A full neuro psych evaluation for ADHD (and other things that look like it) will not simply be a questionnaire and takes quite a bit of time. But the findings may not be conclusive and may instead suggest a high probability of ADHD.
The good thing about such a dx is that it can make a student more open to strategies for dealing with it - strategies that also benefit someone without a dx.
Definitely worth pursuing as bright kids often find suboptimal coping skills that aren’t sustainable over the long term and can be really stressful.