Dementia refers to a collection of neurological conditions characterised by severe declines in memory, reasoning, and the ability to perform everyday tasks, ultimately disrupting independent living. It is an umbrella term that encompasses various brain disorders, including Alzheimer’s disease, vascular dementia, frontotemporal dementia, and Lewy body dementia, which together account for a substantial portion of dementia cases. But what causes 70% of dementia cases? Understanding the root causes of these conditions can help in managing symptoms and potentially preventing the progression of cognitive decline.
In this blog, we will explore the leading causes of dementia, with a particular focus on Alzheimer’s disease, which alone accounts for the largest percentage of its cases. We will also look into how the other forms of dementia contribute to this percentage, the risk factors, and what steps can be taken for dementia prevention and management.
The Leading Cause: Alzheimer's Disease
Alzheimer’s disease is the most common type of dementia, responsible for 60–70% of all its cases. This neurodegenerative disease leads to gradual memory loss and cognitive decline, significantly impacting an individual’s ability to perform everyday tasks.
The exact cause of Alzheimer’s disease is still not fully understood, but researchers believe it results from a combination of genetic, environmental, and lifestyle factors. It is characterized by the build-up of amyloid plaques and neurofibrillary tangles in the brain. These abnormal structures damage neurons, impair communication between brain cells, and ultimately lead to the death of brain cells.
Alzheimer's Disease Risk Factors
Several dementia risk factors have been identified for Alzheimer’s disease:
- Age: The primary risk factor, with risk increasing significantly after age 65.
- Family History: A first-degree relative with Alzheimer’s increases your risk.
- Genetic Factors: Certain genes, like the APOE-e4 allele, are linked to higher risk.
- Cardiovascular Health: Poor heart health, including high blood pressure, diabetes, and high cholesterol, can elevate the risk.
Vascular Dementia: The Second Leading Cause
Vascular dementia is the second most common form, accounting for about 15–20% of cases. It occurs due to reduced blood flow to the brain, often following strokes or blood vessel issues. Unlike Alzheimer’s disease, vascular dementia can appear more suddenly.
Symptoms of Vascular Dementia
- Memory loss
- Confusion
- Difficulty with concentration and problem-solving
- Mood swings and personality changes
- Impaired judgement
Vascular dementia is often linked with conditions such as hypertension, diabetes, and even gum disease. Dementia prevention strategies focus heavily on maintaining cardiovascular health through a healthy lifestyle and medical management when necessary.
Lewy Body Dementia and Frontotemporal Dementia
These are less common forms but still contribute to the total 70% of dementia cases.
Lewy Body Dementia (LBD)
Caused by abnormal protein deposits (Lewy bodies) in the brain, LBD affects movement, cognition, and mood. Symptoms may include memory loss, confusion, motor issues similar to Parkinson’s disease, and REM sleep behavior disorder.
Frontotemporal Dementia (FTD)
FTD involves the degeneration of the brain’s frontal and temporal lobes and typically occurs earlier in life (ages 45–65). It presents with personality changes, behavioral issues, and language difficulties—often without early memory loss.
Mixed Dementia: A Combination of Factors
Some individuals may experience mixed dementia, most commonly a combination of Alzheimer’s disease and vascular dementia. This can result in a more complex symptom profile, including memory loss, impaired judgment, mood swings, and motor challenges.
Dementia Diagnosis and Early Detection
Accurate dementia diagnosis is crucial for understanding the type of dementia and choosing appropriate care strategies. Doctors usually use:
- Medical history reviews
- Cognitive tests (like the Mini–Mental State Examination)
- Brain imaging (such as MRI or CT scans)
- Lab tests to rule out other conditions
Early detection helps manage symptoms better and can improve quality of life.
What Can Be Done for Dementia Prevention?
While there is no known cure for dementia at present, studies indicate that certain lifestyle habits can help reduce the risk and enhance the overall prognosis. These include:
- Eating a healthy, balanced diet, including whole grains and avoiding gum disease
- Engaging in regular physical activity
- Engaging the brain through activities like solving puzzles, reading, or picking up new skills helps keep the mind sharp and stimulated
- Keeping chronic conditions such as high blood pressure and diabetes under control is essential for overall health and brain function
- Participating in social activities to reduce isolation and stimulate cognitive function
Conclusion
In summary, dementia is primarily caused by various neurodegenerative diseases, with Alzheimer’s disease leading the way and accounting for 60–70% of all cases. Vascular dementia, Lewy body dementia, and frontotemporal dementia make up the remaining proportion. Understanding these causes can guide more effective dementia care and highlight the importance of early detection and preventive lifestyle changes.
If you or a loved one is experiencing symptoms of dementia, consult a mental health professional for assessment and guidance. HelloDoc offers online consultations for dementia and related mental health conditions, providing personalised care across Australia.
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