Dementia in Australia

These figures matter because they set the context for every decision made in a residential aged care facility. Dementia is not an edge case in aged care — it is the main event.

446,500

Australians estimated to be living with dementia in 2026 ²

54%

of permanent residential aged care residents had dementia (2021–22, the most recent national data) ¹

cause of death in Australia — 9.4% of all deaths in 2024, ahead of ischaemic heart disease ³

1.7 million

Australians involved in caring for someone living with dementia ²

Dementia is a syndrome, not a diagnosis

When a doctor says “dementia”, they are describing a level of impairment, not naming the cause. The useful question is always the next one: dementia due to what? Alzheimer’s disease, vascular disease, Lewy body disease, frontotemporal degeneration and several less common conditions all produce dementia, but they behave differently, respond differently to medication, and carry different risks.

Getting the underlying cause right is not academic. Antipsychotics that are merely risky in Alzheimer’s disease can be dangerous in dementia with Lewy bodies. Aggressive vascular risk management makes sense in vascular dementia and much less sense in advanced Alzheimer’s disease. A person with frontotemporal dementia who behaves disinhibitedly is not being difficult — their frontal lobes are failing, and the care plan needs to reflect that.

The common types, and how they differ

Mixed pathology is the rule rather than the exception in people over 80 — most residents have more than one process running at once.

Alzheimer’s disease. The most common cause. Typically begins with short-term memory loss and word-finding difficulty, progressing gradually over years to affect orientation, judgement, language and eventually all activities of daily living. Driven by amyloid plaques and tau tangles.
Vascular dementia. Caused by cerebrovascular disease — strokes, small-vessel disease, or both. Often more stepwise in progression, with prominent slowing of processing speed, executive dysfunction, gait disturbance and mood change. Memory may be relatively preserved early.
Dementia with Lewy bodies. Fluctuating attention and alertness, well-formed visual hallucinations, REM sleep behaviour disorder, and parkinsonism. Critically, these residents have marked antipsychotic sensitivity — a standard dose of risperidone or haloperidol can cause severe rigidity, sedation and, rarely, a neuroleptic malignant-type reaction.
Frontotemporal dementia. Younger onset is typical (often 45–65). Presents with personality change, disinhibition, apathy, loss of empathy or progressive language breakdown, with memory relatively spared early. Frequently misattributed to psychiatric illness for years before diagnosis.
Parkinson’s disease dementia. Cognitive decline emerging well after established motor Parkinson’s disease. Overlaps substantially with dementia with Lewy bodies, including antipsychotic sensitivity.
Mixed dementia. Alzheimer’s and vascular pathology together are the most common combination in residential aged care. In one community-based autopsy series, over half of the people who had dementia had more than one pathology, and having multiple pathologies almost tripled the odds of being demented ⁹¹.

What the trajectory usually looks like

Dementia is a terminal illness. That statement is uncomfortable but it is the single most useful reframing available to families, because it changes what “doing everything” means. Median survival from diagnosis varies widely with age, type and comorbidity, but people admitted to residential aged care with dementia in Australia have a median length of stay of roughly two years, and 96% of separations are due to death rather than discharge ¹.

Broadly, early dementia involves independent function with support for complex tasks; moderate dementia involves needing help with dressing, bathing and medication; and advanced dementia involves dependence for all personal care, loss of meaningful speech, immobility, swallowing difficulty and recurrent infection. Weight loss, aspiration pneumonia and pressure injuries are markers that the person has entered the final phase.

The practical implication is that goals of care should be revisited as the person moves through these stages, ideally before a crisis forces the conversation at 2am in an emergency department.

What dementia is not

Normal ageing does not cause dementia. Slower recall of names, needing more time to learn new technology and occasional lapses are age-related; getting lost on a familiar route, repeating the same question within minutes, or being unable to manage finances that were previously handled competently are not.

Delirium is not dementia, although the two are frequently confused and often coexist. Delirium comes on over hours to days, fluctuates markedly, and is usually caused by something treatable — infection, constipation, urinary retention, pain, dehydration, or a new medication. Any acute change in a resident with dementia should be treated as delirium until proven otherwise, and investigated accordingly ⁶⁴. Delirium in a person with dementia is associated with faster subsequent cognitive decline, so it is worth preventing, not just treating ⁶⁴.

Depression can mimic dementia, particularly in older adults, and it is treatable. Apathy, withdrawal, poor concentration and slowed thinking deserve a proper mood assessment before they are attributed to a degenerative process.

Sources cited on this page

1 Australian Institute of Health and Welfare. Dementia in Australia — Residential aged care. (2021–22 ACFI data: 54% of ~242,000 permanent residents had dementia.) View source
2 Dementia Australia. Dementia facts and figures. (Estimated 446,500 Australians living with dementia in 2026.) View source
3 Australian Bureau of Statistics. Causes of Death, Australia, 2024 — media release: Dementia is Australia’s leading cause of death (>17,500 deaths; 9.4% of all deaths). View source
64 Australian Commission on Safety and Quality in Health Care. Delirium Clinical Care Standard. View source
91 Schneider JA, et al. Mixed brain pathologies account for most dementia cases in community-dwelling older persons. Neurology. 2007;69:2197–204. (Autopsy series: over half of those with dementia had more than one pathology.) View source

See every source cited across the dementia section →

General information only, reflecting the interpretation of Umbrella Aged Care’s GPs of the published evidence as at September 2026. It is not individual medical advice, does not create a doctor–patient relationship, and must not be used to start, stop or change any treatment. Evidence and Australian regulatory and PBS arrangements change — always confirm current advice with the treating GP, pharmacist or specialist.