Let's Talk About the Types of Dementia
A range of brain diseases and conditions can cause symptoms of dementia. We help you understand the most the common ones.
It doesn’t matter if you’re 30 or 60, like many Americans you’re probably afraid of losing your memory as you get older. At least that’s what 72% of survey respondents said when 3,000 of them were asked about their biggest fears as they aged. Most people are afraid memory loss equals dementia, but not everyone develops dementia as they become seniors—in fact, it’s not considered a part of normal aging (although getting older increases your risk thanks to many factors, including normal wear-and-tear inside the brain). Dementia isn’t even a disease. Instead, it’s the term doctors use to describe symptoms that are serious enough to interfere with your daily life. There are many different types of dementia, and we’re going to help you understand what they have in common and how they’re different. That can make a difference in arriving at a diagnosis and getting the right treatment.
Our Pro Panel
We went to some of the nation's top experts in dementia to bring you the most up-to-date information possible.
Zoe Arvanitakis, M.D.
Medical Director; Professor of Neurological Studies
Rush Memory Clinic; Rush Medical College
James R. Bateman III, M.D., MPH
Assistant Professor of Neurology and Psychology
Wake Forest School of Medicine
Mary Sano, Ph.D.
Director of the Alzheimer's Disease Research Center and Professor of Psychiatry
Icahn School of Medicine at Mount Sinai
New York City
Dementia refers to cluster of symptoms that mainly affect critical thinking and memory loss and makes it harder for you to go about your daily life without help. If you have mild dementia, you need help with more complicated things like paying your bills and doing errands. As the dementia gets worse, you need a lot of help doing ordinary things like going to the bathroom and making meals. There are several types of dementia, and Alzheimer’s is the most common—about 60% to 80% of folks with dementia have Alzheimer’s.
No, but about half the people who are diagnosed with mild cognitive decline (MCI) go on to develop some type of dementia, mainly Alzheimer’s. When you have MCI, you typically forget appointments, aren’t as efficient as you once were, and might misplace things more often, but you can still drive and work and live your life. If you’ve been diagnosed with MCI, doing things to protect your heart (staying active, reducing stress, eating healthy foods) can keep your brain healthy too.
Yes, but experts now think mixed dementia—when you have two or more types of dementia—is more common than they once thought. In fact, one study found that three-quarters of people who’d been diagnosed with cognitive decline or dementia had two different types of dementia and over half had three.
The second runner-up is vascular dementia, which is caused when the blood vessels in the brain are blocked or damaged from a stroke or years of high blood pressure. But vascular dementia technically isn’t a neurodegenerative disease—the term doctors use for conditions that cause cells in your brain to slowly stop working over time. If you’re speaking about neurodegenerative forms of dementia, then the second most common after Alzheimer’s is dementia with Lewy bodies.
The Difference Between Alzheimer’s and Dementia
People sometimes think Alzheimer’s disease is different from dementia. It’s not. It’s the most common form of dementia. But most types of dementia share a constellation of symptoms, which include:
Loss of memory
Loss of other critical thinking skills, like planning, judgment, and problem-solving
Changes in behavior and the ability to control your emotions
Trouble using words and understanding conversations so you can’t communicate as well as you once did
A decline in attention and focus
Changes to the brain can set you up for dementia, though what exactly causes those changes depends on the type of dementia you have. If you have vascular dementia, a major stroke or a series of small ones block the flow of blood into the brain, causing cells to die. When you have Alzheimer’s, two different proteins in the brain grow uncontrollably so brain cells can’t communicate with one another. But whatever the root cause of dementia, each type affects the cells in different areas of the brain.
Another thing most forms of dementia have in common—they get worse over time. But there are treatments that can help restore memory temporarily and improve behavior. And there are steps you can take now that can either prevent some of these common types of dementia or at least lessen their worst effects.
What Are the Most Common Types of Dementia?
Roughly 9% of Americans over 65 have some form of dementia, and the vast majority (about 60% to 80%) have Alzheimer’s. The other more common forms include vascular, Lewy Body dementia, frontotemporal, and something known as mixed dementia, which may be more common than experts once thought, especially in people over 90. Mixed dementia is usually a combination of Alzheimer’s and vascular dementia. Let’s take a look at each one:
Most people with dementia have Alzheimer’s disease, which gets worse over time. In its mildest stage, you may have trouble driving (because you get lost) and doing complicated tasks (like bill-paying); later on, you become confused, have trouble taking care of yourself, and may be prone to outbursts.
What causes it: A buildup of two proteins in the brain, known as beta-amyloid and tau.
Signs: Repeating questions, losing objects and your way, trouble finding words; later on, more problems communicating and understanding, more apathy and personality changes, more confusion and wandering.
How it’s diagnosed: Usually a complete medical history, blood and urine tests (to rule out more benign reasons for losing your memory, like a thyroid condition or low vitamin levels), and imaging tests, to rule out brain bleeds, tumors, or signs of a stroke. There are tests that can pick up beta-amyloid and tau proteins but these are only done if the doctor isn’t sure you have Alzheimer’s or some other type of dementia.
Medications known as cholinesterase inhibitors, like Aricept (donepezil) and Razadyne (galantamine), and Namenda (memantine). Cholinesterase inhibitors can boost memory temporarily, even as much as a year or two in mild stages and improve day-to-day function and behavior later on. Namenda can help with confusion, behavior, and attention.
Exercise, which can help improve thinking skills and improve your mood and quality of life, even in people with moderate Alzheimer’s.
After Alzheimer’s, this is the second most common form of dementia, but it’s the type you can do most about even in your 60s. If your blood pressure, cholesterol, and blood sugar levels are low, you’re less likely to have a stroke (or small strokes) or damage the blood vessels in the brain—all of which can interrupt the flow of oxygen and nutrients to the brain and cause cells and tissue to die off. The Alzheimer’s Association estimates that about 10% to 15% of people with dementia have vascular dementia alone (versus mixed with Alzheimer’s).
Vascular dementia can be mild or severe. It can get worse over time, but that decline is described as stepwise—it gets worse, then it stays the same, then it gets worse again because you have another stroke or a heart attack or have to have surgery. If your vascular dementia is caused by damaged blood vessels (and not by strokes), then the decline can look more like Alzheimer’s—a gradual worsening.
What causes it: Often a stroke—a large one or several small or even silent ones—block the arteries and cause cells to die off. But not all strokes cause vascular dementia (which, remember, affects thinking, reasoning, and memory so you can’t go about your daily life). It depends on what part of the brain is being deprived of blood. Other causes include progressive small-vessel disease, in which the blood vessels in the brain get narrower or are damaged because of age, high blood pressure, and/or diabetes.
Risk factors: Age (your blood vessels stiffen and harden as you get older); high blood pressure; being overweight; smoking; excessive drinking (more than 14 drinks per week); lack of exercise; eating processed foods; high cholesterol and blood sugar levels.
Signs: If the dementia occurs after a stroke, it depends on the part of the brain affected. So you may have difficulty with language (aphasia), confusion, and disorientation. If the cause is progressive small-vessel disease, then you’ll have more problems with attention, focus, and judgment: You won’t be able to concentrate; you have trouble making decisions or reasoning; you may have personality changes, become apathetic or depressed. And while you typically won’t have the memory loss that Alzheimer’s patients do, you may have trouble walking—you’ll shuffle more and be unsteady on your feet.
How it’s diagnosed: If you’ve had a major stroke, then a doctor can pretty much tell that’s the cause. Otherwise, a provider will:
Take your medical history (including a family history of strokes and other symptoms)
Do a series of memory tests
Order blood work (to check cholesterol and blood sugar levels)
Give you imaging tests, like CT scan or MRI, to check for blood vessel damage and signs of brain bleeds
Treatment: There are no FDA-approved drugs for vascular dementia, but Aricept (donepezil) can help attention and focus. The other drugs for Alzheimer’s have had mixed results. What seems to be more beneficial are lifestyle changes that can help prevent another stroke or more damage and slow the rate of decline down. So:
Eat a heart-healthy or low-sodium diet like the Mediterranean or DASH
Get 20 to 30 minutes of exercise (walking, dancing, gardening) as many days as you can
Take a low-dose aspirin every day to prevent heart attacks or strokes if your doctor thinks it's right for you
Get blood pressure and cholesterol under control, either by taking your meds or getting an Rx for new drugs from your provider
Lewy Body Dementia
Most people heard about this form of dementia after the actor Robin Williams died, when his wife revealed that’s what he’d had. But Lewy Body dementia is actually the umbrella term for two types of related dementias—dementia with Lewy bodies (DLB) and Parkinson’s disease dementia. People with DLB and Parkinson’s disease dementia both have abnormal clusters of a particular protein in their brain that develop into something called Lewy bodies. But while the earliest signs of these two types of dementia are different, later on the symptoms are pretty much the same. The difference is timing—people with Parkinson’s disease dementia develop Parkinson’s disease first (the tremors, the shaking limbs) and then develop the signs of dementia.
Dementia With Lewy Bodies
About 1.4 million Americans have DLB, roughly 5% of all people over 65 with dementia. Like Alzheimer’s, it’s considered neurodegenerative, meaning the cells in the central nervous system stop working and eventually die. Because early symptoms are similar to Alzheimer’s or look like psychosis, people with DLB are frequently misdiagnosed. When you have DLB, you can also develop tremors and issues with walking, so people are sometimes misdiagnosed with Parkinson’s.
Dementia with Lewy bodies gets worse over time, and like Alzheimer’s, there are stages, although they aren’t as clear-cut as the ones in Alzheimer’s, mainly because DLB hasn’t been studied as extensively as Alzheimer’s has. There’s no cure, and no specific treatment, either.
What causes it: In a healthy brain, alpha-synuclein proteins help neurons (brain cells) communicate with one another. But for some reason, these proteins begin to clump together inside the neurons, causing them to communicate less effectively and eventually die; it happens first in the cortex, the area of the brain that controls the processing of information, language, and perception. Lewy bodies also mess up the production of certain brain chemicals known as neurotransmitters, including dopamine (which plays a role in muscle movement) and acetylcholine (which is key in memory formation and sleep regulation).
Risk factors: Age, a family history of Parkinson’s disease, a history of anxiety and depression, and being male. Like Alzheimer’s, there is evidence that having the APOE4 gene can up your chances of developing DLB.
Signs: One of the earliest is a sleep disturbance known as REM sleep behavior disorder, where you literally act out your dreams—you thrash, you kick, you pull your partner’s hair, you scream, you fall out of bed. This happens years and even decades before any of the other cognitive symptoms. Other signs include:
Hallucinations (extremely lifelike), depression, apathy, and delusions (which is why people get diagnosed with a psychiatric disease).
Your alertness and attention can come and go—day by day for some, for others at certain times of the day. You may also sleep more during the day.
You lose what’s known as visual-spatial skills, which means you have trouble processing how things are organized in space. That may mean you can’t find the bathroom in a house you’ve lived in for years because you keep turning down the wrong hallway or you open the fridge to get the milk and you keep reaching in the wrong direction and pull out the butter instead.
Unlike Alzheimer’s, you don’t lose short-term memory, though memory loss can come at a later stage.
You have trouble with your motor skills—you have tremors and shakes, you shuffle, you fall because you lose your balance, or your muscles are stiff. These are also signs of Parkinson’s disease, but in DLB, these symptoms come after the dementia, or at the same time, not before. And they occur in the early stages (unlike in Alzheimer’s, when a shuffling gait is a sign of moderate or severe disease).
Dizziness, fainting, drops in blood pressure, urinary incontinence
How it’s diagnosed: There’s no test that can spot Lewy bodies in the brain while you’re alive. Instead, neurologists tease out a diagnosis based on symptoms and medical history. If a specialist isn’t sure, you might get an imaging test known as a DaTscan. A radioactive tracer is injected into your bloodstream, goes into your brain, and attaches itself to the dopamine transporter. Then you get a scan. If you have DLB (or Parkinson’s) the scan will show lower levels of dopamine.
Treatment: There’s no FDA-approved treatment for DLB. Doctors can try:
Aricept (donepezil), which can be very effective (if only for a year or so) to help boost attention and alertness and decrease hallucinations
Medications to treat muscle stiffness and tremors, like Rytary or Duopa (carbidopa-levodopa), but these meds can sometimes make hallucinations worse
SSRIs like Prozac to treat depression or anxiety
Klonopin (clonazepam) to treat sleep disorders
Rarely, antipsychotics for hallucinations and delusions—many of them can make symptoms worse, though Seroquel (quetiapine) is sometimes effective. Instead, doctors try to treat hallucinations with nonpharma strategies like music therapy, distractions, or keeping to a routine
Physical therapy and staying active can help improve balance and problems walking
Parkinson’s Disease Dementia
About 2% of Americans, usually between 50 and 85, develop Parkinson’s disease, a brain disease that gradually gets worse over time and affects your ability to move normally. People with Parkinson’s shake even when they’re still, have stiff arms and legs, and have trouble with balance and walking. About 70% develop some type of cognitive impairment and dementia because the disease spreads to the parts of the brain involved in thinking and memory, at least a year (and often several years) after the stiffness and tremors.
What causes it: The causes are similar to dementia with Lewy bodies—clumps of alpha-synuclein proteins take over brain cells, forming Lewy bodies. The Lewy bodies start in the part of the brain that controls muscle movement and then spreads.
Risk factors: Your age when you were diagnosed with Parkinson’s (the older you were, the higher the risk); how long you’ve had Parkinson’s (the later the stage, the higher the risk); being a man; more serious motor symptoms.
Signs: The symptoms are similar to dementia with Lewy bodies and include:
Trouble concentrating and focusing
Trouble solving problems and learning new things
Hallucinations and delusions
Anxiety, irritability, and/or depression
Trouble sleeping and/or messed up sleep cycles
Treatment: Similar to DLB, medications are given to manage symptoms, and there is no FDA-approved treatment for Parkinson’s disease dementia yet. Meds include Exelon (rivastigmine) for memory or attention issues, melatonin for sleep disorders, and SSRIs for mood disorders.
Frontotemporal Dementia (FTD)
This is another umbrella term for a group of progressive brain diseases that affect your personality and your ability to think and speak. Roughly, about 60,000 Americans have FTD, with half of these having the kind that affects behavior, while the other half have the type that affects language.
Alarmingly, over 60% of these patients are between 45 and 60, and being (relatively) young is one way doctors can figure out if you have FTD. The disease is still misdiagnosed, though, since doctors may think you have a psychiatric disorder if you have the type that affects behavior or Alzheimer’s if you have the type that affects language. In general, it takes about three to four years to get a diagnosis, according to the Association for Frontotemporal Degeneration.
FTD that affects your personality is called behavior variant frontotemporal dementia (bvFTD). FTD that affects only your ability to communicate is called primary progressive aphasia (PPA), and this form is broken down further into three types:
Semantic PPA, where you lose the ability to understand and form words
Nonfluent PPA, where you get the words out eventually, but you really have to work at it and what comes out isn’t grammatical. You leave out articles or entire words, or your tenses and pronouns might be off.
Logopenic progressive aphasia, where there are impairments in naming and sentence repetition
Like other dementias, FTD gets worse over time. It can affect your muscles and balance (you may have trouble swallowing and walking), which can leave you in a wheelchair. On average, people die eight years after being diagnosed and die from an infection, like pneumonia.
What causes it: Several different types of proteins (including tau proteins) begin to clump in the frontal and temporal lobes of the brain (located in the front and sides of your head), the parts that affect behavior, language, and organizational and planning skills. As the clumps get bigger, they kill off the cells, causing these parts of the brain to shrink.
Risk factors: Genes play a big role here, and around 30% of the cases occur because someone in your family had it. One genetic mutation, the C9orf72 gene, can cause FTLD as well as ALS (Lou Gehrig’s disease). Another risk factor: repeated concussions. So far, the studies showing evidence that diabetes or blood pressure play a role in FTD have been mixed.
Signs: It depends on the type you have, but many times these symptoms overlap. Or they look like one type of FTD in the beginning and a couple years later develop symptoms of another type.
BvFTD signs include:
Your behavior becomes inappropriate and impulsive, which means anything from blurting out rude or offensive comments, shoplifting, touching strangers or standing uncomfortably close to people.
You become indifferent or apathetic about things you used to love, like hobbies or work.
You no longer show empathy or sympathy for others, including family members.
You get a craving for carbs, sometimes eating three boxes of Pop-tarts a day or eating candy all the time, and binge eat.
You do certain ritualistic things over and over, whether it’s pacing, saying a word or a phrase, clapping or rubbing your hands (similar to ritualistic OCD behaviors minus the obsessive thoughts behind them).
You have trouble making good decisions, solving problems, and organizing, leading to mistakes on the job or taking financial risks.
PPA symptoms include:
In semantic PPA, you lose the concept of words and what they mean. So if someone shows you a pen, you not only don’t know the word for pen, you don’t know what a pen is. Later on, your personality may change (you become more rigid) and lose knowledge of abstract concepts like love and happiness.
In nonfluent PPA, you lose the physical ability to form words so you have trouble speaking complete sentences and/or speak ungrammatically, leaving off words, articles, mixing tenses. Your understanding of complex words, sentences, and ideas goes downhill too. You can stop speaking altogether and have problems with your muscles, so you can no longer swallow.
You may also have signs of muscle weakness, tremors, stiffness, loss of balance. If you have these symptoms first, you probably have another type of frontotemporal degeneration that’s more similar to ALS, and develop the decline in thinking, behavior, and language skills later.
How it’s diagnosed: Doctors want to get a thorough medical history, so it pays to bring along someone close to you (a partner, a relative) who can discuss your symptoms. That helps a doctor form a hypothesis, along with other factors (like your age) that can be confirmed by other tools, including:
Cognitive tests to test memory (and to rule out more common forms of dementia, like Alzheimer’s)
An MRI to check if the frontal or temporal lobes have shrunk
Flurodeoxyglucose positron emission tomography (FDG PET) helps doctors see how your brain is working. You get a radioactive tracer containing sugar via an IV and then doctors measure the way your brain metabolizes glucose (which it needs for energy). That helps a doctor see the levels of activity in the frontal and temporal lobes—if there are lower levels of activity, it means those parts of the brain aren’t working as well.
How it’s treated: There’s no cure for FTD and no FDA-approved treatment. The drugs used to treat Alzheimer’s, like Aricept (donepezil) and Namenda (memantine) can make people with FTD worse. Most of the time, meds are used to treat individual symptoms:
Anti-depressants like Zoloft (sertraline) for the OCD-like ritualistic behaviors and to control the binge eating, usually in high doses
Anti-psychotics like Seroquel (quetiapine) for the impulsive or anti-social behaviors, usually in low doses
When people have more than one type of dementia, it’s called mixed dementia, and experts now think it’s way more common than originally thought, especially in people in their 80s and beyond. Typically, those with mixed dementia have Alzheimer’s and vascular dementia, but people can have Alzheimer’s and dementia with Lewy Bodies too or several other types of combinations.
Researchers from Rush University in Chicago examined the brains of 1,000 patients who had taken part in memory studies over the course of 22 years or more and had died in their late 80s. About two-thirds of them had been diagnosed with mild cognitive decline and/or dementia (typically Alzheimer’s). But when they looked at their brains, 94% showed signs of brain disease, whether it was the plaques and tangles of Alzheimer’s, or signs of small strokes, or Lewy bodies. Of these folks, 78% showed signs of two types of disease, 58% three, and more than a third (35%) had four or more conditions that could affect their thinking and memory. So while Alzheimer’s might be the most common form of brain disease, it rarely existed on its own.
This is especially true for African-Americans, another study done by Rush University found. After examining the brains of 122 Alzheimer’s patients after they’d died, researchers found that roughly 71% of black patients versus roughly 51% of white Europeans had mixed dementia—usually a combination of Alzheimer’s, dementia with Lewy Bodies, and signs of strokes—even when accounting for gender, education, and age differences.
What causes it: A combination of factors, from cardiovascular disease that can damage the arteries feeding into the brain to too many plaques and tangles. Experts now speculate that the more conditions you have, the more likely you are to suffer cognitive decline.
Risk factors: The same as many of these brain diseases—from genes to heart disease and diabetes. Not getting enough physical activity, a diet low in fruits and vegetables, and smoking can all up your risk too, mainly because it contributes to a higher chance of developing high blood pressure and diabetes.
What the signs are: Again, it could depend on what combination of diseases you have. For example, you might be having memory loss because of Alzheimer’s and then have a stroke that accelerates the memory loss and tips you into dementia.
Diagnosis: Most mixed dementias are discovered only after death, and only if you donate your brain to science. So doctors tend to diagnose the most dominant form of dementia based on medical history, symptoms, and test results (like MRIs and scans).
How to treat it: Doctors try for a comprehensive approach, depending on the conditions they think are contributing to the dementia. Most often, they’ll:
Prescribe meds approved for Alzheimer’s (like Aricept or another cholinesterase inhibitor), which also seem to work for vascular dementia and dementia with Lewy bodies.
Treat symptoms accordingly, whether it’s the sleep disorders of DLB or controlling cardiovascular health
- Survey on Aging: West Health Institute/NORC Survey on Aging in America. (2017). “Perceptions of Aging during Each Decade of Life After 30.” norc.org/PDFs/WHI-NORC-Aging-Survey/Brief_WestHealth_A_2017-03_DTPv2.pdf
- Dementia Stats: JAMA Internal Medicine. (2017). “A comparison in the prevalence of dementia in the United States in 2000 and 2012.” jamanetwork.com/journals/jamainternalmedicine/fullarticle/2587084
- Drugs for Vascular Dementia: CNS Drugs. (2017). “Pharmacotherapy for Vascular Dementia.” pubmed.ncbi.nlm.nih.gov/28786085/
- Prevention for Vascular Dementia: Journal of Neurochemistry. (2017). “Dementia risk and prevention by targeting modifiable vascular risk factors.” doi.org/10.1111/jnc.14132
- Dementia General Information: The Journal of the Alzheimer’s Association. (2020). “2020 Alzheimer’s Disease Facts and Figures.” doi.org/10.1002/alz.12068
- Dementia With Lewy Bodies Risks: Neurology. (2013). “Risk factors for dementia with Lewy bodies.” ncbi.nlm.nih.gov/pmc/articles/PMC3908463/
- Statistics for Dementia With Lewy Bodies: US National Library of Medicine/Genetics Home Reference. (2018). “Dementia with Lewy bodies.” ghr.nlm.nih.gov/condition/dementia-with-lewy-bodies#statistics
- Dementia With Lewy Bodies General: Molecular Neurodegeneration. (2019). “Dementia with Lewy Bodies: An update and outlook.” ncbi.nlm.nih.gov/pmc/articles/PMC6341685/
- Parkinson’s Disease Dementia: Continuum. (2016). “Lewy Body Dementias: Dementia with Lewy bodies and Parkinson’s Disease Dementia.” ncbi.nlm.nih.gov/pmc/articles/PMC5390937/
- Frontotemporal Dementia: Lancet. (2015). “Non-Alzheimer’s Dementia 1: Frontotemporal dementia.” ncbi.nlm.nih.gov/pmc/articles/PMC5970949/
- FTD Symptoms (1): The Association for Frontotemporal Degeneration. (n.d.). “Behavioral Variant FTD” theaftd.org/what-is-ftd/behavioral-variant-ftd-bvftd/
- FTD Symptoms (2): The Association for Frontotemporal Degeneration. (n.d.). “Primary Progressive Aphasia.” theaftd.org/what-is-ftd/primary-progressive-aphasia/
- Mixed Dementia Prevalence: Annals of Neurology. (2018). “Person-specific contribution of neuropathologies to cognitive loss in old age.” onlinelibrary.wiley.com/doi/abs/10.1002/ana.25123
- Mixed Dementia in African-Americans: Neurology. (2015). “Mixed pathology is more likely in black than white decedents with Alzheimer dementia.” n.neurology.org/content/85/6/528
- Rarer Forms of Dementia: Alzheimer’s Association (n.d.). “Other Types of Dementia.” alz.org/alzheimers-dementia/what-is-dementia/types-of-dementia