On the Mini-Mental State Exam (MMSE), a score of 23 or lower (out of 30) supports a Dx of dementia. You might be surprised how many people over 60 fail to get a passing score. I seem to recall that Trump got a perfect score of 30 a few years ago.
Wasn’t that the Montreal Cognitive Assessment? I did a baseline of that in my mid-60s for comparison in later years. It seemed easy, but it sure was tough. They’d show you something early in the test and, unexpectedly, you were asked to remember it at the end of the test. I did ok, but didn’t ace it. It would be interesting to take it again as I’m nearing the 72nd birthday.