What is young onset dementia?


Young onset dementia is a diverse condition. It affects people aged 18 to 64. Dozens of different brain diseases can cause it. Young onset dementia can bring a range of life changes—and life adaptations, too. Find out more here.

A gridded array of many adults of different ages and cultural backgrounds

The Alzheimer Society of Canada estimates that at least 28,000 people in this country are living with young onset dementia.

Maybe you want to learn more about this dementia because you are living with it too. Or perhaps your friend, family member, neighbour or colleague is living with young onset dementia.

In all cases, here are some essential things to know.

Young onset dementia is diverse

Changes in behaviour. Shifts in ability to do everyday work tasks. Difficulty speaking or writing. Challenges seeing, controlling muscles and balancing.

All of these things can be part of living with young onset dementia. This is a syndrome that manifests in different ways for different people.

Young onset dementia is a diverse condition. Dozens of different diseases can cause it. The main thing those diseases have in common is that they affect the brain. And those brain changes then change the way we remember, think, move and connect daily.

There is no one kind of young onset dementia. There is no one kind of person who gets young onset dementia. And there is no one “right way” to have, live with, or take care of someone with young onset dementia.

Also, there are many different cultural knowledges about young onset dementia.

And there are many different things that change how someone experiences young onset dementia. Contexts like your gender or sexuality, your job or income, or your language or ethnocultural community can all change your own individual experience of living with young onset dementia.

Young onset dementia affects people aged 18 to 64

Dementia is a word medical doctors use when an illness or other situation is making it very hard for someone to remember, move, think or connect.

For medical doctors to use this word—dementia—those problems must be intense enough to affect someone’s daily life.

Often in dementia, those problems are caused by changes to the brain and the way the brain works.

If the person with dementia developed symptoms at age 65 or older, we just call it “dementia.”

But if the person with dementia developed symptoms between ages 18 and 64, we call it “young onset dementia.”

Most people with young onset dementia are in their 40s, 50s or early 60s. But people younger than that can get it too.

Young onset dementia is different from early stage dementia

Doctors talk about any dementia as being divided into stages: early stage, middle stage and late stage.

The term “early stage dementia” is used when someone of any age is starting to show signs of dementia.

The term “young onset dementia” is only used when someone under the age of 65 has dementia.

Many different diseases can cause young onset dementia

Dementia is what doctors sometimes call an “umbrella” term. Lots of different diseases are covered by the dementia “umbrella.”

It’s the same for young onset dementia. More than 50 different diseases or conditions are associated with young onset dementia. Here are some of them:

  • Frontotemporal Dementia (FTD)
  • Alzheimer’s disease
  • Lewy Body Dementia
  • Vascular Dementia
  • Huntington Disease
  • Wernicke-Korsakoff Syndrome
  • Down Syndrome
  • Corticobasal Syndrome
  • Creutzfeldt-Jakob disease
  • Multiple Sclerosis
  • Niemann-Pick disease type C
  • Normal pressure hydrocephalus
  • Parkinson’s disease
  • Posterior cortical atrophy
  • Progressive supranuclear palsy
  • Traumatic brain injury

It is also possible for someone to experience two or more of these at the same time. When there is more than one cause for the dementia, we call it “mixed dementia.”

Some young onset dementia conditions are reversible, and others are not

It’s important to see a doctor to try and find out which disease is causing someone’s young onset dementia. Doctors can prescribe different medicines and therapies for these different diseases.

Some dementias or brain problems happen due to nutrition issues or alcohol use disorders. If caught and treated early enough, some of those types of dementias can be reversed.

Dementia-like symptoms that are caused by brain tumors, brain bleeding or certain kinds of infections can also be reversed at times.

But other kinds of dementias—like Alzheimer’s disease and frontotemporal dementia—can’t be reversed right now. They are caused by brain cell changes that we don’t know how to reverse yet.

Scientists are still trying to understand why some dementias are reversible and others are not.

Young onset dementia varies in timespan and length

Some people in Canada have lived well for 20 years or more with young onset dementia.

Other people in Canada have dementias that progress more quickly over, say, two or three years. They may need more home care or other supports sooner in order to live well.

Some scientists and researchers are still trying to understand why some dementias progress rapidly, while others progress slowly.

Other scientists and researchers are trying to figure out how more people with dementia can live well, no matter how quickly a disease brings changes to their lives.

Stage of life is part of what makes young onset dementia different

Some people with young onset dementia experience certain stresses more than older people with dementia do.

For example, some people with young onset dementia are parenting small children. So, they may have to figure how to help their kids understand this condition.

Some people with young onset dementia are working full-time when they first notice their symptoms. So, they could have more job issues to navigate than someone who is retired.

The people caring for folks with young onset dementia are more likely to be younger, too. Some of these caregivers are in their early twenties or teens—or younger. And they could need to access different types of supports than older caregivers do. Younger caregivers might need more support on chat or social media, with the goal of connecting with others in similar situations, for instance.

Young onset dementia is something the Alzheimer Society can help with

Community changes everything. That’s why the Alzheimer Society is here to help everyone in Canada impacted by dementia.

We are here to link you to the support you need. To find programs in your area right now, locate your local society at alzheimer.ca/find. Or for more information, contact our National Information and Referrals Line at or 1-855-705-4636 or info@alzheimer.ca.

To read more about young onset dementia at your own pace, check out our articles and resources below, or visit alzheimer.ca/youngonset.