> I think OP is just saying that 'ADHD' is not that valid of a diagnosis

I understand this in the comment’s expression too, and it’s emphatically wrong.

> benefit from the use of 'medication' (i.e. amphetamines and derivatives, from Adderall to Desoxyn(methamphetamine) to Ritalin), is mostly unrelated to any 'diagnosis'.

You’re incorrect.

> Personally I think all drugs should be legal and people should be able to take whatever they think helps them

I agree, but this has nothing to do with the validity of actual diagnoses of actually treatable conditions.