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Marijuana: Facts for Teens

Some Things to Think About

A teenage boy, thinking.

People smoke marijuana for a lot of different reasons: to feel good, to feel better, to feel different, or to fit in. Whatever the reason, drug use has consequences.

Addiction:

Marijuana can be addictive. Not everyone who smokes marijuana will become addicted—that depends on a whole bunch of factors, including your genes, the age you start using, whether you also use other drugs, your relationships with family and friends, 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. Research shows that about 9 percent, or about 1 in 11, of those who use marijuana will become addicted (Anthony, 1994; Lopez-Quintero, 2011). This rate increases to 17 percent, or about 1 in 6, in people who start in their teens, and goes up to 25 to 50 percent among daily users (Hall, 2009a; Hall, 2009b).

To help you make an informed choice, here are some brief summaries of what marijuana research is telling us. These topics represent the most popular questions and comments we get every day on our teen website and blog. Share them with your friends to help them separate fact from myth.

Driving:

After alcohol, marijuana is the drug most often linked to car accidents, including those involving deaths. A nationwide study of deadly crashes found that 36.9 percent of drivers who tested positive for drugs had used marijuana (Wilson, 2010). Marijuana affects skills required for safe driving—alertness, concentration, coordination, and reaction time. Marijuana makes it hard to judge distances and react to signals and sounds on the road.

A car accident and an upset teenager with two friends standing outside her damaged car.

School:

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 teens who don’t use, students who smoke marijuana tend to get lower grades and are more likely to drop out of high school (McCaffrey, 2010). Research even shows that it can lower your IQ if you smoke it regularly in your teen years (Meier, 2012). Also, longtime marijuana users report lower life satisfaction, memory and relationship problems, poorer mental and physical health, lower salaries, and less career success (Zwerling, 1990).

Psychosis/Panic:

High doses of marijuana can cause psychosis or panic when you're high. Some people experience an acute psychotic reaction (disturbed perceptions and thoughts, paranoia) or panic attacks while under the influence of marijuana. This reaction usually goes away as the drug’s effects wear off. Scientists don't yet know if marijuana use causes lasting mental illness, although it can worsen psychotic symptoms in people who already have schizophrenia, a severe mental illness with symptoms such as hallucinations, paranoia, and disorganized thinking. It can increase the risk of long-lasting psychosis in some people.

This page was last updated May 2015