Teen drug use has been increasing, with half of new teen drug users being below 18 years old. The most common reasons for teen drug use are experimentation due to curiosity about drugs and peer pressure to fit in. Some signs of possible teen drug use include poor grades, the smell of smoke on their breath or clothes, and losing interest in usual activities. If parents suspect their teen is using drugs, they should intervene early and seek treatment, as drug abuse can lead to addiction.