Dementia is a syndrome — usually progressive — of acquired cognitive decline severe enough to interfere with daily life. It is caused by damage to brain cells from various diseases. Alzheimer's disease (60-70% of cases), vascular dementia, Lewy body dementia and frontotemporal dementia are the main types. Dementia is not a normal part of ageing, though age is the strongest risk factor.

What is the difference between dementia and Alzheimer's disease?

Dementia is an umbrella term for a group of symptoms — memory loss, difficulty thinking, problem-solving and behavioural changes — caused by various underlying brain diseases. Alzheimer's disease is the most common of these underlying diseases, accounting for 60-70% of all dementia cases. Other causes include vascular disease (following strokes), Lewy body pathology and frontotemporal lobar degeneration. "Alzheimer's" and "dementia" are not interchangeable terms.

Can dementia be prevented?

The Lancet Commission on Dementia (2024 update) identified 14 modifiable risk factors that together could prevent or delay up to 45% of dementia cases: less education, hearing loss, hypertension, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol, traumatic brain injury, air pollution, social isolation, untreated vision loss and high LDL cholesterol. Addressing these factors across the life course is the most powerful strategy available before effective treatments are widely accessible.

What are the new Alzheimer's drugs (lecanemab, donanemab)?

Lecanemab (Leqembi) and donanemab (Kisunla) are monoclonal antibodies that target and clear amyloid plaques from the brain — the pathological hallmark of Alzheimer's disease. Both received FDA approval in 2023. In trials, they slowed cognitive decline by approximately 27-35% compared to placebo in people with early-stage Alzheimer's. They do not stop or reverse the disease, carry serious risks of brain oedema and haemorrhage (ARIA), require regular MRI monitoring and currently cost approximately $26,000/year. Access is highly restricted.

What are the warning signs of dementia?

Early warning signs include: memory loss that disrupts daily life (particularly forgetting recent events or newly learned information); difficulty planning or solving problems; confusion with time or place; trouble with familiar tasks (cooking a meal, managing finances); new problems with words in speaking or writing; misplacing things and inability to retrace steps; poor judgement; withdrawal from social activities; and changes in mood or personality. Single memory lapses are common and usually not concerning; multiple progressive symptoms warrant medical evaluation.

How is dementia diagnosed?

Dementia diagnosis requires a comprehensive clinical assessment: detailed history from patient and informant; cognitive testing (MMSE, MoCA); physical examination; blood tests to exclude treatable causes (thyroid disease, vitamin B12 deficiency); and brain imaging (CT or MRI). In specialist settings, cerebrospinal fluid biomarkers (amyloid, tau) and PET imaging can confirm Alzheimer's pathology before symptoms begin. There is no single definitive test.

What is the global dementia care gap?

Dementia diagnosis rates globally remain very low — less than 50% in high-income countries and far lower in LMICs. Most care is provided by family members, predominantly women, with limited professional support. Post-diagnostic support — counselling, respite care, Admiral nurses, memory clinics — is scarce even in wealthy health systems. The economic cost of unpaid caregiving exceeds formal healthcare costs. WHO's Global Action Plan on Dementia 2017-2025 calls for national dementia plans in all member states; progress has been slow.

How does vascular dementia differ from Alzheimer's?

Vascular dementia is caused by damage to brain blood vessels — often from strokes (large or small) or small vessel disease causing white matter lesions. It tends to have a more abrupt onset and stepwise progression (worsening after strokes) rather than the gradual decline of Alzheimer's. Executive function (planning, organisation) is often more affected than memory early on. Prevention and management overlap significantly with cardiovascular disease prevention: blood pressure control, antiplatelet therapy and lifestyle modification are the mainstays.

What is the caregiver burden in dementia?

Dementia caregivers — approximately 75% of whom are women — provide an estimated 15+ billion hours of unpaid care annually. Caregiver burden is enormous: depression affects 40-75% of dementia caregivers, and physical health deteriorates with the sustained demands of care. Social isolation, financial hardship and career disruption are common. Dementia support organisations provide respite care, peer support and educational programmes — but these remain inaccessible to the majority of caregivers globally.

What is Lewy body dementia?

Lewy body dementia (LBD) is the second or third most common dementia type, caused by abnormal protein (alpha-synuclein) deposits in brain cells. It presents with: cognitive fluctuations; visual hallucinations (often detailed and well-formed); Parkinsonian motor features (slowness, rigidity); and REM sleep behaviour disorder (acting out dreams). It is frequently misdiagnosed as Alzheimer's or Parkinson's. Crucially, certain antipsychotics are contraindicated and can cause severe adverse reactions in LBD.

What is the WHO Global Action Plan on Dementia?

The WHO Global Action Plan on the Public Health Response to Dementia 2017-2025 sets seven action areas: dementia as a public health priority; dementia awareness and friendliness; risk reduction; diagnosis, treatment and care; research and innovation; support for caregivers; and information systems. It calls for every country to develop a national dementia plan. By 2022, only around 35 countries had published national plans — the majority lacking specific funding commitments.

How does GMJ News cover dementia?

GMJ News tracks Lancet Commission on Dementia updates, lecanemab and donanemab clinical and regulatory developments, WHO Global Action Plan progress, and dementia risk reduction evidence. As Georgia's population ages rapidly, dementia is becoming an increasingly important topic for the Georgian Medical Journal, PHIG and the health system more broadly.

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Dementia

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Over 57 million people live with dementia worldwide, with nearly 10 million new cases every year — a number set to almost triple by 2050 as populations age (WHO); Alzheimer's disease accounts for 60–70% of cases. The evidence on prevention has strengthened dramatically: the Lancet Commission (2024) identifies 14 modifiable risk factors — from hearing loss and hypertension to smoking and social isolation — that together could prevent or delay around 45% of dementia cases. With anti-amyloid therapies (lecanemab, donanemab) opening a contested new treatment era, the WHO Global Action Plan on Dementia presses for diagnosis, carer support and risk reduction as public-health priorities.

Key messages

Scale

More than 57 million people live with dementia worldwide, with nearly 10 million new cases each year. The number is projected to triple by 2050 as populations age (WHO Global status report on dementia 2021).

Alzheimer's dominates

Alzheimer's disease accounts for 60-70% of all dementia cases. Other types include vascular dementia (second most common), Lewy body dementia and frontotemporal dementia — each requiring different management approaches.

Prevention opportunity

The Lancet Commission on Dementia Prevention, Intervention and Care (2024 update) identified 14 modifiable risk factors — including hearing loss, hypertension, obesity, smoking, depression, social isolation and air pollution — that together could prevent or delay up to 45% of dementia cases.

Economic burden

The global cost of dementia exceeded $1.3 trillion in 2019 and is projected to reach $2.8 trillion by 2030 — driven largely by unpaid family caregiving, which accounts for approximately half the total cost.

New treatment era

Anti-amyloid therapies (lecanemab, donanemab) — the first disease-modifying treatments for Alzheimer's — have demonstrated modest but significant slowing of cognitive decline in early-stage disease. Access is currently limited to high-income settings.

Caregiver burden

Three quarters of dementia care is delivered by family caregivers — predominantly women — whose own physical and mental health is profoundly affected. Caregiver support is a neglected but essential component of dementia strategy.

Key statistics

57M

people with dementia

WHO 2021

10M

new cases/year

WHO 2021

cases expected by 2050

WHO 2021

45%

of cases potentially preventable

Lancet 2024

$1.3T

global economic cost (2019)

WHO 2021

60-70%

are Alzheimer's disease

WHO

Estimated people living with dementia globally (millions) 2019-2050 — WHO/ADI

Source: WHO Global status report on dementia 2021 and Alzheimer's Disease International World Alzheimer Report.

Glossary of key terms

Dementia
WHO ICD-11A syndrome — usually chronic or progressive — of acquired decline in memory, thinking, behaviour and the ability to perform everyday activities. It is not a normal part of ageing. Alzheimer's disease is the most common cause.

Alzheimer's disease
NIA/NINDSThe most common cause of dementia (60-70% of cases) — characterised by accumulation of amyloid plaques and tau tangles in the brain. Progressive and irreversible. Risk increases steeply with age; early-onset Alzheimer's (below 65) is rare and often genetically determined.

Mild cognitive impairment (MCI)
WHO/NIAA state of cognitive decline greater than expected for age that does not yet meet the criteria for dementia. People with MCI have a higher risk of progressing to dementia. MCI is the clinical stage now targeted by disease-modifying therapies.

Anti-amyloid therapy
FDA/EMAA class of antibodies (lecanemab/Leqembi, donanemab/Kisunla) that target and clear amyloid plaques from the Alzheimer's brain. First disease-modifying treatments for Alzheimer's approved (US FDA 2023). Slow but do not stop progression; currently indicated for early-stage disease.

Vascular dementia
WHO ICD-11Dementia caused by damage to blood vessels in the brain — often following stroke or small vessel disease. The second most common dementia type. Shares risk factors with cardiovascular disease; prevention overlaps with stroke prevention.

BPSD
IPABehavioural and Psychological Symptoms of Dementia — including agitation, aggression, wandering, depression, psychosis and sleep disturbance. Affect up to 90% of people with dementia at some stage and are a major driver of caregiver burden and care home admission.