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Overview / Extent of Use / Health Effects / Treatment / Arrests & Sentencing / Production & Trafficking / Legislation / Street Terms / Other Links / Sources


Marijuana is a green, brown, or gray mixture of dried, shredded leaves, stems, seeds, and flowers of the hemp plant (Cannabis sativa). Cannabis is a term that refers to marijuana and other drugs made from the same plant. Other forms of cannabis include sinsemilla, hashish, and hash oil. All forms of cannabis are mind-altering (psychoactive) drugs.

The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). Short-term effects of marijuana use include problems with memory and learning, distorted perception, difficulty in thinking and problem solving, loss of coordination, increased heart rate, and anxiety.

Marijuana is usually smoked as a cigarette (called a joint) or in a pipe or bong. Marijuana has also appeared in blunts, which are cigars that have been emptied of tobacco and refilled with marijuana, sometimes in combination with another drug, such as crack. It can also be mixed into foods or used to brew a tea. 1


Extent of Use

Marijuana is the most commonly used illicit drug. According to the 2006 National Survey on Drug Use and Health (NSDUH), an estimated 97.8 million Americans aged 12 or older tried marijuana at least once in their lifetimes, representing 39.8% of the U.S. population in that age group. The number of past year marijuana users in 2006 was approximately 25.4 million (10.3% of the population aged 12 or older) and the number of past month marijuana users was 14.8 million (6.0%). 2

Among 12-17 year olds surveyed as part of the 2006 NSDUH, 6.7% reported past month marijuana use. Additional NSDUH results indicate that 16.3% of 18-25 year olds and 4.2% of those aged 26 or older reported past month use of marijuana. 3

The 2006 NSDUH results also indicate that there were 2.1 million persons aged 12 or older who had used marijuana for the first time within the past 12 months. This estimate is similar to estimates from past NSDUH surveys dating back to 2002. 4

A 2002 SAMHSA report, Initiation of Marijuana Use: Trends, Patterns and Implications , concludes that the younger children are when they first use marijuana, the more likely they are to use cocaine and heroin and become dependent on drugs as adults. The report found that 62 percent of adults age 26 or older who initiated marijuana before they were 15 years old reported that they had used cocaine in their lifetime. More than 9 percent reported they had used heroin and 53.9 percent reported non-medical use of psychotherapeutics. This compares to a 0.6 percent rate of lifetime use of cocaine, a 0.1 percent rate of lifetime use of heroin and a 5.1 percent rate of lifetime non-medical use of psychotherapeutics for those who never used marijuana. Increases in the likelihood of cocaine and heroin use and drug dependence are also apparent for those who initiate use of marijuana at any later age. 5

Results of the 2007 Monitoring the Future survey indicate that 14.2% of eighth graders, 31.0% of tenth graders, and 41.8% of twelfth graders reported lifetime use of marijuana. In 2006, these percentages were 15.7%, 31.8%, and 42.3%, respectively. 6

Percent of Students Reporting Marijuana Use, 2006–2007

8th Grade
10th Grade
12th Grade







Past month



14.2 %




Past year














Approximately 74.3% of eighth graders, 64.5% of tenth graders, and 54.8% of twelfth graders surveyed in 2007 reported that smoking marijuana regularly was a "great risk." 7

Percent of Students Reporting Risk of Using Marijuana, 2007

Say "great risk" to:
8th Grade
10th Grade
12th Grade

Try marijuana once/twice




Smoke marijuana occasionally




Smoke marijuana regularly




The Youth Risk Behavior Surveillance (YRBS) study by the Centers for Disease Control and Prevention (CDC) surveys high school students on several risk factors including drug and alcohol use. Results of the 2005 survey indicate that 38.4% of high school students reported using marijuana at some point in their lifetimes. Additional YRBS results indicate that 20.2% of students surveyed in 2005 reported current (past month) use of marijuana. 8

Percent of Students Reporting Marijuana Use, 2001–2005

Current use
Lifetime use

Approximately 46.9% of college students and 56.7% of young adults (ages 19–28) surveyed in 2006 reported lifetime use of marijuana. 9

Percent of College Students/Young Adults Using Marijuana, 2005–2006

College Students
Young Adults
Past month
Past year
2 8 .2

According to data from the Bureau of Justice Statistics, approximately 77.6% of State prisoners and 71.2% of Federal prisoners surveyed in 2004 indicated that they used marijuana/hashish at some point in their lives. 10

Percent of Prisoners Reporting Marijuana Use, 1997 and 2004

State Prisoners
Federal Prisoners
At time of offense
In month before offense
Ever in lifetime
* Used drugs at least once a week for at least a month.


Health Effects

Marijuana abuse is associated with many detrimental health effects. These effects can include frequent respiratory infections, impaired memory and learning, increased heart rate, anxiety, panic attacks and tolerance. Marijuana meets the criteria for an addictive drug and animal studies suggest marijuana causes physical dependence and some people report withdrawal symptoms. 11

Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illnesses, a heightened risk of lung infections, and a greater tendency toward obstructed airways. Cancer of the respiratory tract and lungs may also be promoted by marijuana smoke. Marijuana has the potential to promote cancer of the lungs and other parts of the respiratory tract because marijuana smoke contains 50 percent to 70 percent more carcinogenic hydrocarbons than does tobacco smoke. 12

Marijuana's damage to short-term memory seems to occur because THC alters the way in which information is processed by the hippocampus, a brain area responsible for memory formation. In one study, researchers compared marijuana smoking and nonsmoking 12th-graders' scores on standardized tests of verbal and mathematical skills. Although all of the students had scored equally well in 4th grade, those who were heavy marijuana smokers, i.e., those who used marijuana seven or more times per week, scored significantly lower in 12th grade than nonsmokers. Another study of 129 college students found that among heavy users of marijuana critical skills related to attention, memory, and learning were significantly impaired, even after they had not used the drug for at least 24 hours. 13

Of an estimated 106 million emergency department (ED) visits in the U.S. during 2004, the Drug Abuse Warning Network (DAWN) estimates that 1,997,993 were drug-related. DAWN data indicate that marijuana was involved in 215,665 ED visits. 14

DAWN also collects information on deaths involving drug abuse that were identified and submitted by 128 death investigation jurisdictions in 42 metropolitan areas across the United States. Cannabis ranked among the 10 most common drugs in 16 cities, including Detroit (74 deaths), Dallas (65), and Kansas City (63). Marijuana is very often reported in combination with other substances; in metropolitan areas that reported any marijuana in drug abuse deaths, an average of 79 percent of those deaths involved marijuana and at least one other substance. 15



From 1996–2006, the number of admissions to treatment in which marijuana was the primary drug of abuse increased from 192,918 in 1996 to 289,988 in 2006. The marijuana admissions represented 11.7% of the total drug/alcohol admissions to treatment during 1996 and 16.1% of the treatment admissions in 2006. The average age of those admitted to treatment for marijuana during 2006 was 24 years. 16


Arrests & Sentencing

There were an estimated total of 1,889,810 state and local arrests for drug abuse violations in the United States during 2006. Of the drug arrests, 4.8% were for marijuana sale/manufacturing and 39.1% were for marijuana possession. 17

According to the National Drug Intelligence Center there were 5,039 Federal marijuana-related arrests during 2006. This is down from the 5,599 such arrests during 2005. 18

According to a 2004 Bureau of Justice Statistics survey of state and Federal prisoners, approximately 12.7% of state prisoners and 12.4% of Federal prisoners were serving time for a marijuana-related offense. This is a decrease from 1997 when the figures were 12.9% and 18.9%, respectively. 19

During FY 2006, there were 6,423 Federal defendants sentenced for marijuana-related charges in U.S. Courts. Approximately 96% of the cases involved marijuana trafficking. 20


Production & Trafficking

The threat associated with marijuana trafficking and abuse is rising, which is largely the result of a growing demand for high-potency marijuana and a related increase in the drug's availability. An increase in domestic cannabis cultivation by drug trafficking organizations contributes to this threat, particularly the recent expansion of cultivation operations by Mexican, Asian and Cuban organizations. 21

Most foreign-source marijuana smuggled into the United States enters through or between points of entry at the U.S.-Mexico border. During 2006, 1,115,710 kilograms of marijuana were seized along the Southwest Border. Cannabis cultivation in Mexico remains high and most of the marijuana produced in that country is destined for U.S. drug markets. 22

Domestic Cannabis Eradication/Suppression Program (DCE/SP) data indicate that a total of 5,231,658 marijuana plants were seized in the U.S. during 2006. This is up from 4,209,086 plants seized during 2005. The recent increases in cannabis cultivation and marijuana production within the United States coincide with the continued flow of marijuana from foreign sources, which may lead to market saturation in major markets. This saturation could reduce the price of the drug significantly. 23

According to combined 2002, 2003 and 2004 NSDUH data, more than three fourths (78.2%) of the past year marijuana users aged 18 to 25 bought their most recently used marijuana from a friend. The majority (56.0%) of past year marijuana users aged 18 to 25 bought their most recently used marijuana inside a home, apartment or dormitory. 24



Marijuana is a Schedule I substance under the Controlled Substances Act ( CSA ). Schedule I drugs are classified as having a high potential for abuse, no currently accepted medical use in treatment in the United States, and a lack of accepted safety for use of the drug or other substance under medical supervision. 25

In the case of United States v. Oakland Cannabis Club the U.S. Supreme Court ruled that marijuana has no medical value as determined by Congress. The opinion of the court stated that: "In the case of the Controlled Substances Act, the statute reflects a determination that marijuana has no medical benefits worthy of an exception outside the confines of a government-approved research project." 26 The case reached the U.S. Supreme Court after the federal government sought an injunction in 1998 against the Oakland Cannabis Buyers Cooperative and five other marijuana distributors in California. 27

The United States Court of Appeals for the District of Columbia Circuit issued a ruling on May 24, 2002, upholding DEA's determination that marijuana must remain a schedule I controlled substance. The Court of Appeals rejected an appeal that contended that marijuana does not meet the legal criteria for classification in schedule I, the most restrictive schedule under the Controlled Substances Act. 28


Street Terms

"Grass," "pot," and "weed" are common street terms for marijuana. 29 Other terms include:

Marijuana Street Terms

Term Definition Term Definition
420 Marijuana use Homegrown Marijuana
BC bud High-grade marijuana from Canada Hydro Marijuana grown in water (hydroponic)
Bud Marijuana Indo Marijuana term from Northern CA
Chronic Marijuana Kind bud High quality marijuana
Dope Marijuana Mary Jane Marijuana
Ganja Marijuana; term from Jamaica Shake Marijuana
Herb Marijuana Sinsemilla Potent Marijuana


Other Links

A Collection of Articles That Address Research on Marijuana
This resource presents links to and full text of National Institute on Drug Abuse (NIDA) research articles concerning marijuana.

This page lists useful resources regarding marijuana use, its effects and treatment.

Marijuana Myths & Facts: The Truth Behind 10 Popular Misperceptions
This report looks at 10 popular misperceptions about marijuana and, using the latest research findings and statistical information, explains why they are wrong.

Marijuana Photos
This site provides photos of marijuana, hashish, and indoor growing operations.

Marijuana Prevention Initiative
To dispel myths and misconceptions about the drug, ONDCP has launched a comprehensive marijuana prevention initiative.

Marijuana Publications
A listing of publications related to marijuana from various sources.

Medical Marijuana Reality Check
Simply put, the smoked form of marijuana is not considered modern medicine. On April 20th, 2006, the FDA issued an advisory concluding that no sound scientific studies have supported medical use of smoked marijuana for treatment in the United States, and no animal or human data support the safety or efficacy of smoked marijuana for general medical use.

What Americans Need to Know About Marijuana
This document provides important facts about our nation’s most misunderstood illegal drug.

Who’s Really in Prison for Marijuana?
This report de-bunks the myth that our prisons are filled with low-level, non-violent marijuana users.



1 National Institute on Drug Abuse, Marijuana Facts Parents Need to Know , September 2004, What is Marijuana , How is Marijuana Used ?

2 Substance Abuse and Mental Health Services Administration, Results from the 2006 National Survey on Drug Use and Health: National Findings , September 2007

3 Ibid.

4 Ibid.

5 Substance Abuse and Mental Health Service Administration, Initiation of Marijuana Use: Trends, Patterns and Implications , July 2002.

6 National Institute on Drug Abuse and University of Michigan, 2007 Monitoring the Future Study Drug Data Tables, December 2007

7 Ibid.

8 Centers for Disease Control and Prevention, Youth Risk Behavior Surveillance—United States, 2005 , June 2006

9 National Institute on Drug Abuse and University of Michigan, Monitoring the Future National Survey Results on Drug Use, 1975–2006, Volume II: College Students & Adults Ages 19–45 (PDF), 2007

10 Bureau of Justice Statistics, Drug Use and Dependence, State and Federal Prisoners, 2004 , October 2006

11 National Institute on Drug Abuse, InfoFacts: Marijuana , April 2006

12 National Institute on Drug Abuse, Research Report Series—Marijuana Abuse , October 2001.

13 Ibid.

14 Substance Abuse and Mental Health Services Administration, Drug Abuse Warning Network, 2004: National Estimates of Drug-Related Emergency Department Visits , April 2006

15 Substance Abuse and Mental Health Services Administration, Mortality Data from the Drug Abuse Warning Network, 2001 (PDF), January 2003.

16 Substance Abuse and Mental Health Services Administration, Treatment Episode Data Set (TEDS) Highlights—2006 , February 2008

17 Federal Bureau of Investigation, Crime in the United States, 2006 , September 2007

18 National Drug Intelligence Center, National Drug Threat Assessment 2008 , October 2007

19 Bureau of Justice Statistics, Drug Use and Dependence, State and Federal Prisoners, 2004 , October 2006

20 U.S. Sentencing Commission, 2006 Sourcebook of Federal Sentencing Statistics , 2007

21 National Drug Intelligence Center, National Drug Threat Assessment 2008 , October 2007

22 Ibid.

23 Ibid.

24 Substance Abuse and Mental Health Services Administration, The NSDUH Report: How and Where Young Adults Obtain Marijuana , May 2006

25 Drug Enforcement Administration, Controlled Substances Act

26 Supreme Court of The United States, Syllabus: United States v. Oakland Cannabis Buyers' Cooperative Et Al. (PDF), May 2001.

27 Join Together Online, Supreme Court Rules against Medical Marijuana , May 15, 2001.

28 Drug Enforcement Administration, High Court Upholds Marijuana as Dangerous Drug , June 6, 2002.

29 Office of National Drug Control Policy, Drug Policy Information Clearinghouse, Street Terms Drugs and the Drug Trade , Marijuana Terms .