Someone is stealing from them. Someone is following them, or trying to hurt them. Children were in the house last night.
None of it happened. Yet your loved one with dementia remembers it down to every detail.
And what actually did happen? What you said, what you did, what’s coming up tomorrow? They can’t remember it at all.
So how does someone with dementia remember a delusion perfectly, yet not remember what’s really going on? It comes down to two different memory systems in the brain. And dementia doesn’t affect them equally.
Why Dementia Delusions Feel Real: Two Memory Systems in the Brain
One system holds factual memory. The other holds emotional memory.
Factual memory: the hippocampus and prefrontal cortex
Factual memory is the part of the brain that remembers what actually happened. Who did what. Where you put your things. Who visited. What you ate recently. Basically, all the reality-based facts.
This system relies heavily on the hippocampus. That word might sound familiar, because people with Alzheimer’s disease often have a lot of atrophy, or deterioration, in the hippocampus. That’s why people with Alzheimer’s have some of the worst memory problems.
When the hippocampus struggles, recent details, recent conversations and the real order of events become spotty, distorted and fragile. Sometimes they’re completely absent. Your loved one doesn’t even remember that those things happened.
The prefrontal cortex does the reality checking. When it’s affected, your loved one may not be able to use logic and reasoning, have good judgment, or stop and say, “Wait, that doesn’t make sense.”
Emotional memory: the amygdala and the default mode network
Emotional memory lives in areas of the brain called the amygdala and the default mode network. This is where the brain stores fear, anxiety, safety, suspicion, trauma and old habits. It’s where comfort lies, where fear lies, and where imagined stories come from.
This part of the brain stays active much longer through the dementia process. And it’s the part that fuels delusions.
The amygdala is the brain’s alarm center. It stores and scans for fear. It’s the fight-or-flight area of the brain. When anything feels confusing, disorienting or unsafe, the amygdala alerts the brain: Somebody’s stealing from me. Somebody’s trying to harm me. Somebody’s watching me.
That’s why so many people with dementia have that fear-based anxiety. Because those thoughts feel so emotionally true, they come with very strong emotions. And you, the Careblazer, are left trying to figure out how to calm and comfort someone whose reality has turned scary.
The default mode network is trying to make sense of things without having the facts. So it pulls from what it does have: childhood, imagination, dreams and old memories. That might be why your loved one is suddenly fixated on the past.
I’ve talked to so many Careblazers whose loved one kept saying something over and over. They weren’t sure what it meant. Then eventually they discovered it was something from their loved one’s childhood, or a memory from long ago.
What a Dementia Delusion Really Is
A delusion is a very strong, fixed belief that a person holds despite all the evidence to the contrary. It doesn’t matter how much proof you have that what they believe isn’t true. They believe it, very strongly.
That explains why your loved one can’t recall the details of the truth, yet seems to recall every detail of the delusion.
If you’ve been searching for dementia paranoia, or why your loved one keeps accusing someone of stealing, this is often what you’re seeing.
Sometimes people think a person with dementia who has a delusion is just losing touch with reality, or doing it on purpose, or making things up. But delusions are actually the brain’s attempt to fill in the gaps in memory. To make sense out of confusion, reduce fear and increase comfort.
If the brain can’t remember the truth, it fills in the gaps with what it thinks might be the truth.
Delusion or Confabulation: What’s the Difference?
Many people with alcohol-related dementia experience this too, and there’s another term for it: confabulation. The brain is trying to fill in gaps to make sense of things, so they’ll say things that aren’t true or didn’t happen.
The big difference is that a delusion is a fixed belief. Your loved one gets stuck on it and repeats it over and over. It’s a general pattern, the kind that has you thinking, “Oh no, not this again.”
Confabulation can be a one-off. So-and-so came to visit. I ate a pot pie for lunch. All kinds of things, not one fixed belief.
I go further into confabulation in why people with dementia seem to lie.
Whether it’s a delusion or confabulation, it’s not intentional. They’re not doing it on purpose. They have no control over it. Their brain is being forced to rely on emotional memory, because the factual memory centers have deteriorated so much.
Why Delusions Stick When Real Memories Don’t
Delusions stick and factual memories don’t because emotional memories are, well, emotional. We remember those emotions. The brain remembers emotion far longer than it remembers facts.
That’s because emotion activates a chemical called norepinephrine. And norepinephrine stamps memories deeper than ordinary everyday events that aren’t emotionally charged. We will always remember emotionally charged events much more strongly.
So maybe they don’t remember that you visited. But they remember that you, or somebody else in their mind, stole from them. That somebody was in their room. That the neighbor tried to break in again.
What to Do When a Delusion Feels Real to Your Loved One
This is out of their control. They’re not doing it on purpose. Their brain is trying to protect them and keep them safe. And quite honestly, just knowing that can bring a little compassion and understanding to the situation.
But what can you do beyond that? Three things.
1. Respond to the emotion, not the story
I’ve talked about this before. Respond to the emotion your loved one is showing you, not their words and not their story.
You’re never going to win with their story. You’re never going to talk them out of a delusion. They’re going to believe what they believe. What you can do is comfort them, reassure them, and hear what they’re saying.
So instead of saying:
- “Well, that didn’t happen.”
- “You’re wrong.”
- “No one took anything. Nobody came into the house.”
Shift it to:
- “That sounds scary.”
- “I’m here with you.”
- “You’re safe.”
- “It’s going to be okay.”
Whatever their emotion is, respond to that. Let the story and the exact words go.
2. Avoid the urge to argue
Avoid any reflex or urge to argue with them.
3. Be the dementia detective
Look for any patterns or triggers that might be making the delusions, or even hallucinations, worse. For instance:
- the time of day
- what they were doing around the time the symptom appeared
- how they slept
- what they ate
- any changes in medication
- certain visitors who come around
- environmental cues, like the lighting or what’s on TV
We always want to keep building our skills as the dementia detective.
So Why Do People With Dementia Remember Delusions but Not Reality?
The reason your loved one remembers a delusion clearly but can’t remember what you told them 10 minutes ago is that their brain is shifting from factual memory to emotional memory.
It’s hard to stay calm when the person you love is sure you stole from them. Inside the Care Collective, we talk about exactly these moments: what’s happening in the brain, and how to comfort your loved one in real life when nothing you say convinces them. You can learn more here.
