Read Ashlee Vance’s bio of Musk. Even if Elon is not bipolar, it’s obvious he has had some mental issues since childhood.
I am getting some "disagrees" to this post, but I think people actually do need to read Ashlee Vance's book, Elon Musk: Tesla SpaceX, and the Quest for a Fantastic Future. Here are 3 quotes from the book, all from Musk's family members:
(1) Elon's mother, Mae Musk, stated that when Elon was a child, he would "drift off into a trance". "Sometimes, he just didn't hear you", she said. "I do think Elon was always a little different but in a nerdy way. It didn't endear him to his peers" - p.31-32.
(2) Both Elon and his brother Kimbal describe their childhood experience of living with their father Errol as psychological torture. Kimbal stated: "He [Errol] definitely has some serious chemical stuff, which I am sure Elon and I have inherited". Neither Elon, nor Kimbal, nor their mother Mae would say what mind games Errol did to his children, but it was bad enough that Mae gets angry at the mention of Errol. Elon won't let his children meet their grandfather either. - p.36-37
(3) In late 2008, when both SpaceX and Tesla were on the verge of collapse, Elon's 2nd wife, Talulah Riley, described how depressed Elon became. She states: "He [Elon] looked like death itself... he seemed like a man on the brink". She describes his nightmare episodes: "He was in physical pain. He would climb on me and start screaming while still asleep". - p.206.
I don't think that anyone can credibly deny that Elon Musk has had some mental health issues for a long time. Obviously, Elon has been wildly successful despite these issues, so I don't think they are necessarily a problem from an investment standpoint. However, I do think it is something that people should be aware of, and acknowledge. This is not judgment of Elon. It is the truth.
Having known about these things in Elon's past since 2015 has not changed my faith in Tesla or investment in the company.
Edit: I believe it is important for people to know about Elon's mental health, because it puts some of his more recent behavior on Twitter into context. This is who he is, like it or not.