5 Types of Dementia
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Most people hear the word “dementia” and picture one thing. One disease. One path. One set of rules.
That’s not how it works.
Dementia is an umbrella term — not a single diagnosis. Under that umbrella live at least five distinct diseases, each one attacking the brain differently, progressing differently, and showing up in your home differently. Most caregivers don’t find this out until they’re already deep in the middle of it — exhausted and confused about why what worked last month isn’t working anymore.
This is what your doctor should have told you at diagnosis. We’re telling you now.
Why the Type of Dementia Matters
The type of dementia your loved one has determines everything — the symptoms you’ll see, the medications that help versus harm, the behaviors that will emerge, and the progression you’re preparing for. A care approach that works beautifully for Alzheimer’s disease can be completely wrong — and sometimes dangerous — for Lewy Body Dementia.
You cannot care well for someone without knowing what you’re actually dealing with.
Watch the Full Video
Before we go deeper, watch this. It covers all five types in plain language — what’s happening in the brain, what caregivers actually see at home, and what most doctors don’t explain at diagnosis.
1. Alzheimer’s Disease
Alzheimer’s is the most common form of dementia, accounting for 60–80% of all cases. It is caused by the accumulation of amyloid plaques and tau tangles in the brain — abnormal protein deposits that disrupt communication between neurons and eventually cause cell death.
What caregivers see at home:
- Early memory loss, especially recent events — the same question asked three times in an hour
- Difficulty with familiar tasks like managing finances or following a recipe
- Getting lost in places they’ve known for years
- Personality changes — someone who was gentle becoming suspicious or accusatory
- In later stages: loss of language, loss of recognition, loss of physical function
What most doctors don’t say: Alzheimer’s has a long pre-clinical phase — changes in the brain begin 15–20 years before symptoms appear. By the time of diagnosis, significant neurological damage has already occurred. Early intervention matters.
Alzheimer’s Association. 2023 Alzheimer’s Disease Facts and Figures. Alzheimers Dement. 2023;19(4):1598–1695.
2. Lewy Body Dementia
Lewy Body Dementia (LBD) is the second most common form of progressive dementia and the most frequently misdiagnosed. It is caused by abnormal deposits of a protein called alpha-synuclein — called Lewy bodies — that form inside neurons, disrupting brain chemistry and function.
What caregivers see at home:
- Vivid, detailed visual hallucinations — often of people or animals that aren’t there
- Dramatic fluctuations in alertness — fully present one hour, completely unresponsive the next
- REM sleep behavior disorder — acting out dreams physically, sometimes violently
- Parkinsonism — shuffling walk, stiff muscles, tremor
- Extreme sensitivity to antipsychotic medications
What most doctors don’t say: The medication sensitivity in LBD is life-threatening and widely unknown. Antipsychotic drugs commonly prescribed for hallucinations can be fatal in LBD patients. If your loved one has LBD and is prescribed an antipsychotic, this needs an immediate conversation with a specialist. This is not an overstatement.
McKeith IG, et al. Diagnosis and management of dementia with Lewy bodies. Neurology. 2017;89(1):88–100.
3. Frontotemporal Dementia (FTD)
Frontotemporal Dementia affects the frontal and temporal lobes — the parts of the brain responsible for personality, behavior, language, and decision-making. It is the most common dementia in people under 65, and it looks nothing like Alzheimer’s in its early stages.
What caregivers see at home:
- Dramatic personality changes — someone kind and reserved becoming impulsive, crude, or socially inappropriate
- Complete loss of empathy — they know you are upset but cannot feel it
- Compulsive, repetitive behaviors
- Overeating or fixating on specific foods
- Language loss — difficulty finding words or understanding them
- Preserved memory in early stages — which is why it is often misdiagnosed as psychiatric
What most doctors don’t say: FTD is frequently diagnosed as depression, bipolar disorder, or a personality disorder before the correct diagnosis is made. If your family member has been told they have a psychiatric condition but treatment isn’t working and behavior is escalating, push for a full neurological workup.
Rascovsky K, et al. Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia. Brain. 2011;134(9):2456–2477.
4. Vascular Dementia
Vascular Dementia is caused by reduced blood flow to the brain — most commonly following strokes or a series of small, sometimes silent strokes called transient ischemic attacks (TIAs). It is the second most common cause of dementia after Alzheimer’s.
What caregivers see at home:
- Sudden or stepwise decline — a noticeable drop after a stroke event, then a plateau, then another drop
- Slowed thinking and processing speed
- Difficulty with planning, organizing, and problem-solving
- Physical symptoms including weakness on one side, balance problems, and bladder issues
- Depression and emotional lability — crying or laughing without clear reason
What most doctors don’t say: Vascular dementia is one of the most preventable forms of dementia. Controlling blood pressure, cholesterol, diabetes, and stopping smoking directly reduces risk. For someone already diagnosed, the same factors affect rate of progression.
Dichgans M, Leys D. Vascular Cognitive Impairment. Circ Res. 2017;120(3):573–591.
5. CTE-Related Cognitive Decline
Chronic Traumatic Encephalopathy (CTE) is a progressive neurodegenerative disease caused by repeated head impacts — including subconcussive hits that never resulted in a diagnosed concussion. It is found in veterans, contact sport athletes, domestic violence survivors, and anyone with a history of repeated head trauma.
CTE can only be definitively diagnosed after death through brain autopsy. But the clinical presentation — called Traumatic Encephalopathy Syndrome (TES) — is increasingly recognized during life.
What caregivers see at home:
- Memory loss and confusion
- Explosive anger and emotional dysregulation disproportionate to the situation
- Impulsivity and poor judgment
- Depression, hopelessness, and in some cases suicidality
- Parkinsonism in later stages
- Periods of clarity followed by significant decline
What most doctors don’t say: CTE is not on the radar of most general practitioners. If your loved one is a veteran, former athlete, or has a history of repeated head trauma and their symptoms don’t fit the Alzheimer’s or Parkinson’s pattern cleanly, CTE-related decline deserves to be part of the conversation.
McKee AC, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(Pt 1):43–64.
You Are Not Alone in This
Caring for someone with dementia — any type — is one of the hardest things a human being can do. The confusion, the grief, the exhaustion of watching someone you love disappear in pieces while they’re still standing in front of you is real and it is brutal.
You deserve information. You deserve support. You deserve to understand what you’re dealing with so you can show up for them and still have something left for yourself.
That’s why we’re here.
Related Reading
- Why Does Dementia Cause Anger?
- Caregiver Guide for Neurological Decline
- Caregiver Burnout and the Brain
- Caregiver Burnout Warning Signs
- CTE vs. PTSD — Why the Symptoms Can Look Similar
- CTE vs. Dementia Symptoms
- Traumatic Encephalopathy Syndrome (TES) — The Living Face of CTE
Want to Go Deeper?
Our Nest Academy has a full advanced breakdown of all five dementia types with additional peer-reviewed sourcing and clinical detail:
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Peer-Reviewed Citations
- Alzheimer’s Association. 2023 Alzheimer’s Disease Facts and Figures. Alzheimers Dement. 2023;19(4):1598–1695.
- McKeith IG, Boeve BF, Dickson DW, et al. Diagnosis and management of dementia with Lewy bodies: Fourth consensus report of the DLB Consortium. Neurology. 2017;89(1):88–100.
- Rascovsky K, Hodges JR, Knopman D, et al. Sensitivity of revised diagnostic criteria for the behavioural variant of frontotemporal dementia. Brain. 2011;134(9):2456–2477.
- Dichgans M, Leys D. Vascular Cognitive Impairment. Circ Res. 2017;120(3):573–591.
- McKee AC, Stern RA, Nowinski CJ, et al. The spectrum of disease in chronic traumatic encephalopathy. Brain. 2013;136(Pt 1):43–64.
Robbins Nest Alliance is a 501(c)(3) nonprofit providing free brain injury and dementia education for caregivers, veterans, and families. All content is peer-reviewed and cited. This article is for educational purposes only and is not a substitute for medical advice. Always work with your qualified care team.