My mother has had a steady mental decline for the last couple of years. She doesn't remember stuff we've just said, doesn't follow explanations, doesn't remember the day of the week or the month, is convinced people are stealing from her... all the flags.
After a recent financial crisis that my brother and I had to help straighten out with the bank, she seemed ready to talk to the doctor about it. She wanted to know what good seeing the doctor would do, though. I said that they could look for other causes for her problem, like her diabetes, her medications, etc. But what hope can I offer her if it IS a form of dementia? The medications don't cure or slow it down, correct? What can they offer her?
There are many medicarions for dementia. There is unfortunately no cure, but medications can help. Above all, assure her you’ll be there for her to help her.
If your mother's difficulties are caused by something other than dementia, then as you say it may be possible to offer her all kinds of options. And if it is dementia, not knowing won't stop it happening.
What's more, if it is, then there will be all kinds of possibilities for supporting her quality of life for longer. Forewarned is forearmed. If you Google "living well with dementia" you'll find lots of ideas for adaptations and strategies that both support people at home and also enable a well-informed choice when the time comes, if it ever does, to find the right kind of facility.
It's a scary thing to face, but it's an even scarier thing to fear in the dark. So I should tackle the conversation from an "it REALLY won't help not to know" angle.
Mom needs an eval. People on forum have suggested telling LOs Medicare needs them to get a checkup.
That's just one example of why you want to get a complete diagnosis. There are other reasons also, but that was our experience.
I will note that this was not caught by her PCP, nor did he suggest the complete workup. We did that due to my reading here that it was a good idea. We used the Memory and Brain Wellness center at our large local university.
I'm starting to think that I'll have to wait till she's bad enough for APS to be called, because living with her (when she was competent) was very traumatic for me, and much more so for my spouse. I'm not going through that again.