10 Marijuana Myths Advocates Want You to Believe

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By Dr. Christine Miller, Ph.D.
Myth #1. It is rare for marijuana users to experience psychotic symptoms like paranoia.
In fact, about 15% of all users and a much higher percentage of heavy users will experience psychotic symptoms.1 Half of those individuals will become chronically schizophrenic if they don’t stop using.2 Fortunately, some do stop using because psychosis is not pleasant and they wisely recognize that pot caused their problems.
Myth #2. Marijuana-induced psychosis must be due to other contaminating drugs.
Clinical studies under controlled laboratory conditions have shown that administering the pure, active ingredient of pot, ∆9-THC, elicits psychotic symptoms in normal volunteers.3  In addition, epidemiological research of nearly 19,000 drug abusing Finnish subjects showed that it was not LSD, amphetamine, cocaine, methamphetamine, PCP or opiates that most consistently led to a diagnosis of long term schizophrenia, it was marijuana.4 Thus, if you lace your LSD with marijuana, you are more likely to go psychotic.
Myth #3.  If marijuana is associated with the development of chronic psychosis (schizophrenia), it is only because the patients are self-medicating. Correlation does not equal causation.
Actually, four studies have been carried out in Europe to ask the question which comes first, the marijuana use or the schizophrenia. The research was designed to follow thousands of young teen subjects through a course of several years of their lives, and to ask if those who were showing symptoms of psychosis at study onset were more likely to begin smoking pot, or were those who were normal but began smoking pot during the course of the study more likely to become psychotic. Three of the studies5 convincingly showed that the evidence for marijuana triggering schizophrenia was strong, whereas the evidence for self-medication was weak. The fourth concluded that both were happening — marijuana was triggering psychosis and psychotic individuals were self-medicating.6
Myth #4. Those who become schizophrenic from marijuana use were destined to become so anyway because of their genes.
The truth of the matter is that no one is destined to become schizophrenic. Even in the case where one member of an identical pair of twins has schizophrenia, only about half the time does the other twin become schizophrenic as well.7  Thus, there is ample room for environmental factors like marijuana to make a difference between leading a normal life and not.
Myth #5. Studies showing links between marijuana and psychotic disorders like schizophrenia are “cherry picked” to exclude negative studies.
A very large review of all relevant published papers was conducted by a group of researchers from around the world and published in the prestigious medical journal, The Lancet. No attempt was made to exclude results that were negative. The results they obtained by merging all the studies was that marijuana use approximately doubles the risk for schizophrenia.8 Later research has shown that the risk goes up to 6-fold if the use is heavy or if the pot is strong 9 (similar to the strength of marijuana that is coming out of Colorado now).
Myth #6. Marijuana makes you mellow and less aggressive.
This is certainly not the case for the 15% who experience psychotic symptoms and the subgroup who then go on to develop a chronic psychosis. These individuals are up to 9-times more likely to commit serious acts of violence than people whose schizophrenia has nothing to do with drug use.10 Just a few of the very recent high profile cases here on the East Coast include January’s Columbia Mall shooter Darion Aguilar and “multiverse”-ranting Vladimir Baptiste, who drove a truck through a Towson, MD TV station in May. Somewhat less violent cases include White House episodes: Oscar Ortega, charged with shooting at the White House, ex-Navy Seal employee David Gil Wilkerson charged with threatening the life of the President and most recently, fence jumper Dominic Adesanya who is charged with attacking the White House guard dogs this October. In the Rocky Mountain region, soccer dad Richard Kirk became psychotic after his first use of marijuana edibles for his back pain, and while hallucinating that the world was going to end, shot his wife to death as his children listened through a closed door.On the West Coast, the mentally ill marijuana user Aaron Ybarra shot one student dead and wounded two others on the campus of Seattle Pacific University. In Ottawa this past week, rifleman Michael Zehaf-Bibeau was originally thought to have terrorist ties after he killed a young guard at the Capitol, but instead his friends paint a picture of psychosis and law enforcement records reveal more than one arrest for marijuana possession. All of these individuals exhibited psychotic symptoms prior to their acts and their mental illness could be traced to their marijuana habit in my opinion.
Myth #7. Marijuana is good for the symptoms of PTSD and by keeping this drug from our veterans, we are depriving them of an important alternative treatment.
Veterans Affairs Administration studies have shown that those with PTSD who smoke marijuana make significantly less progress in overcoming their condition.11  PTSD victims are already more vulnerable to psychosis and it comes as no surprise that clinicians have witnessed psychotic breaks in PTSD patients who begin marijuana12 because of the abundant literature showing an association between marijuana use and the subsequent development of psychosis. While the symptoms that afflict PTSD patients (anxiety, depression, panic) may be temporarily relieved while the subjects are “high”, these very same symptoms are exacerbated in the long run.13  Even in the context of polydrug use, it is the degree of marijuana use that correlates most significantly with anxiety and depression.14
Myth #8. Marijuana is less dangerous than alcohol and will reduce alcohol consumption, so we’ll end up with safer roadways.
In terms of mental health, marijuana is more dangerous on all counts (depression, anxiety, panic, psychosis, mania). As far as our roadways go, marijuana all by itself impairs driving. Whether it is better or the same as alcohol in that regard is still a matter of debate. What is known is that users all too frequently do both, and this combination is particularly hazardous. The interaction between the two drugs is synergistic,15 not additive.  So you end up with someone who is wildly impaired.
Myth #9. Laws don’t make a difference to rates of marijuana use
Some of the best data available on youth use in regards to laws comes from Europe, where they have a wide range of marijuana laws between the countries. The European organization ESPAD has studied youth use (15 to 16 year olds) across different countries every four years. The two most recent ESPAD reports (2007 and 2011) show that countries with legalization or defacto legalization (The Netherlands, Czech Republic, Italy, Spain) have on average a 3-fold higher rate of youth use than countries in which it has remained illegal. In our country, differences in decriminalization laws have existed between states for several years. If you break out the states with lenient decriminalization laws that also submit data to the CDC to track youth use (CO, AK, MA, ME), their rate of youth use (9-12th grade) is significantly higher (~25% higher) than states that have strict decriminalization codes and report to the CDC. Lenient codes include a low civil fine with no increase in penalties for repeat offenders, no requirement for drug education, no requirement for drug treatment, and no community service. Outright legalization and dedicated recreational pot shops in this country has not been around long enough for the effect on youth use to be determined.
Myth #10. The Drug War on marijuana is too expensive.
It is hard to put a price on the damage done to someone’s life if they develop a chronic psychosis like schizophrenia or psychotic bipolar disorder. But if economics must be considered, the cost of just schizophrenia alone to our country is approximately $64 billion per year, accounting for treatment, housing and lost productivity.16 If all adults were exchange their glass of wine or two over the weekend for a joint or two, our rate of schizophrenia would be expected to double. That $64 billion per year would pay for the drug war on marijuana and much more.
Brief Bio for the author:   Dr. Christine L. Miller obtained her B.S. degree in Biology from the Massachusetts Institute of Technology and her Ph.D. degree in Pharmacology from the University of Colorado Health Sciences Center. For over twenty years she has researched the molecular neuroscience of schizophrenia, ten of those years at Johns Hopkins University.  She is semi-retired, conducting occasional biomedical consulting on medical cases and an active volunteer for SAM-Maryland (Smart Approaches to Marijuana).NotPot
Citations:
  1. Thomas H. A community survey of adverse effects of cannabis use. Drug Alcohol Depend. 1996 Nov;42(3):201-7. Smith MJ, Thirthalli J, Abdallah AB, Murray RM, Cottler LB. Prevalence of psychotic symptoms in substance users: a comparison across substances. Compr Psychiatry. 2009 May-Jun;50(3):245-50. Barkus EJ, Stirling J, Hopkins RS, Lewis S. Psychopathology. Cannabis-induced psychosis-like experiences are associated with high schizotypy 2006;39(4):175-8……………..
  2. Arendt M, Mortensen PB, Rosenberg R, Pedersen CB, Waltoft BL. Familial predisposition for psychiatric disorder: comparison of subjects treated for cannabis-induced psychosis and schizophrenia. Arch Gen Psychiatry. 2008;65(11):1269-74. Niemi-Pynttäri JA, Sund R, Putkonen H, Vorma H, Wahlbeck K, Pirkola SP. Substance-induced psychoses converting into schizophrenia: a register-based study of 18,478 Finnish inpatient cases. J Clin Psychiatry. 2013 74(1):e94-9……………..
  3. D’Souza DC, Perry E, MacDougall L, Ammerman Y, Cooper T, Wu YT, Braley G, Gueorguieva R, Krystal JH. The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: implications for psychosis. Neuropsychopharmacology. 2004 Aug;29(8):1558-72. Morrison PD, Nottage J, Stone JM, Bhattacharyya S, Tunstall N, Brenneisen R, Holt D, Wilson D, Sumich A, McGuire P, Murray RM, Kapur S, Ffytche DH. Disruption of frontal θ coherence by Δ9-tetrahydrocannabinol is associated with positive psychotic symptoms. Neuropsychopharmacology. 2011;;36(4):827-36. Bhattacharyya S, Crippa JA, Allen P, Martin-Santos R, Borgwardt S, Fusar-Poli P, Rubia K, Kambeitz J, O’Carroll C, Seal ML, Giampietro V, Brammer M, Zuardi AW, Atakan Z, McGuire PK. Induction of psychosis by Δ9-tetrahydrocannabinol reflects modulation of prefrontal and striatal function during attentional salience processing. Arch Gen Psychiatry. 2012 Jan;69(1):27-36…………….
  4. Niemi-Pynttäri JA, Sund R, Putkonen H, Vorma H, Wahlbeck K, Pirkola SP. Substance-induced psychoses converting into schizophrenia: a register-based study of 18,478 Finnish inpatient cases. J Clin Psychiatry. 2013 74(1):e94-9………………
  5. Arseneault L, Cannon M, Poulton R, Murray R, Caspi A, Moffitt TE, 2002, Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study.BMJ. 2002 Nov 23;325(7374):1212-3. Henquet C, Krabbendam L, Spauwen J, et al. Prospective cohort study of cannabis use, predisposition for psychosis, and psychotic symptoms in young people. BMJ. 2005;330:11–15. Kuepper R, van Os J, Lieb R, Wittchen HU, Höfler M, Henquet C. Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study.BMJ. 2011 Mar 1;342: d738…………….
  6. Griffith-Lendering MF, Wigman JT, Prince van Leeuwen A, Huijbregts SC, Huizink AC, Ormel J, Verhulst FC, van Os J, Swaab H, Vollebergh WA. Cannabis use and vulnerability for psychosis in early adolescence–a TRAILS study. Addiction. 2013 Apr;108(4):733-40……………..
  7. Gottesman, I.I., Shields, J.,1967. A polygenic theory of schizophrenia. Proc. Natl. Acad. Sci. U.S.A. 58,199-205……………
  8. Moore TH, Zammit S, Lingford-Hughes A, et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet. 2007;370:319–328…..…
  9. Zammit S, Allebeck P, Andreasson S, Lundberg I, Lewis G, 2002, Self reported cannabis use as a risk factor for schizophrenia in Swedish conscripts of 1969: historical cohort study. BMJ. 2002 Nov 23;325(7374):1199. DiForti M, Morgan C, Dazzan P, Pariante C, Mondelli V, Marques TR, Handley R, Luzi S, Russo M, Paparelli A, Butt A, Stilo SA, Wiffen B, Powell J, Murray RM. High-potency cannabis and the risk of psychosis. Br J Psychiatry. 2009,195(6):488-91..………
  10. Fazel S, Långström N, Hjern A, Grann M, Lichtenstein P. Schizophrenia, substance abuse, and violent crime. JAMA. 2009 May 20;301(19):2016-23. Harris AW, Large MM, Redoblado-Hodge A, Nielssen O, Anderson J, Brennan J. Clinical and cognitive associations with aggression in the first episode of psychosis. Aust N Z J Psychiatry. 2010 Jan;44(1):85-93..……
  11. Bonn-Miller, Marcel O.; Boden, Matthew Tyler; Vujanovic, Anka A.; Drescher, Kent D. : Prospective investigation of the impact of cannabis use disorders on posttraumatic stress disorder symptoms among veterans in residential treatment. Psychological Trauma: Theory, Research, Practice, and Policy, Vol 5(2), Mar 2013, 193-200……….
  12. Pierre JM. Psychosis associated with medical marijuana: risk vs. benefits of medicinal cannabis use. Am J Psychiatry. 2010 May;167(5):598-9. ………
  13. Kuepper R, van Os J, Lieb R, Wittchen HU, Höfler M, Henquet C. Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study.BMJ. 2011 Mar 1;342: d738. Moore TH, Zammit S, Lingford-Hughes A, et al. Cannabis use and risk of psychotic or affective mental health outcomes: a systematic review. Lancet. 2007;370:319–328. Zuardi AW, Shirakawa I, Finkelfarb E, Karniol IG. Action of cannabidiol on the anxiety and other effects produced by delta 9-THC in normal subjects. Psychopharmacology (Berl). 1982;76(3):245-50. Patton GC, Coffey C, Carlin JB, Degenhardt L, Lynskey M, Hall W. Cannabis use and mental health in young people: cohort study. BMJ. 2002;325(7374):1195-8. Hayatbakhsh MR, Najman JM, Jamrozik K, Mamun AA, Alati R, Bor W. Cannabis and anxiety and depression in young adults: a large prospective study.J Am Acad Child Adolesc Psychiatry. 2007;46(3):408-17. Hasin DS, Keyes KM, Alderson D, Wang S, Aharonovich E, Grant BF. Cannabis withdrawal in the United States: results from NESARC. J Clin Psychiatry. 2008;69(9):1354-63. Buckner JD, Leen-Feldner EW, Zvolensky MJ, Schmidt NB. The interactive effect of anxiety sensitivity and frequency of marijuana use in terms of anxious responding to bodily sensations among youth. Psychiatry Res. 2009;166(2-3):238-46. Zvolensky MJ, Cougle JR, Johnson KA, Bonn-Miller MO, Bernstein A. Marijuana use and panic psychopathology among a representative sample of adults. Exp Clin Psychopharmacol. 2010 Apr;18(2):129-34…………….
  14. Medina KL, Shear PK. Anxiety, depression, and behavioral symptoms of executive dysfunction in ecstasy users: contributions of polydrug use. Drug Alcohol Depend. 2007 Mar 16;87(2-3):303-11………
  15. Ramaekers JG, Robbe HW, O’Hanlon JF. Marijuana, alcohol and actual driving performance. Hum Psychopharmacol. 2000 Oct;15(7):551-558.
    O’Kane CJ, Tutt DC, Bauer LA. Cannabis and driving: a new perspective. Emerg Med (Fremantle). 2002 Sep;14(3):296-303. Biecheler MB, Peytavin JF; Sam Group, Facy F, Martineau H. SAM survey on “drugs and fatal accidents”: search of substances consumed and comparison between drivers involved under the influence of alcohol or cannabis. Traffic Inj Prev. 2008 Mar;9(1):11-21………
  16. Wu EQ, Birnbaum HG, Shi L, Ball DE, Kessler RC, Moulis M, Aggarwal J. The economic burden of schizophrenia in the United States in 2002. J Clin Psychiatry. 2005 Sep;66(9):1122-9.
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12 thoughts on “10 Marijuana Myths Advocates Want You to Believe”

  1. Great website. My son has just been hospitalized with psychosis symptoms that resemble schizophrenia. THC was in his system when he was admitted so they still don’t know if the hallucinations and delusions were brought on by the cannabis or if he really is schizophrenic. He is 24 but has been using for many years and has shown some symptoms in the past though he just had his first psychotic break. This has been the most devastating period of my life. I had no idea the high percentage of THC content in legal marijuana. (We live in Oregon.) I voted for the legalization but now regret it deeply. I don’t think the general public is aware that pot destroys the brains of the young. Apparently if you are over 30, there is no danger of psychosis but really, who waits till then???? This is an epidemic in the making.

    1. For your sake and his, we hope the hallucinations go away. It’s a shame that both you and he were lied to about marijuana in the interest of passing
      legaliztion. Notice that the recent driver on a rampage in NYC was psychotic perhaps from marijuana.

      Please check out Clear Alliance in Oregon which might lead you to best treatment centers, or one that can do dual diagnosis. (If you don’t find the #, I can give it to you. Please read all our articles under mental health, including a 2-part article on “Mental Health Care fails at addiction Treatment.” It is tricky.

      Christine Miller would say that it’s still possible to have psychosis if you are older than 30, but it is less likely.

      I just that you share the story to the MomsStrong.org website. Or write MomsStrongInfo@gmail.com.

      Since you are in OREGON, please write both your SENATORS and tell them, because they are advocating to decriminalize nationally or reschedule marijuana. If Earl Blumenauer is your Rep in Congress, please write him and set him straight. Please write us again if you have any questions.

      Best to you.

  2. Great article! It’s amazing how all this is reversed and the burden of proof needs to be on all of us who are simply cautioning about the observable and potential hazards of marijuana. This all should be the other way around, that is the pro pot movement should be explaining how all these correlations between marijuana abuse and murder are not medically caused.
    The reason? Because they can’t! In part, much of society is unaware of the scientifically shown link between marijuana abuse and schizophrenia. Then there are millions who used mild forms of marijuana in the past, got their ‘buzzes’ and thus by using themselves as examples erringly assume marijuana is harmless. And finally there are many, many millions who are beholden to marijuana, that is, they indulge regularly, a good percentage are addicted, and their brains have transformed so the brain cells are favorable for marijuana. Their thought processes are unidirectional; they oppose anything that might interfere with their future access to marijuana. And many of them are in the media and thus a lot of valuable information is intentionally suppressed. We are not getting the full story either from incompetence, or by design.

    Just think of the absolute absurdity the West is facing now. Major terrorist attacks, mass shootings and bombings, and thousands upon thousands of homicides occur, many of which are by individuals or groups of individuals who abused a mind altering drug- marijuana. Yet there is an ongoing movement to legalize, and normalize marijuana!

    Look at 9/11 in detail. Very reliable sources indicate the perpetrators also indulged in marijuana while in Germany (and likely elsewhere). It should not be surprising anyway, since virtually all of the Lone Wolf terrorist crimes are being committed by abusers of marijuana (Paris twice, Brussels, Boston Marathon Bombing, etc.) As a matter of fact, why is it no one of national presence at least knows let alone is concerned that ALL the major terrorist organizations of the world, including the drug cartels, are vast dens of drug abuse? Don’t they know this!

    So imagine that Mohammed Atta and his cohorts, all of whom developed a visceral hate for Israel and the West from years of propaganda, use marijuana too. As they indulge and get high, their thoughts, their anger becomes intensified. The mind focuses on and amplifies the thoughts while under the influence. Simultaneously, the brain rewires favorably for marijuana as a new source of pleasure, while lowering inhibitions and affecting mood and behavior. And it’s scientifically shown that the brain makes associations while intoxicated with marijuana. Those associations become inculcated in the mind;s neural networks, which in turn can then stimulate the dopamine source of pleasure to the brain in the future even without the presence of marijuana!

    This is amazing because it appears now the mind seeks solace and pleasure through vengeance, violent thoughts and actions which now substitute for marijuana. This may be the radicalization process, via drug abuse in the name of the Koran.

    And to think 9/11 disrupted and changed the course of history, helped spawn two major wars that killed hundreds of thousands of people, and cost several trillion dollars. And nobody at the national level is at least wondering if this madness might have more to do with marijuana induced mental derangement rather than religion? Wow, something is terribly askew.

  3. As neurologist/toxicologist who study cannabinoids must say so much stupidity I dont read anywhere, author dont have basic knowledge in field of neurology/toxicology or even understanding science.

    For example
    “Myth #3. If marijuana is associated with the development of chronic psychosis (schizophrenia), it is only because the patients are self-medicating. Correlation does not equal causation.” all of this study are epidemiological that is why you cannot rule out ” Correlation does not equal causation” even authors of this studies mention that.

  4. thank you for your informative website. i am from mental health consumer group in south east asia. pro legalization become or challenge as well. the pro pot people do not believe there is link between cannabis and schizophrenia. in fact there are cases. please continue your work in this matter. it will help us a lot.

  5. Thanks for what you guys do! In Denver, broadcast on a 50,000-watt radio station an annual update of our List of Peer Reviewed Papers on the Negative Effects of Marijuana. We’ll now begin to use your site as a resource. Thanks!

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