Bad Grades
High school students who use marijuana are 1.5 to 2 times more likely to have a C average or lower as students who do not use marijuana.¹

Violent Behavior
Teens who have used drugs in the past year are about 2 times more likely as teens who have not used drugs to be involved in violent behavior.²

Accidental Death 
Drivers ages 16–20 are 17 times more likely to die in a crash when alcohol is involved.³

Blackouts
Drinking large amounts of alcohol in a short period of time (“binge drinking”) causes blood alcohol levels to rise very rapidly. This quickly impairs a person’s balance, motor skills, and decision making, and can also cause a “blackout,” a period of time for which an intoxicated person cannot remember key details about a specific event or the event itself. Intoxicated persons risk losing control of what happens to them before, during, and after a blackout, and can find themselves in dangerous or unwanted situations. Because of how females metabolize alcohol, they may be at greater risk for blacking out.⁴

Think About It:

• What kinds of unwanted situations can people find themselves in if they drink too much?
• What is an example of a consequence from drinking too much that can’t be undone?
• Why do you think the loss of control caused by drinking too much is similar to giving someone else control of your decisions?

The “times more likely” examples on these pages compare a teen’s chances of experiencing a particular consequence if a teen uses a specific drug versus a teen not using that drug.

If we could see the future with certainty—like with a crystal ball—we would always make good decisions. In the real world, without crystal balls, we have statistics to help us make smart choices. Valid statistics are calculated from studies measuring the behavior of groups of people (the sample) during a defined period of time. With statistics, we can weigh the likelihood of an event happening to us based on the experiences of others.
 

Valid statistics are:
✓ Published by a reliable source that presents data in a scientific, objective way
✓ Collected from a large sample size of people who were chosen randomly and given anonymity to ensure accuracy
✓ Consistent over time, demonstrating the study isn’t a fluke

The statistics presented on these pages are from health studies that showed how drugs cause harm. Understanding what valid—that is, trustworthy—statistics mean can help us draw important conclusions and make better decisions about our lives.