Marijuana Myths & Facts Emerging Clinical Applications for Cannabis and Cannabinoids

June 3, 8:15 PMPittsburgh History ExaminerDev Meyers

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Pennsylvanians for Medical Marijuana and NORML have been promoting a lot of information to the public in advance of the upcoming hearings which will be a frank discussion on House Bill 1393.  The following represents a selection of their literature.

 Emerging Clinical Applications for Cannabis and Cannabinoids

Myth: Marijuana is More Damaging to the Lungs Than Tobacco. Marijuana smokers are at a high risk of developing lung cancer, bronchitis, and emphysema.

Fact: Moderate smoking of marijuana appears to pose minimal danger to the lungs. Like tobacco smoke, marijuana smoke contains a number of irritants and carcinogens. But marijuana users typically smoke much less often than tobacco smokers, and over time, inhale much less smoke. As a result, the risk of serious lung damage should be lower in marijuana smokers. There have been no reports of lung cancer related solely to marijuana, and in a large study presented to the American Thoracic Society in 2006, even heavy users of smoked marijuana were found not to have any increased risk of lung cancer. Unlike heavy tobacco smokers, heavy marijuana smokers exhibit no obstruction of the lung's small airway. That indicates that people will not develop emphysema from smoking marijuana.

• Center on Addiction and Substance Abuse. “Legalization: Panacea or Pandora’s Box.” New York. (1995): 36.
• Turner, Carlton E. The Marijuana Controversy. Rockville: American Council for Drug Education, 1981.
• 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.

 
Myth: Marijuana Has No Medicinal Value. Safer, more effective drugs are available. They include a synthetic version of THC, marijuana's primary active ingredient, which is marketed in the United States under the name Marinol.

Fact: Marijuana has been shown to be effective in reducing the nausea induced by cancer chemotherapy, stimulating appetite in AIDS patients, and reducing intraocular pressure in people with glaucoma. There is also appreciable evidence that marijuana reduces muscle spasticity in patients with neurological disorders. A synthetic capsule is available by prescription, but it is not as effective as smoked marijuana for many patients. Pure THC may also produce more unpleasant psychoactive side effects than smoked marijuana. Many people use marijuana as a medicine today, despite its illegality. In doing so, they risk arrest and imprisonment.

• 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.

Myth: Marijuana is a Gateway Drug. Even if marijuana itself causes minimal harm, it is a dangerous substance because it leads to the use of "harder drugs" like heroin, LSD, and cocaine.
 

Fact: Marijuana does not cause people to use hard drugs. What the gateway theory presents as a causal explanation is a statistic association between common and uncommon drugs, an association that changes over time as different drugs increase and decrease in prevalence. Marijuana is the most popular illegal drug in the United States today. Therefore, people who have used less popular drugs such as heroin, cocaine, and LSD, are likely to have also used marijuana. Most marijuana users never use any other illegal drug. Indeed, for the large majority of people, marijuana is a terminus rather than a gateway 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.

Myth: Marijuana's Harms Have Been Proved Scientifically. In the 1960s and 1970s, many people believed that marijuana was harmless. Today we know that marijuana is much more dangerous than previously believed.
 

Fact: In 1972, after reviewing the scientific evidence, the National Commission on Marihuana and Drug Abuse concluded that while marijuana was not entirely safe, its dangers had been grossly overstated. Since then, researchers have conducted thousands of studies of humans, animals, and cell cultures. None reveal any findings dramatically different from those described by the National Commission in 1972. In 1995, based on thirty years of scientific research editors of the British medical journal Lancet concluded that "the smoking of cannabis, even long term, is not harmful to health."

• United States. National Commission on Marihuana and Drug Abuse. Marihuana: A signal of misunderstanding. Shafer Commission Report. Washington, D.C.: U.S. Government Printing Office, 1972.
• “Deglamorising Cannabis.” Editorial. The Lancet 356:11(1995): 1241.

Myth: Marijuana Causes an Amotivational Syndrome. Marijuana makes users passive, apathetic, and uninterested in the future. Students who use marijuana become underachievers and workers who use marijuana become unproductive.
 

Fact: For twenty-five years, researchers have searched for a marijuana-induced amotivational syndrome and have failed to find it. People who are intoxicated constantly, regardless of the drug, are unlikely to be productive members of society. There is nothing about marijuana specifically that causes people to lose their drive and ambition. In laboratory studies, subjects given high doses of marijuana for several days or even several weeks exhibit no decrease in work motivation or productivity. Among working adults, marijuana users tend to earn higher wages than non-users. College students who use marijuana have the same grades as nonusers. Among high school students, heavy use is associated with school failure, but school failure usually comes first.

• Himmelstein, J.L. The Strange Career of Marihuana: Politics and Ideology of Drug Control in America. Westport, CT: Greenwood Press, 1983.
• Mellinger, G.D. et al. “Drug Use, Academic Performance, and Career Indecision:  Longitudinal Data in Search of a Model.” Longitudinal Research on Drug Use:  Empirical Findings and Methodological Issues. Ed. D.B. Kandel. Washington, DC: American Psychological Association, 1978. 157-177.
• Pope, H.G. et al., “Drug Use and Life Style Among College Undergraduates in 1989:  A Comparison With 1969 and 1978,” American Journal of Psychiatry 147 (1990): 998-1001.
   

Myth: Marijuana Policy in the Netherlands is a Failure. Dutch law, which allows marijuana to be bought, sold, and used openly, has resulted in increasing rates of marijuana use, particularly in youth.
 

Fact: The Netherlands' drug policy is the most nonpunitive in Europe. For more than twenty years, Dutch citizens over age eighteen have been permitted to buy and use cannabis (marijuana and hashish) in government-regulated coffee shops. This policy has not resulted in dramatically escalating cannabis use. For most age groups, rates of marijuana use in the Netherlands are similar to those in the United States. However, for young adolescents, rates of marijuana use are lower in the Netherlands than in the United States. The Dutch people overwhelmingly approve of current cannabis policy which seeks to normalize rather than dramatize cannabis use. The Dutch government occasionally revises existing policy, but it remains committed to decriminalization.

• 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.
   

Myth: Marijuana Kills Brain Cells. Used over time, marijuana permanently alters brain structure and function, causing memory loss, cognitive impairment, personality deterioration, and reduced productivity.
 

Fact: None of the medical tests currently used to detect brain damage in humans have found harm from marijuana, even from long term high-dose use. An early study reported brain damage in rhesus monkeys after six months exposure to high concentrations of marijuana smoke. In a recent, more carefully conducted study, researchers found no evidence of brain abnormality in monkeys that were forced to inhale the equivalent of four to five marijuana cigarettes every day for a year. The claim that marijuana kills brain cells is based on a speculative report dating back a quarter of a century that has never been supported by any scientific study.

• Heath, R.G., et al. “Cannabis Sativa: Effects on Brain Function and Ultrastructure in Rhesus Monkeys.” Biological Psychiatry 15 (1980): 657-690.
• Ali, S.F., et al. “Chronic Marijuana Smoke Exposure in the Rhesus Monkey IV: Neurochemical Effects and Comparison to Acute and Chronic Exposure to Delta-9-Tetrahydrocannabinol (THC) in Rats.” Pharmacology Biochemistry and Behavior 40 (1991): 677-82.

Myth: Marijuana Impairs Memory and Cognition. Under the influence of marijuana, people are unable to think rationally and intelligently. Chronic marijuana use causes permanent mental impairment.
 

Fact: Marijuana produces immediate, temporary changes in thoughts, perceptions, and information processing. The cognitive process most clearly affected by marijuana is short-term memory. In laboratory studies, subjects under the influence of marijuana have no trouble remembering things they learned previously. However, they display diminished capacity to learn and recall new information. This diminishment only lasts for the duration of the intoxication. There is no convincing evidence that heavy long-term marijuana use permanently impairs memory or other cognitive functions.

• 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.
   

Myth: Marijuana Causes Crime. Marijuana users commit more property offenses than nonusers. Under the influence of marijuana, people become irrational, aggressive, and violent.
 

Fact: Every serious scholar and government commission examining the relationship between marijuana use and crime has reached the same conclusion: marijuana does not cause crime. The vast majority of marijuana users do not commit crimes other than the crime of possessing marijuana. Among marijuana users who do commit crimes, marijuana plays no causal role. Almost all human and animal studies show that marijuana decreases rather than increases aggression.

• Fagan, J., et al. “Delinquency and Substance Use Among Inner-City Students.” Journal of Drug Issues 20 (1990): 351-402.
• Johnson, L.D., et al. “Drugs and Delinquency: A Search for Causal Connections.”  Ed. D.B. Kandel. Longitudinal Research on Drug Use: Empirical Findings and Methodological Issues. New York: John Wiley & Sons, 1978. 137-156.
• Goode, E. “Marijuana and Crime.” Marihuana: A Signal of Misunderstanding, Appendix I. National Commission on Marihuana and Drug Abuse Washington, DC: U.S. Government Printing Office, 1972. 447-453.
• Abram, K.M. and L.A. Teplin. “Drug Disorder, Mental Illness, and Violence.” Drugs and Violence: Causes, Correlates, and Consequences. Rockville: National Institute on Drug Abuse, 1990. 222-238.
• Cherek, D.R., et al. “Acute Effects of Marijuana Smoking on Aggressive, Escape and Point-Maintained Responding of Male Drug Users.” Psychopharmacology 111 (1993): 163-168.
• Tinklenberg, J.R., et al. “Drugs and criminal assaults by adolescents: A Replication Study.” Journal of Psychoactive Drugs 13 (1981): 277-287.

Myth: Marijuana Interferes With Male and Female Sex Hormones. In both men and women, marijuana can cause infertility. Marijuana retards sexual development in adolescents. It produces feminine characteristics in males and masculine characteristics in females.

Fact: There is no evidence that marijuana causes infertility in men or women. In animal studies, high doses of THC diminish the production of some sex hormones and can impair reproduction. However, most studies of humans have found that marijuana has no impact of sex hormones. In those studies showing an impact, it is modest, temporary, and of no apparent consequence for reproduction. There is no scientific evidence that marijuana delays adolescent sexual development, has feminizing effect on males, or a masculinizing effect on females.

• Parents Resource Institute for Drug Education. Marijuana and Cocaine. Atlanta, GA: PRIDE, 1990.
• Center for Substance Abuse Prevention. Female Adolescents and Marijuana Use; Fact Sheet for Adults. Rockville: U.S. Department of Health and Human Services, 1995.
• Center for Substance Abuse Prevention. Marijuana: Tips for Teens. Rockville: U.S. Department of Health and Human Services, 1995.
• Swan, Neil. “A Look at Marijuana’s Harmful Effects.” NIDA Notes. 9:2 (1994): 16.
• Clinton, President Bill. Speech at Framingham High School. Framingham, Massachusetts. 20 Oct. 1994.

Myth: Marijuana Use During Pregnancy Damages the Fetus. Prenatal marijuana exposure causes birth defects in babies, and, as they grow older, developmental problems. The health and well being of the next generation is threatened by marijuana use by pregnant women.

Fact: Studies of newborns, infants, and children show no consistent physical, developmental, or cognitive deficits related to prenatal marijuana exposure. Marijuana had no reliable impact on birth size, length of gestation, neurological development, or the occurrence of physical abnormalities. The administration of hundreds of tests to older children has revealed only minor differences between offspring of marijuana users and nonusers, and some are positive rather than negative. Two unconfirmed case-control studies identified prenatal marijuana exposure as one of many factors statistically associated with childhood cancer. Given other available evidence, it is highly unlikely that marijuana causes cancer in children.

• Mann, Peggy. The Sad Story of Mary Wanna. NY: Woodmere Press, 1988. 30.
• Fried, Peter. Quoted in “Marijuana: Its Use and Effects.” Prevention Pipeline. 8:5 (1995): 4.
• American Council for Drug Education. Drugs and Pregnancy. Rockville: Phoenix House, 1994.
• Swan, Neil. “A Look at Marijuana’s Harmful Effects.” NIDA Notes. 9. 2 (1994): 16.
• Parents Resource Institute for Drug Education. Marijuana – Effects on the Female. Atlanta, GA: PRIDE, 1996.

Myth: Marijuana Use Impairs the Immune System. Marijuana users are at increased risk of infection, including HIV. AIDS patients are particularly vulnerable to marijuana's immunopathic effects because their immune systems are already suppressed.

Fact: There is no evidence that marijuana users are more susceptible to infections than nonusers. Nor is there evidence that marijuana lowers users' resistance to sexually transmitted diseases. Early studies which showed decreased immune function in cells taken from marijuana users have since been disproved. Animals given extremely large doses of THC and exposed to a virus have higher rates of infection. Such studies have little relevance to humans. Even among people with existing immune disorders, such as AIDS, marijuana use appears to be relatively safe. However, the recent finding of an association between tobacco smoking and lung infection in AIDS patients warrants further research into possible harm from marijuana smoking in immune suppressed persons.

• Parents Resource Institute for Drug Education. Marijuana and Cocaine. Atlanta: PRIDE, 1990.
• Preate, Ernest D. Blowing Away the Marijuana Smokescreen. Scranton: Pennsylvania Office of Attorney General, [no date]: 2.
• Spence, W.R. Marijuana: Its Effects and Hazards. Waco: Health Edco, [no date].
• Voth, Eric A. The International Drug Strategy Institute Position Paper on the Medical Applications of Marijuana. Omaha: Drug Watch International, [no date].
• Drug Watch International. By Any Modern Medical Standard, Marijuana is No Medicine. Omaha: Drug Watch International, [no date].

Myth: Marijuana's Active Ingredient, THC, Gets Trapped in Body Fat. Because THC is released from fat cells slowly, psychoactive effects may last for days or weeks following use. THC's long persistence in the body damages organs that are high in fat content, the brain in particular.

Fact: Many active drugs enter the body's fat cells. What is different (but not unique) about THC is that it exits fat cells slowly. As a result, traces of marijuana can be found in the body for days or weeks following ingestion. However, within a few hours of smoking marijuana, the amount of THC in the brain falls below the concentration required for detectable psychoactivity. The fat cells in which THC lingers are not harmed by the drug's presence, nor is the brain or other organs. The most important consequence of marijuana's slow excretion is that it can be detected in blood, urine, and tissue long after it is used, and long after its psychoactivity has ended.

• Committees of Correspondence. Drug Abuse Newsletter 16 (March 1984).
• Mann, Peggy. Marijuana Alert. New York: McGraw-Hill Book Company. 1985. 184.
• Nahas, Gabriel. "When Friends of Patients Ask About Marihuana." Journal of the American Medical Association 233 (1979): 79.
• DuPont, Robert. Getting Tough on Gateway Drugs. Washington, DC: American Psychiatric Press, 1984. 68.

Myth: Marijuana Related Hospital Emergencies Are Increasing, Particularly Among Youth. This is evidence that marijuana is much more harmful than most people previously believed.

Fact: Marijuana does not cause overdose deaths. The number of people in hospital emergency rooms who say they have used marijuana has increased. On this basis, the visit may be recorded as marijuana-related even if marijuana had nothing to do with the medical condition preceding the hospital visit. Many more teenagers use marijuana than use drugs such as heroin and cocaine. As a result, when teenagers visit hospital emergency rooms, they report marijuana much more frequently than they report heroin and cocaine. In the large majority of cases when marijuana is mentioned, other drugs are mentioned as well. In 1994, fewer than 2% of drug related emergency room visits involved the use of marijuana.

• Brown, Lee. Quoted in U.S. Department of Health and Human Services Press Release, National Drug Survey Results Released with New Youth Public Education Materials. Rockville: 12 September 1995.
• Shalala, Donna. "Say ‘No’ to Legalization of Marijuana." Wall Street Journal 18 August 1995: A10.
• Shuster, Charles. Quoted in Drug Enforcement Administration. Drug Legalization: Myths and Misconceptions. Washington, DC: U.S. Department of Justice, 1994. 5.