Know their friends and their parents. Often teens experiment or take drugs with friends rather than by themselves. Get to know the parents of your teen's friends. Talk with these parents and make a pact that if one parent suspects substance use or abuse they will inform you and vice versa. Take it upon yourself to go one step further, read and understand the warning signs of substance abuse.
Attitude changes such as losing interest in specific pleasurable hobbies or sports.
Your teen becomes extremely lethargic, agitated, jittery or restless. Dramatic drop in grades. Missing money or valuables. Significant weight loss in a short amount of time. These characteristics are only a handful of warning signs.