Question: what causes dementia and what age does occur?

Michael Craig answered on 13 Mar 2013:

Hi Ladymiranda,

That’s a great question. Firstly there are different types of dementia and each of those can be caused by different things. The main types of dementia are Alzheimer’s disease and vascular dementia.

Alzheimer’s disease is a tricky one, we are still not sure exactly what causes this and many factors have been suggested to increase peoples risk to getting Alzheimer’s. Things that increase the risk of Alzheimer’s include brain injury and trauma and having an unhealthy hear (and being unfit). The average age that people get diagnosed with Alzheimer’s is around 60-70 years of age. This is when the first symptoms such as memory loss and confusion are often noticed. However, we think that people may suffer from the disease for years before we see any of the symptoms, this is why we are trying to develop tests that can diagnose people even before they show any problems in their memory. There is a special case in Alzheimer’s where people can be more likely to get it if they have a particular type of a gene, this gene is called APOe3 and you can inherit it from your parents. If you do inherit it you are more likely to get Alzheimer’s and at an earlier age compared to others. The average age of this (which we called familiar Alzheimer’s) is around 50-60 years of age which is very young.

Vascular dementia is different to Alzheimer’s. This is where there are problems with the supply of blood to the brain. Vascular dementia is very different between different people with some people going downhill very quickly and others living a lot longer after being diagnosed. There are a number of factors which contribute to us getting vascular dementia including high blood pressure, heart problems, high cholesterol and diabetes. This means it is important that these conditions are identified and treated at the earliest opportunity. Effective treatment of these conditions may significantly delay or stop the development of vascular dementia. Again, similar to Alzheimer’s the average age that people get vascular dementia tends to be around 65 years of age.

I hope that helps answer your question!

Michael