I don't think that your assertion makes sense in its own context. What you are saying is that "SPD" exists, and "ADHD" is just a modern rebranding of it. But why do you decide that "SPD" is the spot at which scientists got it right? Were they free from the corruption that you imply?
I agree with a general skepticism of the pharmaceutical industry. I disagree that all of neurology and pharmacology have been completely subsumed by that industry. It is not entirely free of it either, but there is more nuance here than you seem to be allowing.
I suppose that's one way to do it. I don't think that it makes any sense, but you're entitled to it. I do believe, however, that you are disregarding tens of thousands of principled researchers who have spent their life on this, and substituting outdated knowledge for it.
I agree with a general skepticism of the pharmaceutical industry. I disagree that all of neurology and pharmacology have been completely subsumed by that industry. It is not entirely free of it either, but there is more nuance here than you seem to be allowing.