Generally they won't diagnose before they have started school. There are a lot of things that have ADD type behaviour, and in many cases there is no need for meds. If you do pursue a diagnosis down the track, do a lot of research before agreeing to meds straight up. They already started talking to us about meds for our DS depending on how he goes at school next year, but we have since found out some other information about DS that means it's probably not ADD at all. Thank goodness we found out before we agreed to meds!!