I don't believe Trump is taking hydroxychloroquine. I don't believe anything he says without checking reliable sources. It's incredibly irresponsible that he's pushing an unknown and likely dangerous drug to a gullible public.
He's probably taking something but who knows what, probably amphetamines, circumstantial evidence for that. I mean even hydroxychloroquine could in certain circumstances cause psychosis, but my guess would be it's amphetamines with the dual diagnosis of a personality disorder that is causing his psychosis.

As for hydroxychloroquine I'll leave that to scientists and medical professionals to study.