Reading his current Twitter feed, this reminds me of something a friend of mine went through several years ago. We weren't in very good contact at the time and he told me about it later, but the way his psychiatrist described it to him it was a mental break that resulted in him acting like some sort of billionaire business tycoon, only without any actual money. E.g. making ridiculously bold claims, offering people massive job opportunities when there is actually no money to pay for them, etc. During this time he sent me a Facebook message telling me to get on the next plane to London because he was assembling a team to create a new business and offered me 10 times my salary at that time. Obviously I declined and asked if he was okay, at which point he simply ignored me and continued on that path. Eventually he got help.

Anyway, might not be the same thing, and I don't know what the "official" name for it is, but this stream of tweets definitely sounds exactly like what my friend was saying at the time.