I think the idea of your question is a good one and probably a bit controversial, which always makes for an interesting essay. However, I think it could be worded a bit better. Here are some possible alternatives:
What is the difference between a child who has behavior problems that need to be addressed by a more efficient discipline regimen, and a child who has ADHD?
How is ADHD different from behavior management problems?
Should parents and teachers try different behavior management strategies first before assuming a child has ADHD?
What causes a child to be diagnosed with ADHD?
What is the difference in treating a child with ADHD versus treating a child for behavior problems?