Haven't drugs been used as an explanation for his mammoth missteps with Twitter? Because the way this guy is piloting the ship, he's going to crash it into Prince William Sound at any moment. They'll be scrubbing stupid posts off the seabirds for months.
But some drugs can affect your intelligence, and if he was intelligent enough to at least lay low and take credit for others' work before, it appears he no longer has at least that baseline.
Constant praise by sycophants and people wanting to believe in a better future at the hand of high tech billionaires also does the trick. It works like a pump for inflatable egos.