5 Types of Dementia: Key Differences Families Must Know

Your mom’s doctor just said “dementia.”

But then you hear “Alzheimer’s disease” from one specialist, “possible Lewy body dementia” from another, and “Parkinson’s with cognitive impairment” from a third.

Wait — aren’t these all the same thing?

Not quite. But they’re more related than most people realize.

Here’s what you need to know: Dementia isn’t a single disease. It’s an umbrella term for symptoms of cognitive decline — memory loss, confusion, and difficulty with thinking and reasoning.

Multiple diseases cause dementia. The most common are:

1. Alzheimer’s disease (60-80% of dementia cases)
2. Lewy body dementia (10-15% of cases — often underdiagnosed)
3. Vascular dementia (10% of cases)
4. Parkinson’s disease dementia (50% of Parkinson’s patients within 10 years; 80% if living 20+ years with the disease)
5. Frontotemporal dementia (5-10% of cases)

Understanding which type of dementia your loved one has matters because:

• Symptoms differ — Some types cause hallucinations, movement problems, or behavioral changes
• Progression varies — Some decline rapidly, others slowly
• Treatments differ — Medications that help Alzheimer’s may worsen Lewy body dementia; new disease-modifying drugs only work for specific types
• Care needs change — Different symptoms require different support strategies

And for the first time in history, we have FDA-approved treatments that actually slow Alzheimer’s progression — not just manage symptoms. But they only work in early stages, and accurate diagnosis is more critical than ever.

This article explains the significant types of dementia, what they have in common, what makes them different, breakthrough developments in diagnosis and treatment, and why knowing the specific diagnosis helps you provide better care.

What All Dementias Have in Common

Despite different names and causes, all dementias share core features:

Progressive Cognitive Decline

All dementias worsen over time (though the speed varies):

• Memory problems
• Difficulty thinking, reasoning, and problem-solving
• Language difficulties
• Disorientation (time, place, person)
• Impaired judgment

Loss of Independence

As dementia progresses, people lose the ability to:

• Manage finances
• Take medications correctly
• Cook and clean safely
• Drive
• Live alone

Behavioral and Psychological Symptoms

Most dementias eventually cause:

• Personality changes
• Mood swings
• Depression and anxiety
• Agitation and aggression
• Sleep disturbances

No Cure

There is no cure for any dementia. However, as of 2023-2024, we now have treatments that can slow Alzheimer’s progression — a historic breakthrough after decades of failed drug trials.

The Protein Connection: Why Different Dementias Are Related

Here’s the fascinating science behind why these diseases are linked:

All primary dementias involve abnormal protein buildup in the brain. Think of it like rust accumulating in an engine — the proteins gum up the works, killing brain cells and disrupting communication between neurons.

The Three Problem Proteins

1. Beta-amyloid (forms “plaques”)

• Sticky protein fragments that clump between neurons
• Primary culprit in Alzheimer’s disease
• Also found in other dementias

2. Tau (forms “tangles”)

• A protein that helps stabilize cell structure
• In dementia, it becomes twisted and tangled inside neurons
• Primary culprit in Alzheimer’s disease
• Also found in other dementias

3. Alpha-synuclein (forms “Lewy bodies”)

• A protein that clumps into microscopic deposits
• Primary culprit in Lewy body dementia and Parkinson’s disease dementia
• Named after Dr. Frederic Lewy, who discovered them in 1912

Here’s what makes this confusing: Many people have multiple types of protein buildup simultaneously — called “mixed dementia.”

For example:

• Alzheimer’s patients often have some Lewy bodies
• Lewy body patients often have some amyloid plaques
• Parkinson’s patients may develop tau tangles

This overlap explains why:

• Symptoms can blend between types
• Diagnosis is sometimes uncertain until autopsy
• The same person may receive different diagnoses over time as symptoms evolve

Breakthrough: Blood Tests Can Now Detect Alzheimer’s

This is one of the most significant developments in dementia research in decades.

Until recently, definitively diagnosing Alzheimer’s required either:

• PET brain scan ($5,000+, not covered by most insurance)
• Spinal tap (invasive, uncomfortable)
• Autopsy (only after death)

In May 2025, the FDA cleared the first blood test for Alzheimer’s diagnosis — the Lumipulse G plasma pTau217/Aβ1-42 ratio test.

What’s Available

FDA-cleared Lumipulse blood test (May 2025)

• Accuracy: 91.7% concordance with PET scans (positive results); 97.3% (negative results)
• What it measures: Ratio of phosphorylated tau-217 to amyloid-beta 42 proteins in blood
• Who it’s for: Adults 55+ with symptoms of cognitive impairment
• Estimated cost: $500-$1,000 (expected to be covered by Medicare)

Additional tests in development:

• C2N Diagnostics submitted a multi-analyte blood test using high-resolution mass spectrometry to the FDA in October 2025
• Similar tests already approved in Japan, the UK, and China

Why This Matters

✓ Earlier diagnosis — Identifies Alzheimer’s pathology in symptomatic patients with a simple blood draw

✓ Much easier than previous methods — Simple blood draw vs. expensive scan or invasive spinal tap

✓ Better treatment targeting — New disease-modifying drugs only work in early stages; blood tests identify ideal candidates

✓ More accessible — Can be performed in primary care settings, not just specialty clinics

✓ Monitoring treatment — Track whether new drugs are working

If your loved one is experiencing memory problems, ask their doctor about blood biomarker testing — especially if considering new Alzheimer’s treatments.

The Major Types of Dementia (And How to Tell Them Apart)

1. Alzheimer’s Disease

What it is: The most common form of dementia, caused by the buildup of beta-amyloid plaques and tau tangles that kill brain cells.

Current statistics: An estimated 7.2 million Americans age 65 and older are living with Alzheimer’s in 2025 — expected to reach 13.8 million by 2060.

Primary symptoms:

• Memory loss (especially recent memories) — the hallmark symptom
• Difficulty learning new information
• Repeating questions or stories
• Getting lost in familiar places
• Difficulty with language (finding words)
• Problems with planning and organization
• Misplacing items in odd places

Progression:

• Slow and gradual (averages 8-10 years from diagnosis, but can be longer)
• Memory problems appear first
• Other cognitive abilities decline later
• Movement and physical abilities remain intact until late stages

Unique features:

• Memory loss is the dominant symptom early on
• No hallucinations or movement problems initially
• Patients often don’t realize they’re impaired (anosognosia)

Risk factors:

• Age (biggest risk factor — risk doubles every 5 years after 65)
• Family history (APOE-e4 gene increases risk 3-12x)
• Untreated hearing loss (increases risk by 50%)
• High LDL cholesterol in midlife (newly identified risk factor)
• Untreated vision loss (newly identified risk factor)
• Social isolation (increases risk by 50%)
• Sleep apnea (increases risk by 50%)

Treatment Options

Symptom management medications:

• Cholinesterase inhibitors (Aricept, Exelon, Razadyne) — Modest benefit for memory and thinking
• Memantine (Namenda) — For moderate-to-severe stages

Disease-modifying medications (BREAKTHROUGH):

Leqembi (lecanemab) — FDA traditional approval July 2023

• How it works: A monoclonal antibody that removes amyloid plaques from the brain
• Effectiveness: Slows cognitive decline by 27% over 18 months
• Who it’s for: People with mild cognitive impairment or early-stage Alzheimer’s with confirmed amyloid plaques
• Administration: Biweekly IV infusions; once-weekly subcutaneous injection approved August 2025 for maintenance; once-monthly IV maintenance dosing approved January 2025
• Cost: ~$26,500/year (Medicare covers it)
• Monitoring: Regular MRI scans to watch for brain swelling or bleeding (ARIA)

Kisunla (donanemab) — FDA approved July 2024

• How it works: Similar to Leqembi — targets and removes amyloid plaques
• Effectiveness: 35% slowing of decline in clinical trials
• Administration: Monthly IV infusions
• Unique advantage: Treatment can potentially be stopped once plaques are sufficiently cleared (not necessarily lifelong)
• Medicare coverage: Available as of 2024

Coming in 2026:

• AXS-05 for Alzheimer’s agitation — FDA Priority Review with decision expected April 30, 2026
• MK-2214 (tau-targeting antibody) — Granted Fast Track Designation; Phase 1 data presented December 2025

▶ Critical limitations: New disease-modifying drugs only work in early-stage Alzheimer’s with confirmed amyloid plaques. They are NOT effective for Lewy body, vascular, or frontotemporal dementia.

2. Lewy Body Dementia (LBD)

What it is: Dementia caused by abnormal deposits of alpha-synuclein protein (Lewy bodies) throughout the brain.

Current statistics: 10-15% of all dementia cases, making it the second most common dementia after Alzheimer’s. However, it’s frequently misdiagnosed, so actual prevalence may be higher.

Primary symptoms:

• Visual hallucinations (very common, often vivid and detailed — seeing people, animals, or objects that aren’t there)
• Fluctuating cognition — Alertness and thinking ability vary dramatically from day to day or even hour to hour
• Movement problems similar to Parkinson’s (slow movement, stiffness, shuffling gait, tremor)
• REM sleep behavior disorder — Acting out dreams physically (thrashing, yelling, punching while asleep) — often appears years before other symptoms
• Severe sensitivity to antipsychotic medications (can cause life-threatening reactions)

Progression:

• More variable than Alzheimer’s (7-8 years average survival from diagnosis)
• Cognitive symptoms and movement problems appear around the same time
• Dramatic fluctuations make daily functioning unpredictable

Diagnostic Advances for Lewy Body Dementia

Alpha-synuclein seed amplification assays (SAA) are emerging as powerful diagnostic tools:

• CSF-based SAA shows 95% sensitivity and 97% specificity for detecting Lewy body pathology
• Can identify patients in prodromal stages (mild cognitive impairment phase)
• Research ongoing for less invasive blood-based and skin biopsy tests

Treatment:

• Cholinesterase inhibitors (especially rivastigmine/Exelon) — More effective in LBD than in Alzheimer’s
• Melatonin or clonazepam for REM sleep behavior disorder
• Carbidopa-levodopa for movement symptoms — use cautiously as it can worsen hallucinations
• No FDA-approved disease-modifying therapies yet, but an active research pipeline

▶ CRITICAL SAFETY WARNING: If your loved one has Lewy body dementia, AVOID ANTIPSYCHOTIC MEDICATIONS (Haldol, Risperdal, Seroquel). These can cause severe, potentially fatal reactions. Ensure this is noted prominently in all medical records and on a medical alert bracelet.

3. Parkinson’s Disease Dementia (PDD)

What it is: Dementia that develops in people who already have Parkinson’s disease (a movement disorder). Also caused by Lewy bodies — the same protein as Lewy body dementia.

Current statistics: 50% of Parkinson’s patients develop dementia within 10 years of diagnosis; 80% if they live 20+ years with Parkinson’s.

The key distinction between Parkinson’s Disease Dementia and Lewy Body Dementia:

“One-year rule”:

• Parkinson’s disease dementia — Movement symptoms (tremor, rigidity, slow movement) appear first; dementia develops at least 1 year later
• Lewy body dementia — Dementia symptoms appear first, OR movement symptoms appear within 1 year of cognitive symptoms

In reality, they’re the same disease process (Lewy bodies destroying brain cells) — just different timing of symptom onset.

Primary symptoms:

All Parkinson’s movement symptoms:

• Tremor (shaking, especially at rest)
• Rigidity (stiff muscles)
• Bradykinesia (slow movement)
• Postural instability (balance problems, frequent falls)
• Shuffling gait

Plus cognitive symptoms (develop later):

• Slowed thinking (bradyphrenia)
• Memory problems (less severe than Alzheimer’s early on)
• Difficulty with planning, problem-solving, and multitasking
• Visual-spatial problems
• Hallucinations (visual, often well-formed)

Treatment:

• Same medications as Lewy body dementia
• Challenge: Balancing treatment of movement symptoms (with dopamine drugs) without worsening hallucinations and confusion
• Physical therapy and exercise are critical for maintaining mobility

4. Vascular Dementia

What it is: Dementia caused by reduced blood flow to the brain, usually from strokes (large or many small “silent” strokes) or chronic small vessel disease.

Primary symptoms:

• Symptoms depend on which part of the brain is damaged
• Difficulty with planning, organizing, and problem-solving (often more prominent than memory loss initially)
• Slowed thinking
• Difficulty concentrating
• Mood changes (depression, apathy)
• Physical symptoms (weakness on one side, difficulty walking, bladder problems)

Progression:

• Stepwise decline — Sudden worsening after each stroke, then plateau
• OR a gradual decline caused by chronic small vessel disease

Risk factors: Same as stroke risk — high blood pressure, diabetes, high cholesterol, smoking, heart disease, atrial fibrillation

Treatment:

• Control vascular risk factors — Blood pressure management is critical
• Prevent future strokes — Blood thinners, cholesterol medications, lifestyle changes
• Unlike other dementias, vascular dementia progression CAN be slowed or stopped with aggressive risk factor management

5. Frontotemporal Dementia (FTD)

What it is: A group of disorders caused by progressive nerve cell loss in the frontal or temporal lobes of the brain.

Primary symptoms:

• Dramatic personality and behavior changes (often the first symptom)
  • Loss of inhibition (inappropriate comments, impulsive actions)
  • Apathy and loss of motivation
  • Compulsive behaviors
  • Loss of empathy
• Language problems in some subtypes
• Memory often intact early on — Unlike Alzheimer’s

Unique features:

• Younger onset — Typically ages 45-65 (not 70-80 like Alzheimer’s)
• Behavior changes dominate — family often thinks it’s a psychiatric illness initially
• Hereditary in 10-30% of cases

Treatment:

• No disease-modifying treatments
• Alzheimer’s medications don’t work for FTD
• Focus on managing behavioral symptoms (SSRIs for compulsions/depression)

Why Diagnosis Matters More Than Ever

“Does it really matter which type? They’re all dementia.”

Yes. It matters more now than it ever has before.

1. Different Medications Work (or Don’t Work) — And Some Are Dangerous

Alzheimer’s symptom medications:

• Cholinesterase inhibitors work moderately for Alzheimer’s
• Works VERY WELL for Lewy body dementia
• Don’t help vascular dementia much
• Don’t help frontotemporal dementia at all

New disease-modifying drugs (Leqembi, Kisunla):

• Only works for Alzheimer’s disease with confirmed amyloid plaques
• Completely ineffective for Lewy body, vascular, Parkinson’s, or frontotemporal dementia
• Getting the diagnosis wrong wastes money and exposes patients to unnecessary risks

Antipsychotic medications:

• Sometimes used carefully in Alzheimer’s for severe agitation
• Absolutely contraindicated in Lewy body dementia — can cause coma or death

Getting the diagnosis wrong can be dangerous.

2. Symptoms Require Different Care Strategies

Alzheimer’s:

• Focus on memory support (routines, calendars, labels)
• Reality orientation (early stages)
• Validation therapy (later stages)

Lewy body dementia:

• Manage hallucinations without antipsychotics
• Address dramatic fluctuations in alertness
• Fall prevention (movement problems)
• Autonomic symptom management (blood pressure monitoring when standing)

Parkinson’s disease dementia:

• Balance movement treatment with cognitive needs
• Physical therapy and exercise (critical for mobility)
• Fall prevention and swallowing evaluation

Vascular dementia:

• Aggressive management of cardiovascular risk factors
• Prevent future strokes
• Address physical symptoms (weakness, gait problems)

3. Prognosis and Planning Differ

Alzheimer’s: Slow, predictable decline over 8-12+ years

Lewy body dementia: More variable, average 7-8 years, dramatic fluctuations complicate planning

Vascular dementia: Depends on stroke prevention; can be stabilized with aggressive risk management

Parkinson’s disease dementia: Highly variable; movement problems complicate care earlier

Frontotemporal dementia: Often faster decline (7-13 years), younger onset affects family/career planning

Knowing the type helps families:

• Plan for care needs (when will 24-hour supervision be needed?)
• Make financial and legal decisions
• Understand what to expect
• Connect with appropriate support groups and clinical trials

The Role of Lifestyle: 14 Modifiable Risk Factors

The 2024 Lancet Commission identified 14 modifiable risk factors that account for approximately 45% of all dementia cases worldwide.

This is remarkable: nearly half of all dementias could potentially be prevented or delayed by addressing these factors.

The 14 Modifiable Risk Factors

Early life (under 18):

✓ Less education — Stay mentally stimulated throughout life

Midlife (ages 40-65):

✓ Hearing loss — GET HEARING AIDS (untreated hearing loss increases dementia risk by 50%)

✓ High LDL cholesterol — NEW in 2024; taking statins in midlife removes excess risk

✓ Hypertension — Control blood pressure (especially important in midlife)

✓ Excessive alcohol — Limit to 1-2 drinks per day maximum

✓ Obesity — Maintain a healthy weight

✓ Traumatic brain injury — Wear helmets, prevent falls

Later life (65+):

✓ Smoking — Quit (reduces risk even if you quit late in life)

✓ Depression — Seek treatment

✓ Social isolation — Loneliness increases dementia risk by 50%

✓ Physical inactivity — Exercise 30+ minutes daily (reduces risk by 30-40%)

✓ Diabetes — Control blood sugar

✓ Air pollution — Minimize exposure when possible

✓ Untreated vision loss — NEW in 2024; treating cataracts removes excess risk

Sleep Quality Matters

✕ Less than 6 hours of sleep per night → 30% higher dementia risk

✕ More than 9 hours of sleep per night → 30% higher dementia risk

✕ Sleep apnea (untreated) → 50% higher dementia risk

Why sleep matters: Deep sleep is when the brain clears out toxic proteins (amyloid and tau). Chronic sleep deprivation allows these proteins to accumulate.

✓ Aim for 7-8 hours of quality sleep nightly

✓ Get tested for sleep apnea if you snore or wake frequently

✓ Use CPAP if diagnosed (significantly reduces dementia risk)

Diet: Mediterranean and MIND Diets

Both diets reduce dementia risk by 35-50%:

• Olive oil is the primary fat
• Abundant vegetables, fruits, and leafy greens
• Whole grains, beans, and nuts
• Fish 2-3x per week
• Berries (especially blueberries)
• Minimal red meat and processed foods

Social Connection

Loneliness and social isolation increase dementia risk by 50% — equivalent to smoking 15 cigarettes per day.

✓ Maintain friendships actively

✓ Join clubs, groups, and faith communities

✓ Volunteer

✓ Maintain regular family contact

The goal: Address risk factors as early as possible and maintain healthy habits throughout life. It’s never too early or too late to reduce risk — and these interventions can help even people with increased genetic risk.

How Professional Home Care Supports All Types of Dementia

Regardless of which type of dementia your loved one has, professional in-home caregivers provide essential support that maintains safety, quality of life, and independence.

How All Heart Home Care Helps Families with Dementia

✓ Medication management — Ensuring correct medications at correct times (critical when different dementias require different drugs)

✓ Safety supervision — Preventing wandering, falls, and accidents

✓ Cognitive engagement — Activities tailored to dementia type and stage

✓ Physical exercise — Daily walks, gentle exercise (reduces progression risk by 30-40%)

✓ Meal preparation — Brain-healthy Mediterranean/MIND diet nutrition

✓ Personal care assistance — Bathing, dressing, grooming with dignity

✓ Transportation — Doctor appointments, IV infusion appointments for new Alzheimer’s drugs, social activities

✓ Behavioral management — De-escalating agitation, redirecting effectively

✓ Symptom monitoring — Recognizing when disease progresses or complications arise (especially critical for Lewy body patients who can’t have certain medications)

✓ Fall prevention — Especially critical for Lewy body and Parkinson’s dementia

✓ Hallucination management — For Lewy body dementia (without dangerous antipsychotics)

✓ Respite for family caregivers — Preventing caregiver burnout

✓ Companionship — Reducing isolation and depression (reduces dementia risk by 50%)

✓ Medical team coordination — Attending appointments, communicating changes, ensuring family understands new treatment options

Most importantly: Our dementia-trained caregivers understand that Lewy body dementia requires different strategies than Alzheimer’s — and that new treatment options require careful coordination with medical teams.

The Bottom Line

Dementia isn’t one disease — it’s a family of related brain disorders caused by abnormal protein buildup that kills brain cells.

The major types:

• Alzheimer’s disease (7.2 million Americans) — Memory loss dominates, slow progression, and now has disease-modifying treatments
• Lewy body dementia (10-15% of cases) — Hallucinations, fluctuations, movement problems, extreme sensitivity to antipsychotics
• Parkinson’s disease dementia — Movement symptoms first (tremor, rigidity), dementia later (50% within 10 years)
• Vascular dementia — Caused by strokes, progression can be stopped with risk factor management
• Frontotemporal dementia — Behavior changes, younger onset (45-65)

2025-2026 Breakthroughs:

• Blood tests can now detect Alzheimer’s with over 90% accuracy (FDA-cleared May 2025)
• FDA-approved drugs (Leqembi, Kisunla) that actually slow Alzheimer’s progression by 27-35%
• Subcutaneous dosing for Leqembi approved — easier home administration
• Better understanding of modifiable risk factors (14 factors account for 45% of cases)
• 138 drugs are currently in the Alzheimer’s pipeline

What you can do:

• Push for accurate diagnosis (blood test for Alzheimer’s now available)
• Ask about new treatments if diagnosed with early Alzheimer’s
• Understand the specific symptoms and progression of your loved one’s dementia type
• Adapt care strategies to dementia type (especially critical for Lewy body — NO antipsychotics)
• Reduce controllable risk factors — exercise, diet, hearing aids, sleep, social connections, blood pressure
• Get professional support early

For the first time in decades, there’s real hope — not a cure, but actual disease-modifying treatments for Alzheimer’s, better diagnostic tools, and a clearer understanding of prevention.

We Can Help

At All Heart Home Care, our caregivers receive specialized training in dementia care — including the critical differences between Alzheimer’s, Lewy body, Parkinson’s, and other types of dementia.

We understand that:

• Lewy body patients need different care than Alzheimer’s patients (and can’t have antipsychotics)
• New Alzheimer’s treatments require coordination with medical teams
• Sleep quality, exercise, and social engagement slow progression
• Each dementia type requires tailored strategies

If your loved one has dementia — or you’re concerned about memory changes — call us at (619) 736-4677 for a free in-home consultation.

We’ll assess their specific needs and create a personalized care plan that promotes safety, cognitive engagement, and compassionate support, incorporating the latest evidence-based approaches.

Because understanding the type of dementia is the first step toward providing the right care — and accessing treatments that can actually slow progression.

Quick Reference: Dementia Comparison (2026 Update)

References

1. Alzheimer’s Association. (2025). 2025 Alzheimer’s Disease Facts and Figures. Alzheimer’s & Dementia. alz.org/alzheimers-dementia/facts-figures
2. Livingston, G., et al. (2024). Dementia prevention, intervention, and care: 2024 report of the Lancet standing Commission. The Lancet. doi.org/10.1016/S0140-6736(24)01296-0
3. U.S. Food and Drug Administration. (2025). FDA Clears First Blood Test Used in Diagnosing Alzheimer’s Disease. fda.gov
4. Cummings, J., et al. (2025). Alzheimer’s disease drug development pipeline: 2025. Alzheimer’s & Dementia: Translational Research & Clinical Interventions. doi.org/10.1002/trc2.70098
5. Lewy Body Dementia Association. lbda.org
6. National Institute on Aging. Alzheimer’s Disease and Related Dementias. nia.nih.gov/health/alzheimers-and-dementia

Resources

• Alzheimer’s Association: alz.org (1-800-272-3900)
• Lewy Body Dementia Association: lbda.org
• Parkinson’s Foundation: parkinson.org
• National Institute on Aging: nia.nih.gov/health/alzheimers-and-dementia
• Medicare coverage for Alzheimer’s drugs: medicare.gov

Disclaimer: This article is for informational purposes only and is not intended as medical advice. Always consult with qualified healthcare professionals for diagnosis and treatment decisions. Dementia care should be tailored to each individual’s specific diagnosis, symptoms, and needs.