3.1. List the most common causes of dementia

3.1. List the most common causes of dementia

Dementia Awareness

Care Learning

4 mins READ

This guide will help you answer the NCFE CACHE Level 2 Award in Awareness of Dementia Unit 3.1. List the most common causes of dementia.

Common Causes of Dementia

Dementia is a broad term used to describe a range of neurological conditions that affect memory, cognitive function, and behaviour. Understanding the most common causes of dementia is crucial for anyone working in health and social care, especially those seeking qualifications such as the NCFE CACHE Level 2 Award in Awareness of Dementia. Here, we’ll explore the primary causes in detail.

Alzheimer’s Disease

What is Alzheimer’s Disease?

Alzheimer’s disease is the most prevalent cause of dementia. It accounts for 60-80% of dementia cases. This progressive condition affects memory, thinking, and behaviour. Over time, it gets worse and interferes with daily life.

Causes and Risk Factors

Scientists believe Alzheimer’s results from a combination of genetic, lifestyle, and environmental factors. The exact cause isn’t entirely understood. Key risk factors include:

  • Age: Risk increases significantly after age 65.
  • Family History: A family history of Alzheimer’s can increase risk.
  • Genetics: Certain genes, such as APOE-e4, have been linked to the disease.
  • Other Factors: Head injuries, high blood pressure, and high cholesterol might also play a role.

Vascular Dementia

What is Vascular Dementia?

Vascular dementia, the second most common cause, results from conditions that block or reduce blood flow to the brain. This deprives brain cells of vital oxygen and nutrients. Common conditions include strokes and blood vessel damage.

Causes and Risk Factors

Vascular dementia often arises from:

  • Stroke: A significant cause that blocks blood flow to the brain.
  • Transient Ischaemic Attack (TIA): Often called “mini-strokes,” these can cumulatively cause damage.
  • Chronically Damaged Blood Vessels: High blood pressure, diabetes, and high cholesterol can deteriorate blood vessels over time.
  • Heart Conditions: Issues like arrhythmia or heart attacks that impede blood flow can increase the risk.

Lewy Body Dementia

What is Lewy Body Dementia?

Lewy Body Dementia (LBD) involves abnormal deposits of a protein called alpha-synuclein in the brain. These deposits, or Lewy bodies, disrupt brain function. LBD symptoms overlap with both Alzheimer’s and Parkinson’s diseases.

Causes and Risk Factors

Although the cause of Lewy Body Dementia is not fully understood, some factors have been identified:

  • Genetics: Family history can increase risk.
  • Age: Similar to other dementias, risk rises with age.
  • Co-occurring Conditions: Parkinson’s disease can sometimes progress to LBD.

Frontotemporal Dementia

What is Frontotemporal Dementia?

Frontotemporal Dementia (FTD) primarily affects the frontal and temporal lobes of the brain. These areas are crucial for personality, behaviour, and language. It often manifests at a younger age than other dementias, typically in people 45-65 years old.

Causes and Risk Factors

The precise cause is unknown, but significant factors include:

  • Genetics: Between 30% and 40% of FTD cases have a family history.
  • Gene Mutations: Certain gene mutations, like those in the MAPT and GRN genes, are linked to FTD.
  • Protein Abnormalities: Anomalies in proteins such as tau and TDP-43 can lead to FTD.

Mixed Dementia

What is Mixed Dementia?

Mixed dementia involves a combination of two or more types of dementia. The most common combination is Alzheimer’s disease and vascular dementia. Mixed dementia is often underdiagnosed because symptoms can vary widely.

Causes and Risk Factors

The causes are a blend of those associated with each dementia type present. For instance, a person with both Alzheimer’s and vascular dementia would share risk factors from both conditions.

Other Less Common Causes

Parkinson’s Disease Dementia

Those with Parkinson’s disease may develop dementia in the later stages, often called Parkinson’s Disease Dementia (PDD).

Huntington’s Disease

Huntington’s disease is a genetic disorder that causes dementia symptoms. These typically appear in the later stages of the disease.

Creutzfeldt-Jakob Disease

Creutzfeldt-Jakob Disease (CJD) is a rare, rapidly progressing neurodegenerative disease. It’s caused by abnormal, infectious proteins called prions.

Normal Pressure Hydrocephalus

Normal Pressure Hydrocephalus (NPH) occurs when excess cerebrospinal fluid accumulates in the brain’s ventricles. This can lead to memory loss and other dementia-like symptoms.

Other Causes

  • Chronic Traumatic Encephalopathy (CTE): Caused by repeated head injuries.
  • Wernicke-Korsakoff Syndrome: Often related to alcohol misuse and vitamin B1 deficiency.
  • Multiple Sclerosis (MS): Can lead to symptoms similar to dementia in later stages.

Example answers for unit 3.1. List the most common causes of dementia

Example Answer 1: Alzheimer’s Disease

Alzheimer’s disease is the most common cause of dementia, making up about 60-80% of cases. It’s a progressive condition that worsens over time, affecting memory, thinking, and behaviour. The risk increases mainly with age, but genetic factors and family history also play a significant role. Other risks include head injuries and certain lifestyle factors like high blood pressure and high cholesterol.

Example Answer 2: Vascular Dementia

Vascular dementia is the second most common cause of dementia. It happens because of conditions that block or reduce blood flow to the brain, such as strokes or transient ischaemic attacks (TIAs). Risk factors for vascular dementia include high blood pressure, diabetes, high cholesterol, and heart conditions that affect blood flow. Damage to blood vessels over time can also contribute.

Example Answer 3: Lewy Body Dementia

Lewy Body Dementia (LBD) is attributed to abnormal protein deposits called Lewy bodies in the brain. These disrupt brain function, leading to symptoms that overlap with both Alzheimer’s and Parkinson’s diseases. The exact cause isn’t fully understood, but age and family history are significant risk factors. People with Parkinson’s disease can sometimes develop LBD.

Example Answer 4: Frontotemporal Dementia

Frontotemporal Dementia (FTD) affects the frontal and temporal lobes of the brain, which control personality, behaviour, and language. This type of dementia often appears earlier than others, typically between ages 45 and 65. A strong genetic component is often involved, with many cases linked to mutations in certain genes like MAPT and GRN. Issues with proteins like tau and TDP-43 also play a role.

Example Answer 5: Mixed Dementia

Mixed dementia involves a combination of two or more types of dementia, frequently Alzheimer’s disease and vascular dementia. This can make diagnosis challenging as symptoms may vary. The causes are a mix of the risk factors for the individual types of dementia involved, such as age, genetic factors, and conditions that affect blood flow to the brain.

Example Answer 6: Parkinson’s Disease Dementia

Parkinson’s Disease Dementia (PDD) can develop in people who have Parkinson’s disease, usually in the later stages. This type of dementia combines symptoms of both Parkinson’s disease and dementia, such as memory problems and difficulty with planning and reasoning. The exact cause is unclear, but it’s related to the spread of Lewy bodies and other changes in brain chemistry linked to Parkinson’s disease.


Understanding the common causes of dementia helps you provide better care and support for those affected. Recognising the symptoms and knowing the risk factors can lead to early diagnosis and improved management of these conditions. This knowledge is essential for anyone working in health and social care, especially those pursuing formal qualifications in dementia awareness.

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