Decision-making in teens involves a chemical called dopamine in the brain’s reward center. Dopamine helps transmit signals in the brain that make people feel happy. The number of brain receptors interacting with dopamine is higher in adolescence than at any other time of life. That means that when a teen is exposed to a reward—such as a compliment—the reward center reacts more strongly than it would for an adult.

Also, being with friends increases the sensitivity to rewards and makes the already sensitive reward system even more sensitive. Feeling rewards more strongly and responding more intensely to what peers may think means that there are biological reasons for why teens sometimes decide to do things with their friends that they would never do on their own. This can be positive, by encouraging friends to take on new challenges. But it can also lead to dangerous decisions—such as drug and alcohol use.

Misuse of substances like alcohol and drugs is a growing problem in the US -- and teens and young adults are most at risk, with half of all new drug users being under the age of 18, and 1 in 5 high school students having abused prescription drugs. Additionally, one third of high school students currently use alcohol, 23% use marijuana, and 22% use all forms of tobacco combined.

Drug use and abuse can contribute to harmful short and long-term health risks. In fact, drug abuse can have long-term effects on a developing teenage brain. MRI scans of the brain have shown that people who have been using drugs for a long time have a smaller prefrontal cortex than people who have not been using drugs. The prefrontal cortex is the area where decision-making occurs. Drug use can result in poor grades, memory loss and social problems.

A lot of us have an idea about what a person dependent on drugs looks like. However, anyone can suffer from this type of addiction. Addiction doesn’t depend on income, job, age, race or color. It is a disease of the brain that can happen to anyone. Drug dependency is when a person consumes alcohol or drugs regularly, despite the fact that it causes issues in their life and relationships with others.

Get help if you need it. Encourage your friends to get help too. If you or someone you love is struggling with drug use or abuse call 1-800-662-HELP or visit www.easyread.drugabuse.gov