Are there any scans, blood tests, etc for diagnosing memory loss or personality changes? Not necessarily ALZ/Dementia.

Make sure the physician knows the nature of the changes you have noticed. Keeping a journal can be very helpful.

An MRI can show some changes in the brain. That can be suggestive, but not necessarily definitive.

There are various kinds of written/spoken/action tests that can be administered. These can take hours and would typically be scheduled outside of a routine exam.

I know that urgent research is being conducted to discover biomarkers for various kinds of dementia. As of right now, I do not believe there are any blood or urine tests that help in this area.

Hmmm. I don't know if this is relevant or not, but I just went through a situation where mood/memory issues were caused by environmental factors - my dad's house had a bad mold problem, but it was in between walls where it wasn't at all visible. I learned mycotoxins from mold can cause all kinds of symptoms. My symptoms were similar enough to diabetes that I was tested for it multiple times as I sought out diagnosis/treatment. I've since learned that American doctors aren't taught to look for mold illness at all, but its enough of an issue that Canadian medical schools have recently put mold illness training into the medical curriculum there. If the person suffering the symptoms lives/works in a place where water damage has possibly occurred, you might look into this a little more. A search on YouTube under "mold illness" will net you quite a few informational videos that go into more detail on symptoms.

Make sure the doctor tests for "reversible dementia" causes like low thyroid, Vitamin B12, infections. I don't believe there is any physical test for dementia at this time. If he gets a full Neurological Psychiatric evaluation, that can tell them a lot about how he is functioning.