It's a prescription drug, a controlled substance designed for people with Attention Deficit Disorder. Every drug has some side effects. The real worry is dependence, though. Some kids say that after they've been using Adderall really frequently, they cannot concentrate without it. It is not something to use every day.
Few things are.
I've heard of kids doing 80 mg. Or using it every night. Or even multiple times a day. I take Adderall about once every 10 days. I've been pulling frequent all-nighters for the past four years, using Adderall for one.