People with learning disabilities, particularly those with Down's syndrome, are at increased risk of developing dementia. If a person with a learning disability develops dementia, they will face different and additional challenges to people who do not have a learning disability.

The word dementia describes a set of symptoms that may include memory loss and difficulties with thinking, problem-solving or language. A person with dementia may also experience changes in their mood or behaviour. These symptoms occur when the brain is damaged by diseases, including Alzheimer's disease, or a series of strokes. Dementia is a progressive condition, which means that the symptoms will get worse.

What is a learning disability?

A learning disability is a lifelong condition that affects someone's learning, communication and understanding. The person may require support with some aspects of their life, including planning, learning new skills and socialising. There are estimated to be about 700,000 people living with a learning disability in the UK, although this may be an underestimate.

There are different learning disabilities with various causes. Not all of them are well understood. Some learning disabilities, such as Down's syndrome or fragile X syndrome, occur before birth and are due to genetic disorders. Others occur after birth but before adulthood. These may be due to infection (eg bacterial meningitis), brain injury, lack of oxygen at birth or premature birth. The effects of a learning disability on the individual range from mild to severe to profound (very severe).

Life expectancy for people with Down's syndrome and other learning disabilities has improved significantly in the past 30 years, thanks to advances in medical care. For example, the life expectancy of someone with Down's syndrome has risen from 25 years in 1983 to over 60 years in 2015. One consequence of this improvement is that more people with learning disabilities, such as Down's syndrome, are living to an age where they are likely to develop dementia.

This section looks at Down's syndrome in more detail than other learning disabilities. This is because Down's syndrome is relatively common, with more than 40,000 people living with the condition in the UK, and because people with Down's syndrome are at particular risk of developing dementia.