Street Name / Slang Terms
Aunt Mary, Bobby, Boom, Chronic, Dope ganja, Gangster, Grass, Hash, Herb, Kif, Mary Jane, Pot, Reefer, Sinsemilla, Skunk, Weed

What is it ?
Marijuana is a product of the hemp plant, Cannabis sativa. The main active chemical in marijuana is THC (delta-9-tetrahydrocannabinol). Of the roughly 400 chemicals found in the cannabis plant, THC affects the brain the most.

What does it look like ?
Green or gray mixture of dried, shredded leaves of the hemp plant.

How is used ?
Usually smoked as a cigarette or joint, or in a pipe or bong, marijuana has appeared in blunts in recent years. These are cigars that have been emptied of tobacco and re-filled with marijuana, sometimes in combination with another drug, such as crack. Some users also mix marijuana into foods or use it to brew tea.

Effects of Marijuana on the Brain
Researchers have found that THC changes the way in which sensory information gets into and is acted on by the hippocampus. This is a component of the brain’s limbic system that is crucial for learning, memory, and the integration of sensory experiences with emotions and motivations. Investigations have shown that THC suppresses neurons in the information processing system of the hippocampus. In addition, researchers have discovered that learned behaviors, which depend on the hippocampus, also deteriorate.

Effects of Marijuana on the Lungs
Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers have. These individuals may have daily cough and phlegm, symptoms of chronic bronchitis, and more frequent chest colds. Continuing to smoke marijuana can lead to abnormal functioning of lung tissue injured or destroyed by marijuana smoke.

Regardless of the THC content, the amount of tar inhaled by marijuana smokers and the level of carbon monoxide absorbed are three to five times greater than among tobacco smokers. This may be due to marijuana users inhaling more deeply and holding the smoke in the lungs.

Other Short Term Effects
Dry mouth and/or throat, problems with memory and learning, distorted perception (sights, sounds, time, touch), trouble with thinking and problem solving, loss of motor coordination, increased heart rate, and anxiety. These effects are even greater when other drugs are mixed with marijuana.

Persons high on marijuana show the same lack of coordination on standard drunk driver tests as do people who have had too much to drink.

Long Term Effects
Marijuana smoke contains some of the same cancer-causing compounds as tobacco, sometimes in higher concentrations. Someone who smokes 1 to 3 joints can produce the same lung damage and potential cancer risk as smoking five times as many cigarettes.

Federal Classification
Schedule I

National Institute on Drug Abuse

Marijuana Statistics

  • Marijuana is the most commonly used illicit drug in the United States.1
  • The percentage of youth aged 12–17 indicating a great risk of smoking marijuana once a month remained unchanged between 1999 and 2000 (37.2% in 1999 and 37.7% in 2000).2
  • Marijuana contains more than 400 chemicals, including most of the harmful substances found in tobacco smoke. Smoking one marijuana cigarette deposits about four times more tar into the lungs than a filtered tobacco cigarette.3
  • Harvard University researchers report the risk of a heart attack is five times higher than usual in the hour after smoking marijuana.4
  • The risk of using cocaine is estimated to be more than 104 times greater for those who have tried marijuana than for those who have never tried it.5
  • Smoking marijuana can injure or destroy lung tissue. In fact, marijuana smoke contains 50–70% more of some cancer causing chemicals than does tobacco smoke.6
  • Reaction time for motor skills, such as driving, is reduced by 41% after smoking one joint and is reduced 63% after smoking two joints.7
  • There have been over 7,000 published scientific and medical studies documenting the damage that marijuana poses. Not one study has shown marijuana to be safe.7
U.S. Dept. of Justice
U.S. Dept. of Health & Human Services
Drug Enforcement Administration
Marijuana & Heart Attacks, Washington Post, 3/3/2000
Marijuana: Facts Parents Need to Know, National Institute on Drug Abuse
American Lung Association

Additional Online Resources

Facts and tips for parents about simple things they can do to help prevent their teens from using marijuana.

Prevention posters for youth audiences featuring contemporary design and hard-hitting information about marijuana.

Postcards that debunk myths and provide the facts about marijuana.

Brochure dispelling popular myths and misconceptions about marijuana and providing tips on how parents can keep their children from using the drug.

Seven-minute video highlights the latest research and features commentary by leading experts about the effects of marijuana on youth. It also includes television ads for youth on the negative consequences of marijuana use, for parents on the importance of monitoring their kids and for the general audience on the importance of community coalitions.

Scientific information about harmful effects, research-based information on the myths and misperceptions, and strategies to reduce and prevent youth marijuana use.

Just how “harmless” is marijuana? Quizzes for youth and adults.

Fellowship of men and women sharing experience, strength, and hope to help one another recover from marijuana addiction. There are no affiliations with any religious or secular institution or organization and there are no membership dues or fees. The only requirement is a desire to stop using marijuana.

Information on marijuana trafficking, seizures, price, and purity.

Resources regarding marijuana use, its effects, and treatment.

Publications related to marijuana from various sources.

Review of marijuana-related activities 1900–2001.

Nationwide effort to prevent marijuana use among youth; educational information, research, activities, and publications.

Factual information about marijuana for teens.

Publications, research, and news related to marijuana. (National Institute on Drug Abuse)