Hallucinations and delusions — when to worry and when it's the medication
This article is for educational purposes only and does not constitute medical, legal, or financial advice. Every family situation is different, and you should consult with appropriate professionals about your specific circumstances.
You're watching your parent's decline and a darker thought is running underneath it. Not just the sadness and the difficult logistics of caregiving. A thought that's more selfish and more primal: is this coming for me? Did they pass it down? Will I spend my seventies the way they're spending theirs?
You're also watching them get the diagnosis. Maybe it's Alzheimer's disease. Maybe it's Lewy body dementia or Parkinson's or frontotemporal dementia. Maybe it's just "probable dementia" because the exact cause is unclear. And the first thing you think, underneath the compassion and the fear for them, is whether you inherited it.
This is an understandable fear. It's a human fear. But it's also often not a rational fear, because the genetics of cognitive decline are much more complicated than "your parent has it so you will too." Some types of dementia do run in families. Most don't, not in the simple way you're imagining. And even if there's a genetic component, genetics isn't destiny. Understanding what that means is important for your own peace of mind.
The Fear Underneath
Watching a parent decline is frightening. Watching them lose themselves is one of the hardest things many people do. And underneath that fear, sometimes, is a second fear: that you're watching your own future. That this is the timeline of your life, just moved forward by thirty or forty years. That you're going to spend your last couple of decades the way they're spending theirs.
This fear is powerful partly because you share a genetic relationship with your parent. You look like them sometimes. You have their mannerisms sometimes. You inherited their body in some ways. Of course you inherited their diseases, the fear goes. That's how inheritance works.
But the inheritance of disease is not the same as the inheritance of eye color. Eye color is controlled by a relatively small number of genes and the inheritance pattern is fairly straightforward. Alzheimer's disease and most other dementias are controlled by hundreds or thousands of genes. They're influenced by environment and by lifestyle and by other diseases and by luck. They're complicated in ways that eye color is not.
The fear is real, and it's worth taking seriously. But it's worth understanding, too. Because once you understand what the genetics actually say, you can let go of some of the catastrophizing and focus on things you can actually control.
What Genetics Actually Says
Some dementias have strong genetic components. Early-onset familial Alzheimer's disease is caused by mutations in specific genes. If your parent has that diagnosis, and they're sure about it, then you do have a increased risk because you inherited a gene variant that predisposes you to the disease. But early-onset familial Alzheimer's is relatively rare. Maybe five percent of all Alzheimer's cases.
The much more common type is late-onset Alzheimer's disease, which develops in people in their sixties, seventies, eighties, and beyond. Late-onset Alzheimer's has some genetic component. Having a parent with Alzheimer's does increase your risk compared to someone with no family history. But it's an increase in statistical risk, not a guarantee. You might inherit the predisposition and get the disease. You might inherit the predisposition and never get the disease. You might not inherit any predisposition and develop dementia anyway.
The gene that's most studied in late-onset Alzheimer's is the apolipoprotein E gene. There are different variants of this gene. Everyone has two copies, inherited one from each parent. If you have certain variants, particularly the E4 variant, your risk for Alzheimer's is higher. But not everyone with the E4 variant gets Alzheimer's. And not everyone with Alzheimer's has the E4 variant. It's a risk factor, not a cause.
Other dementias have different genetic patterns. Lewy body dementia has some genetic component but it's less clear and less studied. Vascular dementia is more about the state of your blood vessels than about specific genes. Frontotemporal dementia sometimes runs in families but often doesn't. Primary age-related tauopathy, a disease that's being recognized more recently, may or may not have genetic components that we understand yet.
Most dementia is not primarily genetic. Most dementia is multifactorial. It's caused by a combination of things. Some of those things are genetic. Some are environmental. Some are lifestyle. Some are just aging. Some are the accumulation of damage over decades. Your parent might have Alzheimer's for reasons that have nothing to do with you.
Risk Factors Versus Destiny
Here's the thing about genetics and disease: having a genetic risk factor is not the same as having a disease. Your parent might have genetic risk factors for dementia and still develop dementia because of something else. They might have genetic risk factors and never develop dementia. You might have the same genetic risk factors and have a completely different outcome.
This is where understanding the difference between genes and environment becomes important. If you and your parent have the same genes but different environments, you might have different outcomes. If your parent had high blood pressure for decades and didn't control it well, and you control your blood pressure, that's an environmental difference that might matter. If your parent had a serious head injury and you didn't, that's an environmental difference. If your parent had untreated depression and you treat your depression, that's different. If your parent didn't exercise and you do, that's different.
There's also the phenomenon called incomplete penetrance. Some people have the genetic risk factors for a disease and never develop the disease. Some people have the same genetic risk factors and definitely develop the disease. Scientists don't fully understand why. But it happens. You might carry the genes and never get sick.
There's also variable expressivity. Even among people who do have a genetic disease, the severity and age of onset can vary. Your parent might develop Alzheimer's at seventy. Their sibling might develop it at eighty-five. You might develop it at ninety, if at all. The genes might be similar but the expression is different.
The honest truth is that predicting whether someone will develop dementia based on their parent having dementia is not very accurate. You can't look at a person and their parent and say with certainty what's going to happen to them. Doctors can say that their risk is higher than someone with no family history. They can give you a statistical probability based on studies. But they can't tell you your personal future.
What You Can Control
This is where the conversation becomes more hopeful. You can't control your genes. You inherited what you inherited. But you can control a lot of other things. You can control the things that lower your risk for dementia.
Cardiovascular health is important. Your heart and your brain are connected. What's good for your heart is good for your brain. Managing blood pressure, managing cholesterol, not smoking, maintaining a healthy weight. These things matter. If your parent had uncontrolled hypertension and you keep your blood pressure in a healthy range, that's a difference that might matter over decades.
Physical activity is important. Exercise seems to be protective against cognitive decline. You don't have to run marathons. Regular walking, swimming, dancing, anything that gets you moving and that you actually enjoy and will stick with. Your parent might have been sedentary and you can choose to be active.
Sleep is important. Getting enough sleep, good quality sleep. Sleep seems to be when the brain clears out some of the debris that accumulates during the day. Sleep deprivation is bad for cognition. You can prioritize sleep in ways your parent might not have.
Cognitive engagement is important. Keeping your brain active. Learning new things. Having engaging hobbies. Reading. Puzzles. Social interaction. Your brain benefits from being challenged in ways that are interesting to you.
Social engagement is important. Isolation is bad for the brain. Social connection is good. Having people you talk to. Having a community. Having purpose. These things matter. If your parent became isolated and you maintain strong relationships, that's a protective factor.
Diet seems to matter. Mediterranean diet and similar diets that emphasize vegetables, fruits, fish, nuts, olive oil seem to be associated with better cognitive outcomes. You can eat better than your parent did. You can pay attention to what goes into your body.
Managing stress and mental health matters. Depression increases dementia risk. Anxiety increases dementia risk. Managing these conditions with therapy or medication if needed is protective. Having coping strategies. Mindfulness or meditation or whatever actually helps you calm your nervous system.
Managing other health conditions matters. Diabetes increases dementia risk. Managing blood sugar matters. Same with heart disease, same with stroke risk. Same with infections, same with head injuries, same with hearing loss and vision loss. All of these things affect cognitive health and all of them are more manageable if you're paying attention.
Not drinking too much alcohol is protective. Some alcohol is associated with lower dementia risk. A lot of alcohol is associated with higher risk. Especially as people age, too much alcohol is bad for the brain.
You can also choose to avoid risks that your parent might have faced. If your parent had repeated head injuries, you can take precautions to prevent that. If your parent had a traumatic brain injury that went untreated, you can make sure to get proper evaluation if you ever have a head injury. If your parent was exposed to something toxic or lived in a particular environment that might have affected their health, you can try to minimize similar exposure.
The point is that even if genetics is part of your story, it's not the whole story. You have agency. You have choices. Every day is an opportunity to do something that's good for your brain health.
Living With the Question
The question will probably never go away completely. You're going to watch your parent and you're going to wonder sometimes. You're going to have a moment of forgetting something and you're going to have a split second of panic. You're going to see something on the news about dementia and you're going to feel a little grip in your chest. These moments are normal.
But you don't have to let the fear take over your life. You don't have to spend decades worrying about a future that might not happen. You don't have to take genetic testing if you don't want to, even though testing is available. You don't have to know whether you carry the apolipoprotein E4 variant or whatever. Knowing might actually not help. It might just increase anxiety about a future that's uncertain anyway.
Some people do want the testing. Some people want to know their risk because knowing helps them be motivated to make changes. Some people want to know because they want to plan. Some people want to know because uncertainty is harder than knowledge. This is a personal choice.
If you do get tested and you find out you have genetic risk factors, remember that this is not a sentence. This is information. You use it to motivate yourself to do the things that are protective. You use it to stay engaged with your healthcare. You use it to make choices that are good for your brain. But you don't use it to assume that dementia is inevitable.
If you get tested and you find out you don't have major genetic risk factors, that's good news. But also remember that genetics isn't the only thing that matters. Environmental and lifestyle factors matter. You still need to do the things that are protective. You still need to stay active and engaged and connected. You still need to manage your health.
Living with the uncertainty is hard. You have to hold two truths at the same time. The first truth is that your risk is higher than someone with no family history. The second truth is that most people don't get dementia, even people with family history. You might be okay. You might not be. You don't know. And you have to figure out how to not let that uncertainty paralyze you.
One way to do that is to focus on the things you can control. Every time you exercise, you're doing something protective. Every time you engage with people you care about, you're doing something protective. Every time you learn something new, you're doing something protective. Every time you manage your health conditions, you're doing something protective. These things matter. You can't control whether you inherited risk. But you can control how you live your life.
Your parent's decline is real and it's sad and you're allowed to grieve what they're losing. But your parent's decline doesn't have to be your destiny. You have choices. You have decades. You have time to do things differently. You have time to do things right. You have time to give your brain the best chance you can give it. That's not a guarantee. But it's not nothing. It's something real that you can actually do.
How To Help Your Elders is an educational resource. We do not provide medical, legal, or financial advice. The information in this article is general in nature and may not apply to your specific situation. If you are concerned about a loved one's cognitive health or safety, consult with their healthcare provider or contact your local Area Agency on Aging for guidance and support.