You should know very well that an ADHD diagnosis is a lot more than just that question. In my case four people close to me were given questionnaires, I was lucky enough to still have all my school reports, which were no grades but a page of solid text back in 1989 to solidify my suspicion. There's also an IQ test and a very annoying attention test on the computer. Matter of fact, one of those who filled out the questionnaire (and is not related to me) was like "If you have ADHD I'm even more likely to have it".