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Marijuana

Brief Description

Marijuana is a dry, shredded green and brown mix of leaves, flowers, stems, and seeds from the hemp plant Cannabis sativa. In a more concentrated, resinous form, it is called hashish, and as a sticky black liquid, hash oil. The main psychoactive (mind-altering) chemical in marijuana is delta-9-tetrahydrocannabinol, or THC. Learn more

Statistics and Trends

2012 Monitoring the Future (MTF) Study: for 8th-Graders, 10th-Graders, and 12th-Graders (in percent)*
Drug Time
Period		 8th-
Graders		 10th-
Graders		 12th-
Graders
Marijuana/Hashish Lifetime 15.2 33.8 45.2
Past Year 11.4 28 36.4
Past Month 6.5 17 22.9
Daily 1.1 3.5 6.5

* Data in brackets indicate statistically significant change from the previous year.

Previous MTF Data

 

2011 National Survey of Drug Use and Health (NSDUH) for Ages 12 and Older (in percent)*
Drug Time
Period		 Ages 12 or
Older		 Ages
12-17		 Ages
18-25		 Ages 26
or Older
Marijuana/Hashish Lifetime 41.9 17.5 51.9 43.2
Past Year 11.5 14.2 30.8 7.9
Past Month 7 7.9 19.0 4.8

* Data in brackets indicate statistically significant change from the previous year.

Previous NSDUH Data

 

Latest Science

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Marijuana (Topics in Brief)

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Presented in question-and-answer format and targeted to teens, provides facts about marijuana and its potential harmful effects. En Español

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Marijuana: Facts Parents Need to Know

Published April 2001. Revised March 2011.
Brochure, in question-and-answer format, that provides facts about marijuana for parents and offers tips for talking with their children about the drug and its potential harmful effects. En Español

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Published October 2002. Revised September 2010.
Explores the latest research on marijuana, including the scope of marijuana use in the U.S., health consequences, its effects on every-day activities, available treatments. En Español

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Marijuana (Mind Over Matter)

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Explains how THC, the active ingredient in marijuana, causes changes in the brain that affect memory, emotions, balance, and judgment. En Español

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This page was last updated December 2012

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