Over one million Australians will be living with dementia in 40 years — more than double the current number — according to a new report by the Australian Institute of Health and Welfare (AIHW).
The Dementia in Australia report predicts that by 2065, the number of Australians living with dementia will more than double, reaching 1.1 million from just under 425,000 in 2024.
The AIHW warns these estimates should be interpreted with caution, as long-term demographics are inherently uncertain.
Nearly 266,000 women and 159,000 men were living with dementia in 2024, according to the report, but it says the "the exact number" is unknown because "there is no single authoritative data source for deriving dementia prevalence".
The estimated more than doubling of people living with dementia will also occur as Australia's population grows and ages.
The AIHW in part uses the Australian Bureau of Statistics' (ABS) population projections to establish its prevalence rates.
In 2024, Australia's population was about 27 million, and the ABS projects it could reach between 33.96 million and 43.61 million in 2065.
"This trend is driven by the projected continued growth and ageing of Australia’s population, as dementia is increasingly common in older age," the report says.
The report also found dementia was Australia's leading cause of death in 2023, making up 9.5 per cent of all deaths — about 17,400 people. It is different to ABS estimates for that year, which put ischaemic heart diseases as the leading cause because AIHW counted a small number of deaths from forms of dementia that the ABS does not include in its reporting.
AIHW found the second leading cause of death that year was coronary heart disease.
"Between 2009 and 2023, the number of deaths due to dementia has more than doubled, from 8,500 deaths to 17,400 deaths," the report says,
"The rate of deaths due to dementia also increased from 39 to 65 deaths per 100,000 population."
'Need to double everything'
Dementia is not one specific disease but is an umbrella term for a group of symptoms caused by disorders affecting the brain.
Dementia and impaired brain function can impact memory, speech, thought, personality, behaviour and mobility. It is a degenerative, terminal illness.
There are many forms of dementia, with the most common being the degenerative brain disease Alzheimer's disease.
Lee-Fay Low, a professor in ageing and health at The University of Sydney, describes the new projection of one million people living with dementia as a "scary number".
"Dementia affects a person and how well they can live life, but it really affects their whole family because then they need to give that person more support," she told SBS News.
"If we really wanted to properly diagnose and treat a million people, we would need to double our capacity in our memory clinics. We would need to double our capacity in our nursing homes. We would need to double everything," Low said.
What are the risk factors?
Associate professor Lyndsey Collins-Praino from the University of Adelaide, whose research specialises in neurodegenerative diseases, said: "The number one risk factor for dementia is older age."
"In a relatively small number of cases, there's a clear genetic call. This would be about five to 10 per cent of cases. And this would include where there's a specific genetic change that leads to dementia," she told SBS News.
"That's not to say that genetic factors may not play a role in other cases, but that the genetic change isn't causative in those cases. Instead, there's a variety of environmental risk factors that have been implicated."
A 2024 study by 27 leading dementia experts, published in The Lancet, identified 14 risk factors associated with the development of dementia.
These include limited education, hearing loss, high blood pressure, smoking, obesity, depression, physical inactivity, diabetes, excessive alcohol consumption, traumatic brain injury, air pollution, social isolation, high cholesterol, and untreated vision loss.
These risk factors relate to three distinct stages of life: early, mid, and later life.
"In early life, having a lower level of education is one of those risk factors," Collins-Praino said.
"In middle life, these include things like hearing loss, having high LDL [Low-Density Lipoprotein or 'bad'] cholesterol levels, physical inactivity, type 2 diabetes, high blood pressure and obesity, with many of these linked to cardiac risk factors."
"When we move to later life, things like social isolation and not being sort of actively involved in leisure activities and social engagement and also having uncorrected visual loss are some of the risk factors that come up," Collins-Praino said.
Some academics have commended The Lancet study, but say it's not possible to conclusively link these risk factors directly to dementia.
"It’s also important to note that when the report refers to the proportions of dementia cases that could be prevented, this is notional, and based on observational evidence," said Charles Marshall, a professor of clinical neurology at Queen Mary University of London, after the report's release.
"We don’t really have evidence that dementia cases are prevented by addressing any of these risk factors."
The hidden workforce
According to the AIHW report, it's estimated there were at least 102,000 unpaid primary carers of people living with dementia in the community in 2024.
Dementia Australia also estimates that around 1.7 million people are involved in their care, as of recent reports in 2025.
"It's expensive for both health and aged care in terms of making the diagnosis and, hopefully, treatments on the horizon, but also because people living with dementia need more support for everyday life," Low said.
The report states that nearly $3.7 billion of the total health and aged care expenditure in 2020-2021 was spent directly on dementia.
