Understanding the umbrella term: What is dementia?
In Australia, dementia is described as a collection of symptoms resulting from disorders affecting the brain. It is not a single disease but rather a syndrome—a grouping of symptoms—caused by various underlying conditions. These symptoms are severe enough to interfere with a person's daily life and typically include memory loss, confusion, difficulty with problem-solving, and changes in mood or behaviour. Critically, dementia is not a normal part of ageing, although it is more common in older people.
Many different diseases and conditions can cause dementia. Aside from Alzheimer's, other common types include:
- Vascular Dementia: Caused by reduced blood flow to the brain, often following a stroke or a series of mini-strokes.
- Lewy Body Dementia (LBD): Characterised by the build-up of protein deposits called Lewy bodies in the brain, which can lead to changes in movement, sleep, and visual hallucinations.
- Frontotemporal Dementia (FTD): Affects the frontal and temporal lobes of the brain, typically causing changes in personality, behaviour, and language before affecting memory.
- Mixed Dementia: A combination of two or more types of dementia, most commonly Alzheimer's and vascular dementia.
Alzheimer's disease: The most common type of dementia
In Australia, Alzheimer's disease is the most frequent cause of dementia, responsible for an estimated two-thirds of cases. It is a specific, physical brain disease that leads to progressive damage of brain cells over time. The disease is characterised by the build-up of two abnormal protein structures: amyloid plaques and tau tangles, which disrupt communication between brain cells and eventually cause them to die. This cell death results in the gradual shrinking of the brain, affecting memory and cognitive function.
Comparison: Dementia vs. Alzheimer's in Australia
To clarify the distinctions, the table below summarises the key differences between the overarching syndrome of dementia and the specific disease of Alzheimer's.
| Feature | Dementia | Alzheimer's Disease |
|---|---|---|
| Definition | An umbrella term for a group of symptoms affecting cognitive abilities. | A specific, progressive brain disease and the most common cause of dementia. |
| Cause | Caused by numerous conditions, including vascular disease, Lewy body disease, and Alzheimer's disease. | Caused by the build-up of amyloid plaques and tau tangles in the brain. |
| Onset | Onset depends on the underlying cause. Symptoms may appear differently depending on the type. | Onset is typically gradual, often beginning with subtle memory loss that worsens over time. |
| Progression | All types are progressive, with symptoms worsening over time, but the rate of decline varies. | Progressive, with distinct stages from mild cognitive impairment to severe disability. |
| Early Symptoms | Varies by type; can include memory loss, judgement issues, language difficulties, or behavioural changes. | Often begins with persistent short-term memory loss, such as forgetting recently learned information or recent events. |
The Australian diagnostic pathway
In Australia, obtaining a diagnosis involves a comprehensive medical evaluation, as there is no single test for dementia or Alzheimer's. The process typically begins with a General Practitioner (GP) and can include referrals to specialists like neurologists or geriatricians. The assessment involves:
- A detailed medical history, including family medical history.
- A physical examination and laboratory tests to rule out other conditions like vitamin deficiencies or infections.
- Cognitive testing to assess memory, language, and problem-solving skills.
- Brain imaging (e.g., CT or MRI scans) to check for brain structure changes and help differentiate between types of dementia.
An accurate and early diagnosis is crucial, as it provides access to treatments that may help manage symptoms and slow progression, as well as enabling planning for the future. Support services, such as those provided by Dementia Australia, are also more accessible after a formal diagnosis.
Supporting individuals in Australia
Understanding the specific type of dementia is vital for tailoring care and support. The symptoms and progression can vary significantly, meaning a different approach is needed for each person. For example, a person with Lewy body dementia may benefit from different strategies to manage hallucinations compared to someone with frontotemporal dementia who experiences severe behavioural changes.
Across Australia, support and resources are available for both those with a diagnosis and their caregivers. As dementia becomes a more prominent health issue, support networks are expanding to meet the growing need. According to Dementia Australia, over 1.7 million Australians are involved in caring for someone with dementia.
Conclusion: The critical distinction
The central takeaway is that while the terms are often used interchangeably, dementia is the broad category of symptoms, and Alzheimer's is one specific disease that causes those symptoms. In Australia, Alzheimer's is the most common cause of dementia, affecting hundreds of thousands of people. An early and accurate diagnosis is essential for accessing the right support and care, and it is important to remember that support is available through dedicated organisations like Dementia Australia.
