Marijuana Policy Project

The U.S. has some of the world's most punitive drug policies and also the world's highest rates of marijuana and cocaine use, according to this World Health Organization survey of 17 countries, conducted by some of the world's leading substance abuse researchers.

While federal officials regularly note with alarm that marijuana use is associated with poor grades, this study suggests that poor grades may be a cause of teen marijuana use, not the result. Interestingly, school grades were often a stronger predictor of future marijuana use than were attitudes or beliefs about marijuana.

This biennial Centers for Disease Control survey of U.S. high school students looks at a variety of behaviors that might put young people at risk, including behaviors related to violence, sex, alcohol, and drugs.

Conducted by researchers from the University of Alberta, this ethnographic study of 41 adult Canadian marijuana users found that there is no such thing as a "typical marijuana user."

The U.S. has some of the world's most punitive drug policies and also the world's highest rates of marijuana and cocaine use, according to this World Health Organization survey of 17 countries, conducted by some of the world's leading substance abuse researchers.

What is the real "gateway drug"? This study of twins suggests that use of any drug by young people is an early warning signal that later use of other drugs is likely, with alcohol and cigarettes commonly coming before marijuana or other illicit drugs.

This report -- based on U.S. government data -- details the enormous volume of marijuana harvested and sold untaxed in the U.S., where in 2006 it was the country's number one cash crop, worth more than the corn and wheat crops combined.

With the estimated retail value of the U.S. marijuana market at $113 billion, the local, state, and federal governments are forgoing $31.1 billion in potential sales tax each year. At the same time, marijuana arrests cost taxpayers $10.7 billion annually.

This 60-page report is an evidence-based literature review of marijuana, based only upon research that followed well-accepted research designs, included strong statistical and procedural controls, and passed a careful review by independent scientists.

This British government survey tracks the continuing drop in marijuana use by both adults and teens after Britain ended most marijuana possession arrest in 2004, with marijuana use in the past year reaching its lowest level in more than a decade.

When Britain legally downgraded marijuana in 2004, ending arrests for most marijuana possession cases, critics complained that the move would encourage marijuana use, particularly among young people. This official British government survey -- one of an annual series -- charts a continuing drop in overall drug use, and a significant drop in the use of marijuana, particularly by young people.

In this examination of the gateway theory, researchers studied more than 4,000 Australian twins whose use of marijuana and other drugs was followed in detail from adolescence into adulthood and matched the real-world data from the twins to mathematical models based on 13 different explanations of how use of marijuana and other illicit drugs might be related.

The gateway theory suggests that marijuana use leads to use of hard drugs like heroin and cocaine. This study suggests that underlying genetic and environmental factors -- not marijuana use -- are what encourage use of marijuana and other drugs.

Rob Kampia's Presentation at Freedom Fest in Las Vegas, July 2007

Marijuana Use by Young People: The Impact of State Medical Marijuana Laws

Common Questions About Marijuana Answered by the Institute of Medicine