Marijuana is the most commonly used illicit drug (17.4 million past-month users) according to the 2010 National Survey on Drug Use and Health (NSDUH)1. That year, marijuana was used by 76.8 percent of current illicit drug users (defined as having used the drug at some time in the 30 days before the survey) and was the only drug used by 60.1 percent of them.1
Marijuana use is widespread among adolescents and young adults. According to the Monitoring the Future Survey—an annual survey of attitudes and drug use among the Nation's middle and high school students—most measures of marijuana use decreased in the past decade among 8th-, 10th-, and 12th-graders. However, this decline has stalled in the past few years as attitudes have softened about marijuana's risks. In 2011, 12.5 percent of 8th-graders reported marijuana use in the past year, and 7.2 percent were current users. Among 10th-graders, 28.8 percent had used marijuana in the past year, and 17.6 percent were current users. Rates of use among 12th-graders were higher still: 32.8 percent had used marijuana during the year prior to the survey, and 20.6 percent were current users.2
The Drug Abuse Warning Network (DAWN), a system for monitoring the health impact of drugs, estimated that in 2009, marijuana was a contributing factor in over 376,000 emergency department (ED) visits in the United States, with about two-thirds of patients being male, and 12 percent between the ages of 12 and 17. 4
As a result of scientific research, we know that addiction is a disease that affects both brain and behavior.