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What Recent Science is Discovering about the Long-term, Adverse Impacts of Marijuana Use on Adolescents

What Recent Science is Discovering about the Long-term, Adverse Impacts of Marijuana Use on Adolescents. By Deborah Williams AYDC. Outline. 1 . The Adolescent Brain: A period of tremendous biological change 2. What science is telling us about impacts of marijuana on the developing brain

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What Recent Science is Discovering about the Long-term, Adverse Impacts of Marijuana Use on Adolescents

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  1. What Recent Science is Discovering about the Long-term, Adverse Impacts of Marijuana Use on Adolescents By Deborah Williams AYDC

  2. Outline • 1. The Adolescent Brain: A period of tremendous biological change • 2. What science is telling us about impacts of marijuana on the developing brain • 3. Youth Perceptions of Marijuana Harm • 4. Protective Factors • 5. Commercialization Of Marijuana- A Glimpse What’s next

  3. Two types of Brain Cells: Neurons and Glial Cells • Neurons (Grey Matter): Carry information through electrochemical processes – 100 billion

  4. White Matter: Glial Cells and Myelin: clean, support, make more efficient • Astrocyte(Astroglia): Star-shaped cells that provide physical and nutritional support for neurons: 1) clean up brain "debris"; 2) transport nutrients to neurons; 3) hold neurons in place; 4) digest parts of dead neurons; 5) regulate content of extracellular space; 6) neurogenesis • Microglia: Like astrocytes, microglia digest parts of dead neurons. • Oligodendroglia: Provide the insulation (myelin) to neurons in the central nervous system. • Satellite Cells: Physical support to neurons in the peripheral nervous system. • Schwann Cells: Provide the insulation (myelin) to neurons in the peripheral nervous system. ( Eric Chudler, University of Washington)

  5. The Adolescent Brain • 1. “Striking (brain) changes take place during the teen years.” (National Institute of Mental Health) • 2. Spurt of neuron (grey matter) growth in frontal cortex before puberty, and then a pruning of neurons and wrapping of white matter (myelin) around other connections to stabilize and strengthen them. Rewiring, strengthening, pruning, organizing.

  6. Damage to Brain • http://www.dampkring.nl/files/post/23c59db6z11fc4459b8dz7277_500_457.jpg?id=1365_9 • "Studies of normal brain development reveal critical areas of the brain that develop during late adolescence, and our study shows that heavy cannabis use is associated with damage in those brain regions," said study leader ManzarAshtari, Ph.D., director of the Diffusion Image Analysis and Brain Morphometry Laboratory in the Radiology Department of The Children's Hospital of Philadelphia. (Science News (2009))

  7. Hazardous to White Matter • “Our finding indicate long-term cannabis use is hazardous to the white matter of the developing brain.” “Microstructural impairment” (Zalesky, et.al. (2012)). • “Long-term heavy cannabis use in healthy individuals is associated with smaller cerebellar white-matter volume similar to that observed in schizophrenia. Reduced volumes were even more pronounced in patients with schizophrenia who use cannabis.” (Solowij, et.al (2011)). .

  8. Harmful to Glial Cells • Astrocytes, a type of glia, have a principal role in working memory. • Marijuana impairs glial cells (Scientific American (2012))

  9. Reduction in Cognitive Functioning “For those who met criteria for cannabis dependence…, the average drop in IQ was 8 points (between age 13 and 38)… The decline in IQ included all four indices of IQ: working memory, processing speed, perceptual reasoning and verbal comprehension” (“Persistent cannabis users show neuropsychological decline from childhood to midlife,” Meier, et. al.(2012))ruled out pre-existing difference in IQ; also showed that those who used marijuana heavily before age 18 showed mental decline even after they quit consuming.

  10. Increased Risk for Psychosis and Development of Psychotic Symptoms • “In conclusion, the available evidence support the hypothesis that cannabis is an independent risk factor, both for psychosis and the development of psychotic symptoms.” • (“Cannabis as a risk • factor for psychosis: • systematic review,” • Semple, et.al.(2005))

  11. Increased Risk for Psychosis and Development of Psychotic Symptoms • “Smoking high amounts of cannabis (in adolescence) is associated with increased levels of all three symptom dimensions: psychotic, negative and depressive.” (“Cannabis use at a young age is associated with psychotic experiences,” Schubart, et.al.(2011)).

  12. Psychiatric Hospitalizations • “We found a dose–response relationship between the amount of cannabis use and the odds for psychiatric hospitalization. • Adjusted odds ratios for hospitalization increased with the amount of cannabis consumed. • Exposure to cannabis before the age of 12 years was found to carry a 4.8 (95% CI: 2.9–7.8) times increased odds for past psychiatric hospitalizations. (Schubart, et.al. (2011)).

  13. Cannabis use and Childhood Trauma Interact Additively • “…the psychosis-inducing effects of cannabis were stronger in individuals exposed to earlier sexual or physical mistreatment” • Replication in two independent population-based samples that childhood maltreatment and cannabis use synergistically impact on psychosis risk. (Konings, et. al. (2012))

  14. ER admission rates rising Cannabis-related emergency hospital admission rates have been rising sharply in the US. • From an estimated 16, 251 in 1991 to over 374,000 in 2008 Source: SAMHSA, 2011

  15. And in mice, too -- Important • Cortical oscillations are patterns of activity of neurons in the brain. They are very abnormal in schizophrenia and other brain disorders. • Scientists exposed adolescent mice to small amounts of active ingredient in marijuana for 20 days, then allowed them to return to siblings.

  16. And in mice, too -- Important • In adult mice (exposed to marijuana ingredients in adolescents), scientists found • “cortical oscillations were grossly altered, and they exhibited impaired cognitive abilities…and impaired cognitive behavioral performance…. • The striking finding is that, even though the mice were exposed to very low drug doses, and only for a brief period during adolescence, their brain abnormalities persisted into adulthood.” • (Raver, et.al.(2013))

  17. Summary and Dependence • The researchers reviewed over 120 studies that looked at different aspects of the relationship between cannabis and the adolescent brain… • "Data from epidemiological studies have repeatedly shown an association between cannabis use and subsequent addiction to heavy drugs and psychosis (i.e. schizophrenia). …When the first exposure occurs in younger versus older adolescents, the impact of cannabis seems to be worse in regard to many outcomes such as mental health, education attainment, delinquency and ability to conform to adult role," Dr Jutras-Aswad said. • the researchers note that rat models enable scientists to explore and directly observe the same chemical reactions that happen in human brains. …As the structure of the brain changes rapidly during adolescence (before settling in adulthood), scientists believe that the cannabis consumption at this time greatly influences the way these parts of the user's personality develop. • (ScienceDaily (8/27/13))

  18. Summary and Dependence • "Of the illicit drugs, cannabis is most used by teenagers since it is perceived by many to be of little harm. This perception has led to a growing number of states approving its legalization and increased accessibility. .. • …approximately one in four of teenage users of cannabis will develop an abusive or dependent relationship with the drug.," Jutras-Aswad said. • (ScienceDaily (8/27/13))

  19. “Cannabis during pregnancy endangers fetal brain development”(Science Daily 1/27/14) • “The study highlights that consuming Cannabis during pregnancy clearly results in defective development of nerve cells of the cerebral cortex, the part of the brain that orchestrates higher cognitive functions and drives memory formation. • In particular, THC negatively impacts if and how the structural platform and conduit for communication between nerve cells, the synapses and axons, will develop and function. • Researchers also identified Stathmin-2 as a key protein target for THC action, and its loss is characterized as a reason for erroneous nerve growth.” (Study: EMBO Journal 1/2014)

  20. THC: Psychoactive Ingredient

  21. Green Crack

  22. Impact on Driving • Driver culpability studies show that drivers testing positive to marijuana “are significantly more likely to be responsible for fatal car crashes than are drug-free drivers.” (University of Washington ADAI) • “the acute effect of moderate or higher doses of marijuana impairs the skills related to safe driving and injury risk”, particularly “attention, tracking and psychomotor skills.”

  23. Legalizing Will Likely Increase Use Among Teens • Nearly two-thirds (65%) of teens who reported using marijuana at least once in their lifetime said that legalizing the drug would make them more likely to use it. • In addition, more than three-fourths (78%) of heavy marijuana users reported that legalizing the drug would make them more likely to use it. • Sixteen percent of teens who reported that they had never used marijuana agreed that they would be more likely to use marijuana if it were legal. (Center for Substance Abuse Research from The Partnership for a Drug-Free America and the MetLife Foundation, The Partnership Attitude Tracking Study (PATS): Teens and Parents, 2013.)

  24. Increased use among teens • Among youth (12-17) marijuana use rates in states with medical marijuana laws is 8.6% compared to 6.9% in states without such laws • In states with medical marijuana laws, adolescents’ perception of the harmful effects of marijuana have significantly decreased. Source: Wall, M., et al., 2011; Johnston, L.D., et al., 2011.

  25. Availability among Teens • 50% and 44% of youth report that they can obtain alcohol and cigarettes, respectively, within a day. • Youth are least likely to report that they can get marijuana within a day (31%); 45% report that they would be unable to get marijuana at all. Source: The National Center on Addiction and Substance Abuse at Columbia University (CASA), 2012

  26. How things change

  27. Perception of Risk • Versus 15.1% of students who think smoking one or more packs of cigarettes per day is no or slight risk; • Versus 34.5% of students who think one or two drinks of alcohol nearly every day is no or slight risk • % of Anchorage students who think smoking marijuana regularly is no or slight risk: • Total: 49.2% • Male: 57.4%; • Female: 40.7%) (2011 YRBS)

  28. Parental • Versus 79.3% of students who believe their parents consider it very wrong for them to smoke cigarettes • Versus 52.6% of students who believe their parents consider it very wrong for them to drink alcohol regularly. • Percentage of students who believe their parents consider it very wrong for them to smoke marijuana • 65.4% (Male: 61%; Female: 70%)

  29. Relationship between perceptions and use

  30. Protective Factors:Current Marijuana Use v. Number of Protective Factors: A significant difference in proportion of youth currently smoking marijuana who have 0-2 protective factors versus having 3-5 and 6-8.

  31. The Tobacco Industry Connection “The use of marijuana ... has important implications for the tobacco industry in terms of an alternative product line. [We] have the land to grow it, the machines to roll it and package it, the distribution to market it. In fact, some firms have registered trademarks, which are taken directly from marijuana street jargon. These trade names are used currently on little-known legal products, but could be switched if and when marijuana is legalized. Estimates indicate that the market in legalized marijuana might be as high as $10 billion annually.” From a report commissioned by cigarette manufacturer Brown and Williamson (now merged with R.J. Reynolds) in the 1970s.

  32. Marijuana-based medicines • Sativex® is in the process of being studied in the USA. • THC:CBD = 1:1 • It is administered via an oral mouth spray • Already approved in Canada and Europe • Also Epidiolex ®, pure CBD, no THC

  33. Commercialization of Marijuana

  34. Commercialization of Marijuana

  35. Commercialization of Marijuana

  36. A variety of medical marijuana products and ‘edibles’ can be found at dispensaries: • Brownies, carrot cake, cookies, peanut butter, granola bars, ice cream. • Many such as ‘Ring Pots’ and ‘Pot Tarts’ are marketed with cartoons and characters appealing to children.

  37. Really?

  38. Alcohol&Tobacco:Money Makers or Dollar Drainers? • For every 1$ gained from alcohol and tobacco tax revenues, $10 is lost in legal, health, social, and regulatory costs $$$$$$$$$$$ Source: Urban Institute and Brookings Institute, 2012; Tax Policy Center, 2008

  39. The Initiative • Will be on the August primary ballot • All about commercialization • Impacts on Youth critical to consider

  40. Thank youandQuestions Deborah Williams AYDC

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