Marijuana Facts for Teens from the National Institute on Drug Abuse

Marijuana is addictive. Of course, not everyone who smokes marijuana will become addicted—that depends on a whole bunch of factors—including your family history (genes), the age you start using, whether you also use other drugs, your family and peer relationships, success in school, and so on. Repeated marijuana use can lead to addiction—which means that people have trouble controlling their drug use and often cannot stop even though they want to.

Marijuana is unsafe if you are behind the wheel. Marijuana is the most common illegal drug involved in auto fatalities. It is found in the blood of around 14 percent of drivers who die in accidents, often in combination with alcohol or other drugs. Marijuana affects a number of skills required for safe driving—alertness, concentration, coordination, and reaction time—so it’s not safe to drive high or to ride with someone who’s been smoking. Marijuana makes it hard to judge distances and react to signals and sounds on the road. And combining marijuana with drinking even a small amount of alcohol greatly increases driving danger, more than either drug alone.

Marijuana is linked to school failure. Marijuana’s negative effects on attention, memory, and learning can last for days and sometimes weeks—especially if you use it often. Someone who smokes marijuana daily may have a ‘dimmed-down’ brain most or all of the time. Compared with their peers who don’t use, students who smoke marijuana tend to get lower grades and are more likely to drop out of high school. Research even shows that it can lower your IQ if you smoke it regularly in your teen years. Also, longtime marijuana users themselves report being less satisfied with their lives, having memory and relationship problems, poorer mental and physical health, lower salaries, and less career success.

How is marijuana likely to affect you?
Learning: Marijuana’s effects on attention and memory make it difficult to learn something new or do complex tasks that require focus and concentration.
Sports: Marijuana affects timing, movement, and coordination, which can harm athletic performance.
Judgment: Marijuana, like most abused substances, can alter judgment. This can lead to risky behaviors that can expose the user to sexually transmitted diseases like HIV, the virus that causes AIDS.

What does marijuana do to the brain?
We know a lot about where marijuana acts in the brain and how it affects specific sites called cannabinoid receptors. These receptors are found in brain regions that influence learning and memory, appetite, coordination, and pleasure. That’s why marijuana produces the effects it does. We know much less about what happens to
the brain in the long run when someone is a regular marijuana smoker. Scientists use brain imaging techniques to study the living human brain, but we are still in the early stages of that research when it comes to marijuana. So, while we do know there are differences in the brains of marijuana users (versus nonusers), we do not yet know what these differences mean or how long they last—especially if someone stops using the drug. One reason is that it’s hard to find people who only smoke marijuana without using alcohol, which has its own negative effects on the brain.

The NIDA Web site has information on a variety of drugs and related topics. NIDA’s teen site covers a lot of ground, with free downloads, entertaining and informative videos and games, and our Sara Bellum blog for teens, where you can even leave us a comment or two. Learn how different drugs affect the brain and body, and read real stories from teens who have struggled with drug abuse and addiction.

NIDA Marijuana Facts for Teens

According to the 2014 Oregon Student Wellness Survey, 93% of Linn County eighth grade students and 83% of eleventh graders do not smoke marijuana (past 30-day use).