Marijuana has been the most common illicit substance used in the United States for several decades, and among illicit substance use disorders, marijuana use disorders are the most prevalent in the population, according to background information in the article. Marijuana use is associated with impaired educational attainment, reduced workplace productivity, and increased risk of use of other substances. Marijuana use plays a major role in motor vehicle crashes and has adverse effects on the respiratory and cardiovascular systems. Despite the seriousness of marijuana abuse and dependence, no long-term trend information has been available.
Wilson M. Compton, M.D., M.P.E., from the National Institute on Drug Abuse, National Institutes of Health, Department of Health and Human Services, Bethesda, Md., and colleagues assessed changes in marijuana use, abuse, and dependence in the U.S. population. The study consisted of face-to-face interviews conducted in 2 large national surveys conducted 10 years apart: the 1991-1992 National Longitudinal Alcohol Epidemiologic Survey ([NLAES] n=42,862) and the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions ([NESARC] n = 43,093).
Among the U.S. adult population, the prevalence of marijuana use remained stable at about 4 percent over the past decade, while the prevalence of marijuana dependence or abuse significantly increased between 1991-1992 (1.2 percent) and 2001-2002 (1.5 percent). The greatest increases were among young black men and women and young Hispanic men. Marijuana use disorders among marijuana users increased in the absence of increased frequency and quantity of marijuana use. The authors speculate that these findings may be attributable, in part, to increased potency of marijuana.
"Concerning public health implications, it is important to communicate that the increased potency of marijuana over the past decade may, in part, be responsible for increases in abuse and dependence among users. This is critical information for parents, teachers, peers, physicians, and other health professionals. From a broader public health perspective, the results of this study highlight the need to strengthen existing prevention and intervention efforts and to develop and implement widely new programs with the sex, racial/ethnic, and age differentials observed in this study in mind. Specifically, programs targeting young adults, especially black and Hispanic young adults, need to be designed and tested for their effectiveness as quickly as possible," the authors conclude. (JAMA. 2004;291:2114-2121. Available post-embargo at JAMA.com)
Editor's Note: The National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) is funded by the National Institute on Alcohol Abuse and Alcoholism (NIAAA) with supplemental support from the National Institute on Drug Abuse (NIDA).