What Is: Dementia

Illustration Credit: Scientific Frontline

The End of the Passive Era

The year 2025 marks a definitive inflection point in the history of neuroscience and geriatric medicine. For decades, the field of dementia care was characterized by a certain fatalism—a paradigm of "diagnose and manage" where the clinician’s role was largely to document decline and support the family. That era has officially closed. We have entered the age of precision intervention, defined by the ability to detect neurodegenerative pathology in blood plasma decades before symptoms arise, the availability of disease-modifying immunotherapies that clear toxic proteins from the brain, and a nuanced biological understanding that has shattered the monolithic concept of "senility" into a spectrum of distinct, treatable molecular events.

Our Scientific Frontline report provides an exhaustive analysis of the dementia landscape as it stands in late 2025. It synthesizes data from the latest clinical trials, including the landmark approval of subcutaneous maintenance dosing for anti-amyloid therapies, and examines the emerging economic reality where the global cost of dementia is projected to triple by mid-century. We explore the biological underpinnings of conditions ranging from classic Alzheimer’s Disease to the newly characterized Limbic-predominant Age-related TDP-43 Encephalopathy (LATE), and we evaluate the transformative potential of 14 modifiable risk factors that could prevent nearly half of all cases.

Cholesterol-lowering drugs could reduce the risk of dementia

Low cholesterol can reduce the risk of dementia, a new University of Bristol-led study with more than a million participants has shown.

The research, led by Dr Liv Tybjærg Nordestgaard while at the University of Bristol and the Department of Clinical Biochemistry at Copenhagen University Hospital – Herlev and Gentofte, found that people with certain genetic variants that naturally lower cholesterol have a lower risk of developing dementia.

The study, which is based on data from over a million people in Denmark, England, and Finland, has been published in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association. 

Some people are born with genetic variants that naturally affect the same proteins targeted by cholesterol-lowering drugs, such as statins and ezetimibe. To test the effect of cholesterol-lowering medication on the risk of dementia, the researchers used a method called Mendelian Randomization — this genetic analysis technique allowed them to mimic the effects of these drugs to investigate how they influence the risk of dementia, while minimizing the influence of confounding factors like weight, diet, and other lifestyle habits.

Where you live and what cardiometabolic conditions you have affects risk of developing dementia

Image Credit: Gerd Altmann

People in the United States and England who have multiple cardiometabolic conditions such as diabetes and high systolic blood pressure are more likely to develop dementia than their peers who are relatively healthy, according to new research from the University of Surrey.

The study also found that people living in China have an increased risk of developing dementia if they have obesity and hypertension when compared to those in their country who are relatively healthy.

Panagiota Kontari, a post-graduate researcher in the School of Psychology at the University of Surrey, said:

“Dementia affects 55 million people worldwide and there is currently no cure, so prevention is key. Cardiometabolic conditions have been shown to increase likelihood of developing the syndrome due to their link with vascular, biological and neurodegenerative diseases, which might accelerate brain ageing and cognitive decline.

“Understanding how cardiometabolic conditions are clustered and which particular combination of them leads to a greater risk of dementia across the world is important as such knowledge could help design tailored prevention strategies that target varying risk factors in different countries.”

Risk of young-onset dementia could be reduced through targeting health and lifestyle factors

Researchers have identified a wide range of risk factors for young-onset dementia. The findings challenge the notion that genetics are the sole cause of the condition, laying the groundwork for new prevention strategies.

The largescale study identified 15 risk factors, which are similar to those for late-onset dementia. For the first time, they indicate that it may be possible to reduce the risk of young-onset dementia by targeting health and lifestyle factors.

Relatively little research has been done on young-onset dementia, though globally there are around 370,000 new cases of young-onset dementia each year.

Published in JAMA Neurology, the new research by the University of Exeter and Maastricht University followed more than 350,000 participants younger than 65 across the United Kingdom from the UK Biobank study. The team evaluated a broad array of risk factors ranging from genetic predispositions to lifestyle and environmental influences. The study revealed that lower formal education, lower socioeconomic status, genetic variation, lifestyle factors such as alcohol use disorder and social isolation, and health issues including vitamin D deficiency, depression, stroke, hearing impairment and heart disease significantly elevate risk of young-onset dementia

Poverty is linked to increased dementia risk, regardless of genetics

Researchers looked at poverty and low socioeconomic status.
Photo Credit: Leroy Skalstad

People who live in poverty are significantly more likely to develop dementia compared to people of higher socioeconomic status, regardless of genetic risk, new research concludes.

A largescale study published in the American Journal of Preventative Medicine examined data from 196,368 UK Biobank participants whose genetic risk for developing dementia was assessed.

In the paper, researchers looked at poverty, or low socioeconomic status, on two levels. The researchers investigated the contribution of individual socioeconomic deprivation, including low income and low wealth. They also looked at area-level socioeconomic deprivation, including rates of employment, and the number of people who owned a car or home. They calculated risk of developing dementia, and compared these with genetic risk for dementia.

They found that deprivation, both linked to socioeconomic conditions of households and at area level, contributed to risk of dementia. The increased risk was particularly associated with people living in very disadvantaged neighborhoods.

Study reveals reasons for misdiagnosis of frontotemporal dementia

Researchers have discovered patterns in the misdiagnosis of frontotemporal dementia
Photo Credit: Anna Shvets

University of Queensland researchers discovered that nearly 70 per cent of suspected frontotemporal dementia patients ultimately did not have the disease, in a study aimed at identifying factors that contribute to misdiagnosis of this notoriously difficult to diagnose disorder.

Psychiatrist Dr Joshua Flavell, working with cognitive neurologist Professor Peter Nestor at the Mater Hospital Memory and Cognitive Disorders clinic and UQ’s Queensland Brain Institute, analyzed data from 100 patients suspected of having frontotemporal dementia who had been referred by specialist physicians like neurologists, psychiatrists or geriatricians.

“Of the 100 patients, 34 were true-positive, and 66 were false-positive for frontotemporal dementia,” Dr Flavell said.

“We found that misinterpretation of brain scans, particularly nuclear imaging, led to 32 patients being incorrectly diagnosed.

UQ study explains link between sleep apnea and dementia

Professor Elizabeth Coulson said the findings suggest CPAP treatment of obstructive sleep apnea has the potential to reduce dementia risk.
Credit: University of Queensland

Researchers at The University of Queensland have discovered a link between obstructive sleep apnea and an increased risk of developing dementia.

Professor Elizabeth Coulson from UQ’s Queensland Brain Institute and School of Biomedical Sciences and her team found a causal relationship between a lack of oxygen to the brain during sleep and Alzheimer’s disease in mice.

“We found sleep deprivation alone in mice caused only mild cognitive impairment,” Professor Coulson said.

“But we developed a novel way to induce sleep-disrupted breathing and found the mice displayed exacerbated pathological features of Alzheimer’s disease.

“It demonstrated that hypoxia – when the brain is deprived of oxygen – caused the same selective degeneration of neurons that characteristically die in dementia.”

Professor Coulson said the next step would be to determine what levels of hypoxia result in brain degeneration in humans.

Scientists from NUS and NUHS identify predictive blood biomarker for cognitive impairment and dementia

Prof Barry Halliwell (left) and Dr Irwin Cheah (right), together with their collaborators from the National University Health System, have discovered that low levels of ergothioneine in blood plasma may predict an increased risk of cognitive impairment and dementia.
Photo Credit: National University of Singapore

Identification of elderly persons at risk of developing cognitive impairment and dementia could be made possible by examining ergothioneine levels in the blood

A recent study by a team comprising researchers from the National University of Singapore (NUS) and the National University Health System (NUHS) revealed that low levels of ergothioneine (ET) in blood plasma may predict an increased risk of cognitive impairment and dementia, suggesting possible therapeutic or early screening measures for cognitive impairment and dementia in the elderly.

The research teams were led by Professor Barry Halliwell from the Department of Biochemistry under the NUS Yong Loo Lin School of Medicine and Associate Professor Christopher Chen and Dr Mitchell Lai from the Memory, Ageing and Cognition Centre under NUHS. The results of their most recent study were published in the scientific journal Antioxidants.

Patients with delirium more likely to develop dementia

Professor Ruth Hubbard interacting with a patient.
Photo Credit: The University of Queensland

University of Queensland researchers have found older patients who experience delirium are three times more likely to develop dementia.

Professor Ruth Hubbard from UQ’s Centre for Health Services Research (CHSR) said the study also found that every episode of delirium increased the chance of developing dementia by 20 per cent.

“Delirium is an acute confusional state which particularly impacts older people and can have long term detrimental effects on patients,” Professor Hubbard said.

“Our study found that it is also strongly linked to dementia.”

The researchers analyzed a cohort of more than 110,000 patients from New South Wales hospitals over five years.

Lead author and CHSR research fellow, Dr Emily Gordon, said more than 55,000 patients who had experienced delirium were compared to patients who had not.

Social isolation may impact brain volume in regions linked to higher risk of dementia

Elderly woman in the middle stages of Alzheimer 
Credit: Steven HWG

Social isolation is linked to lower brain volume in areas related to cognition and a higher risk of dementia, according to research published today in Neurology. The study found that social isolation was linked to a 26% increased risk of dementia, separately from risk factors like depression and loneliness.

“Social isolation is a serious yet underrecognized public health problem that is often associated with old age,” said study author Professor Jianfeng Feng of Fudan University in Shanghai, China. “In the context of the COVID-19 pandemic, social isolation, or the state of being cut off from social networks, has intensified. It’s more important than ever to identify people who are socially isolated and provide resources to help them make connections in their community.”

The study looked at over 460,000 people across the United Kingdom with an average age of 57 at the beginning of the study who were followed for nearly 12 years before the pandemic. Of those, almost 42,000 (9%) reported being socially isolated, and 29,000 (6%) felt lonely. During the study, almost 5,000 developed dementia.

Researchers collected survey data from participants, along with a variety of physical and biological measurements, including MRI data. Participants also took thinking and memory tests to assess their cognitive function. For social isolation, people were asked three questions about social contact: whether they lived with others; whether they had visits with friends or family at least once a month; and whether they participated in social activities such as clubs, meetings or volunteer work at least once a week. People were considered socially isolated if they answered no to at least two questions.

Study explores links between people taking multiple medications and dementia

Photo credit: Ksenia Yakovleva

People with dementia are likely to have taken more than three medications for other health conditions in the five years directly before their diagnosis, according to new research.

The study is the first to provide an in-depth exploration of the links between evolving polypharmacy – which involves a patient being prescribed more than one drug at any given time – and a dementia diagnosis.

Published in the Aging and Disease journal, it is based on an analysis of the records of more than 33,000 dementia patients in Wales between 1990 to 2015.

Experts in e-health used machine learning techniques to identify potentially damaging patterns in a patient’s medicine usage, and how these patterns evolve in the run-up to diagnosis.

They found that in the 20 years leading up to them being diagnosed, the proportion of patients taking three or more medications rose from 5.5% (for the period 16 to 20 years prior to diagnosis) to 82.16% among those less than five years from a diagnosis.

Sugar molecule in blood can predict Alzheimer’s

Photo Credit: Gerd Altmann

Early diagnosis and treatment of Alzheimer’s disease requires reliable and cost-effective screening methods. Researchers at Karolinska Institutet have now discovered that a type of sugar molecule in blood is associated with the level of tau, a protein that plays a critical role in the development of severe dementia. The study, which is published in Alzheimer's & Dementia, can pave the way for a simple screening procedure able to predict onset ten years in advance.

“The role of glycans, structures made up of sugar molecules, is a relatively unexplored field in dementia research,” says the study’s first author Robin Zhou, medical student and affiliated researcher at the Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institutet. “We demonstrate in our study that blood levels of glycans are altered early during the development of the disease. This could mean that we’ll be able to predict the risk of Alzheimer’s disease with only a blood test and a memory test.”

In Alzheimer’s disease, the neurons of the brain die, which is thought to be a result of the abnormal accumulation of the proteins amyloid beta and tau. Clinical trials for Alzheimer’s drugs show that treatment should commence early in the pathological process, before too many neurons have died, to reverse the process before it is too late.

Does isolated REM sleep behavior disorder predict Parkinson’s disease or dementia?

Image Credit: Gerd Altmann

An international research team led by Université de Montréal medical professor Shady Rahayel has made a major breakthrough in predicting neurodegenerative diseases. 

Thanks to two complementary UdeM studies, scientists are now able to determine, years in advance, which individuals with a particular sleep disorder will develop Parkinson’s disease or dementia with Lewy bodies (DLB). 

The studies focus on isolated REM sleep behavior disorder (iRBD)—a condition in which people yell, thrash, or act out their dreams, sometimes violently enough to injure a bed partner. 

“It’s not just restless sleep—it’s a neurological warning sign,” said Rahayel, a neuropsychologist and researcher at the Centre for Advanced Research in Sleep Medicine at Sacré-Cœur Hospital in Montreal. 

Roughly 90 per cent of people with this sleep disorder will go on to eventually develop Parkinson’s disease or DLB. Until now, however, it was impossible to know which disease would occur—or when. 

Fluctuating blood pressure: a warning sign for dementia and heart disease

Photo Credit: CDC

A new study by Australian researchers has shown that fluctuating blood pressure can increase the risk of dementia and vascular problems in older people.

Short blood pressure (BP) fluctuations within 24 hours as well as over several days or weeks are linked with impaired cognition, say University of South Australia (UniSA) researchers who led the study.

Higher systolic BP variations (the top number that measures the pressure in arteries when a heart beats) are also linked with stiffening of the arteries, associated with heart disease.

The findings have been published in the journal Cerebral Circulation – Cognition and Behavior.

Lead author Daria Gutteridge, a PhD candidate based in UniSA’s Cognitive Ageing and Impairment Neuroscience Laboratory (CAIN), says it’s well known that high blood pressure is a risk factor for dementia, but little attention is paid to fluctuating blood pressure.

“Clinical treatments focus on hypertension, while ignoring the variability of blood pressure,” Gutteridge says.

Risk factors for faster aging in the brain revealed in new study

Governments have been urged to act decisively before 2035 to ensure global warming can be kept below 2°C by 2100.
Photo Credit: Nöel Puebla

Researchers from the Nuffield Department of Clinical Neurosciences at the University of Oxford have used data from UK Biobank participants to reveal that diabetes, traffic-related air pollution and alcohol intake are the most harmful out of 15 modifiable risk factors for dementia.

The researchers had previously identified a ‘weak spot’ in the brain, which is a specific network of higher-order regions that not only develop later during adolescence, but also show earlier degeneration in old age. They showed that this brain network is also particularly vulnerable to schizophrenia and Alzheimer’s disease.

In this new study, published in Nature Communications, they investigated the genetic and modifiable influences on these fragile brain regions by looking at the brain scans of 40,000 UK Biobank participants aged over 45.

The researchers examined 161 risk factors for dementia, and ranked their impact on this vulnerable brain network, over and above the natural effects of age. They classified these so-called ‘modifiable’ risk factors − as they can potentially be changed throughout life to reduce the risk of dementia − into 15 broad categories: blood pressure, cholesterol, diabetes, weight, alcohol consumption, smoking, depressive mood, inflammation, pollution, hearing, sleep, socialization, diet, physical activity, and education.

Brain inflammation treatment could be ally in fight against dementia

Samira Aghlara-Fotovat
Photo Credit: Jeff Fitlow/Rice University

Scientists from Rice University and Houston Methodist have developed a new way to reduce inflammation in the brain, a discovery that could help fight diseases such as Alzheimer’s and Parkinson’s.

The team created “AstroCapsules,” small hydrogel capsules that enclose human astrocytes ⎯ star-shaped brain cells that support healthy nervous system function. Inside the capsules, the cells were engineered to release interleukin-1 receptor antagonist, an anti-inflammatory protein. Tests in human brain organoids and mouse models showed the treatment lowered neuroinflammation and resisted immune rejection.

Rice bioengineer Omid Veiseh, whose lab studies how to design biomaterials that work with the immune system, is co-corresponding author on the paper published in Biomaterials.

“Encapsulating cells in a way that shields them from immune attack has been a central challenge in the field,” said Veiseh, professor of bioengineering at Rice, Cancer Prevention and Research Institute of Texas Scholar and director of the Rice Biotech Launch Pad. “In our lab, we have been working on biomaterials for many years, and this project was an opportunity to draw from that experience to address the uniquely complex immune environment of the brain. Our hope is that this work will help move cell therapies closer to becoming real treatment options for patients with neurodegenerative disease.”

Scientists uncover how the brain falls asleep

Scientists have been able to pinpoint, for the first time, the exact moment the brain transitions into sleep, and precisely map the unfolding process in real time.
Photo Credit: Zohre Nemati

In the new study, the researchers demonstrated that the human brain falls asleep abruptly, rather than gradually, with a ‘tipping point’ marking the transition from wakefulness into sleep. They were then able to predict the momentary progression into sleep with unprecedented precision. 

The findings could be used to develop new ways to diagnose and treat sleep disorders, such as insomnia, and as a marker of brain health in the context of ageing and neurodegenerative disease, and even to improve how we monitor anesthesia during surgical procedures.  

New study reveals strong connection between heart and brain health

A growing amount of evidence points to interactions between heart health and brain health.

Cardiovascular diseases serve as a crucial backdrop for brain diseases like stroke, dementia, cerebral small vessel disease and cognitive impairment. Studies have shown, for example, that atrial fibrillation, even in stroke-free individuals, is associated with an increased incidence of dementia and silent cerebral damage. Heart failure has been linked to cognitive impairment and dementia due to reduced cerebral blood flow caused by a failing heart. Conversely, mental disorders and negative psychological factors may contribute to the onset and progression of cardiovascular diseases. Individuals with conditions such as schizophrenia, bipolar disorder, epilepsy or depression are more prone to cardiovascular diseases.

Despite this growing knowledge, previous studies on heart-brain interactions and associated risk factors have been limited in scope, focusing on specific diseases or utilizing small sample sizes. Consequently, the overall understanding of the structural and functional links between the heart and brain remains incomplete.

A new study conducted by researchers from UNC-Chapel Hill, the University of Pennsylvania and Purdue University leverages large magnetic resonance imaging (MRI) data to shed light on the close relationship between cardiovascular diseases and brain diseases such as stroke, dementia and cognitive impairment, unraveling the underlying genetic signatures and inter-organ connections between the heart and brain.

Brain health in over 50s deteriorated more rapidly during the pandemic

Photo Credit: Gabriel Porras

Brain health in over 50s deteriorated more rapidly during the pandemic, even if they didn’t have COVID-19, according to major new research linking the pandemic to sustained cognitive decline.

Researchers looked at results from computerized brain function tests from more than 3,000 participants of the online PROTECT study, who were aged between 50 and 90 and based in the UK. The remote study, led by teams at the University of Exeter and the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, and part-funded by NIHR Maudsley BRC, tested participants’ short-term memory and ability to complete complex tasks.

Through analyzing the results from this big dataset, researchers found that cognitive decline quickened significantly in the first year of the pandemic, when they found a 50 per cent change to the rate of decline across the study group. This figure was higher in those who already had mild cognitive decline before the pandemic, according to the research published in The Lancet Healthy Longevity.

An action plan to prevent Alzheimer’s disease

As the population ages, the number of people with Alzheimer’s disease in Europe will double by 2050.
Image Credit: Gerd Altmann

A task force led by UNIGE and HUG is laying the foundations for a preventive protocol.

Memory loss, behavioral changes, cognitive deficits: Alzheimer’s disease leads to a dramatic loss of autonomy for those affected and has a heavy impact on health costs. Its prevention has become a real social challenge. An international task force, led by the University of Geneva (UNIGE) and the Geneva University Hospitals (HUG), is setting out guidelines for innovative services to prevent Alzheimer’s disease. These will soon be an integral part of second-generation memory clinics. These guidelines are detailed in an article published in the Lancet Regional Health - Europe.

With 10 million people affected in Europe, Alzheimer’s disease is the most common neurodegenerative disease. It is characterized by progressive disabling memory loss and cognitive deficits caused by an accumulation of toxic proteins in the brain. Its social and economic impact is considerable. On a global scale, it is estimated to be worth around USD 1,500 billion per year* and in Switzerland CHF 11.8 billion per year**.