Relevance: Dementia states lead to severe medical and social consequences. Most researchers consider Alzheimer's disease to be the most frequent cause of cognitive impairment in elderly people, the second place is occupied by vascular dementia. In the Republic of Belarus, vascular dementia has the largest share in the structure of morbidity of dementia of various genesis among different age groups. The aim of this study was to investigate the epidemiology of dementias in the Republic of Belarus, including dementia with Alzheimer's disease and vascular dementia, characterization of morbidity and disability due to this pathology in dynamics for the period from 2016 to 2023.

Research materials and methods: The study of indicators of primary and general morbidity, data on patients under dispensary supervision, treated in psychiatric hospitals, disability in dementia was carried out according to the data from the forms of state statistical reporting approved by the National Statistical Committee of the Republic of Belarus for 2016-2023. To calculate intensive indicators, data from the National Statistical Committee of the Republic of Belarus on the number and sex and age structure of the population were used. Indicators of dementia morbidity were studied in dynamics.

Results: At the end of 2023, the number of persons with disabilities due to dementia in the Republic of Belarus was 8,424, or 9.16 per 10,000 of population, of whom 1,573, or 1.71 per 10,000 of population, were due to dementia due to Alzheimer's disease; 3,600, or 3.91 per 10,000 of population, were due to vascular dementia. In the structure of disability due to dementia, the proportion of women, on average over three years, was 58.9 per cent, for dementia due to Alzheimer's disease - 69.5 per cent, for vascular dementia - 66.3 per cent. 1Of the total number of disabled due to dementia, 99.7% of patients were disabled of group I or II. The data obtained show that women are more often in need of psychiatric care for dementia.

Conclusion: Prevention, early diagnosis, treatment and rehabilitation of patients with dementia is the key to success in providing specialized care for these patients. Given the severity of the disease, the high level of disability and the increase in morbidity, it is necessary to focus efforts on the introduction of screening diagnostic tools to identify signs of dementia at an early stage. It is also necessary to inform the population about the problems of dementia and encourage patients and their relatives to seek specialized medical care as early as possible.

Keywords: Alzheimer's disease, vascular dementia, morbidity, disability

Over the past decades, an increase in the absolute and relative number of elderly people has been observed in many countries of the world, including the Republic of Belarus. If in 1998 1,332,336 people aged 65 and over lived in the Republic of Belarus, or 13.2% of the total population, in 2023 there were 1,517,148 people in this age group, which was 16.5% of the total population. This creates serious social, economic and medical problems, as the prevalence of organic mental disorders, including dementia, increases as the age group increases.

Most researchers consider Alzheimer's disease to be the most common cause of cognitive impairment in the elderly, with vascular dementia taking the second place.¹ In the Republic of Belarus, vascular dementia has the highest proportion in the structure of the incidence of dementia of various origins among different age groups.^1–4

The purpose of this study was to study the epidemiology of dementia in the Republic of Belarus, including dementia in Alzheimer's disease and vascular dementia, and to characterize the incidence and disability rates due to this pathology in dynamics over the period from 2016 to 2023. The study of indicators of primary and general morbidity, data on patients under medical supervision, treated in psychiatric hospitals, and disability with dementia was carried out according to data from the state statistical reporting forms approved by the National Statistical Committee of the Republic of Belarus (form 1-psychiatry (Ministry of Health)) for 2016-2023

To calculate the intensive indicators, data from the National Statistical Committee of the Republic of Belarus on the number and age structure of the population were used. In the period from 2016 to 2023, an average of 19500 patients per year applied to healthcare organizations providing psychiatric care in outpatient settings for dementia (ICD 10 code: F00-F03) (Table 1). Of these, 15.2% were referrals for dementia in Alzheimer's disease (2968 referrals per year), 49.1% were referrals for vascular dementia (9566 referrals per year). The majority of those who applied were women: 62.7% of those who applied for dementia in general, 69.3% of those who applied for dementia in Alzheimer's disease, 66.6% of those who applied for vascular dementia. In the structure of treatment for dementia, the proportion of the urban population was 77.0%, the rural population accounted for 33.0%, including 83.6% of patients with Alzheimer's disease and 76.1% of patients with vascular dementia.

The incidence rates of dementia were studied in dynamics. On average, for the period 2016-2023, the total incidence of dementia was 207.84 per 100,000 population. Over the past 8 years, the incidence has increased by 3.6%: from 206.78 per 100,000 population in 2016 to 214.21 in 2023 (p<0.001), mainly due to its increase in the urban population (from 179.57 per 100,000 urban population in 2016 to 230.30 in 2023, an increase of 28.2%, p<0.001), while in rural areas this indicator decreased by 48.3% (from 301.73 per 100,000 rural population in 2016 up to 155.87 in 2023, p<0.001) (Table 2). The overall incidence of dementia in Alzheimer's disease increased by 24.6% from 2016 to 2023 (from 27.78 per 100,000 population in 2016 to 34.63 in 2023, p<0.001). In vascular dementia, during the study period, there was an increase in the overall incidence from 95.52 to 107.01 per 100,000 population, or by 12.0% (p<0.001) (Table 1).

The incidence rates of dementia were studied in dynamics. On average, for the period 2016-2023, the total incidence of dementia was 207.84 per 100,000 population. Over the past 8 years, the incidence has increased by 3.6%: from 206.78 per 100,000 population in 2016 to 214.21 in 2023 (p<0.001), mainly due to its increase in the urban population (from 179.57 per 100,000 urban population in 2016 to 230.30 in 2023, an increase of 28.2%, p<0.001), while in rural areas this indicator decreased by 48.3% (from 301.73 per 100,000 rural population in 2016 up to 155.87 in 2023, p<0.001) (Table 2). The overall incidence of dementia in Alzheimer's disease increased by 24.6% from 2016 to 2023 (from 27.78 per 100,000 population in 2016 to 34.63 in 2023, p<0.001). In vascular dementia, during the study period, there was an increase in the overall incidence from 95.52 to 107.01 per 100,000 population, or by 12.0% (p<0.001) (Table 2).

According to the average annual data for 8 years, the overall incidence of dementia among men was 1.5 times lower than among women (167.12 per 100,000 male population versus 243.09 per 100,000 female population, p<0.001), and among the urban population it was 6.7% lower than among rural (204.84 per 100,000 urban population against 218.55 per 100,000 rural population, p<0.001). In Alzheimer's disease, the incidence among men was 2.0 times lower than among women (20.93 per 100,000 male population versus 40.89 per 100,000 female population, p<0.001), the incidence rates among the urban population were 42.4% higher than among the rural population (33.84 per 100,000 urban population versus 23.76 per 100,000 rural population, p<0.001). In vascular dementia, the average annual incidence rates among men were 1.7 times lower than among women (73.45 per 100,000 male population versus 126.63 per 100,000 female population, p<0.001), and among the urban population – 12.12% lower than among rural (99.31 per 100,000 urban population versus 111.37 per 100,000 rural population, p<0.001) (Table 3).

An analysis of the primary incidence of dementia in the Republic of Belarus showed that more than 4,700 people were diagnosed with this disease for the first time every year: the average annual value for 2016-2023 was 4,783 cases per year, of which, on average, 730 cases per year (15.3%) were diagnosed with Alzheimer's disease, 2,659 cases (55.6%) – vascular dementia (Table 3). Among those who applied for the first time, the proportion of women with dementia was 69.6%, with Alzheimer's disease – 74.9%, with vascular dementia – 71.4%. In the structure of treatment for dementia, the proportion of the urban population was 81.7%, including 85.4% for dementia in Alzheimer's disease and 81.2% for vascular dementia (Table 4).

The rates of primary morbidity in dementia tend to decrease. Over the past 8 years, there has been a slight (6.1%) decrease in morbidity: from 53.27 per 100,000 population in 2016 to 50.04 in 2023 (p<0.01) (Table 4). On average, for the period 2016-2023, the primary incidence of dementia was 50.97 per 100,000 population. The primary incidence of dementia in Alzheimer's disease decreased by 15.0% in three years (from 8.97 per 100,000 population in 2016 to 7.62 in 2023, p<0.01), due to its decrease in rural areas (from 7.09 per 100,000 rural population in 2016 to 3.92 in 2023, a decrease of 44.7%, p<0.001). In vascular dementia, the primary incidence decreased by 17.3% (p<0.001): from 29.61 per 100,000 population in 2016 to 24.50 in 2023, with an annual average of 28.34 per 100000 population. A decrease in the primary incidence of vascular dementia was observed mainly in rural areas (from 34.73 per 100,000 rural population in 2016 to 14.79 in 2023, a decrease of 57.4%, p<0.001).

On average, the primary incidence of dementia among men during the study period was 2.0 times lower than among women (33.44 per 100,000 male population versus 66.15 per 100,000 female population, p<0.001) (Table 4). The primary morbidity rate among the rural population was on average 24.8% lower than among the urban population (53.29 per 100,000 urban population versus 42.70 per 100,000 rural population, p<0.001).

In Alzheimer's disease, the primary incidence among men was 2.6 times lower than among women (4.21 per 100,000 male population versus 10.88 per 100,000 female population, p<0.001), and among the urban population it was 1.6 times higher than among rural (8.51 per 100,000 urban population versus 5.19 per 100,000 of rural population, p<0.001). In vascular dementia, the average annual rates of primary morbidity among men were 2.2 times lower than among women (17.45 per 100,000 male population versus 37.77 per 100,000 female population, p<0.001), and the rates among the urban population are 20.7% higher than among the rural population (29.45 per 100,000 urban population versus 24.40 per 100,000 rural population, p<0.001).

The number of those under medical supervision for dementia, according to the average annual data, was 10.2% of the total number of those under medical supervision for mental and behavioral disorders. At the end of 2023, 11,860 people, or 128.90 per 100,000 population, were under medical supervision for dementia; of these, 2018 people, or 21.93 per 100,000 population, for dementia in Alzheimer's disease; 5,609 people, or 60.96 per 100,000 population, for vascular dementia (Table 5, 6). In the structure of those under medical supervision for dementia, the proportion of women, on average for 8 years, was 61.6%, for dementia in Alzheimer's disease – 73.8%, for vascular dementia – 66.0% (Table 5, 6).

In the period from 2016 to 2023, 3,523 patients with dementia were treated in psychiatric hospitals in the republic on average per year, the average duration of hospitalization was 45.9 days (Table 7). On average, 480 patients per year were treated for Alzheimer's disease with an average duration of hospitalization of 37.8 days, and 1,471 patients per year for vascular dementia with an average duration of hospitalization of 44.1 days (Table 7).

Dementia-related conditions lead to severe medical and social consequences. At the end of 2023 the number of people with disabilities due to dementia in the Republic of Belarus was 8,424, or 9.16 per 10,000 population; 1,573 of them due to dementia in Alzheimer's disease, or 1.71 per 10,000 population; 3,600 due to vascular dementia, or 3.91 per 10,000 population (Table 8, 9). In the structure of disability due to dementia, the proportion of women, on average for three years, was 58.9%, for dementia in Alzheimer's disease – 69.5%, for vascular dementia – 66.3%. Of the total number of people with disabilities due to dementia, 99.7% of patients were disabled in groups I or II, including 99.8% of people with disabilities due to dementia in Alzheimer's disease and 99.8% due to vascular dementia (Table 8,9).

In the period from 2016 to 2023, medical rehabilitation expert commissions of the Republic of Belarus established disability due to dementia in an average of 1779 cases per year during initial examination, including 338 cases per year for dementia with Alzheimer's disease, and 958 cases per year for vascular dementia (Table 10). Women were diagnosed with disability more often (70.2%) than men (29.8%), including dementia with Alzheimer's disease – in 75.3% of cases, vascular dementia – in 71.3% (Table 10).

The level of primary disability due to dementia according to the average annual data for the period 2016-2023 was 1.90 per 1000 population, including due to dementia in Alzheimer's disease – 0.36 per 10000 population, due to vascular dementia – 1.02 per 10000 population (Table 11). Of the total number of patients recognized as disabled due to dementia for the first time, 99.9% of patients were disabled in groups I or II, including 99.9% of those with disabilities due to dementia in Alzheimer's disease and 99.9% due to vascular dementia. The data obtained show that women are significantly more likely to need psychiatric care for dementia (Table 11.

According to world statistics, Alzheimer's disease is the most common among neurodegenerative diseases and accounts for 60-80% of all cases. It is followed by vascular dementia of 20-40% and others, such as dementia caused by Lewy bodies, Parkinson's disease, and frontotemporal dementia, which account for less than 1%.⁵ In the Republic of Belarus, vascular dementia has the highest proportion in the structure of the incidence of dementia of various origins among different age groups. The ratio between the incidence of Alzheimer's disease and vascular dementia is 3:1 (Table 1). This fact attracts attention and requires clarification to determine the reason for this discrepancy, an additional comparative study with foreign protocols is planned on the following aspects: standardization of psychological diagnostic tools, sample size, study of risk factors, comorbidity, and other aspects.^6,7

In modern society, there is a high prevalence of dementia among the elderly, and numerous studies conducted in industrialized and non-industrialized countries have shown an age-standardized prevalence of dementia ranging from 5% to 7% in most countries.⁸ Belarus is no exception. It should be noted that the level of primary morbidity in dementia tends to decrease. On average, the incidence of dementia regresses by 6.1%. This is due to the reduction of vascular damage (for example, by reducing smoking and treating high blood pressure). There is an active fight against many risk factors for dementia (for example, low education, hearing loss, hypertension, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injury, air pollution, social isolation).⁹

Nevertheless, the number of patients with dementia in Alzheimer's disease and vascular dementia continues to increase, which is associated with an increase in life expectancy and the development of innovative therapeutic and preventive measures.^1,10 According to WHO data, as of March 2023, there were more than 55 million people with dementia worldwide. There are almost 10 million new cases of dementia every year. Dementia is recognized as one of the priority problems of public health. A comprehensive action program is being implemented under the auspices of the World Health Assembly to raise awareness of dementia and create favorable social conditions for people with dementia; reduce the risk of dementia; diagnosis, treatment and care; scientific research and innovation.¹¹

The development of interdisciplinary and interdepartmental cooperation in the prevention, early diagnosis, treatment and rehabilitation of patients with dementia is the key to success in providing specialized care to these patients.^{12, 13} To better identify people with dementia, it is necessary to introduce screening diagnostic tools aimed at this pathology at the level of the primary outpatient medical network, as well as inform the population about dementia problems and target patients and their relatives to seek specialized medical care as early as possible.

None.

Nothing to declare.

1. Evsegneev R. Psychiatry: what has changed in the last three decades. 2018;12:21–28.
2. Korotkevich TV, Golubeva TS, Chumakov YuA, et al. Psychiatric care for the population of the Republic of Belarus 2018–2020: inform-statistic guide. Minsk: 2021;215.
3. Korotkevich TV, Golubeva TS, Zhilevich LA. Indicators of mental health of elderly citizens in the Republic of Belarus. 2022:137–140.
4. Korotkevich TV, Golubeva TS, Loginova AY, et al. The state of mental health of the population over the working age in the Republic of Belarus according to the indicators of state statistical reporting. Psychiatry and Narcology. 2022;(20):74–76.
5. Garre-Olmo J. Epidemiology of Alzheimer's disease and other dementias. Rev Neurol. 2018;66(11):377–386.
6. Ian James Martins. Early diagnosis and nutritional treatment stabilizes neuropsychiatric disorders. Glob J Med Res. 2018;1(1):1–7.
7. Ian James Martins. Insulin therapy and autoimmune disease with relevance to nonalcoholic fatty liver disease. 2018.
8. Lopez OL, Kuller LH. Epidemiology of aging and associated cognitive disorders: prevalence and incidence of Alzheimer's disease and other dementias. Handb Clin Neurol. 2019;167:139–148.
9. Livingston G, Huntley J, Sommerlad A, et al. Dementia prevention, intervention, and care: 2024 report of the lancet standing commission. Lancet. 2024;404(10452):572–628.
10. Mukadam N, Wolters F, Walsh S, et al. Changes in prevalence and incidence of dementia and risk factors for dementia: an analysis from cohort studies. Lancet Public Health. 2024;9(7):e443–e460.
11. Prince M, Guerchet M, Prina M. The epidemiology and impact of dementia-current state and future trends. WHO Thematic Briefing. 2022.
12. Korotkevich TV, Golubeva TS, Loginova AY, et al. Mental health of the population over the working age: the main trends in morbidity and disability. Organ Inform Healthc. 2022;1(110):64–75.
13. Khodzhaev AV, Dakukina TV, Golubeva TS, et al. Trends in the reorganization of psychiatric services at the present stage. Psychiatry Psychother Clin Psychol. 2022;13(3):360–369.