What causes dementia?

Dementia is a complex condition that can be caused by a number of factors or issues that affect the brain. Broadly speaking dementia is caused by some form of damage or deterioration in the brain. Over time the damage will often worsen which causes symptoms to become more pronounced and the impact on day to day life more severe.

The most common forms of dementia are Alzheimer’s disease, frontotemporal dementia and dementia with Lewy bodies. These forms of dementia are classified as neurodegenerative diseases where by brain cells degenerate and die far more quickly than normal. Whilst brain cell degeneration is part of the aging process with these conditions the speed of that degeneration is far more accelerated and is caused by a build-up of irregular proteins within the brain.

Each type of neurodegenerative dementia is associated with the build-up of a different type of protein in the brain. It is not clear what causes these protein build-ups in some people but not others although there is some evidence to suggest that a small number cases may run in families. These small numbers of hereditary cases are associated with Alzheimer’s disease and frontotemporal dementia.

Vascular dementia has a more clear cause. This type of dementia occurs due to an interruption in blood supply to the brain which results in the death of brain cells causing brain damage.

Dementia can also be caused by vitamin deficiencies. Alcohol abuse can result in deficient levels of thiamine or vitamin B1 leading to a form of dementia called Wernicke-Korsakoff syndrome.