My mother has begun saying she's not in her house and asking us how we made everything look like her house but it’s not her house. How do I respond?

Well this is happening to my Mom and has been for a few months. It is at its weirdest when to much is going on. This weekend my sister and boyfriend came to visit her. Sister and I were doing dishes and she was just standing there and said " This is crazy how much this looks like my kitchen but this isn't my house." These "house" comments come during Sundowning time usually. It's started happening almost every evening now but can happen in the day when the regular routine is changed. You cannot change the subject. You walk off and she comes after you. Fibs do NOT work. If anyone finds an answer, let me know!!!! Once in a blue moon I can say that is your clock Mom above the mantel of the fireplace. For some reason this calms her. I'm going to look up capgrass. Because this really sounds like it here!

Catalina7, there are times when someone who has memory issues wants to be in their childhood home. Your Mom maybe thinking that but wondering why the inside looks like her previous house.

As other above has suggested, distraction or using "therapeutic fibs" can be helpful.

"This is not my house!"

"Yes, but aren't we lucky to have something so much like your house while the water main is being fixed? The kitchen is even like yours. Shall I make us some tea?"

Thank you so much for your help. It’s very difficult to know what to say to her. But I think we’ve been trying to get her to understand that it is her home and that just causes her extreme anger. So I guess I’m going to try to just identify with her feelings. Great idea to need to leave the discussion. I’ve tried distraction with little success. I appreciate the info you all have provided. Thank you!

Look up Capgras syndrome, which is the name of this delusion of thinking people or locations are imposters. The Healthline website has a short, readable article. I don't think you are going to find a cure or even a sure-fire way to handle it, but at least you'll know this is not rare. (I've read that 17% of people with Lewy Body Dementia experience this. I don't know what the rate is for ALZ.)

Sometimes it is better to go along with what a person is saying just to calm them down but as Sue said this isn't one of those situations. You can't really agree with her that it is not her house she has always lived in yet trying to get her to understand that it is indeed her house will only cause her more anxiety. Sue's right in her suggestion to distract your mother. It's exhausting but I think it's all you can do at this point.

Have some snacks your mom enjoys and when she begins to worry about where her house is offer her a little snack. Is she on anti-anxiety medication? That may help. And do as Sue suggests, when your mom begins to talk about the house remove yourself from the discussion. 

Hi Catalina,
This stage is so difficult.
Arguing doesn't work, the brain is broken and they don't have the capability to figure it out. You can't really agree with her either, due to the nature of her accusations.
The only thing that partially worked for me was distraction. You could try to change the subject but usually they catch on to that.
"Remember" that you have something on the stove, you need to use the restroom, you have to make a phone call, you need a drink of water...anything to break up the discussion. Some days my mother just won't let it go no matter what I do. Unfortunately, we need to remove ourselves from the situation or we will become very frustrated.
I wish I had a better answer. Like I said, this is one of the awful parts of Alzheimer's.