Marijuana and methamphetamine use among teenagers has declined in the past five years, but the rise in prescription drug use among teens is a growing concern.

According to a University of Michigan study, teen drug use has declined 23 percent since 2001, less use of nearly every drug except the prescription drug OxyContin, which saw a 30 percent increase in use during the last year.
There was also a rising use of prescription drugs like Adderall and Xanax. Adderall is used to treat children with attention-deficit or hyperactivity disorders. The drug is a stimulant and many users claim it helps them focus. Kids who use Adderall want it for its speed effect. A lot of kids who abuse Adderall will find someone at school who is ADHD and buy the pills from them. (Source)