Are Those Repeated Work Mistakes Just “Fatigue”? Early-Onset Dementia Affecting People in Their 40s and 50s: Why “Quitting Before Diagnosis Is a Bad Idea”

I found myself repeating the same story over and over to my boss and coworkers. I’d forget instructions I was sure I’d heard, leading to more mistakes. Double bookings became more frequent.

Even when these issues pile up, many people convince themselves, “It’s probably just stress” or “I must be tired.” Yet the anxiety persists, so they visit a clinic, take their medication as prescribed, and review their lifestyle habits. And yet, the situation doesn’t improve.

“Perhaps the cause isn’t stress after all.”

When you have that thought, Ayako Edahiro of the Tokyo Metropolitan Institute of Gerontology suggests considering the possibility of early-onset dementia.

“Dementia is often thought of as a disease of the elderly, but in fact, as of 2022, it is estimated that there are approximately 36,000 people nationwide with early-onset dementia—that is, dementia that develops before the age of 65.And, in very rare cases, it can even develop in people in their 40s and 50s—right in the prime of their working lives. That rarity is also what makes this disease so tricky.”  

Because there are no familiar examples, the person themselves, their family, colleagues, and even doctors tend to think, “That can’t be possible.”

“Early Symptoms” That Strike People in Their Prime

When we think of dementia, we tend to imagine “forgetfulness” in the elderly, but early-onset dementia, which strikes people in their 40s and 50s—right in the prime of their working lives—manifests in a slightly different way than the “forgetfulness” we typically picture.

For example, the following changes may occur:

• Inability to multitask.
• Failing to meet deadlines. Leaving tasks undone.
• Inability to plan work effectively.
• Suddenly being unable to recall the faces or names of business partners or customers.
• The right words don’t come to mind during conversations.
• I fly into a rage over minor criticisms.
• Conversely, you may lose all motivation to do anything.

Such “unprecedented behaviors or changes” can sometimes appear in the early stages of early-onset dementia.

According to a survey conducted by Mr. Edahiro and his team involving 770 individuals with the condition and their family members, the most common early symptom was “increased forgetfulness,” accounting for 69.6% of responses. This was followed by “more mistakes at work or with household chores” (43.8%).

Furthermore, the manifestations vary depending on the diagnosed condition. While “forgetfulness” was particularly high at 75.7% for Alzheimer’s disease, “a loss of motivation for everything” accounted for 34.9% in frontotemporal dementia, and “trouble finding the right words” accounted for 41.3% in vascular dementia.

“It’s not merely a matter of forgetting things; a very large number of people—especially those who are employed—report a decline in their actual work performance.Because they suddenly start performing differently in tasks they used to handle without any problems, they worry, ‘Why am I struggling so much?’ or ‘Why are my colleagues pointing this out to me again and again?’—and it’s not uncommon for them to become withdrawn, much like someone suffering from depression” (Ayako Edahiro; same below).

Why Are “Changes in the 40s” Overlooked?

Despite frequent work mistakes that would have been unthinkable for their former selves, why do both the individuals themselves and those around them fail to recognize that this is “early-onset dementia”?

“The fundamental reason is that onset in one’s 40s and 50s is extremely rare, so the reality is that there are no familiar cases or people to consult with. Without opportunities to gain accurate knowledge, both the individual and those around them assume, ‘There’s no way it could be me (or my family member, colleague, or boss).’”

This assumption is also present among doctors, he says. However, Dr. Edahiro continues, this isn’t simply a matter of a lack of diagnostic experience.

“Even setting aside misdiagnoses or a doctor’s experience, diagnosing dementia is difficult in the first place. People in their 40s and 50s are a generation facing countless sources of stress—raising children, caring for aging parents, work, and loans. As a result, even when there are changes in emotions or behavior, people don’t immediately connect those changes to symptoms of an illness.”

Furthermore, there are cases where even diagnostic tests lack conclusive evidence.

“In younger patients, even with imaging tests, it’s often difficult to clearly identify which areas are changing and how. So, even if the patient complains of feeling unwell, we can’t gather enough information to reach a diagnosis.”

On top of that, there are significant barriers to finding a place to seek help.

“While some municipalities have set up dementia consultation services, some people feel, ‘Dementia is something that affects the elderly—I’m in my 40s, so why would I go there?’”

Such reservations lead to delays in seeking medical care. It’s common for several months to half a year to pass between first noticing something was off and actually seeing a specialist; for some, it takes over a year.

It’s not uncommon for those affected to deliberately choose a hospital far away out of concern for what others might think. “I’ve seen people living in urban areas with ample medical resources who drove for hours to a distant hospital, and others who took the Shinkansen to another prefecture to see a specialist they’d seen on TV,” says Mr. Edahiro.

“Even when they finally walk through the hospital doors, as I mentioned earlier, they aren’t immediately diagnosed with early-onset dementia. At first, they may be diagnosed with ‘menopausal symptoms’ or ‘depression.’

They then go through a process of taking antidepressants to see how things develop, and time passes without knowing whether the medication is actually working. During this time, because they see no improvement, it’s not uncommon for them to fall into a cycle of ‘doctor shopping’—visiting multiple hospitals—or to lose trust in the medical system.”

Meanwhile, something else is happening at work.

“Since those around them don’t know they’re ill, a sudden increase in work mistakes can make it seem like they’re ‘not trying hard enough’ or ‘lacking motivation.’ What starts as a mild reprimand can eventually turn into harsh criticism.”

Even if the person offering the criticism means no harm, the individual in question may already be feeling cornered. Some people panic the more they’re scolded, becoming enraged and lashing out, while others withdraw into themselves. In this way, workplace relationships quietly become strained.

In smaller companies, the issue goes beyond just interpersonal relationships.  

“In small companies, mistakes directly result in financial losses for the company, so employees may be encouraged to resign at that point.”  

A good rule of thumb for seeking medical attention is “if resting doesn’t help.”

Often, the person themselves is not the first to notice something is wrong.

“In a survey of 559 individuals, workplace colleagues noticed something was wrong in 149 cases. Family members, siblings, and others outside the workplace noticed in 410 cases. Among these, only 15 percent of the individuals noticed the changes in themselves.”

The longer people spend time with someone, the more likely they are to notice changes. However, it’s difficult to connect those changes to an illness. That’s precisely why a guideline is needed.

“For example, if taking time off doesn’t make a difference, or if symptoms persist for several months. First, please consult the ‘Early-Onset Dementia Call Center’—a nationwide helpline—or the early-onset dementia support coordinator in your prefecture.”

Early-Onset Dementia Support Coordinators are professionals who serve as specialized consultation points for this condition. They listen to the individual and their family, then connect them to the necessary medical, welfare, and employment resources. Their locations vary by region; some are based at medical institutions, while others are operated by professional organizations such as family support groups or associations of social workers.

It is possible that, even after seeking advice, a person might not be diagnosed with dementia upon actually seeing a doctor. So, what kind of support can you actually expect when you consult one of these coordinators?

“Even if you seek advice early on, it can sometimes be difficult to make a definitive judgment. However, if it seems like a medical evaluation is necessary, they can refer you to specialized medical facilities, such as dementia care centers. They can also work with you to determine whether a medical evaluation is even necessary at this stage. We accept consultations not only from the person with dementia but also from their families.”

Most inquiries received at the help desk come from family members, and they can also offer advice on how to approach a person who is reluctant to seek medical care. In fact, there have been cases where a medical visit was arranged by saying, “Let’s go discuss the symptoms that are concerning you right now,” without actually mentioning the word “dementia.”

Resigning for personal reasons before receiving a diagnosis is a big no-no!

“Many people feel relieved after being diagnosed with early-onset dementia. Since they’ve been sensing that ‘something’s off’ themselves, they take it as, ‘Thank goodness—my poor health was due to an illness after all.’”

So, when should you take action?

“I strongly recommend consulting with a professional while you’re still working. Once you’ve retired, the types of pensions you’re eligible for change, so it’s crucial to get diagnosed while you’re still employed to protect your financial security.”

The type of disability pension you are eligible for depends on which pension system you were enrolled in on the date of your initial medical diagnosis for that illness. If your initial diagnosis occurred while you were enrolled in the Employees’ Pension Insurance, you are eligible for the Employees’ Disability Pension, which begins at Grade 3—the level where there are significant restrictions on your ability to work.

On the other hand, if the initial diagnosis occurs after you’ve retired and switched to the National Pension, you’re limited to the Basic Disability Pension, which is only paid out if you are classified as Grade 2 or higher—meaning daily life is extremely difficult.

In addition to pensions, there are other systems available. While Long-Term Care Insurance generally covers those aged 65 and older, individuals with early-onset dementia aged 40 or older but under 65 can utilize it under the “specific diseases” framework; furthermore, welfare services for people with mental disabilities are also available as options.

While it is possible to utilize both, many people are simply unaware that these systems even exist. Because these are rare diseases, there are few opportunities to access accurate information.

“There are several programs available to people who develop the disease at a young age, such as medical expense assistance and disability certificates. However, even if you were given a list, you wouldn’t know what each one entails or which one you should use, would you? That’s where a coordinator comes in.

They have the expertise to determine how to effectively combine the disability support framework with the mental health framework. They provide guidance that looks ahead to what kind of support you can receive from a particular provider and how much easier your life will become as a result.”

As you sort through the available programs, a wider range of work options opens up.

“Some people take a break using their paid leave, receive sickness benefits, and then continue working under a disability employment program. Alternatively, there’s the option of changing jobs and steering their career in a different direction.”

It’s not just work arrangements that offer choices.

“There are far more people with early-onset dementia than you might imagine who have found their purpose and are engaging in meaningful work. That’s why I don’t think a diagnosis means ‘the end.’ If you’re feeling anxious, please don’t keep it to yourself—be sure to contact a counseling service for early-onset dementia.”

▼Ayako Edahiro: Researcher, Research Team for Promotion of Independence and Mental Health, Research Institute, Tokyo Metropolitan Institute of Gerontology. Dentist, Ph.D. (Dentistry). She specializes in oral function and dietary support for people with dementia and is also conducting research on the prevalence and early symptoms of early-onset dementia based on surveys of people with the condition and their families nationwide.