Today is World Alzheimer’s Day. On this occasion, the World Health Organization (WHO) has updated its fact sheet on dementia, and released resources 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.
It affects memory, thinking, orientation, comprehension, calculation, learning capacity, language, and judgement. Consciousness is not affected.
The impairment in cognitive function is commonly accompanied, and occasionally preceded, by deterioration in emotional control, social behaviour, or motivation.
Worldwide, around 47 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 to 8 per 100 people.
The total number of people with dementia is projected to near 75 million in 2030 and almost triple by 2050 to 132 million. Much of this increase is attributable to the rising numbers of people with dementia living in low- and middle-income countries.
Symptoms and Signs:
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.
Alzheimer’s disease is the most common form of dementia and may contribute to 60–70% of cases.
Other major forms include
- vascular dementia,
- dementia with Lewy bodies (abnormal aggregates of protein that develop inside nerve cells), and
- a group of diseases that contribute to frontotemporal dementia (degeneration of the frontal lobe of the brain).
The boundaries between different forms of dementia are indistinct and mixed forms often co-exist.
Treatment and care:
There is no treatment currently available to cure dementia or to alter its progressive course.
The principal goals for dementia care are:
- early diagnosis in order to promote early and optimal management
- optimizing physical health, cognition, activity and well-being
- identifying and treating accompanying physical illness
- detecting and treating challenging behavioural and psychological symptoms
- providing information and long-term support to carers.
Risk factors and prevention:
Age is the strongest known risk factor for dementia. However, dementia 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.
Risk factors include
- physical inactivity,
- unbalanced diets,
- tobacco use,
- harmful use of alcohol,
- diabetes, and
- midlife hypertension.
Additional modifiable risk factors include
- low educational attainment,
- social isolation, and
- cognitive inactivity.
Social and economic impacts:
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.
Global Action Plan on the Public Health Response to Dementia 2017-2025:
Link to the updated WHO fact sheet:
Link to WHO’s Global Dementia Observatory (GDO):
Link to WHO page on Dementia:
Link to WHO’s iSupport online training program for caregivers of people with dementia:
Links to infographics on dementia: