Questions and answers

It's natural for anyone whose life has recently been affected by Alzheimer's to have a lot of questions. Unfortunately, because of the complex nature of dementia and the low level of funding for research into Alzheimer's and related illnesses, there is a lot that we still don't yet know. Here, however, are a few answers to some common queries.

Does dementia run in the family?

Mrs Hinds, Essex

Only very rare forms of dementia are caused by inherited factors alone. These represent about 1% of all cases of Alzheimer's and the symptoms usually appear in people aged under 60. If one parent is affected, the child will have a 50% chance of inheriting the gene. Except for these purely hereditary cases, there is currently no genetic test that can tell you if you are likely to develop Alzheimer's.

For dementia in the over 65s, the genetics are very complex. There are genes that affect the risk of dementia, but many people have these genes and do not develop the condition. The bottom line is that the commonest form of Alzheimer's disease - that in the over 65s - is caused both by inherited and non-inherited factors (such as age and lifestyle) and that several of these factors need to be present in an individual to develop the disease.

I am 65 and keep forgetting things. Have I got dementia?

A supporter from Glasgow

Probably not. People forget things at any age, although when people get older they worry that forgetfulness may mean they are ill. Occasionally forgetting things, like people's names or where the car keys are, does not mean someone has dementia.

If forgetfulness is persistent, for example if somebody repeatedly asks the same question within a few hours, and especially if it involves forgetting not so much where things are, but what they are used for, then it would be advisable to see a doctor for some simple memory tests. This kind of forgetfulness is not necessarily a sign of disease but if it happens with other changes then it may be worth investigating.

Why are the benefits from Aricept and other cholinesterase inhibitor drugs only temporary?

Mrs Woodlock, West Midlands

In a healthy brain, a chemical called acetylcholine transmits messages in the brain. In Alzheimer's, the brain cells that produce acetylcholine are damaged so reducing amounts of the chemical are produced. Aricept, Exelon and Reminyl work by blocking the action of an enzyme that breaks down acetylcholine so more of it is left in the brain to transmit messages. However, the nerve cells continue to be damaged and killed off by the disease and eventually there isn't enough acetylcholine produced for the drugs to have any effect.

What is the average time that somebody has Alzheimer's for?

Mr Anderson, Cornwall

Alzheimer's affects people in different ways and the decline may occur relatively rapidly in some and more gradually in others. The disease shortens the life span and, although patients may live for as many as 15 years after diagnosis, the average period to death, usually from an infection, is about 8 years.

Are we near to a cure for dementia?

Mrs Jones of Cardiff

In general, research is looking to develop ways of alleviating all of the symptoms, halting the disease process or preventing it in the first place. There are some drugs that may help slow the progression of dementia, but these are in the early stages of development and are not likely to be available for some years.

While we may not completely regain what has been lost in brain function, some effects of Alzheimer's and related diseases could be reversible. It is now realistic to hope that, with enough research funding, scientists could find a level of cure for some people affected by dementia within our lifetimes.

Alzheimer's disease and related conditions are extremely complex. The greatest hope for overcoming dementia lies in further research. The Alzheimer's Research Trust aims to fund the most promising high-quality research as quickly as possible to find an answer to the devastation of dementia.