Melodie de Jager
People often use the words “dementia” and “Alzheimer’s disease” as if they mean the same thing, but they don’t.
They are related, but not identical. Knowing the difference helps families and caregivers understand what’s happening and what care is needed (World Health Organization [WHO], 2023; Alzheimer’s Association, 2024).
Dementia: The Big Picture
Dementia is not one disease – it’s an umbrella term for a group of symptoms that affect memory, memory, reasoning, and behaviour badly enough to interfere with daily life.
It’s similar to saying someone has a “fever.” The fever tells you something is wrong, but not what’s causing it. In the same way, dementia tells us there’s a problem with brain function, but not the exact cause (NIA, 2024; WHO, 2023).
There are many causes of dementia, including:
- Alzheimer’s disease the most common cause
- Vascular dementia caused by strokes or poor blood flow to the brain
- Lewy body dementia linked to abnormal protein deposits
- Frontotemporal dementia affecting personality and speech.
Sometimes people have more than one type of dementia, called mixed dementia (Alzheimer’s Association, 2024).
Alzheimer’s Disease: One Type of Dementia
Alzheimer’s disease is the most common cause of dementia, making up about 60-70% of all cases worldwide. It happens when harmful proteins – amyloid plaques and tau tangles – build up in the brain, damaging and killing brain cells over time (NIA, 2024; Gustavsson et al., 2022).
Typical symptoms include:
- Trouble remembering recent events
- Repeating questions or losing track of conversations
- Difficulty finding words or following directions
- Getting lost in familiar places
- Personality or mood changes
Alzheimer’s disease is progressive – meaning it worsens slowly over several years (Levine et al., 2023).
How and Dementia & Alzheimer’s Disease Differ
How Doctors Tell Them Apart
Doctors look at:
- When symptoms started and how they have changed
- Cognitive tests (e.g. memory and attention tasks)
- Brain scans (MRI or CT) to check for shrinkage or small strokes
- Blood or spinal fluid tests for proteins linked to Alzheimer’s disease
These tests help identify whether dementia is due to Alzheimer’s disease or another cause (NIA, 2024; American Psychiatric Association [APA], 2022).
Why The Difference Matters
Understanding the difference helps families find the right support, medications, and community resources.
While there’s no cure yet for Alzheimer’s, new drugs and therapies can slow progression and improve quality of life. Early diagnosis gives people time to plan and get the most out of treatment and care options (Alzheimer’s Association, 2024; NIA, 2024).
In a Nutshell
Think of dementia as the symptom, and Alzheimer’s as one possible reason for it.
- Dementia – is a group of symptoms that affect memory, movement and thinking.
- Alzheimer’s disease – one specific cause of dementia (WHO, 2023; NIA, 2024).
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Sources
- World Health Organization (WHO). (2023). Global status report on the public health response to dementia. Geneva: WHO. https://www.who.int/news-room/fact-sheets/detail/dementia
- National Institute on Aging (NIA). (2024). What Is the Difference Between Dementia and Alzheimer’s Disease?S. Department of Health and Human Services. https://www.nia.nih.gov/health
- Alzheimer’s Association. (2024). Dementia vs. Alzheimer’s Disease. https://www.alz.org/alzheimers-dementia/difference-between-dementia-and-alzheimer-s
- American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th ed., Text Revision). Washington, DC: APA.
- Gustavsson, A., et al. (2022). ADHD as a risk factor for dementia and mild cognitive impairment: a population-based register study. Journal of Alzheimer’s Disease, 89(2), 567–580.
- Levine, S. Z., Rotstein, A., Weinstein, G., et al. (2023). Adult ADHD and the Risk of Dementia. JAMA Network Open, 6(10), e2338088.
