Marijuana Reality Check
by Robert L. DuPont, M.D, guest columnist
President, Institute for Behavior and Health, Inc.
Supporters of “medical marijuana” and marijuana legalization ignore the serious damages that marijuana use causes each year to Americans of all ages. About 9% of people who use marijuana become addicted to the drug, up to about 17 percent among individuals who start at a young age. Among daily marijuana users, between 25% and 50% become addicted. [i]
Marijuana is a primary cause of substance use disorders. Over 60% of all Americans aged 12 and older who have an illegal drug-related substance use disorder, abuse or are dependent on marijuana.[ii] More teens are in treatment with a primary diagnosis of marijuana dependence than all other illicit drugs combined.
Early marijuana use is especially dangerous. Adults age 18 and older who first started marijuana use at age 14 or younger are most likely to have abused or been dependent on illicit drugs in the past year.[iii] Additionally, adults who first used marijuana at or before age 14 were six times more likely to have a substance use disorder than those who initiated marijuana use at age 18 or older (12.6% vs. 2.1%) and two times more likely than those who initiated marijuana use between the ages of 15 and 17 (12.6% vs. 6.6%).
Preventing marijuana use by youth will not only limit the likelihood of later substance use disorders, but will also decrease initiation to other illegal drug use. Youth who use marijuana are more likely to have higher rates of other illegal drug use [iv] and to develop abuse and dependence.[v] A recent study of adolescents showed that among marijuana users, the risk for other illicit drug use was 21 times higher among experimental marijuana users and 124 times higher among daily marijuana users than non-users.[vi]
The short- and long-term effects of marijuana use, particularly heavy chronic marijuana use, are vast including deficits related to the brain, cognitive function, attention, et al.[vii] [viii] [ix] [x] [xi] [xii] [xiii] Marijuana use is associated with lower academic achievement[xiv] and increased rates of dropout.[xv] [xvi] [xvii] Marijuana contains about four times as much tar[xviii] [xix]and 60% more cancer-causing chemicals[xx] than cigarettes. Perhaps most concerning is the growing body of research showing an association between early marijuana use and the development and worsening symptoms of schizophrenia.[xxi] [xxii] [xxiii]
Marijuana use does not only harm the individual users. National rates of drugged driving show that marijuana is the most prevalent drug found among randomly stopped drivers[xxiv] and among fatally injured drivers.[xxv] Recent research confirms the danger of marijuana use amongst drivers in that marijuana use doubles the risk for crash.[xxvi] [xxvii]
Rates of marijuana use among adults and youth have increased in recent years. [xxviii] [xxix] With a growing number of Americans showing support for “medical marijuana” and marijuana legalization,[xxx] marijuana-based initiatives must be effectively combated with knowledge about the serious consequences of marijuana use.
For more information marijuana and its effects, visit:
– Office of National Drug Control Policy’s Marijuana Resource Center: www.whitehouse.gov/ondcp/marijuanainfo
– National Institute on Drug Abuse: www.drugabuse.gov
– Prevent Teen Drug Use: www.PreventTeenDrugUse.org
– Institute for Behavior and Health, Inc.: www.ibhinc.org
[i] National Institute on Drug Abuse. (2010, November). Marijuana. NIDA Info Facts. Rockville, MD: National Institute on Drug Abuse. Available: http://www.drugabuse.gov/publications/infofacts/marijuana
[ii] Substance Abuse and Mental Health Services Administration. (2011). Results from the 2010 National Survey on Drug Use and Health: Summary of National Findings. NSDUH Series H-41, HHS Publication No. (SMA) 11-4658. Rockville, MD: Substance Abuse and Mental Health Services Administration.
[iii] Center for Substance Abuse Research (2010, October 25). Early marijuana use related to later illicit drug abuse and dependence. CESAR Fax, 19(11). Available: http://www.cesar.umd.edu/cesar/cesarfax/vol19/19-41.pdf
[iv] Martin, K. R. (2003). Youths’ opportunities to experiment influence later use of illegal drugs. NIDA Notes, 17(3). Available: http://archives.drugabuse.gov/NIDA_Notes/NNVol17N5/Youths.html
[v] Agrawal, A., Neale, M.C., Prescott, C.A., & Kendler, K.S. (2004). A twin study of early cannabis use and subsequent use and abuse/dependence of other illicit drugs. Psychological Medicine, 34(7), 1227-1237.
[vi] Mayet, A., Legleye, S., Falissard, B., & Chau, N. (2012). Cannabis use stages as predictor of subsequent initiation with other illicit drugs among French adolescents: Use of a multi-state model. Addictive Behaviors, 37(2), 160-166.
[vii] Crean RD, Crane NA, Mason BJ. (2011). An evidence-based review of acute and long-term effects of cannabis use on executive cognitive functions. Journal of Addictive Medicine, 5(1):1-8.
[viii] Hall, W. & Solowij, N. (1998). Adverse effects of cannabis. The Lancet, 352(9140), 1611-1616.
[ix] Jager, G., & Ramsey, N.F. (2008). Long-term consequences of adolescent cannabis exposure on the development of cognition, brain structure and function: An overview of animal and human research. Current Drug Abuse Reviews, 1(2), 114-123.
[x] Ehrenreich, H., Rinn, T., Kunert, H.J., Moeller, M.R., Poser, W., Schilling, L., Gigerenzer, G., Hoehe, M.R. (1999). Specific attentional dysfunction in adults following early start of cannabis use. Psychopharmacology, 142(3), 295-301.
[xi] Hall, W., & Degenhardt, L. (2009). Adverse health effects of non-medical cannabis use.
[xii] Rubino, T., Realini, N., Braida, D., Guidi, S., Capurro, V., Vigano, D., É Parolaro, D. (2009). Changes in hippocampal morphology and neuroplasticity induced by adolescent THC treatment are associated with cognitive impairment in adulthood. Hippocampus, 19(8), 763-772.
[xiii] Wilson, W., Matthew, R., Turkington, T., Hawk, T., Coleman, R.E., & Provenzale, J. (2000). Brain morphological changes and early marijuana use: A magnetic resonance and positron emission tomography study. Journal of Addictive Diseases, 19(1), 1-22.
[xiv] Lynskey, M., & Hall, W. (2000). The effects of adolescent cannabis use on educational attainment: A review. Addiction, 9(5), 1621-1630.
[xv] Ellickson, P. L., Bui, K., Bell, R., & McGuigan, K. (1998). Does early drug use increase the risk of dropping out of high school? Journal of Drug Issues, 28(2), 357-380.
[xvi] Hunt, J., Eisenberg, D., & Kilbourne, A.M. (2010). Consequences of receipt of a psychiatric diagnosis for completion of college. Psychiatric Services, 61(4), 399-404.
[xviii] Tashkin, D. P. (2006). Smoked marijuana as a cause of lung injury. Archives for Chest Disease, 63(2), 93-100. Available: http://science.iowamedicalmarijuana.org/pdfs/safety/Tashkin%20MJ%20Lung%20Injury%20Monaldi%20Arch%20Chest%20Dis%202005.pdf
[xix] Wu, T.C., Tashkin, D.P., Djahed, B., & Rose, J.E. (1988). Pulmonary hazards of smoking marijuana as compared with tobacco. New England Journal of Medicine, 318(6), 347-51.
[xx] Drug Enforcement Administration. (2003, March 10). Health, education, safety experts join White House drug czar to educate parents about risks of marijuana use. Washington, DC: Drug Enforcement Administration. Available: http://www.justice.gov/dea/concern/ondcp_marijuana.html
[xxi] Zammit, S., et al. (2002). Self-reported cannabis use as a risk factor for schizophrenia in Swedish conscripts of 1969: historical cohort study. British Medical Journal, 325, 1199-1201.
[xxii] Foti, D.J., Kotov, R., Guey, L.T., Bromet, E.J. (2010). Cannabis use and the course of schizophrenia: 10-year follow up after first hospitalization.The American Journal of Psychiatry, 167(8), 987-93.
[xxiii] Fergusson, D.M., Horwood, L.J., & Ridder, E.M. (2005). Tests of causal linkages between cannabis use and psychotic symptoms. Addiction, 100(3), 354-366.
[xxiv] Compton, R., & Berning, A. (2009, July). Results of the 2007 National Roadside Survey of Aclohol and Drug Use by Drivers. Washington, DC: National Highway Traffic Safety Administration. Available: http://www.nhtsa.gov/DOT/NHTSA/Traffic%20Injury%20Control/Articles/Associated%20Files/811175.pdf
[xxv] CESAR Fax. (2010, December 20). One-third of fatally injured drivers with known test results tested positive for at least one drug in 2009. CESAR FAX, 19(49). Available: http://www.cesar.umd.edu/cesar/cesarfax/vol19/19-49.pdf
[xxvi] Li, M., Brady, J.E., DiMaggio, C.J., Lusardi, A.R., Tzong, K.Y., & Li, G. (2011). Marijuana use and motor vehicle crashes. Epidemiological Reviews. Epub ahead of print].
[xxvii] Ashbridge, M., Hayden, J. A., & Cartwright, J. L. (2012). Acute cannabis consumption and motor vehicle collision risk: Systematic review of observational studies and meta-analysis. British Medical Journal, 344:e536 doi: 10.1136/bmj.e536
[xxviii] Substance Abuse and Mental Health Services Administration. (2011). Results from the 2010 National Survey on Drug Use and Health: Summary of National Findings, NSDUH Series H-41, HHS Publication No. (SMA) 11-4658. Rockville, MD: Substance Abuse and Mental Health Services Administration.
[xxix] Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2012). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2011. Ann Arbor: Institute for Social Research, The University of Michigan.
[xxx] Backus, F. (2011). Marijuana and medical marijuana. CBS News Poll, October 28-31. Retrieved February 10, 2012 from http://www.cbsnews.com/htdocs/pdf/poll_marijuana_111811.pdf