People start using to have fun, out of boredom, curiosity, to feel good, etc. Over time they can develop problems. Teens need to learn that they have choices. They need information on what the risks are to help them in making their choices. Most children and teens have been affected by or know of someone who is chemically dependent.
Some teens use chemicals to cope with other difficulties, such as depression or family problems.
Change in friends. Change in dress or appearance. Change in patterns of sleeping or eating. Friends no longer being brought home. Adamant defensive of the right to use alcohol.