[walterbell]

Questionnaires are cheap but less reliable than brain (PET, fMRI) scanning or quantitative attentional testing. What is the impact of a false positive diagnosis on a still-developing young brain?

Adults are a different story - they can make their own decisions.

[bayesianhorse]

I mentioned questionnaires as a means of reaching a diagnosis which is not dependent on instrumental testing, to make a point about the consistency of subjective evaluation, objective findings, suffering and treatment.

But in General, ADHD diagnosis is not based on PET, fMRI or EEG.