My 17 year old son was diagnosed with ADHD since he was 6. I didn't put him on medication for the same reasons that you stated. However during the last semester of second grade I finally relented and he started with Ritalin. It was a God-send. Now he is taking Concerta once a day and he does great. He is able to focus in school, he is calmer at home, it is just good.
The reason that I gave in to medicating him is that his psychologist recommended a book. This book gave both sides, medication vs. non. I got scared because the book said that most teenagers with ADD/ADHD usually begin to self-medicate during their teenage years. I did a little more research and it was enough to send me to his MD for meds.
This worked for our family. Talk to your MD and see what he/she thinks. Or go to a psychologist who specializes in this disorder.