Wow, that is crazy. I am surprised insurance filled 20 mg for a 4 year old. There are usually restrictions on age. Vyvance is something like 6 years old, Mydayis is 13 years old, and the others are 3. I have seen 8 different psychiatrists over the years for my kids. They all have said start with the lowest dose. There is a swab test they can do now Genesight to see what medication works best for them. I wish you all the luck, it is an endless battle.