Is Dementia Hereditary? What Family History Means for Your Risk

Most dementia is not directly inherited, but family history and certain genes can raise risk; here's what's known about Alzheimer's and other types, what APOE4 means, and what you can do.

By Jim Pavlish, Editor · Last updated: October 25, 2026 · Editorial policy

If a parent or grandparent had dementia, it's natural to wonder, "Will I get it too?" The short answer: for most people, dementia is not passed down directly from parent to child. Family history can raise risk somewhat, but it is only one of many factors, and many of the others are things you can influence.

This page is general information. If you're worried about your family history, a doctor or genetic counselor can talk through your own situation.

Two kinds of genetic influence

Scientists separate genes into two broad groups:

Risk genes make a disease more likely but don't guarantee it. Many people with a risk gene never develop dementia, and many people without one do.

Deterministic (causative) genes directly cause a disease. Someone who inherits one of these is almost certain to develop the condition, often at a younger age. These are rare.

Alzheimer's disease

Late-onset Alzheimer's (symptoms after about age 65) is by far the most common type. It is not caused by a single gene. It comes from a mix of age, many genes with small effects, health conditions and lifestyle.

The best-known risk gene is APOE. Everyone has two copies, and the version called APOE4 raises risk. According to the Alzheimer's Association, inheriting one copy of APOE4 raises risk compared with the most common version, and inheriting two copies raises it more. Still, not everyone with APOE4 develops Alzheimer's, and many people with Alzheimer's have no APOE4 at all. Read more in Genetic Testing and APOE4.

Having a parent, brother or sister with Alzheimer's also makes a person somewhat more likely to develop it. Families share genes, but they also share habits and environments, which is part of the picture.

Early-onset familial Alzheimer's is different. It is caused by changes in one of three genes (APP, PSEN1 or PSEN2) and usually starts in a person's 30s, 40s or 50s. A parent with one of these gene changes has a 50% chance of passing it to each child. This form is rare, accounting for less than 1% of all Alzheimer's cases. Most people with young-onset dementia do not have one of these gene changes (see Young-Onset Dementia).

People with Down syndrome have an extra copy of chromosome 21, which carries the APP gene, and they have a much higher chance of developing Alzheimer's (see Down Syndrome and Alzheimer's). Down syndrome itself is usually not inherited.

Other types of dementia

• Frontotemporal dementia (FTD) has a stronger genetic link than most types. A notable share of people with FTD have a family history, and in some families it is caused by a single gene change passed from parent to child (see Frontotemporal Dementia).
• Huntington's disease is always inherited. Each child of an affected parent has a 50% chance of inheriting the gene (see Huntington's Disease).
• Vascular dementia is usually not directly inherited, though conditions that raise its risk, like high blood pressure and diabetes, can run in families. A rare inherited form called CADASIL exists (see Vascular Dementia).
• Lewy body dementia is not usually inherited, though researchers are studying genes that may raise risk (see Lewy Body Dementia).
• Creutzfeldt-Jakob disease is usually not inherited, though a small share of cases are familial (see Creutzfeldt-Jakob Disease).

Signs a family pattern may be genetic

Talk with a doctor about a genetics referral if several close relatives across generations developed dementia, if relatives developed it at an unusually young age (for example, before 60), or if a specific gene change has already been found in your family.

Should you get a genetic test?

For most people, there is no strong medical reason to be tested for APOE, and a result can't tell you whether or when you'll get dementia. Testing for the rare deterministic genes is a big decision. Experts recommend doing it with a genetic counselor who can explain what results mean for you and your relatives, and discuss practical issues such as insurance. See Genetic Testing and APOE4 for more.

Some research studies enroll people with a family history; see Joining a Clinical Trial and Prevention Trials.

What you can do, whatever your genes

Your genes are not your destiny. The 2024 Lancet Commission estimated that nearly half of dementia cases worldwide might be linked to risk factors that can be changed, including high blood pressure, hearing loss, physical inactivity, smoking, diabetes, high LDL cholesterol, social isolation and others. Some studies suggest healthy habits are linked to lower risk even in people with higher genetic risk. See Reducing Dementia Risk: The 14 Risk Factors for the full list and practical steps.

The takeaway

A family history of dementia is a reason to pay attention to your health, not a reason to panic. Most dementia is not directly inherited, and much of your risk depends on things you can work on today.

Sources

1. National Institute on Aging: Alzheimer's Disease Genetics Fact Sheet
2. Alzheimer's Association: Genetics
3. MedlinePlus Genetics: Alzheimer disease
4. Alzheimer's Society (UK): Genetics of dementia
5. NHS: Causes of dementia

Not medical advice. This article is general information, not a diagnosis or treatment plan for any individual. Talk with a doctor about your situation.

Related articles

• Genetic Testing and APOE4
• Alzheimer's Disease
• Young-Onset Dementia
• Frontotemporal Dementia
• Huntington's Disease