Government Underestimates Marijuana Use, RAND Study Finds
Marijuana use is clearly identified by addiction specialists and public health experts as a reliable source of cases of both drug abuse and drug addiction. Despite this fact, there is a widening trend in the U.S. to decriminalize or legalize this drug and make it available for adult intake. In a report issued to the White House Office of Drug Control Policy in March 2014, researchers from the RAND Corporation estimated the number of marijuana users in the U.S. in each year from 2000 to 2010. This estimate indicates that the level of marijuana use reported by some federal agencies may be a significant underestimate of the true total.
Several federal projects track trends in marijuana use across the country. These projects include the Substance Abuse and Mental Health Services Administration’s National Survey on Drug and Health (NSDUH), the National Institute on Drug Abuse’s Monitoring the Future (MTF) and an interagency undertaking called the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). The most broad-based and regularly updated of these projects is the National Survey on Drug Use and Health, which includes basic estimates for monthly and annual marijuana use among all people in the U.S. age 12 or older. As of early 2014, the most recent available information from this survey covers 2012. It indicates that, in that year, slightly fewer than 19 million individuals in the targeted age range used the drug at least one time in the average or representative month. Figures from the NSDUH also indicate that about 5.4 million Americans used marijuana on at least 300 days of the year.
Estimates of Monthly Use
As the name implies, the National Survey on Drug Use and Health is a survey project that relies on participants to accurately record their own involvement in substance use. However, the RAND Corporation researchers believe that surveys on such a sensitive subject commonly end up underestimating the number of affected individuals. Such surveys also frequently miss or overlook certain segments of the population (including incarcerated individuals and the homeless) that have a higher-than-average rate of drug use. In order to overcome limitations of this sort, the researchers drew their findings from a number of other sources in addition to the NSDUH, including the Arrestee Drug Abuse Monitoring Program, which tracks drug use among individuals in the custody of the criminal justice system.
Using this wider range of sources, the RAND Corporation researchers tracked trends in marijuana use (as well as the use of several other substances) between 2000 and 2010. While the National Survey on Drug Use and Health estimated only about 18 million monthly marijuana users in 2010, the authors of the 2014 report estimate a total number of slightly fewer than 25 million monthly users for the same period of time.
Estimates of Yearly Use
The RAND Corporation researchers also gave an estimate of the total number of people who used marijuana at any point during all of 2010, then broke this total down into five levels of intake: infrequent intake, light intake, weekly intake, more-than-weekly intake and daily or near-daily intake. All told, the researchers believe that over 35 million Americans used marijuana to any extent in the 2010 calendar year. Roughly 13 million of these individuals qualified as infrequent users, while over 10 million qualified as light users. Approximately 6 million to 7 million people used marijuana on a weekly basis in 2010, according to the RAND Corporation estimates, while fewer than 5 million people used the drug more often than once a week, but not daily. In addition, roughly 7 million individuals were identified as daily users of marijuana.
In 2010, the National Survey on Drug Use and Health identified slightly fewer than 12 million people as infrequent annual marijuana users. The estimated number of light users fell between 6 million and 7 million, while the estimated number of weekly users fell between 4 million and 5 million. In addition, the NSDUH results identified roughly 3 million individuals as more-than-weekly marijuana users. The survey results identified 6.9 million people as daily or near-daily users of the drug in the year 2010.
Significance and Considerations
While the marijuana use-related findings of the RAND Corporation report and the National Survey on Drug Use and Health vary in important ways, they also overlap in important ways. For example, both projects indicate that much of the recent upward trend in marijuana intake stems from an increase in the number of people who use the drug on a daily or near-daily basis. This is critically important information, since 25 percent to 50 percent of all daily users of the drug eventually meet the criteria for diagnosing cannabis use disorder (marijuana/hashish abuse or addiction).