Be wary of self-diagnosis. As you probably already know, it's really easy to introduce bias into self-analysis.
Is there a way respondents can code their answers so that jsalvatier can perform an analysis while blinded? For example, don't just say which behaviors are associated with ADHD. Instead, ask a question about whether he exhibits certain behaviors which may be correlated (or negatively correlated, or not at all correlated) with ADHD. But only include which it is in a rot13'd paragraph.
He can first answer that question and then decode the rot13 "answer." This would give him much clearer, unbiased evidence.
EDIT: An (obviously untrue) example for clarity...
Do you like popcorn?
Fhpu naq fhpu n fghql sbhaq gung n yvxvat bs cbcpbea jnf fgebatyl cerqvpgvir bs fbzrbar univat NQUQ.
Yes, that's clearly a concern. I wasn't planning on self diagnosing, but going to a psychiatrist to be evaluated. That's one thing I wondered about questionnaires used for evaluation, do they include questions which are not related to ADHD?
I've long had attention and focus problems, but never explored the possibility that I have ADHD till recently. I understand that it's a standard term, but I'm still a bit suspicious; Psychiatry doesn't seem like the most reliable field.
Are there good reasons for picking out the behaviors associated with ADHD and giving them a name? Obviously this is a different question than whether ADHD is a 'disorder' or 'disease', and whether ADHD medication is good or bad for people.
Answers that would satisfy me