over medicated?

 Hello all. Recently I had some concerns with concerta so today when my son(8) and i went to his doc I told her to switch him to Adderall XR, which she did. However, she told me that he could just stop taking the Concerta and go right the Adderall, I thought that one had to be weened off first before starting a new drug; any input? Also, he is on prozac for depression, hydroxizine for sleep, and she wanted me to give him this med that makes him hungry, but I haven't given it to him yet, just because it kind of freaked me out. Anyway , after talking with my son today, she decided to put him on Depakote for his mood swings. Okay so that is 5 meds, I really concerned that if I give him all of this that he'll be way over medicated, but mental illnesses(I know adhd is not a mental illness, i'm talking about the other stuff) do run in my family and if he needs this I want to make sure I do the right thing. What do you guys think? Has anyone else run into this problem?