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Scary Stats

Here are some facts to show you how this drug can affect you.

Impaired Driving

  • Even low doses of marijuana affect your concentration and perception and delay your coordination and reaction time, which are skills needed to drive safely. Marijuana use can make it difficult for you to judge distance and react to signals and sounds while driving. The effects of marijuana can last up to 24 hours after smoking it.
  • After alcohol, marijuana is the most frequently found substance in car crashes.
  • About 33% of DUI drivers are high on marijuana.1
  • Marijuana and alcohol combined can increase your BAC level three times, dangerously affecting your driving ability.
  • For nonfatally injured drivers about 24% of those under 21 tested positive for drugs other than alcohol.2
  • Data shows that people who drive high on marijuana show the same lack of coordination as drunk drivers.3


  • Marijuana is the most-used drug, after alcohol, present in the blood of injured and fatally injured persons.
  • In 2005, 215,666 emergency room visits involved the use of marijuana.4
  • Smoking marijuana leads to changes in the brain similar to the effects caused by cocaine, heroin, and alcohol.
  • Marijuana smoke causes lung damage and contains the same cancer-causing chemicals as tobacco.
  • Marijuana can lead to increased anxiety, panic attacks, thoughts of suicide, and depression in teens.

Grades in School

  • Heavy use of marijuana ruins your ability to concentrate and retain information. So it leads to poor performance in school. Also, teen brains are still developing, so marijuana can really mess them up.
  • Teens who smoke marijuana are more likely to cut school and get a D average in all classes.
  • One survey shows that 59% of students using marijuana reported that they often forgot what a conversation was about even before it ended.5
  • After 24 hours of heavy marijuana use, students are not able to focus or to organize data.


  • Teens who use marijuana take unnecessary risks that put their futures in danger, such as delinquency, having sex, viewing drugs as being harmless, and having friends with delinquent behavior.
  • Teens who use marijuana are nine times more likely to use other drugs, five times more likely to steal, and four times more likely to become violent.
  1. Dan Brookoff, et al. “Testing reckless drivers for cocaine and marijuana.” New England Journal of Medicine 331:518�522.
  2. Dan Brookoff, et al.
  3. National Highway Traffic Safety Administration. Drug-Impaired Driving. (accessed Oct. 28, 2007).
  4. Drug Abuse Warning Network.

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