Alzheimer’s disease: current status and perspective

Aging is an undeniable fact of life and the global population is aging to a historically unprecedented degree.The population aged 65 years or older comprises 750 million people,representing nearly 10％of the global population.As a result of prolonged life expectancy and falling mortality rates,China has become one of the most rapidly aging countries in the world,even surpassing sev-eral high-income countries in North America and Europe.The pro-portion of China's population over the age of 65 years reached 13.5％in 2021 and is expected to reach approximately 30％by 2050.Moreover,the group of people aged 80 years or older is expected to grow faster than any other age group,from approxi-mately 36.6 million(1.6％)in 2020 to a projected 1.59 billion(12％)in 2050(Text S1 online).As the population ages,the number of people with dementia increases.Dementia is not an inevitable part of aging but is a common disease.A lack of awareness and understanding of this disease results in stigmatization and barriers to diagnosis and care.Alzheimer's disease(AD)is the main cause of dementia in older adults.We previously reported that the overall prevalence of dementia in China is 6.0％,and 15.07 million adults in China aged 60 years or older have dementia[1].More than 10 million of them have AD,and this number is expected to exceed 40 million by 2050.Moreover,we calculated that the total cost of AD in China accounted for 1.47％of the gross domestic product in 2015,which is even higher than that of cancer and cardiovascu-lar diseases[2].Although the estimated impact and cost of demen-tia care are high,the true cost may be underestimated.As their cognitive abilities and behavior gradually deteriorate,patients with AD have increasing difficulty meeting basic personal care needs.However,as long-term care systems in low-and middle-income countries(LMICs)are not well prepared for such patients,care services are usually supplied by family members or other non-profit,public,and private providers.Most caregivers lack edu-cation on dementia management since the existing services are concentrated in the main cities and support is underdeveloped and underfunded.