I can only tell you that when our daughter was diagnosed with ADHD it was through extensive medical testing and ONLY her doctor could prescribe the medication. She took it at home and not at school. The school never even hinted that she should be tested; it was our decision. She took it for three years and then all concerned made the decision she could stop. I still think it was an important aid for her during those years.
I would agree that the medications are overprescribed and overused, but I don't think the school can just order up a batch and started medicating.
Thanks for the comments. A number of others chimed in as well to make it known the process that seemed to be rather similar for each of them. I'm glad it worked well for your daughter.