Ten meds seems like an awful lot. I once had a pdoc, that every time I had a side effect, he called it a symptom, and instead of trying a new med, he just piled on another to counteract the new "symptom". I hope that's not the case with your son.
I'm with Serafena, if in doubt, get a second opinion. Considering where you are now, I don't see how it could hurt. I'm on four meds, and I thought that was alot. I'm no medical professional, but if it were MY child, I'd want to be absolutely certain before I loaded him with that many drugs. It makes me wonder how they can even tell which ones are working, and which ones aren't.
Good luck to you and your son. I hope you find your answers.
Good judgement comes from experience and alot of that comes from bad judgement.
You just have to accept that some days you're the pigeon, and some days you're the statue.