Most marijuana users never use any other illicit drug.
Morral, Andrew R.; McCaffrey, Daniel F. and Susan M. Paddock. “Reassessing the marijuana gateway effect.” Addiction 97.12 (2002): 1493-504.
United States. National Household Survey on Drug Abuse: Population Estimates 1994. Rockville, MD: U.S. Department of Health and Human Services, 1995.
National Household Survey on Drug Abuse: Main Findings 1994. Rockville, MD: U.S. Department of Health and Human Services, 1996.
D.B. Kandel and M. Davies, “Progression to Regular Marijuana Involvement: Phenomenology and Risk Factors for Near-Daily Use,” Vulnerability to Drug Abuse, Eds. M. Glantz and R. Pickens. Washington, D.C.: American Psychological Association, 1992: 211-253.
Most people who use marijuana do so occasionally. Increasing admissions for treatment do not reflect increasing rates of clinical dependence.
United States. Dept. of Health and Human Services. DASIS Report Series, Differences in Marijuana Admissions Based on Source of Referral. June 24 2005.
Johnson, L.D., et al. “National Survey Results on Drug Use from the Monitoring the Future Study, 1975-1994, Volume II: College Students and Young Adults.” Rockville, MD: U.S. Department of Health and Human Services, 1996.
Kandel, D.B., et al. “Prevalence and demographic correlates of symptoms of dependence on cigarettes, alcohol, marijuana and cocaine in the U.S. population.” Drug and Alcohol Dependence 44 (1997):11-29.
Stephens, R.S., et al. “Adult marijuana users seeking treatment.” Journal of Consulting and Clinical Psychology 61 (1993): 1100-1104.
Claims about marijuana potency increases are vastly overstated. In addition, potency is not related to risk of dependence or health impacts.
Henneberger, Melinda. "Pot Surges Back, But It’s, Like, a Whole New World." New York Times 6 February 1994: E18.
Brown, Lee. “Interview with Lee Brown,” Dallas Morning News 21 May 1995.
Drug Enforcement Administration. U.S. Drug Threat Assessment, 1993. Washington, DC: U.S. Department of Justice, 1993.
Kleiman, Mark A.R. Marijuana: Costs of Abuse, Costs of Control. Westport: Greenwood Press, 1989. 29.
Bennett, William. Director of National Drug Control Policy, remarks at Conference of Mayors. 23 April 1990.
Marijuana has not been shown to cause mental illness.
Iverson, Leslie. “Long-term effects of exposure to cannabis.” Current Opinion in Pharmacology 5(2005): 69-72.
SBD Bahri, MC Jockers-Scherübl. “Cannabis induces different cognitive changes in schizophrenic patients and in controls,” Klinik für Psychiatrie und Psychotherapie, Charité, Universitätsmedizin Berlin, Pharmacopsychiatry 2005; 38
Weiser and Noy. “Interpreting the association between cannabis use and increased risk of schizophrenia.” Dialogues in Clincal Neuroscience 1(2005): 81-85.
"Cannabis use will impair but not damage mental health." London Telegraph. 23 January 2006.
Andreasson, S. et al. “Cannabis and Schizophrenia: A Longitudinal study of Swedish Conscripts,” The Lancet 2 (1987): 1483-86.
Degenhardt, Louisa, Wayne Hall and Michael Lynskey. “Testing hypotheses about the relationship between cannabis use and psychosis,” Drug and Alcohol Dependence 71 (2003): 42-4.
Weil, A. “Adverse Reactions to Marijuana: Classification and Suggested Treatment.” New England Journal of Medicine 282 (1970): 997-1000.
Marijuana use has not been shown to increase risk of cancer.
Tan WC, Lo C, Jong A, et al.; for the Vancouver Burden of Obstructive Lung Disease (BOLD) Research Group. Marijuana and chronic obstructive lung disease: a population-based study. Canadian Medical Association Journal 2009;180:814–20.
Nahas, Gabriel G. and Nicholas A. Pace. Letter. “Marijuana as Chemotherapy Aid Poses Hazards.” New York Times 4 December 1993: A20.
Inaba, Darryl S. and William E. Cohen. Uppers, Downers, All-Arounders: Physical and Mental Effects of Psychoactive Drugs. 2nd ed. Ashland: CNS Productions, 1995. 174.
Marijuana has been proven helpful for treating the symptoms of a variety of medical conditions.
Vinciguerra, Vincent; Moore, Terry and Eileen Brennan. “Inhalation marijuana as an antiemetic for cancer chemotherapy.” New York State Journal of Medicine 85 (1988): 525-27.
McCabe M, Smith FP, Macdonald JS. “Efficacy of tetrahydrocannabinol in patients refractory to standard antiemetic therapy.” Investigational New Drugs 6.3 (1988): 243-46.
Gorter, R., et al. “Dronabionol effects on weight in patients with HIV infection.” 1992. AIDS 6 (1992):127-38.
Foltin, R.W., et al. “Behavioral analysis of marijuana effects on food intake in humans.” Pharmacology Biochemistry and Behavior 25 (1986): 577-82.
Crawford, W.J. and Merritt, J.C. “Effect of tetrahydrocannabinol on Arterial and Intraocular Hypertension.” International Journal of Clinical of Pharmacology and Biopharmaceuticals 17 (1979):191-96.
Merritt, J.C., et al. “Effects of marijuana on intraocular and blood pressure on glaucoma.” Ophthamology 87 (1980):222-28.
Baker, D., Gareth Pryce and J. Ludovic Croxford. “Cannabinoids control spasticity and tremor in a multiple sclerosis model.” Nature 404.6773 (2000): 84-7.
Hanigan, W.C., et al. “The Effect of Delta-9-THC on Human Spasticity.” Clinical Pharmacology and Therapeutics 39 (1986):198.
Marijuana use rates in the Netherlands are similar to those in the U.S. despite very different policies.
Fromberg, E. “The Case of the Netherlands: Contradictions and Values in Questioning Prohibition.” 1994 International Report on Drugs, Brussels: International Antiprohibitionist League, 1994. 113-124.
Sandwijk, J.P., et al. Licit and Illicit Drug Use in Amsterdam II. Amsterdam: University of Amsterdam, 1995.
Gunning, K.F. Crime Rate and Drug Use in Holland. Rotterdam: Dutch National Committee on Drug Prevention. 1993.
Marijuana has not been shown to cause long-term cognitive impairment.
Wetzel, C.D. et al., “Remote Memory During Marijuana Intoxication,” Psychopharmacology 76 (1982): 278-81.
Deadwyler, S.A. et al., “The Effects of Delta-9-THC on Mechanisms of Learning and Memory.” Neurobiology of Drug Abuse: Learning and Memory. Ed. L. Erinoff. Rockville, MD: National Institute on Drug Abuse 1990. 79-83.
Block, R.I. et al., “Acute Effects of Marijuana on Cognition: Relationships to Chronic Effects and Smoking Techniques.” Pharmacology Biochemistry and Behavior 43 (1992): 907-917.
There is no compelling evidence that marijuana contributes substantially to traffic accidents and fatalities.
Center on Addiction and Substance Abuse. “Legalization: Panacea or Pandora’s Box”. New York. (1995):36.
Swan, Neil. “A Look at Marijuana’s Harmful Effects.” NIDA Notes. 9.2 (1994): 14.
Moskowitz, Herbert and Robert Petersen. Marijuana and Driving: A Review. Rockville: American Council for Drug Education, 1982. 7.
Mann, Peggy. Marijuana Alert. New York: McGraw-Hill, 1985. 265.
More than 800,000 people are arrested for marijuana each year, the vast majority of them for simple possession.
United States. Federal Bureau of Investigation. Uniform Crime Reports for the United States, 2009. Washington: U. S. Dept. of Justice, 2010.
Gettman, Jon B. National Organization for the Reform of Marijuana Laws. Crimes of Indescretion: Marijuana arrests in the United States. Washington: NORML, 2005.