Dementia
An umbrella term, not a single disease — and not a normal part of growing older. This page is the plain-language ground under everything else on this site: what dementia is, what causes it, what can look exactly like it and be treatable, and how it is diagnosed.
One word covering a range of conditions that affect the brain and worsen over time.
Dementia is the loss of the ability to think, remember and reason to a degree that affects daily life and activities.
Some people with dementia cannot control their emotions or other behaviours, and their personality may change. It is caused by changes in certain brain regions that stop neurons — nerve cells — and their connections from working properly.
1 in 3
About one third of all people aged 85 or older may have some form of dementia.
National Institute on AgingNot ageing
Dementia was once called “senility” and thought to be a normal part of getting older. It is not. Not everyone develops dementia as they age.
National Institute on AgingMidlife
In rare cases dementia begins in midlife — which is part of why a baseline taken early is worth having.
National Institute on AgingIn most cases the underlying cause is unknown. Researchers have connected particular brain changes to particular forms of dementia, and for a small number of people rare genetic variants that cause dementia have been identified. Some people are diagnosed simply with “dementia” — but knowing the specific type is what makes it possible to tailor treatment and plan ahead.
They share many features and commonly occur together, which is why they are often described as one family: Alzheimer’s disease and Alzheimer’s disease-related dementias.
The most common diagnosis in older adults
Typically associated with abnormal build-ups of proteins in the brain, along with a loss of connection between nerve cells.
In the brain: amyloid plaques and tau tangles. These can be seen during life using a PET scan.
FTD · rare · often under 60
Named for the areas of the brain affected. Changes in the frontal lobe lead to behavioural symptoms; changes in the temporal lobe lead to problems with language and emotions.
In the brain: abnormal amounts or forms of the proteins tau and TDP-43, and loss of nerve cells.
LBD
Symptoms include problems with thinking, movement, behaviour and mood — the combination is what distinguishes it.
In the brain: abnormal deposits of a protein called alpha-synuclein, known as Lewy bodies.
Blood supply to the brain
Diagnosed in people who have vascular changes in the brain, such as a stroke or injury to the small vessels carrying blood to it.
In the brain: changes in white matter — the connecting “wires” relaying messages between regions. Seen with an MRI.
More than one thing at once
A diagnosis connected to a mixture of brain changes — for example evidence of both Alzheimer’s and vascular changes in the same person.
Still being worked out: how and why several distinct dementia-related changes develop at the same time.
This is the part of the page worth reading twice.
Talk with your doctor if you experience serious memory problems or other symptoms of dementia. A proper diagnosis is important to getting the right treatment.
Look at the second item. Depression, anxiety and stress are on the list of things that can look like dementia and be treated. In an older adult, depression is regularly mistaken for dementia — and unlike dementia, it is treatable. That is the reason the mental-health questions come first in a sitting rather than last, and the reason pain is asked about at all: untreated pain wrecks sleep, mood and concentration, and the result can read as cognitive decline.
Two of the four instruments used here ask the person about themselves; two ask someone close to them about change over time. None of them diagnoses anything. What they produce is a dated record that a clinician can read — including the possibility that what looks like decline is something else entirely, and something that can be helped.
Many people associate dementia with memory loss. Memory problems are often an early symptom, but they are not the only one — symptoms vary with the type of dementia and with which areas of the brain are affected.
People with dementia and those caring for them can face great challenges: the person’s ability to handle tasks, changes in family relationships, loss of work, and the need for more care as the underlying disease progresses. People in the earlier stages may need help with daily activities; people with advanced dementia may need constant care and supervision.
People with intellectual and developmental disabilities can also develop dementia as they age. Recognising the symptoms can be difficult, because they may be attributed to the person’s existing disability. What matters is considering the person’s existing ability and watching for change over time.
To diagnose dementia a doctor will complete a medical history, a physical examination, and neurological tests assessing balance, sensory response, reflexes, and memory and thinking skills. A doctor may also order brain scans, blood tests, genetic tests, a spinal tap and a mental health evaluation.
Because different types of dementia share similar symptoms, an accurate diagnosis can be difficult — and it is harder still because a person can have more than one type at once. Visiting a primary care doctor is usually the first step. They may refer you to a neurologist, a specialist in disorders of the brain and nervous system, who generally has the expertise needed to diagnose dementia.
There is currently no cure for Alzheimer’s or related dementias, but medicines are emerging to treat disease progression. There are also medications that may temporarily improve or stabilise memory and thinking skills in some people, and that may help manage certain symptoms and behavioural problems. A team of specialists — doctors, nurses and therapists — can help with maintaining mobility, addressing speech and swallowing problems, and learning new ways to handle the loss of skills with everyday tasks such as feeding oneself.
If you are concerned about memory problems or other symptoms of dementia, call your doctor. If you or someone you know has recently been diagnosed, it is worth educating family, friends and caregivers about the diagnosis. In-person and online support groups offered by non-profit organisations can give families and caregivers additional resources and a place to share experiences. Participating in a clinical trial or study is another option.
To volunteer for dementia research or find a clinical trial, the National Institute on Aging can be reached by phone at 800-438-4380 or by email at adear@nia.nih.gov.
Nothing on this page is something a screening questionnaire can settle. A diagnosis takes a clinician, an examination and usually tests. What a dated run of sittings can do is show which way things are going — and give the person in the room something better than memory to work from, including the possibility that the answer is one of the treatable ones.
If you are worried about someone right now, that is a reason to call their clinician rather than to wait for a quarterly review. In crisis, call or text 988 (Suicide & Crisis Lifeline). The Alzheimer’s Association Helpline is 800.272.3900, 24 hours a day.