Marijuana – Extent of Use

Extent of Use

Monitoring the Future Study (MTF) *

The NIDA-funded MTF provides an annual assessment of drug use among 12th, 10th, and 8th grade students and young adults nationwide. After decreasing for over a decade, marijuana use among students began to increase in the early 1990s. From 1998 to 1999, use of marijuana at least once (lifetime use) increased among 12th- and 10th-graders, continuing the trend seen in recent years. The seniors’ rate of lifetime marijuana use is higher than any year since 1987, but all rates remain well below those seen in the late 1970s and early 1980s. Past year and past month marijuana use did not change significantly from 1998 to 1999 in any of the three grades, suggesting the sharp increases of recent years may be slowing. Daily marijuana use in the past month increased slightly among all three grades as well.

Percentage of 8th-Graders Who Have Used Marijuana:

Monitoring the Future Study, 1999

Percentage of 10th-Graders Who Have Used Marijuana:

Monitoring the Future Study, 1999

Percentage of 12th-Graders Who Have Used Marijuana

Monitoring the Future Study, 1999

Community Epidemiology Work Group (CEWG)**

In 1998, marijuana indicators continued an upward trend in most of the 20 CEWG metropolitan areas. Rates of emergency department men-tions of marijuana increased significantly in seven sites, with the largest increases occurring in Dallas (emergency room mentions increased to 63.9 percent), Boston (to 44.1 percent), Denver (to 40 percent), San Diego (to 35.1 percent), and Atlanta (to 31.7 percent). The highest percent increase in emergency room mentions comparing the first half of 1997 and the first half of 1998 was among 12- to 17-year olds.

Treatment data for primary abuse of marijuana increased in six CEWG sites and remained stable elsewhere. Marijuana treatment admissions were highest in Denver (41 percent of all admissions), Miami (30 percent), New Orleans (22 percent), and Minneapolis/ St. Paul (20 percent). Half of the treatment admissions for marijuana in Minneapolis/St. Paul were under age 18.

In six of the CEWG sites, juvenile arrestees testing positive for marijuana ranged from a low of 40.3 percent in St. Louis to a high of 63.7 percent in Phoenix. More than 50 percent of juvenile arrestees in Los Angeles, Denver, and Washington, D.C. tested positive for marijuana, and 48.9 percent in San Diego. Among all arrestees, Seattle was the only site where women were more likely than men (37.9 percent vs. 35.4 percent) to test positive for marijuana.

National Household Survey on Drug Abuse (NHSDA)***

Marijuana remains the most commonly used illicit drug in the United States. There were an estimated 2.1 million people who started using marijuana in 1998. According to data from the 1998 NHSDA, more than 72.0 million Americans (33 percent) 12 years of age and older have tried marijuana at least once in their lifetimes, and almost 18.7 million (8.6 percent) had used marijuana in the past year. In 1985, 56.5 million Americans (29.4 percent) had tried marijuana at least once in their lifetimes, and 26.1 million (13.6 percent) had used marijuana within the past year.

* MTF is an annual survey on drug use and related attitudes of America’s adolescents that began in 1975. The survey is conducted by the University of Michigan’s Institute for Social Research and is funded by NIDA. Copies of the latest survey are available from the National Clearinghouse for Alcohol and Drug Information at 1-800-729-6686.

** CEWG is a NIDA-sponsored network of researchers from 20 major U.S. metropolitan areas and selected foreign countries who meet semiannually to discuss the current epidemiology of drug abuse. CEWG’s most recent reports are available on the CEWG web site.

*** NHSDA is an annual survey conducted by the Substance Abuse and Mental Health Services Administration Copies of the latest survey are available from the National Clearinghouse for Alcohol and Drug Information at 1-800-729-6686