Bipolar disorder in children?

We have a 13 yr old grandson that his parents claim has been diagnosed as bipolar and ADHD. The reason we say claim is that his stepmom is quit the hypochondriac and we think is looking for something wrong with him because she doesn't treat him the same as her other bio children-in other words he is treated like a "stepchild". The concern we have is that we have had him with us for a week with no meds and absolutely no problems-except what a normal teen boy would act. Our question is: do all bipolar and/or ADHD need or have to be on meds all of the time? We know for sure that there is no counseling, thereapy, etc. going on and no meds were sent with him for this visit. His parents even have HIM convinced that he has these disorders. We are searching for help because as grandparents, we only want what is best for him.