I sorta question this. In my un-professional opinion, yeah...he probably is. But for a doctor to say so, he/she would have to examine the patient. And that hasn't been done to the best of my knowledge. It's hard to render a medical opinion without conducting whatever examination is appropriate.

Don't exclude the many years of experience with diagnosing and caring for patients with dementia that underlie these conclusions. There are tell-tale behaviors. And I can tell you from personal experience that once you've spent significant time with dementia patients, you're able to recognize the signs quite easily. And the experience of these professionals dwarfs my experiences. Early on, testing is used to determine whether it's mild cognitive impairment/MCI (which may or may no progress to dementia) or actual dementia. And if dementia, assessments are required to determine the type. From my experiences, Trump has progressed beyond MCI. And combined with the demonic narcissism that drives him, it's a very dangerous dynamic to allow in the White House.

I find Biden's lapses to be very different. His memory has its slips (he could benefit from a few helpful supplements). But on the whole, he grasps what he is dealing with and his behavior makes sense.