Understanding the different types of dementia

Dementia is not a single condition, but an umbrella term for a group of symptoms affecting memory, thinking, and communication. It can impact daily life in various ways, and knowing the different types of dementia can help you better understand the experiences of those affected.

1. Alzheimer’s disease

Alzheimer’s disease is the most common form of dementia, accounting for around 60-70% of cases. It typically develops gradually, starting with mild memory loss and progressing to difficulties with language, decision-making, and recognising loved ones.

Key symptoms:

• Memory problems (like forgetting recent events or conversations)

• Difficulty finding the right words

• Confusion and getting lost in familiar places

• Changes in mood and personality

Why it happens: Alzheimer’s is caused by the build-up of abnormal proteins in the brain, which damage nerve cells and disrupt brain function over time.

2. Vascular dementia

Vascular dementia is caused by reduced blood flow to the brain, often following a stroke or small blood vessel damage. It’s the second most common type of dementia in the UK.

Key symptoms:

• Problems with planning and decision-making

• Slower thinking

• Memory loss (though often less prominent than in Alzheimer’s)

• Physical symptoms, such as difficulty walking or balance issues

Why it happens: Vascular dementia occurs when the brain does not get enough oxygen and nutrients due to poor circulation, leading to brain cell damage.

3. Lewy body dementia

Lewy body dementia shares symptoms with both Alzheimer’s and Parkinson’s disease. It’s caused by abnormal deposits of proteins called Lewy bodies in the brain.

Key symptoms:

• Visual hallucinations (seeing things that aren’t there)

• Fluctuations in alertness and attention

• Problems with movement, such as tremors or stiffness

• Sleep disturbances (acting out dreams)

Why it happens: the Lewy bodies interfere with chemical signals in the brain, leading to difficulties with cognition, movement and mood.

4. Frontotemporal dementia

Frontotemporal dementia tends to affect people under 65 and is caused by damage to the front and sides of the brain. It can lead to noticeable changes in behaviour and personality.

Key symptoms:

• Personality changes (such as becoming impulsive or socially inappropriate)

• Difficulty with language (speaking or understanding words)

• Apathy or lack of interest in usual activities

Why it happens: In frontotemporal dementia, nerve cells in the brain’s frontal and temporal lobes are damaged, which impacts behaviour, emotions and speech.

5. Mixed dementia

Some people have more than one type of dementia. For example, Alzheimer’s disease and vascular dementia often occur together. This is known as mixed dementia.

Key symptoms: symptoms can vary depending on which types of dementia are present, but they may include memory loss, difficulties with thinking, and physical challenges.

Why it happens: mixed dementia occurs when different brain changes happen at the same time, leading to overlapping symptoms.

6. Rarer types of dementia

While the types listed above are the most common, there are also rarer forms of dementia, such as:

• Parkinson’s disease dementia: affects people with Parkinson’s as the condition progresses.

• Creutzfeldt-Jakob disease: a rare and rapidly progressing form of dementia.

• Huntington’s disease: an inherited condition causing dementia symptoms in later stages.

How to get support

If you or someone you know is experiencing memory problems or any of the symptoms mentioned, it’s important to seek support. Your GP can help with an assessment, and organisations like Alzheimer’s Society, Dementia UK, and the NHS offer excellent resources, advice and support for people living with dementia and their loved ones.

Understanding the different types of dementia is the first step to providing the right support and care. Remember, you are not alone, and help is always available.

Sources: NHS, Alzheimer's Society, Dementia UK