What is dementia?

Dementia is not a single disease in itself, but rather an umbrella term to describe a number of illnesses that predominantly affect people over the age of 65. Dementias are progressive brain disorders that affect a person’s ability to function normally. The condition results in the degeneration of brain cells, with common symptoms including memory loss (particularly recent memory), confusion, personality change, withdrawal and a loss of ability to do everyday tasks.

Alzheimer’s disease, which initially affects the areas in the temporal lobe that control memory, accounts for 50 to 70 per cent of all dementia cases. Other common types of dementia are vascular dementia, Parkinson’s disease, dementia with lewy bodies, fronto-temporal lobar degeneration, Huntington’s disease, alcohol-related dementia (Korsakoff’s syndrome) and Creutzfeldt-Jacob disease.

Ageing dementia is one of the country’s most pressing health problems. Alzheimer’s affects more than two-thirds of dementia patients, and approximately a quarter of a million Australians. The total number of dementia cases in Australia is expected to rise to 1 million by 2050. It presents significant challenges to the health care system, which makes directed research programs aimed at preventing and treating ageing dementia all the more urgent.

Types of dementia

Dementia has many causes, the most common of which is Alzheimer’s disease, which accounts for over 60% of cases. Other common causes of dementia include vascular dementia, frontotemporal dementia, and dementia with lewy bodies. There are more than 50 known causes of dementia.

 Alzheimer's disease

 Vascular dementia 

Who gets dementia?

Dementia affects around 10 per cent of people over the age of 65 and 35 per cent of people aged over 85, and is of growing concern as the world’s population ages.

Stages of dementia

There are four key stages in dementia. The first stage involves being unable to remember everyday tasks while in the second phase patients are more likely to accept the condition. By the third phase people may become fixated on earlier memories and in the final stage, patients tend to withdraw completely.

Learn more about dementia