What do I say when mother insists the clothes in her closet is not hers?

Put the name tag on every single clothes, she might forget her clothes, but remember her name....

My mom is in memory care, one time the caregivers took my mom's glasses and put them in the nurses office for the night. They gave them back to her the next morning. Ever since then, she refuses to wear her glasses saying they are not her glasses, they make her vision blurry. The first time mom told me this, I looked at her glasses and noticed the anti glare coasting was peeling off the lenses. I took them to her eye dr. and had them put in new lenses, plus they checked the prescription of the lenses on the glasses and confirmed they were her glasses. She has had her vision checked once in Feb. of this year and again in October, her vision is fine with her glasses. It is all Alzheimer's related. When she brings it up, I just tell her everything is fine and if she doesn't want to wear the glasses, she doesn't have too. Just go along with it like Jeanne suggested, tell her the clothes are new, write her name on the label of all the clothes and let her be a part of labeling the clothes. Don't expect anything to be permanent solution because as galdimhere said, once it is stuck in their head, they will ask or talk about it over and over again.

Your mom probably is not the only resident, nor the first to believe this. I would try to distract her by telling her whatever she is wearing looks great on her. My mom also sometimes thinks that her things are missing or someone else's. And when these delusions begin they get stuck in her brain and we have to go over and over again that everything is fine. Distraction works so much better.

I can be a bit lighter with my mother. When things go amiss in the house, I just tell her it must be those pesky gremlins again. This probably wouldn't work with anyone who is paranoid or might believe in the existence of gremlins.

ps, dementia can do a lot of weird things, with or without medications! :-)

Take a good look at her meds, overmedication can do a lot of weird things. Get a complete neurological workup including brain CT scan.

Can you sneak some clothes out? Then bring them in the next day. "Oh look! Good news! Here are your missing clothes. They were misplaced in the laundry room. I'm glad we know that the cleaning lady didn't take them. She seems like a nice person."

The challenge is to go along with her delusions (you aren't going to talk her out of them!) but without putting blame on an innocent person.