The World Health Organization (WHO) has updated its fact sheet on dementia.
Dementia is a syndrome – usually of a chronic or progressive nature – in which there is deterioration in cognitive function (i.e. the ability to process thought) beyond what might be expected from normal ageing.
- learning capacity,
- language, and
Consciousness is not affected.
The impairment in cognitive function is commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behaviour, or motivation.
Although dementia mainly affects older people, it is not a normal part of ageing.
Worldwide, around 50 million people have dementia, with nearly 60% living in low- and middle-income countries. Every year, there are nearly 10 million new cases.
The estimated proportion of the general population aged 60 and over with dementia at a given time is between 5-8%.
The total number of people with dementia is projected to reach 82 million in 2030 and 152 in 2050. Much of this increase is attributable to the rising numbers of people with dementia living in low- and middle-income countries.
Dementia is one of the major causes of disability and dependency among older people worldwide.
It has a physical, psychological, social, and economic impact, not only on people with dementia, but also on their carers, families and society at large. In 2015, the total global societal cost of dementia was estimated to be US$ 818 billion, equivalent to 1.1% of global gross domestic product (GDP). The total cost as a proportion of GDP varied from 0.2% in low- and middle-income countries to 1. 4% in high-income countries.
Dementia results from a variety of diseases and injuries that primarily or secondarily affect the brain, such as Alzheimer’s disease or stroke.
Alzheimer disease is the most common form of dementia and may contribute to 60–70% of cases.
Age: Although age is the strongest known risk factor for dementia, it is not an inevitable consequence of ageing. Further, dementia does not exclusively affect older people – young onset dementia (defined as the onset of symptoms before the age of 65 years) accounts for up to 9% of cases.
Additional risk factors include
- low educational attainment,
- social isolation, and
- cognitive inactivity.
Dementia affects each person in a different way, depending upon the impact of the disease and the person’s personality before becoming ill. The signs and symptoms linked to dementia can be understood in three stages.
Early stage: the early stage of dementia is often overlooked, because the onset is gradual. Common symptoms include:
- losing track of the time
- becoming lost in familiar places.
Middle stage: as dementia progresses to the middle stage, the signs and symptoms become clearer and more restricting. These include:
- becoming forgetful of recent events and people’s names
- becoming lost at home
- having increasing difficulty with communication
- needing help with personal care
- experiencing behaviour changes, including wandering and repeated questioning.
Late stage: the late stage of dementia is one of near total dependence and inactivity. Memory disturbances are serious and the physical signs and symptoms become more obvious. Symptoms include:
- becoming unaware of the time and place
- having difficulty recognizing relatives and friends
- having an increasing need for assisted self-care
- having difficulty walking
- experiencing behaviour changes that may escalate and include aggression.
There is no treatment currently available to cure dementia or to alter its progressive course. Numerous new treatments are being investigated in various stages of clinical trials.
Prevention and Control:
Studies show that people can reduce their risk of dementia by
- getting regular exercise,
- not smoking,
- avoiding harmful use of alcohol,
- controlling their weight,
- eating a healthy diet, and
- maintaining healthy blood pressure, cholesterol and blood sugar levels.
People with dementia are frequently denied the basic rights and freedoms available to others. In many countries, physical and chemical restraints are used extensively in care homes for older people and in acute-care settings, even when regulations are in place to uphold the rights of people to freedom and choice.
Global Action Plan on the Public Health Response to Dementia 2017-2025:
Link to the updated fact sheet:
Link to the Global Dementia Observatory:
Link to WHO’s iSupport: E programme for carers of people living with dementia:
Link to Global Action Plan on the Public Health Response to Dementia 2017-2025: