The different types of dementia

Dementia is an umbrella term that refers to a number of different conditions, all of which can impair cognitive function. The causes, symptoms and outlook for those with dementia will depend largely on the individual, but could also be impacted by the specific type of dementia they have. 

To help you understand more about this condition, we are breaking down the different types of dementia there are, what sets them apart from each other, more rare kinds you may come across, how diagnosis works, and more. 

At Home Instead, our aim is to help people age positively and in place by bringing expert care to their home. For nearly 20 years, we have been providing the highest standard of care, and creating industry-leading training programmes for our Care Professionals that are accredited by nursing and medical professionals. Today, we are the world’s largest global home care network, supporting over 100,000 older adults with personalised, tailored care at home. So whatever questions you have about dementia care, we can help. 

What are the most common types of dementia? 

There are many types of dementia, however only a few are particularly common in the UK. Here are the types of dementia you are most likely to come across:

1. Alzheimer’s disease

How common is it?

Alzheimer’s is the most common type of dementia, affecting around 6 in 10 people with dementia in the UK. 

What causes it?

The cause of Alzheimer’s disease is mostly unknown, but it is thought that one reason is a build-up of two substances in the brain called amyloid and tau, which can form plaques and tangles. This can make cognitive function harder, and in the long-term it can reduce the chemicals necessary for sending messages around the brain, and cause certain parts of the brain to become smaller.

What are the symptoms?

People with Alzheimer’s tend to experience memory problems, difficulties with reasoning, communication problems, changes to the way they see and hear things, and changes in their mood. 

You can read more about this condition in our dedicated article: What Is Alzheimer’s?

2. Vascular dementia

How common is it?

This is the second most common type of dementia, which affects around 150,000 people in the UK. 

What causes it?

Conditions interrupting the flow of blood vessels and oxygen within the brain. Symptoms can be impacted by the size, location, and number of vascular changes in the brain, and these can develop either gradually or suddenly.

What are the symptoms?

Like other types of dementia, vascular dementia can cause changes to memory, cognition, and behaviour. People with vascular dementia will continue to decline over time, although they may see short periods of improvement.

3. Lewy body dementia (LBD)

How common is it?

The third most common type affects around 10-15% of those with dementia, which means around 100,000 people in the UK, but it is often misdiagnosed as Alzheimer’s in the early stages. There are two subtypes; dementia with Lewy bodies, and Parkinson’s. It is important to note those with Parkinson’s have a higher risk of dementia, but this does not mean they will definitely develop it. 

What causes it?

It is unclear what causes Lewy body dementia, but it is thought to possibly be caused by abnormal clumps of protein gathering inside cells in the brain. 

What are the symptoms?

Symptoms that set Lewy body dementia apart from other types of dementia include hallucinations and fluctuations in alertness. Those with Parkinson’s may also have difficulty with movement. Sleep disturbances are a key feature of Lewy body dementia, affecting up to 90% of those with the condition (as a comparison, sleep disturbances only affect around 40% of Alzheimer’s patients). 

4. Frontotemporal dementia (FTD)

How common is it?

Frontotemporal dementia is a less common type of dementia, but still accounts for around 1 in 30 cases of dementia in the UK, which is estimated to be around 31,000 people. This type of dementia is most common in people aged between 40 and 60.

What causes it?

This is another umbrella term which refers to a number of dementia conditions impacting the frontal and temporal lobes in the brain. It is thought to occur due to a buildup of proteins that can be genetic for some people with the condition. 

What are the symptoms?

The frontal and temporal lobes are the areas in charge of our personality, behaviour, language and speech, so frontotemporal dementia mainly causes symptoms involving these functions. Memory loss issues that are more common in other types of dementia are not the norm for the early stages of frontotemporal dementia. 

5. Mixed dementia

How common is it?

This type of dementia means a person is diagnosed with more than one type of dementia, and this is the case for at least 1 in every 10 people with dementia. More than one dementia diagnosis is most common in those aged over 75, and the most common combination is Alzheimer’s disease and vascular dementia. 

What causes it?

Mixed dementia means more than one type of dementia, so the causes may also be mixed. 

What are the symptoms?

As the name suggests, mixed dementia means a person with more than one type of dementia would experience symptoms from more than one condition.

6. Young-onset dementia

How common is it?

Despite the stereotype of dementia only affecting older adults, younger people can in fact develop dementia too. In fact, around 70,800 people with dementia in the UK are thought to be under 65. 

What causes it?

There is no clear reason why some people develop young-onset dementia, although it is thought that certain types of dementia in young people may be inherited.  

What are the symptoms?

Dementia in younger people tends to manifest differently, for example, they are more likely to develop a rare form of dementia, less likely to experience memory loss early on, and more likely to experience issues with movement, walking, coordination or balance. 

Are there rarer types of dementia? 

As well as the more common types of dementia mentioned above, in the UK around 1 in 20 people with dementia have a more rare version. These include:

• Atypical Alzheimer’s disease  – This is another form of Alzheimer’s where the changes occur in a different part of the brain, causing different symptoms than would typically be expected with Alzheimer’s. Under the umbrella of atypical Alzheimer’s disease, there is also frontal variant Alzheimer’s disease (fvAD) which affects around 1 in 50 people with Alzheimer’s and impacts the frontal lobes of the brain in the early stages, and posterior cortical atrophy (PCA) which affects the back region of the brain called the visual cortex. 

• CADASIL – CADASIL stands for Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy, and is a rare, inherited vascular disease that can cause symptoms of dementia. It is caused by a faulty gene, which can lead to the person having a number of mild strokes that damage the brain tissue connecting parts of the brain. Symptoms often appear in those aged 30 to 50, and around 2 in 3 people with CADASIL will develop dementia at some point in their lives.

• Corticobasal syndrome (CBS) – This type of dementia typically affects those aged between 60 and 80, and causes symptoms like issues with movement, language, memory and visual perception. Movement issues may include stiffness or slowness, moving in a jerky motion, having issues with balance or coordination, and more. There is currently no cure for this condition, but certain medications can help to reduce some symptoms.

• Creutzfeldt–Jakob disease (CJD) – This rare brain disorder can lead to dementia, with symptoms similar to those found in Alzheimer’s disease. The exception is that it is more fast-acting, as symptoms tend to progress within a few weeks to a few months. Creutzfeldt–Jakob disease is extremely rare, affecting only around 1 or 2 people per million around the world yearly.

• HIV-associated neurocognitive disorder (HAND) – Many people with HIV take a medicine called ‘combination antiretroviral therapy’ (cART), which keeps levels of the virus low in the body. However, before this medicine existed, those with HIV could develop dementia. Though this is now uncommon, people with HIV may still experience mild cognitive impairment, called HIV-associated neurocognitive disorder. For this reason, those diagnosed with HIV should have their cognitive and emotional wellbeing assessed once a year.

• Huntington’s disease – This rare disease leads to progressive degeneration of nerve cells in the brain, which can impact functional abilities in a similar way to dementia conditions, and lead to movement, cognitive and psychiatric disorders. The condition is caused by an inherited difference in a single gene, and most often first appears in people in their 30s or 40s. While there are medications available to help manage symptoms, they do not prevent the physical, mental and behavioural decline that the condition can cause. 

• Normal pressure hydrocephalus (NPH) – This brain disorder causes excess cerebrospinal fluid to accumulate in the brain’s ventricles, which can cause movement, thinking and reasoning problems similar to dementia conditions. It most often affects those in their 60s and 70s, and an estimated 700,000 adults suffer from the condition, although it is often misdiagnosed as Alzheimer’s or Parkinson’s. 

• Progressive supranuclear palsy (PSP) – This rare brain disorder causes serious issues with balance, eye movement, swallowing and more, and results from the breakdown of cells in areas of the brain that control movement and other functions. The cause is not known, and the only proven risk factor is age, as it tends to affect those in their late 60s and 70s. Research shows that this condition causes excess amounts of a protein called tau to build up within the brain, which is a characteristic of disorders like Alzheimer’s disease. There is no cure for progressive supranuclear palsy, but treatment can help to manage symptoms. 

How is dementia diagnosed? 

There is no cure for dementia, so getting an accurate diagnosis as early as possible can help to ensure you receive the appropriate care before requiring more help. Your GP will often be the first person to discuss a possible dementia diagnosis with, however they may refer you to a neurologist specialising in the brain and nervous system, or a geriatric psychiatrist.

Some of the steps involved in reaching a diagnosis include: 

• Ruling out other treatable conditions that can have cognitive-based symptoms. This may be done via a physical exam to assess vital signs, blood, hormones, and more.
• A review of medical and family history to ascertain dementia risk.
• Cognitive and neurological tests to evaluate thinking and physical functioning.
• Brain scans to identify strokes, tumours and other issues that could be causing dementia, as well as changes to the brain’s structure and function. These might include scans such as computed tomography (CT), magnetic resonance imaging (MRI), or positron emission tomography (PET).
• A psychiatric evaluation to determine why someone is experiencing behavioural or mood changes.
• Genetic tests to find out if dementia is caused by the person’s altered genes.
• Cerebrospinal fluid (CSF) tests may be ordered to measure the level of proteins and other fluids that surround the brain and spinal cord.

While a dementia diagnosis can be a worrying and uncertain time, you should never put off receiving a diagnosis, as performing these tests and examinations as early as possible means doctors can identify signs and symptoms of dementia conditions and start available treatments to help you or your loved one manage the condition and plan ahead for the future.

You may also find our article on Managing The Stages Of Dementia useful. 

Home Instead is an award-winning home care provider and part of a worldwide organisation devoted to providing the highest-quality relationship-led care for older people in their own homes. Arranging care for yourself or your loved one shouldn’t be stressful, so whatever questions you would like answered, feel free to reach out to the Home Instead team to discuss your needs.