Experts suggest that you start talking about drinking, smoking, and using drugs when your child is between ages 5 and 7, and that you keep the discussion going.
When possible, look for teachable moments. For example, if family members drink wine with dinner, talk about why they do and what it means to drink responsibly. Or if your younger child is watching TV and a beer commercial comes on, discuss the fact that although the people in the commercial appear to be having a good time, drinking too much alcohol can cause you to make bad decisions. It can also cause you to hurt yourself or others. Talking with your child at a young age is especially important if family members have alcohol or drug problems. Children with a family history of substance abuse are more likely to become substance abusers.
As your child gets older, continue to talk regularly about drugs, alcohol, and tobacco. But do so in a way that's right for your child's age. Make your views on the subject clear and repeat them often. If you don't approve of smoking or drinking, be sure your child knows this and the reasons for your beliefs. Your child needs to understand that under no circumstances is drug use acceptable and that there are no safe street drugs.