The Rise of Dementia through Time and Space
Author: Janna Dinneweth
Imagine being 51 years old, gradually losing your grip on reality. Your memory begins to fail, language slips away, familiar faces become unrecognisable, and daily routines unravel into confusion…
Such was the experience of Auguste Deter, who, in 1901, was admitted to a mental institution in Frankfurt. Her unusual symptoms captured the attention of Alois Alzheimer, a young psychiatrist and neurologist. So began the search into the causes of dementia and what is now known as Alzheimer’s disease.
In Belgium, as in many high-income countries, dementia has emerged as a leading cause of death, particularly among older women. Follow along and discover how scientific breakthroughs accompanied a growing awareness of the disease and an increasing number of patients.
What is Dementia?
What is Dementia
Dementia is a syndrome of cognitive decline, affecting memory, reasoning, language, and daily activities. It results from neurodegenerative diseases like Alzheimer’s.
Where Does Dementia occur?
Dementia primarily affects older adults, making it prevalent in high-income countries with ageing populations. The global burden is increasing.
Diagnosis and Treatment
Diagnosis is based on clinical assessment, with neuroimaging improving accuracy. There is no cure, so treatment focuses on symptom management and support.
Prevention and Control
While incurable, modifiable risk factors like hypertension and inactivity are linked to increased risk. Public health efforts focus on prevention.
The First Known Case of Alzheimer’s Disease
After Auguste Deter died in 1906, Alois Alzheimer conducted a post-mortem examination, identifying hallmark abnormalities in her brain (amyloid plaques and neurofibrillary tangles) that would later define the condition bearing his name. Although descriptions of dementia date back to antiquity, Alzheimer’s observations marked the beginning of its modern medical conceptualisation. What began as a rare case study has since evolved into one of the most pressing public health concerns in ageing societies, with Alzheimer’s disease now recognised as the most common form of dementia.
In Belgium, as in many high-income countries, dementia has emerged as a leading cause of death, particularly among older women. Changes in disease classification, improved awareness among physicians, and the demographic transition have all contributed to this rise. By the early 21st century, dementia was no longer merely a comorbid condition, but frequently cited as the primary cause of death, reflecting both epidemiological trend and sociocultural transformations in end-of-life care and certification practices.
A Brief History
Awareness of memory problems in old age stretches back to ancient Greece. Thinkers like Pythagoras compared old age to childhood, noting a decline in cognitive ability. Solon warned that aging could affect good judgement. Ancient physicians, including Hippocrates, attributed these changes to bodily imbalances, such as having too much “black bile”.
Engraving attributed to H. David after C.Vignon. (© Wellcome Collection)
By the 1600s and 1700s, doctors began to connect brain changes with cognitive decline. For example, they observed that changes in the brain could affect behaviour, and the term “amentia senilis” was used to describe memory loss in older adults.
By the late 1800s, researchers began to study the brain in more detail. Dementia was linked to brain shrinkage, and forms of dementia caused by vascular issues were described.
In the early 1900s, Alois Alzheimer studied the woman named Auguste Deter and identified the plaques and tangles now synonymous with Alzheimer’s disease. Emil Kraepelin officially named the condition “Alzheimer’s disease” in 1910. For decades, it was considered rare until the 1970s, when it became recognized as the leading cause of dementia in older adults.
Today, scientists have developed new ways to detect and treat Alzheimer’s, including tools that look at brain changes and drugs to help slow the disease. Still, dementia remains incurable, with many unanswered questions about its causes and treatment.
Dementia Mortality Over Time
In nineteenth-century Belgium, dementia was rare and still grouped together with idiocy. In 1869, the government only counted 286 cases of death by dementia or idiocy. More cases were reported in rural Belgium (in towns of less than 5.000 inhabitants) then in the big cities (towns with more than 5,000 inhabitants). More men were attained by ‘dementia and idiocy’ then women.
Deaths from 'dementia and idiocy' in towns with more (urban) and less (rural) inhabitants in Belgium, 1869
More recently, dementia has become an increasingly common cause of death. The figure below shows how in the early 1970s, dementia accounted for less than 1% of all deaths. From then on the number has been rising steadily. By 2019, dementia is responsible for approximately 9% of all deaths. A slight dip in 2020 likely reflects the COVID-19 pandemic, which may have disrupted diagnosis or reporting.
Percentage share of dementia deaths to total mortality by sex, Belgium 1970-2020
Source: Statistics Belgium, calculations by author
In the 1970’s men and women were equally affected by dementia. Over the years, dementia accounts for a greater share of deaths among women than among men. This sex difference has become bigger over time. Interestingly, this gap between sexes has widened, even as life expectancy has become more equal. Sex differences in dementia development are often explained by the fact that women tend to live longer, used to have fewer years of schooling, and lose protective hormones like oestrogen after menopause.
Dementia in Belgium Through Space
Dementia mortality in Belgium has changed a lot over time. The maps below show the evolution of dementia from 1970 to 2018. We see a strong increase in the number of deaths, and in the most recent period, Flanders had the highest rates. In 1970 and 1990, most dementia deaths occurred in Flanders. In 2000 and 2010, the numbers were more evenly spread across the country. By 2019, however, Flanders again showed higher dementia mortality than the rest of Belgium, which can be clearly seen on the map.
Age Standardized Total Dementia Mortality Rates (per 10,000 population aged ≥ 45 years),
1969-1970, 1989-1991, 2000-2002, 2009-2011, and 2017-2019
Source:
Alternative way to show the evolution through time:
How can this be explained? One possible reason could be that people in Flanders tend to live longer than in other regions, and dementia is more common at older ages. Still, other things probably also play a role. For example, Flanders has more people living close together and higher air pollution, which can affect people’s health as they get older. Social factors, such as the types of jobs people have or the support they receive, may also matter. In addition, the way doctors record and report dementia on death certificates may differ between regions. These kinds of environmental, social, and administrative differences can help explain why dementia death rates are higher in Flanders.
Inequality in Dementia Mortality?
Not everyone faces the same risk of dying with dementia. In Belgium, data from 2011 to 2016 show clear social inequalities among people aged 65 and older. Both education and income influenced dementia mortality.
The figure below shows mortality rate ratios for men and women, with people with higher education used as the reference group. This means we compare all other groups to them. Because this is a relative measure, the reference group is set to 1, so we can see whether different groups have a higher or lower risk.
The figure shows that people with lower education were more likely to die with dementia. Men in this group were 1.2 times more likely, and women more than 1.3 times more likely, than highly educated people.
Differences in Dementia Mortality by Education Level Among Older Adults in Belgium (2011–2016)
Source: Statistics Belgium, calculations by author
Income also matters, although the pattern looks different for men and women. Among men, the relationship is clear: those in the lowest income group were almost 1.2 times more likely to die with dementia than those in the highest income group. The difference narrows at higher income levels but remains noticeable.
For women, the pattern is less straightforward. The first two income groups show little difference, but women in the third income group were still around 1.1 times more likely to die with dementia than those with the highest incomes.
Differences in Dementia Mortality by Income Level Among Older Adults in Belgium (2011–2016)
Source: Statistics Belgium, calculations by author
These findings highlight that social and economic inequalities are reflected not only in how long people live, but also in how they die, including the likelihood of dying with dementia.
Conclusions
Dementia, once considered a rare condition, is now a leading cause of death in Belgium. Its prevalence is shaped by biological, social, and environmental factors, with clear inequalities in risk based on gender, education and income. While treatments have improved, dementia remains incurable, emphasizing the importance of prevention, early detection, and societal support for patients and caregivers.
Further Reading
Do you want to know more about our dementia research? You can explore our published articles below.
- Dinneweth, J., & Gadeyne, S. (2024). Socioeconomic Disparities in Neurodegenerative Disease Mortality: A Population-Based Study among Belgian Men and Women Aged 65 or Older. INQUIRY: The Journal of Health Care Organization, Provision, and Financing, 61, 00469580241237113.
- Dinneweth, J., & Gadeyne, S. (2024). Unravelling the Evolution of Neurodegenerative Disease Mortality: Insights from 50 Years of Belgian Data. Espace populations sociétés. Space populations societies, (2023/3-2024/1).
- Dinneweth, J., & Gadeyne, S. (2025). Linking Social and Environmental Indicators to Neurodegenerative Disease Mortality in Belgian Municipalities Using Spatial Regression Analysis. Vrije Universiteit Brussel, Vakgroep Sociologie, BRISPO. https://doi.org/10.5281/zenodo.14859170
Literature
- Livingston, G. et al. (2024). Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet, 404(10452), 572-628.
- Berchtold, N. C., & Cotman, C. W. (1998). Evolution in the conceptualization of dementia and Alzheimer’s disease: Greco-Roman period to the 1960s. Neurobiology of aging, 19(3), 173-189.
- Grand, J., & Feldman, H. H. (2007). Historical concepts of Alzheimer’s disease and dementia. In Atlas of Alzheimer’s Disease (pp. 1-26). CRC Press.
- Goedert, M., & Ghetti, B. (2007). Alois Alzheimer: his life and times. Brain pathology, 17(1), 57-62.
- Assal, F. (2019). History of dementia. Front Neurol Neurosci, 44, 118-126.
- Vatanabe, I. P., Manzine, P. R., & Cominetti, M. R. (2020). Historic concepts of dementia and Alzheimer’s disease: From ancient times to the present. Revue neurologique, 176(3), 140-147.
- Maheshwari, S., et al. (2024). Navigating the dementia landscape: Biomarkers and emerging therapies. Ageing Research Reviews, 94, 102193.
- Eggerickx, T., Sanderson, J. P., & Vandeschrick, C. (2020). Mortality in Belgium from nineteenth century to today: Variations according to age, sex, and social and spatial contexts. Quetelet Journal, 8(2), 7-59.
Sources
- Département de l’intérieur (1869). Documents statistiques publiés par le Département de l’intérieur. Brussels: TH. Lesigne.
- Statbel Statistics Belgium
