How is dementia diagnosed? How doctors test for dementia

Around 1 in 3 older people develop some form of dementia. It is currently the leading cause of death in England and Wales. You may never develop dementia, but being armed with knowledge of symptoms to watch out for and how to test for dementia and get a diagnosis can help you to catch it early and to make arrangements for your future.

Diagnosis rates for dementia

Diagnosis rates for dementia are surprisingly low. According to Alzheimer’s Research UK, in 2017/18 the UK country with the highest rate of diagnosis in people over 65 with dementia was Northern Ireland, at 73%. The lowest was Wales, with a little over half of estimated cases, 53%, having a formal diagnosis.

It is not clear why diagnosis rates are low.

It may be that many people do not realise they have dementia, do not want to have that ‘label’ for personal reasons or because they know there isn’t a cure anyway, or because they think their care will cost more if they have been formally diagnosed.

Covid-19 may also have had an impact, with suggestions that remote appointments may be in part to blame for falling diagnosis rates.

Why should you get a dementia diagnosis?

Dementia is a progressive illness and while there is no cure, getting diagnosed as early as possible can enable you to access medications and therapies to help with symptoms, as well as make arrangements for your future care and legal affairs such as appointing a Power of Attorney.

Going to a GP if you suspect dementia can also rule out other health issues that are causing your symptoms. It may not be dementia at all. Some symptoms associated with dementia can also be a sign of depression, delirium or other neurological conditions.

Seeking a diagnosis can enable you to get the right treatment or support for the right condition.

Symptoms of dementia

Early symptoms of dementia include:

• Memory problems
• Finding everyday tasks such as cooking, housework and washing more difficult
• Changes in behaviour and personality
• Poor judgement
• Difficulty making decisions
• Struggling to find the right words
• Getting lost in familiar places

Risk factors for developing dementia

Sometimes people don’t think to get tested for dementia, particularly if they are younger. Dementia certainly is most prevalent in the over 65s but it can happen in younger people to. Young-onset dementia makes up around 5% of all cases, according to Dementia UK.

Often getting dementia is luck of the draw, but there are risk factors that can make you more susceptible.

These include:

• Age – The vast majority of people living with dementia are over the age of 65, and your likelihood of getting it increases steadily after that age.
• Family history – While dementia is not usually hereditary, some types can be. There are hereditary forms of Alzheimer’s disease and frontotemporal dementia, called familial Alzheimer’s disease and familial frontotemporal dementia, respectively.
• Lifestyle – The Alzheimer’s Society found that 4 in 10 cases of dementia are preventable. Lifestyle factors that can raise your risk include:
  • Smoking
  • Lack of exercise
  • An unhealthy diet (also Type 2 Diabetes)
  • Drinking too much alcohol
  • Lack of cognitive stimulation
• Depression and loneliness
• Hearing loss
• Conditions that affect the brain, such as stroke or traumatic head injury

How can I get tested for dementia?

If you suspect that you or a loved one may have dementia, the first port of call is a GP.

They will conduct some preliminary assessments. This is to see if anything else may be causing your symptoms. If they think you may have dementia, they will refer you for further tests.

Gathering the history of your symptoms

Your GP needs a holistic picture of the current state of your health. They may ask permission to speak to your loved ones or carers to help them to learn more about your experience.

As well as your medical history and any conditions that may be relevant, such as a stroke, depression or a history of alcohol use, your GP will need to know about how long you have been experiencing symptoms and if they are getting worse. They will also want to know how your symptoms affect your day-to-day life and your ability to care for yourself.

If you can have any of this information to hand when you go to the GP, all the better.

Cognitive assessment(s) for dementia

Cognitive assessments explore your mental abilities through a series of questions and exercises. Your GP may carry out an initial cognitive assessment then refer you for more, depending on your results. 

They do understand that it’s normal to have days when you are less mentally agile, such as if you are tired or stressed, so diagnosis shouldn’t be based on a single assessment.

You will do a mix of pen and paper questions and discussion with your assessor.

The questions and activities are looking at your:

• Ability to remember information. One way your assessor may do this is by giving you a short piece of information and asking you to repeat it back to them, then asking you again later if you still remember it. Often this is something like an address with several components to remember, such as a made-up person’s name, house number, street and town.
• Orientation. This means your awareness of where and when you are. You may be asked questions such as:
  • What is your name?
  • What time is it?
  • How old are you?
  • What season are we in?
  • Where do you live?
  • Do you know where you are now?
  • How did you get here today?
  • Do you know why you’re here today?

You may also be tested on your visual-spatial awareness, such as by asking you to draw a clockface.

• Ability to use language and communicate, both verbally with your assessor and in writing, effectively.
• Reasoning and problem-solving abilities. These exercises are about your ability to use it to come to a conclusion; they are not tests of intelligence. You may also be asked to count backwards or name the months of the year in reverse, as this demonstrates skills in using information, not just remembering it.

If English is not your first language and you would like a translator present, you will need to contact the bookings team at the hospital or medical facility where the assessment is being held, who can arrange one. Family members aren’t allowed to act as translators. Sometimes it is required to have a translator in order to establish your identity.

Brain scans for dementia

If necessary, you may undergo scans of your brain. You may have a CT scan and/or an MRI scan, depending on what medics are looking for.

These scans can test for:

• Inhibited blood flow to the brain
• Evidence of a stroke or mini stroke
• Brain tumours
• Where any damage (or atrophy) is, as which part of the brain is affected can help to determine which type of dementia (if any) you have

Other tests for dementia diagnosis

Other scans you may have include:

• Blood tests
• Urine tests
• An EEG – This stands for electroencephalography and measures brain activity, it’s used to see if you have epilepsy that may be causing your symptoms
• A PET scan or SPECT scan – These are imaging tests that are often combined with a CT or MRI scan to get a more detailed picture of what’s going on in your brain and body.
• A lumbar puncture – This is a needle in your spine that takes fluid, when analysed this fluid can show evidence of proteins that cause Alzheimer’s disease, as well as other conditions and infections linked with dementia

These tests look at how various organs in your body are functioning; this can help doctors to rule out other conditions and to determine which type of dementia you have.

There are different assessments to establish whether somebody still has mental capacity to make informed decisions about their care and finances.