Marijuana, which contains the active ingredient of delta-9-terahydrocannabinol (THC), is typically smoked in hand-rolled cigarettes (joints), cigars (blunts), pipes, or water pipes (bongs). Marijuana is a Schedule I substance under the Controlled Substance Act and is classified as having a high potential for abuse. Marijuana is the most commonly used illicit drug. According to a 2002 national survey, marijuana was used by 75 percent of current illicit drug users. In addition, an estimated 40.4 percent of Americans age 12 or older had used marijuana or hashish in their lifetime. Marijuana use is associated with numerous detrimental health effects, such as respiratory infections, impaired memory and learning, increased heart rate, and anxiety. Approximately 55 percent of youth ages 12 to 17 surveyed in 2002 felt that it would be fairly or very easy to obtain marijuana. During 2002, the Drug Enforcement Administration (DEA) made 5,502 marijuana-related arrests which represented 18.6 percent of the total drug arrests made by the agency during the year. In 2001, some 8,000 convicted Federal drug offenders had committed an offense involving marijuana of which 7,758 were convicted of committing a trafficking offense. Among all Federal drug offenders receiving a prison sentence, those charged with marijuana offenses received the shortest ones. The number of admissions to drug and alcohol treatment in the United States increased from 1,527,930 in 1992 to 1,739,796 in 2001, with about 40 percent of those treated during 2001 being between the ages of 15 and 19 at admission. Tables and references