When a family member starts showing signs of dementia, it can cause an avalanche of questions and emotions to arise. One of the first questions being, “Is dementia genetic?”
A reasonable question if you’re currently caring for a parent with dementia.
Before we can answer, “Is dementia genetic?” or “How heritable is Alzheimer’s?” we need to define our terms. Alzheimer’s Disease (Alzheimer’s) and dementia are commonly used interchangeably. However, there are significant differences between the two.
First, we’ll explain the difference between Alzheimer’s and dementia, then answer some more pressing questions, such as “Is dementia or Alzheimer’s hereditary?”
What’s the Difference Between Dementia and Alzheimer’s?
When most people think of dementia, they usually associate it with memory loss or assume it’s the same diagnosis as Alzheimer’s. Although similar, they are not the same.
Dementia is an umbrella term for a group of symptoms associated with a decline in memory, reasoning, or other cognitive functions. The ten types of dementia that most commonly appear in elderly adults are:
- Alzheimer’s disease
- Creutzfeldt-Jakob disease
- Lewy body dementia
- Frontotemporal dementia
- Huntington’s disease
- Normal-pressure hydrocephalus
- Posterior cortical atrophy
- Parkinson’s disease
- Vascular dementia
- Mixed dementia
As seen on the list, Alzheimer’s is a degenerative brain disease that includes dementia symptoms. The first symptom of Alzheimer’s is usually trouble remembering new information, known as short-term memory loss.
Alzheimer’s alone accounts for up to 80% of all dementia cases. And if you think Alzheimer’s is a normal part of aging, it’s not. Learn more about Alzheimer’s risk factors at alz.org.
Now that we’ve briefly differentiated dementia and Alzheimer’s, let’s discuss whether dementia is hereditary.
Is Dementia Genetic or Environmental?
“Is dementia genetic?” – a question researchers have studied for years.
According to the Alzheimer’s Association, “When diseases like Alzheimer’s and other dementias tend to run in families, either genetics (hereditary factors), environmental factors — or both — may play a role.” So, officially, yes and yes.
Let’s look into both genetic and environmental risk factors of dementia to learn more about each.
Genetic Risk of Dementia
“Is dementia hereditary?”
Remember, dementia is a collection of symptoms. A genetically complex disease, such as Alzheimer’s, often causes dementia. In these cases, genes may increase the risk of developing dementia, but they don’t cause it directly.
In rare cases, dementia is caused directly by a single-gene disease, which can be inherited from parent to child. For example, a single-gene change most likely causes frontotemporal dementia (FTD), which affects the brain’s frontal and temporal lobes.
Environmental Risk of Dementia
“Is dementia environmental?”
According to the study, Environmental risk factors for dementia: a systematic review (2016), environmental factors can increase the risk of dementia.
Researchers found moderate evidence noting that air pollution exposures increase dementia risk. However, they found strong evidence confirming vitamin D deficiency increases a person’s risk of dementia.
So, the answer to “Is dementia genetic or environmental?” seems to be a muddy, “Yes.”
How Heritable is Alzheimer’s?
You don’t need a parent or relative with Alzheimer’s in order to develop the disease.
However, researchers have concluded that people who have at least one first-degree relative with Alzheimer’s are more at risk of developing the disease than those who do not. In addition, if someone has more than one first-degree relative with Alzheimer’s, they’re at an even higher risk.
The heritability of Alzheimer’s can best be explained by genetics. Two categories of genes influence whether a person develops a disease: risk and deterministic.
Risk genes do not necessarily guarantee that you will inherit a disease, but they do increase your likelihood.
APOE-e4 is the first risk gene researchers identified and remains the gene with the most substantial impact on a person’s risk for inheriting Alzheimer’s.
Deterministic genes directly cause disease. Therefore, anyone who inherits a deterministic gene will inevitably develop the disease associated with it.
These genes account for 1% or less of Alzheimer’s cases and cause familial early-onset forms of dementia, which develop between your 40s and 50s. However, the vast majority of people are diagnosed with late-onset Alzheimer’s disease, occurring at age 65 or later.
Unfortunately, we still don’t know the exact cause of dementia, and healthcare professionals are still working to find treatments and cures. However, we know more about it today than we did yesterday.
Circling back to our original question: Is dementia or Alzheimer’s hereditary?
Data shows us that both dementia and Alzheimer’s can be hereditary, but there are variables, such as environmental factors, to consider.
The question becomes: If your parents have dementia, will you care for them, or will someone else?
Geriatric Care Management for Older Adults With Dementia
Caring for an aging loved one with any form of dementia can be equally emotional and challenging. Most family caregivers don’t know how to handle a parent with dementia, let alone one who refuses help.
If you’ve reached a point where you’re burnt out, lacking resources, and searching for help, connect with Stowell Associates.
We’ve been providing premium elder care solutions in Wisconsin for over four decades. We have a passion for equipping and supporting families like yours. Our trained geriatric care managers are here to walk alongside you as you make informed decisions regarding your ailing parent’s specialty care needs.
Are you considering in-home care for your elderly family member? Our partnership with TheKey gives you access to in-home caregivers, enabling your senior parent with dementia to comfortably age in place.
Contact us today to speak with a dementia care manager who can develop a Whole-person Care Plan for your aging loved one.