The teen years are a time of newfound independence, as kids begin to become adults, venturing out into the world, making their own decisions. It's also a time many will experiment with drugs and alcohol. Experimenting with drugs and alcohol is nothing new for teens. Consider these statistics: by the age of 14, 41 percent of kids will have had at least one drink. The average American boy will take his fist sip of alcohol when he's 11, while American girls try it a little later, by age of 13. The average teen begins drinking regularly just before turning 16, around the time they get their learner's permit and driver's license. Drinking or using drugs before the age of 15 triples their risk of becoming addict. Consider this sobering stat: right now, three million teenagers in the U.S. are alcoholics. And that's just one substance. Teens today have greater access to a lot more drugs than ever before. And many of them can be found right inside your house. High school and college students have been known to abuse ADHD drugs like Ritalin to help them study or control their appetite. They might try steroids to help them bulk up. Or they snag their parents' prescription painkillers from the medicine cabinet because they've heard you can get high off of them. Teens' brains are not yet fully developed. Pot, alcohol and other drugs can impair brain development and lead to permanent changes in the teenaged brain. Taking drugs at any age can lead to addiction. But teenagers are at even greater risk. The younger you are when you start using drugs, the greater your chances of developing a dependency. Parents need to stay involved in their kids' lives, and let them know early on about the dangers of drug use. Providing your teen with a stable home environment and a close, loving relationship is the best thing you can do to prevent alcohol and drug abuse. Establishing rules and boundaries is a key part of that. Even if they don't like it, kids need to know what's expected of them and what is acceptable behavior. Peer pressure can also play a big role in substance abuse. Whether a teenager is a misfit or runs with the popular crowd, having a low self-esteem and feeling like they don't fit in can make them try things in order to look cool. If all of their friends are doing it, there's a good chance that they will do it, too. That's why it is imperative for parents to keep the lines of communication open. Common signs of alcohol or drug abuse in teens include: withdrawing from family and friends, doing poorly in school, discipline problems, anger, and hostility. If you suspect that your teen is using any illegal substances, even if he or she is just experimenting, talk to them immediately. If their behavior continues or worsens, seek professional help. Remember the sooner you can get them help, the better their chances of kicking an addiction.