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What is Alzheimer’s disease?

Alzheimer’s disease is a brain disorder that disrupts the brain’s neurons, affecting how they work and communicate with each other. It is a physical brain condition that slowly destroys memory and thinking skills, resulting in impaired memory, thinking and behaviour. Alzheimer’s disease is the most common cause of dementia. It can sometimes be hereditary, but this is quite rare.

Our research is looking for ways to prevent and treat Alzheimer’s disease.

History of Alzheimer’s disease

Alzheimer’s disease is named after Alois Alzheimer (1864-1915), a German psychiatrist and neuropathologist who is credited with identifying the first published case of “presenile dementia”. His colleague, Dr Emil Kraepelin, identified the condition as Alzheimer’s disease and named it in 1910.

Symptoms of Alzheimer’s disease

Often a family member or friend will see the changes in a person, even when the person experiencing symptoms may be unable to recognise any change in themselves.

Symptoms vary as the condition progresses and as different areas of the brain are affected. A person’s abilities may fluctuate from day to day, or even within the same day. Symptoms can worsen in times of stress, fatigue or ill-health.

Our research is investigating ways to diagnose Alzheimer’s disease, even before symptoms begin to appear.

Symptoms of Alzheimer’s disease may include:

  • Persistent and frequent short-term memory loss, especially recalling more recent events
  • Repeatedly saying the same thing, or vagueness in conversation
  • Changes in ability to plan, solve problems, think logically and organise things
  • Taking longer to do routine tasks
  • Language and comprehension difficulties (such finding the right word)
  • Increasing disorientation in times, places and people
  • Problems in motivation and initiating tasks
  • Changes in behaviour, personality and mood

Alzheimer’s disease is a type of dementia

Dementia describes a collection of symptoms caused by disorders affecting the brain that cause problems with memory and cognitive ability. It is not one specific disease, and it is not a normal part of the ageing process. No two people experience dementia in the same way.

People with dementia might have problems thinking, remembering and speaking. They might find it hard to do their daily activities, and might do things that seem strange to others. Eventually, they will lose the ability to carry out the simplest tasks. 

There is no cure. Dementia is always fatal.

Dementia is the second leading cause of death in Australia, following heart disease. 250 Australians are diagnosed with dementia every day. For women, dementia is already the leading cause of death in Australia and close to two-thirds of people who die from dementia are female.

Dementia has emerged as a prominent cause of death in Australia, with a significant increase of 53.8% between 2012 and 2021. More than 472,000 Australians currently live with dementia and Alzheimer’s disease. It is estimated that more than one million Australians will have Alzheimer’s by 2058 without a significant medical breakthrough.

Other types of dementia include:

  • Vascular dementia – A form of dementia caused by brain damage resulting from restricted blood flow in the brain.
  • Dementia with Lewy bodies (DLB) is a type of dementia characterized by changes in behaviour, cognition, sleep, movement, and regulation of automatic bodily functions. Memory loss is not always an early symptom. Lewy bodies are microscopic structures that can be seen inside some of the brain cells of people diagnosed. Parkinson’s disease dementia and DLB are the two Lewy body dementias.
  • Frontotemporal dementia causes progressive damage to either or both the frontal or temporal lobes of the brain. It can affect one or more of the following: behaviour, personality, language and movement. Memory often remains unaffected, especially in the early stages of the condition. Frontotemporal dementia is more commonly diagnosed in people under the age of 65.

Diagnosing Alzheimer’s disease

To diagnose Alzheimer’s, doctors must use a range of physical and mental tests and assessments, medical history, neurological exams, diagnostic tests and brain imaging. There is no single test to diagnose Alzheimer’s disease. A diagnosis is made after careful clinical consultation, but in many cases, this can some time – even years.

It is important to have an early and accurate diagnosis to determine whether symptoms being investigated are being caused by Alzheimer’s disease, or by a different condition requiring its own specific treatment.

Some symptoms may not be caused by dementia, but instead be the result of conditions such as vitamin and hormone deficiencies, depression, medication effects, infections or brain tumours. If symptoms are not caused by dementia or Alzheimer’s disease, early diagnosis will be helpful to treat these other conditions.

This is why it is important to get a doctor’s diagnosis as soon as symptoms appear.

More about Alzheimer’s disease

Alzheimer’s disease is a physical brain disease that causes dementia, resulting in impaired memory, thinking and behaviour. Alzheimer’s disease is a progressive dementia – caused by a progressive degeneration of brain cells. The brain is the control centre for your whole body and different regions of the brain are responsible for different behaviours. The brain degeneration that occurs in Alzheimer’s disease affects memory, thinking skills, emotions, behaviour and mood. As a result, a person’s ability to carry out daily activities becomes impaired. As the disease progresses, symptoms worsen.

Alzheimer’s disease is characterised by specific changes in the brain. There is an abnormal build up of a protein called beta amyloid, which forms “plaques” outside the brain cells. Inside the brain cells, another protein called tau builds up into “tangles”. These abnormal protein accumulations disrupt messages within the brain because they damage connections between brain cells. The brain cells eventually die and brain volume shrinks. These brain changes occur gradually and actually begin many years (on average around 15 years) before symptoms of dementia occur. The brain is able to compensate for the early damage, but eventually the damage becomes too great and brain function is affected. As Alzheimer’s disease affects different areas of the brain, specific functions or abilities are lost. Memory of recent events is often the first to be affected, but as the disease progresses, long-term memory is also lost. The disease also affects many of the brain’s other functions and consequently language, attention, judgement and many other aspects of behaviour are affected.