Editing my answer to add - I guess I didn't answer your question! I do know a couple of families who use ADHD medication, and find that it helps their school-aged kids to do much better in school. But all of their kids were much older when they started (2nd grade, 4th grade.)
I have a son who is 7 and who was diagnosed with ADHD at age 5.5. He hasn't been medicated. I'm not against medication, and if he does need it to cope at some point, we'll try it. But I do feel a little aggravated with these rapid-diagnosis doctors. One of the first ones we saw when we were looking for help just said, "medication!" and didn't provide any other ideas for us. Right after that he was evaluated by a pediatric occupational therapist, who diagnosed sensory integration disorder. Although he has ADHD, it wasn't causing the behavior problems he was having right then - the sensory stuff was. Plus he tested in the single-digit percentiles (very poor) on many of the things they tested related to making sense out of visual information, balance, etc. The OT worked with him for about a year and a half, and that made a huge, huge difference in his ability to control himself.
He still has attention, focus, and organization issues, and we work closely with his teacher and we do a lot with him to help him learn to organize himself, focus, etc. He's doing well right now, and the neuropsych who diagnosed the ADHD didn't recommend medication at this point.
So I guess the short answer is - I'm glad to know that a medication can help kids with ADHD, maybe my kid at some point. I think it would be wrong to withhold the medication if he wasn't able to function and learn without it. But I'm also very glad we went through the longer process we did, because the OT was needed and very helpful for all of us, and it gave us time to really understand, with the help of another caring professional who saw him every week, what was up with him. If we had listened to the first doctor and just walked out with a prescription, I think we would have missed a window of opportunity to work on those physical and sensory deficits he had.
You can contact your school district, even if he's not in school yet, and request an evaluation. (I didn't know that, so didn't do it at the time.) Or you could ask your pediatrician for a referral to someone who is expert in behavioral disorders - that's how we were referred to the neuropsychologist we saw (Dr. Appleby at Loyola Medical Center in Maywood.)