There is increasing talk about the possibility of the so-called President suffering from some form of dementia. A lot of people criticize those who raise this question, especially since the conclusions are not based on in-person examinations. But there is no blood test for dementia, nor is there an X-Ray or MRI that would reveal the condition. It would all be based on observation - something we all can do from afar. The biggest and most justifiable objection to suggesting dementia is the emotional response many have to this president, and that this emotion may cloud someone's judgment.
But there ARE some markers for dementia. Memory, irrationality, impaired judgment, etc. These are things that make dementia the problem it is.
The article below is from February this year and refers to many things he has done and said in the past. It's scary.