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National Survey on Drug Use and Health Daily Marijuana Users
November 26, 2004

Daily Marijuana Users

In Brief

  • In 2003, 3.1 million persons aged 12 or older used marijuana daily (i.e., on 300 or more days) in the past year

  • Daily marijuana users were more likely to be unemployed compared with those who used it less than daily and those who did not use it in the past year

  • Nearly two thirds of daily marijuana users used at least one other illicit drug in the past 12 months
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Marijuana use impairs physical and mental health, cognitive abilities, career status, and social life.1 Heavy marijuana use critically lowers learning skills, and daily use may result in overall reduced intellectual functioning.2 The National Survey on Drug Use and Health (NSDUH) asks persons aged 12 or older to report how many days they used marijuana in the past year.3 NSDUH also includes a series of questions to assess dependence on or abuse of marijuana and other substances. These questions are designed to measure substance dependence or abuse based on criteria specified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).4 This report examines the associations between daily marijuana use and other substance use, as well as dependence on or abuse of marijuana.
Past Year Daily Marijuana Use

In 2003, more than 25 million persons (10.6 percent) aged 12 or older reported past year use of marijuana. An estimated 3.1 million persons (1.3 percent of the population and 12.2 percent of past year marijuana users) were daily marijuana users (i.e., they used marijuana on 300 or more days in the past 12 months).

Demographic Differences in Daily Marijuana Use

Among young adults aged 18 to 25, approximately 4.3 percent reported daily marijuana use compared with about 1.1 percent of youths aged 12 to 17 and 0.8 percent of adults aged 26 or older (Table 1). Between 2002 and 2003, the number of 12 to 17 year olds reporting daily use of marijuana decreased from 358,000 to 282,000, while there were no changes in the number of daily marijuana users among 18 to 25 year olds or adults aged 26 or older.

Males were almost 3 times more likely to report daily marijuana use compared with females (2.0 vs. 0.7 percent).

Table 1. Estimated Numbers (in Thousands) and Percentages of Daily Marijuana Users, by Age and Gender: 2003

Figure 1. Employment among Adults Aged 18 to 64, by Frequency of Marijuana Use
Table 1. Estimated Numbers (in Thousands) and Percentages of Daily Marijuana Users, by Age and Gender: 2003 Figure 1. Employment among Adults Aged 18 to 64, by Frequency of Marijuana Use
Daily Marijuana Use and Employment

A larger percentage of daily marijuana users (12.9 percent) aged 18 to 64 reported being unemployed5 compared with less than daily marijuana users (7.9 percent) and nonusers (3.9 percent) (Figure 1). Persons who were less than daily marijuana users were more likely to be employed part time than daily marijuana users and nonusers.

Other Substance Use among Daily Marijuana Users

Nearly two thirds (63.3 percent) of daily marijuana users had used another illicit drug6 in the past 12 months compared with less than daily marijuana users and nonusers (38.8 and 4.6 percent, respectively) (Figure 2). Daily marijuana users also were more likely to smoke cigarettes in the past 30 days and to report heavy alcohol use in the past 30 days7 compared with less than daily marijuana users or nonusers.

Figure 2. Use of Substances Other Than Marijuana, by Frequency of Marijuana Use: 2003

Figure 3. Past Year Substance Dependence or Abuse, by Frequency of Marijuana Use in Past Year: 2003
Figure 2. Use of Substances Other Than Marijuana, by Frequency of Marijuana Use: 2003 Figure 3. Past Year Substance Dependence or Abuse, by Frequency of Marijuana Use in Past Year: 2003
Substance Dependence or Abuse among Daily Marijuana Users

More than half of daily marijuana users (53.3 percent) reported dependence on or abuse of alcohol or an illicit drug compared with those who were less than daily marijuana users (36.5 percent) and those who were nonusers (5.6 percent) (Figure 3). An estimated 39.2 percent of daily marijuana users were dependent on or abused marijuana compared with 13.5 percent of less than daily marijuana users (Figure 3).

End Notes
  1. Polen, M. R., Sidney, S., Tekawa, I. S., Sadler, M., & Friedman, G. D. (1993). Health care use by frequent marijuana smokers who do not smoke tobacco. Western Journal of Medicine, 158, 596–601.

  2. Pope, H. G., Jr., & Yurgelun-Todd, D. (1996). The residual cognitive effects of heavy marijuana use in college students. Journal of the American Medical Association, 275, 521–527.

  3. For this report, past year marijuana users by frequency of use are defined as follows: (1) "daily marijuana users" used marijuana on 300 or more days in the past 12 months; (2) "less than daily marijuana users" are all past year marijuana users who used marijuana on fewer than 300 days in the past 12 months; and (3) "nonusers" are those who have used marijuana sometimes in their lifetime, but not in the past year OR persons who have never used marijuana.

  4. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (4th ed.). Washington, DC: Author.

  5. "Unemployed" refers to respondents who reported no employment during the reference period, were available for work, except for temporary illness, and had made specific efforts to find employment some time during the reference period. Persons who were waiting to be recalled to a job from which they had been laid off need not have been looking for work to be classified as unemployed.

  6. Any illicit drug other than marijuana includes cocaine (including crack), heroin, hallucinogens, inhalants, or any prescription-type drug used nonmedically.

  7. Heavy alcohol use is defined as drinking five or more drinks on the same occasion on 5 or more days in the past 30 days.
Figure and Table Notes

* "Other" refers to retired persons, disabled persons, homemakers, students, or other persons not in the labor force.

** Past year marijuana dependence or abuse is not applicable among nonusers.

Source (all figures and table): SAMHSA, 2003 NSDUH.

The National Survey on Drug Use and Health (NSDUH) is an annual survey sponsored by the Substance Abuse and Mental Health Services Administration (SAMHSA). Prior to 2002, this survey was called the National Household Survey on Drug Abuse (NHSDA). The 2003 data are based on information obtained from 67,784 persons aged 12 or older. The survey collects data by administering questionnaires to a representative sample of the population through face-to-face interviews at their place of residence.

The NSDUH Report is prepared by the Office of Applied Studies (OAS), SAMHSA, and by RTI International in Research Triangle Park, North Carolina. (RTI International is a trade name of Research Triangle Institute.)

Information and data for this issue are based on the following publication and statistics:

Office of Applied Studies. (2004). Results from the 2003 National Survey on Drug Use and Health: National findings (DHHS Publication No. SMA 04–3964, NSDUH Series H–25). Rockville, MD: Substance Abuse and Mental Health Services Administration.

Also available online: http://www.oas.samhsa.gov.

Because of improvements and modifications to the 2002 NSDUH, estimates from the 2002 and 2003 surveys should not be compared with estimates from the 2001 or earlier versions of the survey to examine changes over time.

The NSDUH Report (formerly The NHSDA Report) is published periodically by the Office of Applied Studies, Substance Abuse & Mental Health Services Administration (SAMHSA). All material appearing in this report is in the public domain and may be reproduced or copied without permission from SAMHSA. Additional copies of this report or other reports from the Office of Applied Studies are available on-line: http://www.oas.samhsa.gov. Citation of the source is appreciated. For questions about this report please e-mail: shortreports@samhsa.hhs.gov.

This page was last updated on May 16, 2008.