En español
NIDA

Search

Menu

Marijuana

Brief Description

Marijuana is the most commonly used illegal drug in the U.S. It is made up of dried parts of the Cannabis sativa hemp plant.

Street Names

Pot, ganga, weed, grass, 420

Effects

Short-term effects of marijuana use include euphoria, distorted perceptions, memory impairment, and difficulty thinking and solving problems.

Statistics and Trends

In 2009, 28.5 million Americans age 12 and older had abused marijuana at least once in the year prior to being surveyed. Source: National Survey on Drug Use and Health (Substance Abuse and Mental Health Administration Web Site). The NIDA-funded 2010 Monitoring the Future Study showed that 13.7% of 8th graders, 27.5% of 10th graders, and 34.8% of 12th graders had abused marijuana at least once in the year prior to being surveyed. Source: Monitoring the Future (University of Michigan Web Site).

Latest Science

Related Publications

Marijuana (DrugFacts)

Revised December 2012.
Offers facts about marijuana, including how it is used, its effects on the brain and overall health, treatment options, and the potential of marijuana as a therapy for various health problems. En Español

Graph: Percentage of U.S. 12th Grade Students Reporting Past Month Use of Cigarettes and Marijuana, 1975 to 2011

Marijuana (Topics in Brief)

Revised December 2011.
Provides a brief update on the research on marijuana use, including its health effects, the potential for addiction, treatment, and marijuana in medicine.

Publication Cover

Marijuana: Facts for Teens

Published April 2001. Revised March 2011.
Presented in question-and-answer format and targeted to teens, provides facts about marijuana and its potential harmful effects. En Español

Publication Cover

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

Publication: Research Report Series - Marijuana Abuse

Marijuana Abuse (Research Reports)

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

Is Marijuana Medicine? (DrugFacts)

Published July 2012.
Offers facts about marijuana's viability as a legal medical treatment. En Español

Publication Cover

Marijuana (Mind Over Matter)

Published January 1997.
Explains how THC, the active ingredient in marijuana, causes changes in the brain that affect memory, emotions, balance, and judgment. En Español

Related Resources

Marijuana Lesson Kit

Other Resources

Past information on many drugs of abuse is available on our Archives site.

Tags

This page was last updated December 2012

Emerging Drugs

Get more information on K2/Spice, Salvia and Bath Salts. NIDA will update this page with the latest research findings on these and other emerging drugs as they develop.

Looking for Treatment?

Use the SAMHSA Treatment Locator or 1-800-662-HELP.

Featured Publication

Featured Publication

Drugs, Brains, and Behavior - The Science of Addiction

As a result of scientific research, we know that addiction is a disease that affects both brain and behavior.