Proposing a "new perspective on dementia" aimed at social inclusion: The government's first basic plan to address the projected increase in the number of patients

Dementia is expected to increase steadily with the aging of the Japanese population. The total number of patients with dementia and people with mild cognitive impairment (MCI) has already exceeded 10 million and will reach an estimated 12 million by 2040. In response to such a serious situation, the government's "Ministerial Council on the Promotion of Dementia Care Policies (headed by Prime Minister Shigeru Ishiba)" formulated the "Basic Plan for the Promotion of Policies on Dementia," which was approved at a Cabinet meeting on December 3.

The Basic Plan clearly states that "anyone can develop dementia," and delivers a new perspective on the disease stating that "having dementia does not mean being incapable of doing anything, and persons with dementia can continue to live by their own values in hope."

Research on early diagnosis and treatment of Alzheimer's disease, which accounts for nearly 70% of all dementia cases, has made progress in recent years. The Basic Plan aims to realize an inclusive society in which Alzheimer's disease, a progressive disease, is detected as early as possible, and entities around the patients, including the family, community, and local government, support each other without isolating the patients.

A meeting of the government's Ministerial Council on the Promotion of Dementia Care Policies was held on November 29 to formulate the Basic Plan. During the meeting, Ishiba stated, "It is necessary to realize a society in which (people with dementia) can keep relationships with people around them and continue to live with hope in their familiar neighborhood."

1 in 3.6 elderly people already living with dementia or predementia

Dementia is a condition in which cognitive function declines due to the functional deterioration of neurons in the brain, interfering with daily life. Alzheimer's disease, which accounts for nearly 70% of all dementia cases, is a progressive disease associated with the accumulation of amyloid beta and a protein called "phosphorylated tau 217 (tau)" in the brain, which causes the breakdown of neurons and gradual impairment of cognitive function. Symptoms of Alzheimer's disease include memory loss and impaired judgment. Other types of dementia include vascular and Lewy body dementia.

The Basic Plan was formulated based on the "Dementia Basic Act on Dementia," which was enacted on January 1, 2024 and aims to promote comprehensive and systematic dementia-related policies. The basic principle of the Act was to realize a society in which "people with dementia can live in dignity with a sense of purpose."

According to statistics from the Ministry of Health, Labour and Welfare (MHLW), which were included in the Basic Plan, approximately 4.43 and 5.59 million elderly people had dementia and MCI, referred to as "predementia," respectively, in 2022. This means that about 1 in 3.6 elderly people had dementia or predementia. Moreover, these numbers are estimated to be about 5.84 million and 6.13 million, respectively, in 2040.

In 2004, the government changed the Japanese term for dementia - i.e., from somewhat of a contemptuous term to a real medical term of the disease - to eliminate misunderstanding and prejudice. However, the idea that "persons with dementia cannot understand or do anything" persistently remains. Even now, some persons with dementia are socially isolated, and their own will is not fully respected.

The Basic Plan defines the new perspective on dementia as "People with dementia can or want to do some things (even after the development of symptoms), and they can keep relationships with community members and continue to live by their own values in their familiar neighborhood." The Basic Plan then points out, "Given the fact that anyone can develop dementia these days, now is the time that each and every one of us, regardless of age, should understand dementia as a matter directly relevant to ourselves, let people around us know that we or someone in our families have dementia, and think about what we should do to continue to live by our own values."

Four priority goals, including "respecting the will of patients with dementia" and 12 policies

The Basic Plan, established by the government, set four priority goals for the "first plan period," which ends in 2029. Then, for each of them, evaluation measures are set to help achieve the goals. The first priority goal is to let each and every citizen understand the "new perspective on dementia" so that persons with dementia can continue to live in hope. The designated measures include the number of "Dementia Supporters" who support people with dementia and their families.

The second goal is "to respect the will of persons with dementia in their daily lives." The measures include the number of municipalities hosting "meetings for persons with dementia" in which the persons with dementia discuss their experiences and requests among themselves and government officials participate. The third goal is to enable people with dementia "to live secure lives in the community." The measures include the percentage of people with dementia who feel they are playing some role in the community. The fourth goal is "to utilize new knowledge and technology." The measures include the number of real-world examples in which the results of related research projects supported and conducted by the national government have been implemented in society.

In addition to priority goals and evaluation measures, the Basic Plan lists the following 12 specific policies to be promoted:

1. (1) Promotion of public understanding
2. (2) Promotion of "dementia barrier-free" for independent living
3. (3) Ensuring opportunities for social involvement, such as "peer support activities" in which people with dementia discuss their problems with each other
4. (4) Supporting decision-making and protecting the rights and interests of people with dementia
5. (5) Development of systems for insurance medical services, such as specialized medical services, and welfare services
6. (6) Establishment of consultation systems at community comprehensive support centers and companies
7. (7) Promotion of research on dementia-related matters, including prevention, diagnosis, treatment, and long-term care
8. (8) Dementia prevention based on scientific findings
9. (9) Conducting surveys necessary for policy development
10. (10) Collaboration among various stakeholders and organizations such as family doctors, support doctors, and community support centers
11. (11) Support for local governments, including provision and sharing of reference examples
12. (12) International cooperation with foreign governments, international organizations, and related groups

Among these, (3) social involvement is particularly noteworthy. This policy encourages peer support activities, aiming to create an environment where individuals suffering from dementia are prevented from being isolated and can live with a sense of purpose. As for (9), the surveys will also target those with young-onset dementia, aiming at strengthening the system to support their social involvement and employment.

The government has been promoting national dementia measures based on the "National Framework for Promotion of Dementia Policies" but has "upgraded" it to the Basic Plan because dementia has become a larger social issue. The Basic Plan developed reflects the opinions of people with dementia.

Accumulation starts 15-20 years before the onset of symptoms

In May, an announcement by the MHLW shocked the public: "The number of patients with dementia will reach 5.84 million when the population over 65 years old will almost peak in 2040, and 6.45 million in 2060. The number of people with MCI will be 6.32 million. Thus, a total of 12.77 million people, or 1 in 2.8 elderly persons, will have dementia or MCI."

A monthly lecture meeting of the Japanese Association of Science and Technology Journalists (JASTJ) was held on October 9. At the meeting, Professor Takeshi Iwatsubo, a leading researcher on Alzheimer's disease at the University of Tokyo Graduate School of Medicine, provided the following view: "At this point, dementia cannot be cured once the disease has reached an advanced stage. Nevertheless, further advances in research will open various possibilities for treatment."

Iwatsubo, who also serves as the executive president of the Japanese Society for Dementia Research, specializes in neuropathology but was formerly a clinician in neurology. Currently, he has expectations for the possibilities of new therapeutic agents from both clinical and basic perspectives. According to Iwatsubo, dementia is a symptom rather than a disease, and is attributable to three causative diseases, including Alzheimer's disease.

He explains that amyloid beta and tau begin to gradually accumulate in the brain 15-20 years before the onset of Alzheimer's disease. There is a long "preclinical period" even before MCI, he said. He noted, "This disease is on a continuum from the normal state."

Cognition is impaired because so many neurons in the cerebral cortex are shed that neuronal circuits cannot be maintained. The hippocampus remains functional even when some neurons are lost. However, functional impairment begins to occur when about 30% of cells are shed or lost. Language function, spatial perception, abstract thinking, and memory are impaired.

Shedding some light on early diagnosis and treatment

The government's Basic Plan has proposed a positive new perspective on dementia aiming at social inclusion, even in the situation where an increase in the number of patients is inevitable. Recent rapid advancements in early diagnosis and treatment, including the advent of drugs based on new mechanisms, underlie this perspective.

Specifically, "lecanemab," a new drug to prevent the breakdown of neurons through binding between an artificially created antibody and accumulated amyloid beta at a stage before it hardens, was introduced. Insurance coverage and clinical use of lecanemab began in December 2023. Lecanemab reduced amyloid beta by about 60% in 18 months and improved symptom aggravation by 27% compared to placebo in clinical trials. "Donanemab" was also approved in September 2024. Expectations for new drugs are growing.

However, both of the new drugs are indicated only for MCI or mild dementia and cannot be expected to completely stop symptoms from worsening or restore the original brain condition. The key to the effectiveness of the new drugs is early diagnosis. Tests to visually confirm amyloid beta accumulation, such as positron emission tomography (PET) and cerebrospinal fluid analysis, are essential, and such tests are available only at large medical institutions. In the case of lecanemab, the annual cost is nearly one million yen, even for a senior citizen who pays a 30% copayment.

In addition to the advent of new drugs, there is another piece of good news. In May, Mr. Iwatsubo's research group attracted attention when they announced that they could accurately predict the onset of dementia by a blood test to measure and analyze two proteins, amyloid beta and tau. Although there are high expectations for practical application, no tests, including those studied in the U.S., have been approved yet. It will take some time before the biomarkers are put to practical use, according to Iwatsubo.

Iwatsubo says, "The biggest risk factor (for the increase in dementia patients) is the aging of society. The new drugs and early diagnosis methods still have issues to solve. Nevertheless, the forecasted number of dementia patients, which came as a shock, should decrease as further progresses are made in development research.