[Retra]

I'm not willing to say that ADHD is a fabrication or anything. I'm just somewhat skeptical that it could be diagnosed without long term observations. (In lieu of self-reported descriptions of symptoms.)

Your crude test really is crude, though: by itself, it invents a condition to match the result of the application of a drug. You could do the same with any drug: "You have VPFP if you use [insert drug here] and feel it improves your life, and you don't otherwise. Let's start writing prescriptions to treat VPFP."