Learning disabilities and dementia

What proportion of people with a learning disability develop dementia?

People with a learning disability are living longer and are more likely to develop illnesses associated with older age. In addition to this, they are at a greater risk of developing dementia as they get older compared with the general population (Cooper, 1997).

To improve the care environment ensure that it makes sense and is calm, familiar, predictable and suitably stimulating.

Kerr (2007) reports that three studies found the following prevalence rates of dementia among people with a learning disability: 13 per cent of people over 50 years old, and 22 per cent of those over 65.

For people with Down’s syndrome, the risk of developing dementia is significant and increases with age: Lai and Williams (1989) report a 55 per cent prevalence rate among 50- to 59-year-olds, while Prasher (1995) puts this at 36.1 per cent. Both studies report a 75 per cent prevalence rate for those aged 60 years and older. The growing number of people living with a learning disability and dementia presents significant challenges to care services and the staff who work in them, to provide the right type of support.

Recognising early changes: is this dementia?

A person with a learning disability gets lost on a familiar route to the shops. Or they seem to be having difficulty recognising familiar faces. Would these be signs of dementia?

It’s really important to recognise changes in a person with a learning disability, and then to establish what sort of changes these are. Are the changes physical, social or emotional? We mustn’t assume that dementia is the cause of every change as a person gets older. Family and friends as well as familiar carers have an important role to play in recognising early changes and bringing them to the attention of those who can help. Most importantly we need to listen to the person with a learning disability themselves, including noting non-verbal changes. We should record all these observations and comments.

Rule out other causes of confusion and memory loss

A number of conditions – for example urinary tract infections, depression or dehydration – can make a person present as confused, prompting others to wonder if the person is developing dementia. It is very important to explore whether there could be other reasons behind these symptoms, and whether these symptoms can be treated.

Once these other causes have been excluded, it is important to consider dementia. Earnshaw and Donnelly (2001) have developed a chart to help differentiate whether the changes the person is presenting with are as a result of dementia or other factors. This type of chart should continue to be used even if a person has a diagnosis of dementia, as further changes in their cognitive function could be a result of other factors which are treatable. Click here to see the chart (reproduced with permission).

Some issues that may arise with getting a diagnosis

When making a diagnosis of dementia, it can be difficult to distinguish between symptoms of dementia and the impairments a person with a learning disability may already have, such as:

Without a thorough process of diagnosis, it is more likely that the person’s difficulties will be attributed simply to their learning disability. Or the problems may be explained away by the fact that the person is getting ‘older’ or is being ‘uncooperative’.

Sometimes, staff may struggle to come to terms with the fact that the person with a learning disability has dementia. They may try to compensate for the person’s needs because they are concerned about the consequence of a diagnosis of dementia, such as loss of a place at a day centre or relocation to different accommodation.

Even so, it is critical that staff supporting people with a learning disability recognise the possibility of the onset of dementia and take seriously the need to undertake effective assessment and observations. Good records kept by staff can assist greatly to build up a picture that will inform the process of assessment and diagnosis.

Why design matters

The design of the built environment is important for someone with a learning disability. This becomes even more critical if the person develops dementia. Researchers in the Home for good study (Wilkinson et al 2007) investigated the experiences of 18 people with learning disabilities who had developed dementia, living in a range of situations. They found that, while service providers hoped to continue to support the person as their dementia progressed, this task was made more difficult by lack of appropriate living environments. They noted problems with noise, activity levels, lighting, colours and signage, as well as a lack of familiar, predictable and barrier-free environments. Unless staff understand the importance of these issues, and any necessary changes are made, it becomes harder for the person with a learning difficulty and dementia to remain in their familiar setting.

In the book 'Living with dementia: Adapting the home of a person who has Down’s syndrome and dementia', author Karen Watchman (2007) explains the importance of supporting people during times of change, for example if their home needs adjusting. She says: ‘Too many changes too quickly can lead to an increase in confusion of the person with Down’s syndrome, often mistaken for a progression in dementia. There is always a reason for the person behaving in a certain way. It is not deliberately to annoy or upset you’.

The most important things we can do to improve the care environment are to ensure that it makes sense and is calm, familiar, predictable and suitably stimulating.

Other health needs to consider for people with learning disabilities

Even after a diagnosis of dementia, a person with a learning disability will have other health care needs associated with ageing. Older people with learning disabilities have higher rates of arthritis and other problems that impair mobility. Respiratory disorders are common. The person may have hypertension which in turn is associated with cerebrovascular disease.

People with Down’s syndrome are particularly vulnerable to thyroid difficulties and hearing problems. This is partly due to the fact that their ear canal is narrow. Ear wax can build up and block the canal, causing a hearing reduction or loss to the person. A regular ear hygiene programme is important to avoid understanding being made worse by the person not hearing the information.


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