How many different types of dementia are there?

Dementia is not a single disease—it is an umbrella term encompassing multiple conditions that cause cognitive decline, memory loss, and changes in behaviour. While Alzheimer’s disease is the most well-known, there are over 100 different types of dementia, each with its distinct symptoms, progression, and underlying causes.

Understanding these types is crucial for aged care leaders, caregivers, and families navigating a dementia diagnosis. It not only helps in providing better care but also challenges outdated perceptions of the condition, ensuring those living with dementia receive the support and dignity they deserve.

The big four: The most common types of dementia

1. Alzheimer’s disease – The most recognised

Alzheimer’s disease accounts for 60–70% of all dementia cases, making it the most prevalent form worldwide. It is characterised by the build-up of amyloid plaques and tau tangles in the brain, leading to a progressive decline in memory, reasoning, and daily functioning.

Early symptoms include forgetfulness, difficulty finding words, and confusion about time and place. As the disease progresses, individuals may struggle to recognise loved ones, complete basic tasks, and communicate effectively.

2. Vascular dementia – When blood flow to the brain Is restricted

Vascular dementia is the second most common type and occurs when reduced blood flow damages brain cells. This can result from strokes, small vessel disease, or other cardiovascular conditions.

Unlike Alzheimer’s, where memory loss is often the first sign, vascular dementia typically affects problem-solving, attention, and decision-making abilities. Its progression is often described as “stepwise”—a person may experience sudden declines after each vascular event rather than a gradual decline.

3. Dementia with Lewy bodies – The chameleon of dementia

Dementia with Lewy bodies (DLB) is often misdiagnosed due to its overlap with both Alzheimer’s and Parkinson’s disease. It is caused by the accumulation of Lewy body proteins in the brain, leading to fluctuating cognition, visual hallucinations, and movement issues similar to Parkinson’s.

One of the hallmark features of DLB is its unpredictability—someone may appear lucid one day and highly disoriented the next. These fluctuations make it particularly challenging for caregivers and healthcare professionals to manage.

4. Frontotemporal dementia (FTD) – When personality changes first

Unlike Alzheimer’s, which primarily affects memory, frontotemporal dementia (FTD) targets the frontal and temporal lobes, leading to personality changes, impulsivity, and language difficulties.

People with FTD may exhibit inappropriate social behaviours, lose empathy, or struggle with speech production. It is one of the leading causes of early-onset dementia, often affecting individuals in their 40s and 50s.

Beyond the big four: other forms of dementia

Mixed dementia

Many people develop a combination of two or more types of dementia, most commonly Alzheimer’s disease and vascular dementia. This can complicate diagnosis and treatment, as symptoms may not follow a clear pattern.

Parkinson’s disease dementia (PDD)

While Parkinson’s is primarily a movement disorder, up to 80% of people with Parkinson’s will eventually develop cognitive impairment, leading to Parkinson’s disease dementia. Symptoms include slowed thinking, difficulty with problem-solving, and hallucinations.

Korsakoff syndrome (alcohol-related dementia)

This form of dementia is caused by severe, long-term alcohol abuse and a deficiency in vitamin B1 (thiamine). It primarily affects memory, with individuals often experiencing severe gaps in recollection but maintaining normal social behaviour.

Creutzfeldt-Jakob Disease (CJD) – The rapid dementia

One of the rarest but most aggressive forms of dementia, Creutzfeldt-Jakob disease (CJD) is caused by prion proteins damaging the brain. Unlike other types, CJD progresses extremely fast, often leading to death within months.

Dementia is not one-size-fits-all

With so many different types of dementia, it is clear that a one-size-fits-all approach to care is ineffective. Each type presents unique challenges, requiring tailored care strategies, specialised support, and ongoing research.

For families, caregivers, and aged care providers, understanding the differences between these conditions can significantly improve the quality of life for those living with dementia. Whether creating dementia-friendly environments, investing in staff training, or advocating for policy changes, awareness and education remain the most powerful tools in tackling this global health challenge.

As research progresses, new treatments and interventions are emerging, offering hope for the millions affected by dementia. Until then, the priority remains ensuring those with dementia live with dignity, respect, and the highest possible quality of care.

For more information, visit Dementia Australia, the leading national body providing support, research, and advocacy for those affected by dementia.

Disclaimer

This content is for informational purposes and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical concerns. We do not guarantee the accuracy or completeness of this information. If you have a medical emergency, seek immediate help.