may become more difficult, doing mathematical calculations in your head may take more time, and balancing your checkbook will be a bit slower than it used to be. But according to the Fisher Center for Alzheimer’s Research Foundation, someone with early dementia may find it impossible to do everyday tasks—like balancing a checkbook—that once were easy. If someone used to be a gourmet cook and now has difficulty following a complex recipe, that can be a red flag, too. (Find out 16 things people with Alzheimer’s wish you knew.)

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You feel confused

All of us occasionally forget an appointment, get lost when going somewhere new, or briefly think it’s Tuesday when actually it’s Wednesday. But a possible sign of early-onset Alzheimer’s disease is, say, forgetting the route to the supermarket where you shop weekly. People with the disease may have trouble understanding something if it isn’t happening immediately, and may sometimes forget where they are or how they got there. “You shouldn’t have confusion about where you are or what day it is from normal aging,” says Caccappolo.

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Feeling depressed, or a personality shift

Up to 40 percent of people with Alzheimer’s experience depression, according to the Alzheimer’s Association. “People with Alzheimer’s who are depressed tend to be apathetic and irritable and to have sleep disturbances, but they are less likely to feel guilty or have a risk of suicide than depressed people without Alzheimer’s.” Other changes in personality that might indicate early-onset Alzheimer’s include mood swings, anxiety, aggression, anger, fear, suspicion, and loss of inhibitions. (Check out 12 common illnesses that have been linked to Alzheimer’s.)

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Making poor decisions

Nobody is perfect, and we all make bad choices on occasion (remember that perm?). But people with early-onset Alzheimer’s may have poor judgment and start making bad decisions with greater consequences. They may spend money indiscriminately or even give it away; they could stop taking care of themselves (not showering regularly, for example). (Read this woman’s account of how a diagnosis of Alzheimer’s has changed her life.)

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Trouble speaking or writing clearly

People with signs of early-onset Alzheimer’s disease may have trouble participating in a conversation or writing down their thoughts. Most people will occasionally pause to search for the right word and eventually remember it. But someone with signs of early-onset Alzheimer’s disease may experience the problem frequently, substitute an inappropriate word for the one they can’t remember, or be unable to continue speaking because they don’t know what to say. (Don’t fall for these 15 myths about Alzheimer’s.)

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Losing interest in work and socializing

It’s normal to want to try to balance work and social life, to wish you could spend more time with your family or work fewer hours. But withdrawing from work projects or social activities you used to enjoy—for instance, losing interest in a sports team you once followed religiously—could be a sign of early Alzheimer’s disease and depression. A feeling of apathy or a loss of interest in once-favorite hobbies is also a sign, suggests the Alzheimer’s Association.

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Friends and relatives are concerned

People with early-onset Alzheimer’s disease may not recognize their decline—but those closest to them could notice changes. “If a loved one expresses concern, says that you seem really different, is worried that something is going on, that’s a legitimate basis for a medical evaluation,” says Dr. Tariot. Don’t dismiss these concerns, since they may be the key to getting an early diagnosis, along with early treatment that perhaps can slow the progression of cognitive changes. (Check out the 6 Alzheimer’s breakthroughs.)

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You have a family history of early-onset Alzheimer’s

This is the biggest risk factor. “Early-onset Alzheimer’s disease has a very strong genetic component,” explains Stephen Rao, PhD, a neuropsychologist, chair and director of the Schey Center for Cognitive Neuroimaging at the Cleveland Clinic. “If your parent or another close relative had early-onset, you should probably be tested—neuropsychologically tested, but also genetically tested, as there are some definitive genetic markers.” Check out this recent study that may help determine someone’s risk for developing Alzheimer’s by using a linguistic test.

The good news is that early-onset Alzheimer’s disease is much rarer than late-onset. Most people worried about memory and other cognitive issues before age 65 are probably just experiencing normal aging changes. And when there is some cognitive impairment, it’s likely to be due to reasons other than early-onset Alzheimer’s disease, such as medical conditions, emotional problems like depression or stress, sleep impairment, or medication side effects. (Make sure your diet includes these 4 best foods to boost brain health.)