Can you mix Adderall and norco?

I don't know if you should mix Adderall and norco but I have both adderall and norco and I have mixed them with no effect from mixing them. It doesn't vreate a high of any sort. I think that because adderall is an upper (causes you to have increased energy, etc.) and Norco is a downer, they kind of cancel each other out when it comes to side effects.