I am not a medical professional, and I will not pretend to know what is truly happening here. It’s become a common conversation topic in Washington to muse on whether the president is suffering from some form of cognitive decline or psychological malady. I don’t think those hypotheses are necessary or meaningful. Whatever the cause, it is plainly obvious from Trump’s words that this is not a man fit to be president, that he is not well or capable in some fundamental way. That is an uncomfortable thing to say, and so many prefer not to say it, but Trump does not occupy a job where such deficiencies can be safely ignored.
Source: Donald Trump’s New York Times interview is scary to read – Vox