Young Onset Dementia

Our online Young Onset Dementia forum is on the first Tuesday of the month, with the sessions starting at 5:30pm and ending around 7pm.

If you’d like to know more about this group, or would like to join us please phone 01332 208845 or email derbyshire@alzheimers.org.uk

Young Onset Dementia

This is the term used for people living with a dementia diagnosis, under the age of 65. This is not for a biological reason but is because 65 was the usual age of retirement for many people. People sometimes use the terms ‘early-onset dementia’ or ‘working-age dementia’.

Dementia is caused by a wide range of different diseases. This is similar for younger and older people (‘late-onset dementia’), but there are important differences in how dementia affects younger people. These include the following:

A wider range of diseases cause young-onset dementia.
A younger person is much more likely to have a rarer form of dementia.
Younger people with dementia are less likely to have memory loss as one of their first symptoms.
Young-onset dementia is more likely to cause problems with movement, walking, co-ordination or balance.
Young-onset dementia is more likely to be inherited (passed on through genes) – this affects up to 10% of younger people with dementia.
Many younger people with dementia don’t have any other serious or long-term health conditions.

Someone who is diagnosed under the age of 65 needs to adjust to living with a long-term condition as a younger person. They might be concerned about the effects this will have on their family, relationships, finances and daily life. They may also be worried that any children or siblings will have a higher risk of developing dementia

Like all people with dementia, younger people may experience a wide range of symptoms, especially in the early stages of dementia. However, they are likely to need different support to older people.

What are the causes of young-onset dementia?

The causes of young-onset, or early-onset dementia are similar to the diseases that usually cause dementia in older people. However, some causes, such as frontotemporal dementia (FTD), are more common in younger people. Dementia in younger people often has different symptoms, even when it’s caused by the same diseases as in older people.

Atypical Alzheimer’s disease

Younger people are much more likely to have an ‘atypical’ (unusual) form of Alzheimer’s disease. The symptoms depend on the specific form a person has:

In posterior cortical atrophy (PCA) the first symptoms are usually problems with understanding visual information, such as struggling to read or judge distances.
In logopenic aphasia the first symptoms are usually difficulties with language, such as problems finding the right word, or taking long pauses while they speak.
In behavioural/dysexecutive Alzheimer’s disease the first symptoms are usually difficulties with planning and decision making and behaving in socially inappropriate ways.

Up to 1 in 3 younger people with Alzheimer’s disease have one of these forms, but only 1 in 20 older people with Alzheimer’s disease have an atypical form.

Familial Alzheimer's disease

Familial Alzheimer’s disease is a very rare form of Alzheimer’s disease. It is caused by genetic mutations (changes in genes) that run in families. Three genes have been found to have these rare mutations – PSEN1 (presenilin 1), PSEN2 (presenilin 2) and APP (amyloid precursor protein).

There is a 50% risk of a parent passing on the familial Alzheimer’s disease mutation to their children. People with the condition usually have a strong family history of the disease and will know a range of family members who were affected at a similar age, along with one of their parents.

Symptoms of familial Alzheimer’s disease usually start in someone’s 30s, 40s or 50s. The earlier the symptoms start, the more likely it is that the disease is genetic. Familial Alzheimer’s disease is very rare and probably accounts for fewer than 1 in 100 people with Alzheimer’s disease. For more information see Types of genetic testing.

Learning disabilities and dementia

People with Down’s syndrome and other learning disabilities are more likely to develop dementia when they are younger. Dementia in people with Down’s syndrome is usually caused by Alzheimer’s disease, but not always.

The reasons why people with Down’s syndrome are at increased risk of Alzheimer’s disease are not well understood. It is thought to be due to chromosome 21, which most people with Down’s syndrome have an extra copy of. This leads to an overdevelopment of a protein (amyloid precursor protein) which forms plaques on the brain. These plaques are a feature of Alzheimer’s disease. By the age of about 40, almost all people with Down’s syndrome have changes in the frontal lobe of their brain. However, not everyone will develop the symptoms of dementia.

Vascular dementia

Vascular dementia is caused by problems in the blood supply to the brain. It is closely linked to diabetes and to cardiovascular diseases such as stroke and heart disease.

Symptoms of vascular dementia vary from person to person. Early memory loss is less common. However, other symptoms are more common in vascular dementia, including slower speed of thought and problems with:

planning
organising
making decisions
solving problems
following a series of steps
concentrating

Physical symptoms (such as limb weakness) are common in vascular dementia when a person develops it after a stroke.

CADASIL

CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is a rare genetic form of vascular dementia. It is a disease of the blood vessels in the brain. Symptoms include migraines and repeated strokes, loss of mental abilities, seizures, apathy and depression. They usually start when a person is in their mid-30s.

CADASIL is caused by a genetic mutation in the NOTCH3 gene. It is usually inherited from a parent who has a 50% chance of passing on the mutated copy of the gene.

For more information see rarer types of dementia.

Frontotemporal dementia

Frontotemporal dementia is caused by damage to the lobes at the front and/or sides of the brain. It is much more common in younger people with dementia than in older people. FTD is most often diagnosed in people between the ages of 45 and 65. This is different to Alzheimer’s disease, vascular dementia and dementia with Lewy bodies, which all become more likely as people get older. There are three different types of FTD which cause different changes as the first symptoms.

Is FTD inherited? – About 20–40% of people with FTD have a family history of dementia. About 10% of people with FTD have a strong family history, with several close relatives from different generations affected.

The three main mutations causing FTD are in the progranulin (GRN), microtubule-associated protein tau (MAPT) and chromosome 9 open reading frame 72 (C9ORF72) genes.

The children or siblings of someone with a genetic mutation known to cause FTD have a 50% chance of carrying the same mutation. Families with a known mutation should be offered genetic counselling.

Dementia with Lewy bodies (DLB)

Dementia with Lewy bodies is caused by the build-up of tiny protein deposits (Lewy bodies) in the brain. DLB is less common in younger people with dementia than in older people. Lewy bodies also cause Parkinson’s disease and about one-third of people with Parkinson’s eventually develop dementia.

Symptoms of dementia with Lewy bodies can include hallucinations and varying levels of alertness. People can also develop the features of Parkinson’s disease (such as slower movement, stiffness and trembling limbs).

What are the rarer types of dementia?

Most people who are living with dementia have Alzheimer’s disease or vascular dementia. However, many other diseases and conditions can also cause dementia. These pages explain some of these rarer types.

In the UK, about 1 in 20 people living with dementia have a rarer type. Alzheimer’s Society provides support and information for anyone affected by dementia:

Atypical Alzheimer’s disease
Frontal variant Alzheimer’s disease (fvAD)
Posterior cortical atrophy (PCA)
CADASIL
Corticobasal syndrome (CBS)
Creutzfeldt–Jakob disease (CJD)
HIV-associated neurocognitive disorder (HAND)
Huntington’s disease
Normal pressure hydrocephalus (NPH)
Progressive supranuclear palsy (PSP)

Dementia is caused when the brain is damaged by diseases, such as Alzheimer’s disease, or a series of strokes. Rarer types of dementia can involve these same changes, but they may start in a different part of the brain to more common types. For this reason, a person with a rarer type of dementia might have different symptoms, particularly during the early stages of the condition.

Rarer types of dementia may also be caused by something different, such as an infection that affects the brain. Others, such as CADASIL and Huntingdon’s disease, are caused by a person having a faulty gene. It is not fully understood why a person might develop a rarer type of dementia rather than a common type.

Helpful Information

For more information on any of these topics please follow the links below;