You will need to check the regulations for your state. Here, the retesting is required every three years unless there is a significant change in the child's status. For my dd, we were able to get retesting at 1 year when we discovered that she had absence seizure activity, so once she was "stabalized" with medication, retesting was warrented. So I would think that if you changed your approach since the ADHD diagnosis (added meds, behavior plan, etc.) that would be a significant change in your child's status.
Good luck!
