How do you get them to wear depends?

Have you tried different brands? My mom wore pull ups and she preferred certain brands over others. Maybe they aren’t fitting well and aren’t comfortable.

You just have to keep at it. It took years for me to get grandma to wear them. So far, 3 years and counting with mom. She's good for about half the time now.

That's tough. Your profile says that your mother has dementia. It sounds like she may not be able to process that she needs to wear the depends. I might try to discuss it with her and her doctor, so the doctor can tell her that she needs to do it. Sometimes, the doctor's words mean more, but, if she has progressed past the point of remembering what the doctor says, you may just need to remove all her regular underwear and then supervise her wearing and changing of the depends. I'd also prepare for in the future for double incontinence as well. My LO went to depends quite easily, but, I think that a polite request is not sufficient with some people who have dementia. You may have to ensure that it happens.