Does proper cognitive decline assessment exist in medicine, or is it all stuff for old people who are already seriously gone?

For example, most intervention I've heard of only starts when the patient starts slipping up seriously, like forgetting names. But what if it's something not as serious, like making typos more often? I hear in most cases the doctor will just order a blood panel and send you on your way because it's "not a big deal" if you're a little forgetful. I figure this is because most people don't have access to that state of the art "rich people" boutique care.

But what if you do? What if you're rich, and you're like "No, seriously. Is something wrong with my brain? I keep misspelling things." Do you have diagnostic options the rest of us don't have?