Negative Health Consequences of Marijuana Use

  1. Marijuana addiction:
    • According to NIDA, about 9 percent of marijuana users become addicted to marijuana. 1
    • An estimated 2.7 million people 12 years of age and older meet criteria for dependence on marijuana. 2
    • Early and regular marijuana use predicts an increased risk of addiction. 1,3
  2. Impact on the brain and mental health:
    • Marijuana can cause brain damage in areas that develop during late adolescence and underlie hallucinations and schizophrenia. 4
    • It is associated with decreased brain function 5 and structural abnormalities. 6
    • Is a risk factor for stroke especially in adolescents 7 and can leads to neuropsychological and cognitive decline in adulthood. 8
    • Marijuana use may cause later major depressive disorder and substance abuse disorders in the late 20s through adulthood. 9
    • Increases the risk of psychotic symptoms 10 and of developing depression. 11
  3. Marijuana and pregnancy:
    • Marijuana use during the first month of pregnancy could lead to anencephaly (the absence of a major portion of the brain, skull, and scalp) and increased risk of stillbirth. 12,13,14,15,16
    • Used during mid- and late pregnancy marijuana leads to growth retardation and lower birth weight, 17,18,19 and alterations of neurobehavioral performance. 20
    • Marijuana affects child intellectual development 21 and is related to child behavioral problems (increased hyperactivity, impulsivity, inattention, and delinquency, and externalizing problems.) 22
    • Prenatal exposure to marijuana is associated with deficits in language, attention, cognitive performance 12,23,24 and increased risk of schizophrenia, depression, and addiction later in life. 25
  4. Impairment of lung function:
    • Marijuana causes wheezing, cough, chest tightness and large airway obstruction. One marijuana joint has similar airway obstructing effects as 2-5 cigarettes. 26
    • Marijuana smoking is associated with episodes of acute bronchitis and increase in airways resistance. 27
  5. Marijuana and cancer risk:
    • Carcinogens in marijuana smoke are similar to tobacco smoke. Cannabis exposure doubles the risk of developing lung cancer. 28,29 In 2009, California EPA called marijuana smoke as a “chemical known to the state to cause cancer” 30,31 and listed 33 unique chemicals in marijuana smoke that are carcinogens. 32
  6. Marijuana and the heart:
    • Marijuana use is associated with arterial disease such as stroke, myocardial infarction, and sudden cardiac death, especially in young people without any medical history. 33,34,35
  7. Marijuana and gastric issues:
    • Chronic marijuana use can lead to Cannabinoid Hyperemesis Syndrome (CHS), characterized by cyclical nausea and vomiting, abdominal pain, and an unusual compulsion to take hot showers to ameliorate the symptoms. 36,37,38
  8. Marijuana and Psychological Effects:
    • Spatial and time perception are distorted after marijuana use. 39
    • Marijuana impairs cognitive and psychomotor performance, including slowing of reaction time, motor incoordination, defects in short-term memory, difficulty in concentration and particular impairment in complex tasks performance. 40,41,42
    • The impairments of attention, memory and ability to process complex information resulted from marijuana use can last for days, weeks even months after cessation of cannabis use. 43
    • Marijuana impairs road-driving performance, and have linked its use with increased incidence of road traffic accidents. 40,44,45
    • Marijuana has been shown to seriously impair aircraft piloting skills. 46

References:

  1. NIDA 2014. http://www.drugabuse.gov/publications/drugfacts/marijuana
  2. http://www.samhsa.gov/data/NSDUH/2012SummNatFindDetTables/Index.aspx
  3. Chen CY et al., Early-onset drug use and risk for drug deoendence problems. Addict Behav 34: 319-22, 2009
  4. Ashtari M et al., Diffusion abnormalities in adolescents and young adults with a history of heavy cannabis use. J Psychiatr Res. 43(3):189-204,2009
  5. Block RI et al., Cerebellar hypoactivity in frequent marijuana users. Neuroreport. 20; 11(4):749-53, 2000
  6. Gilman JM et al., Cannabis Use is Quantitatively Associated with Nucleus Accumbens and Amygdala Abnormalities in Young Adult Recreational Users. Neurobiology of Disease. 34(16):5529-5538, 2014
  7. Geller T et al., Cerebellar infarction in adolescent males associated with acute marijuana use. Pediatrics. 113(4):e365-70, 2004
  8. Meier MH et al., Persistent cannabis users show neuropsychological decline from childhood to midlife. Proc Natl Acad Sci U S A. 109(40):E2657-64, 2012
  9. Brook DW et al., Drug use and the risk of major depressive disorder, alcohol dependence, and substance use disorders. Arch Gen Psychiatry. 59(11):1039-44, 2002
  10. Kuepper R et al., Continued cannabis use and risk of incidence and persistence of psychotic symptoms: 10 year follow-up cohort study. BMJ. 342:d738, 2011
  11. Office of National Drug Control Policy, Executive Office of the President. Teen Marijuana Use Worsens Depression. 2008
  12. American Academy of Pediatrics, Pediatrics 131; e1009, 2013
  13. Psychoyos D and Vinod KY, Marijuana, Spice ’Herbal High’, and Early Neural Development: implications for rescheduling and legalization, Drug Test Analysis 5: 27–45, 2013
  14. Hayatbakhsh MR et al., Birth outcomes associated with cannabis use before and during pregnancy, Pediatric Research, 71: 2012
  15. vanGelder MM , et al., Maternal Periconceptional Illicit Drug Use and the Risk of Congenital Malformations, Epidemiology 20: 60-66, 2008
  16. Varner MW et al., Association Between Stillbirth and Illicit Drug Use and Smoking During Pregnancy, Obstetrics & Gynecology 123: 113-125, 2014
  17. Beckc AO et al., Marijuana Impairs Growth in Mid-Gestation Fetuses, Neurotoxicology and Teratology 27: 221–229, 2005
  18. El Marroun H et al., Intrauterine Cannabis Exposure Affects Fetal Growth Trajectories: The Generation R Study, J. Am. Acad. Child Adolesc. Psychiatry, 48: 1173-1181, 2009
  19. WHO 2014, http://www.who.int/substance_abuse/facts/cannabis/en/
  20. De Moraes Barros MC, et al., Exposure to Marijuana During Pregnancy Alters Neurobehavior in the Early Neonatal Period, J Pediatr 149:781-7, 2006
  21. Goldschmidt L et al., Prenatal Marijuana Exposure and Intelligence Test Performance at Age 6, J. Am. Acad. Child Adolesc. Psychiatry, 47:254-263, 2008
  22. Goldschmid L et al., Effects of Prenatal Marijuana Exposure on Child Behavior Problems at Age 10,Neurotoxicology and Teratology 22: 325–336, 2000
  23. Irner TB, Substance exposure in utero and developmental consequences in adolescence: A systematic review, Child Neuropsychology, 18:6, 521-549, 2012
  24. Day NL et al., The Effects of Prenatal Marijuana Exposure on Delinquent Behaviors are Mediated by Measures of Neurocognitive Functioning Neurotoxicology and Teratology 33: 129 – 136, 2011
  25. Tortoriello G et al., Miswiring the brain: Δ9-tetrahydrocannabinol disrupts cortical development by inducing an SCG10/stathmin-2 degradation pathway. EMBO J. 33:668-85, 2014
  26. Aldington S et al., Effects of cannabis on pulmonary structure, function and symptoms. Thorax. 62(12):1058-63, 2007
  27. Underner M et al., Cannabis use and impairment of respiratory function. Rev Mal Respir. 30(4):272-85, 2013
  28. Aldington S et al., Cannabis and Respiratory Disease Research Group. Cannabis use and risk of lung cancer: a case-control study. Eur Respir J.31(2):280-6, 2008
  29. Underner M et al., Cannabis smoking and lung cancer. Rev Mal Respir. 31(6):488-498, 2014
  30. Marijuana smoke listed effective June 19, 2009 as known to the state of California to cause cancer
    http://www.oehha.org/prop65/docs_state/mjcrnr061909.html
  31. California Proposition 65 list of chemicals known to the state to cause cancer or reproductive toxicity (November 8, 2013) http://oehha.ca.gov/prop65/prop65_list/files/P65single110813.pdf
  32. Evidence on the carcinogenicity of Marijuana smoke, August 2009 http://oehha.ca.gov/prop65/hazard_ident/pdf_zip/FinalMJsmokeHID.pdf (page 11)
  33. Desbois AC and Cacoub P., Cannabis-associated arterial disease. Ann Vasc Surg. 27(7):996-1005, 2013
  34. Thomas G et al., Adverse cardiovascular, cerebrovascular, and peripheral vascular effects of marijuana inhalation: what cardiologists need to know. Am J Cardiol. 113(1):187-90, 2014
  35. Hodcroft CJ et al., Cannabis-associated Myocardial Infarction in a Young Man with Normal Coronary Arteries. J Emerg Med. . pii: S0736-4679(13)01403-0, 2014
  36. Choung RS et al., Cyclic vomiting syndrome and functional vomiting in adults: association with cannabinoid use in males. Neurogastroenterol Motil.24(1):20-6, 2012
  37. Sontineni SP et al., Cannabinoid hyperemesis syndrome: clinical diagnosis of an underrecognised manifestation of chronic cannabis abuse. World J Gastroenterol. 15(10):1264-6, 2009
  38. Ukaigwe A et al., A Gut Gone to Pot: A Case of Cannabinoid Hyperemesis Syndrome due to K2, a Synthetic Cannabinoid. Case Rep Emerg Med. 2014:167098.
  39. D’Souza DC et al., The psychotomimetic effects of intravenous delta-9-tetrahydrocannabinol in healthy individuals: implications for psychosis. Neuropsychopharmacology. 29(8):1558-72, 2004
  40. Neavyn MJ et al., Medical Marijuana and Driving: a Review. J Med Toxicol. Mar 20, 2014
  41. Lisdahl KM et al., Considering Cannabis: The Effects of Regular Cannabis Use on Neurocognition in Adolescents and Young Adults. Curr Addict Rep 1:144–156, 2014
  42. Smith MJ et al., Cannabis-Related Working Memory Deficits and Associated Subcortical Morphological Differences in Healthy Individuals and Schizophrenia Subjects. Schizophrenia Bulletin vol. 40 no. 2:287–299, 2014
  43. Solowij, N. Cannabis and Cognitive Functioning Cambridge: Cambridge University Press. 1998
  44. Laumon B et al., SAM Group. Cannabis intoxication and fatal road crashes in France: population based case-control study. BMJ. 331(7529):1371, 2005
  45. Fergusson DM et al., Is driving under the influence of cannabis becoming a greater risk to driver safety than drink driving? Findings from a longitudinal study. Accid Anal Prev. 40(4):1345-50, 2008
  46. Leirer VO et al., Marijuana carry-over effects on aircraft pilot performance. Aviat Space Environ Med.62(3):221-7, 1991

Prepared by the Marijuana Science Forum, Oct. 2014

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