If you want the psychiatric paper that says you have ADD, you'll take an attention test(like T.O.V.A.), just fail it (but believably) and you'll be fine. Vaguely reference getting ADD medication as a child, but you don't remember the name, you believe it was adderall or something or other.
If you want you can try and talk to a general practitioner, bemoan the fact that you're suffering from ADHD symptoms, and you have vague memories of medication as a child. That could also work, though some doctors will require you to see a psychiatrist anyway before they give you the pills.>>11036
All this and only at the cost of heart damage over time, and possibly nutrition issues if you forget to eat like an idiot and weaken your bones.