Alzheimer's disease

Alzheimer’s Disease

What is Alzheimer's disease?

Alzheimer's disease is type of dementia that causes a progressive decline in the mental functions that affect memory, thinking, language and behaviour. It is most common in people aged 65 and older, although it can also affect younger people. However, Alzheimer’s disease is not a normal or inevitable part of ageing – the symptoms are more severe than the mild memory loss that many people may experience as they grow older.

Nearly 40,000 people in Ireland suffer from Alzheimer’s disease or some related form of dementia, and with our ageing population, this figure is expected to grow even higher over the coming years.

What are the symptoms?

Symptoms vary from person to person, and may at first go by unnoticed. However, symptoms gradually worsen as the disease progresses. They may include:

Alzheimer’s disease progresses through three main stages: mild, moderate and severe. In mild Alzheimer’s disease, there may be slight lapses of memory and altered mood. Later on however, more obvious problems may develop – for instance the person may not recognise once familiar people or places, they may become confused or agitated, and may wander. The person may also eventually start to develop physical symptoms, such as losing bladder or bowel control – and eventually they may become incapable of caring for themselves.

What causes Alzheimer's disease?

In Alzheimer’s disease, certain changes take place in the brain, which means that the brain cells no longer function properly. ‘Plaques’ made up of a protein called amyloid and ‘tangles’ of twisted fibres develop in the brain of affected people, which gradually damage and eventually destroy the brain cells. People with Alzheimer’s disease also have a reduction in the level of a chemical messenger (or ‘neurotransmitter’) in their brain called acetylcholine – which is necessary for the brain cells to function properly.

It is not fully understood what causes these changes in the brain. However, it is thought that a combination of factors is most likely, including age, genetic factors, environmental factors, diet and overall general health. Age, however, is the most important risk factor.

How is it diagnosed?

The first step if you think that you or somebody else is experiencing symptoms of Alzheimer’s disease, is for the person affected to visit their GP. The GP may conduct screening tests that involve asking simple questions to assess the person’s mental ability. The GP may then refer the person to a specialist, who will conduct a full assessment. This may include a detailed assessment of memory, a full history of the person’s medical and family background, and other tests – such as a brain scan and blood tests.

It is also important that other treatable diseases that may resemble the symptoms of Alzheimer’s disease – such as thyroid problems, infections, vitamin deficiencies and depression – are also ruled out.

How is it treated?

There is no medication available at present that can cure or prevent the development of Alzheimer's disease. The focus is therefore on managing the symptoms of the disease and on trying to help the person affected to live as independently as possible, for as long as possible.

There are medications available in Ireland that can help to manage the symptoms and delay the progression of Alzheimer’s disease. Cholinesterase inhibitors, which are only suitable for people with mild to moderate Alzheimer’s disease, act to increase the level of the chemical messenger acetylcholine in the brain. This can slow the progression of some of the symptoms, such as memory loss and changes in thinking and judgement. However, these drugs can only ease symptoms temporarily, and not all people respond to them. They should not be considered as a cure for the condition.

Ebixa (memantine) is another type of drug which may be given to people in later stages of the disease. Again, this drug can only treat symptoms and delay progression of the disease temporarily.

Research into a treatment or preventive strategy for Alzheimer’s disease continues.

Caring for someone with Alzheimer’s disease

As the disease progresses, ensuring that the person has enough assistance to meet their everyday needs will become the most important aspect of therapy. A person with severe Alzheimer’s disease may eventually become totally incapable of caring for themselves.

It is also important that the relatives / carers themselves have appropriate support – caring for someone with Alzheimer’s disease can be very demanding. Counselling, support groups and day or respite care can help to relieve the burden on carers and may make it possible for the sufferer to be cared for at home for longer than would otherwise be possible. In advanced cases of Alzheimer’s, however, inpatient care may be necessary.

What can I do to help my friend/relative with Alzheimer's disease?


Visit the Alzheimer's Clinic for more information on symptoms of Alzheimer's disease, treatments and advice for carers.

Reviewed: October 18, 2006