Look, I can tell you've got a chip on your shoulder about this and are probably a conspiracy theorist, so I'm not going to argue anymore.
I will say if you search for "chemical imbalance debunked" as discussed, the first result for me is a paper that also says dyslexia cannot be proved to be a disorder. Which just from vibes feels really conspiratorial, even without making comments on the veracity of the academic paper.