[Getready]

Kid was being treated since age 15? Poor Rob. Saddled with a kid like that. A chronic schizophrenic since adolescence? No excuse for Robs incessant, insane, lying bashing of Trump, but perhaps Robs frustration for his inability to solve kids problems pushed Rob to be a complete a**hole. No excuse for Rob...but that would be sad, if so.
IMHO

[Right_Wing_Madman]

He checked in at 4am, just hours after he and his parents had an intense argument at Conan O'Brien's holiday party

Almost all these arguments have to do with money. The Reiners probably told him at the party that support was cut off, because they knew the money was funding his drug habit. Kid freaked out because he didn't know how he was going to get his next hit.