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Teaching about Marijuana & the Brain VACALC Workshop 3-6-2012 Adrienne Keller [Susie Bruce] University of Virginia.

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Presentation on theme: "Teaching about Marijuana & the Brain VACALC Workshop 3-6-2012 Adrienne Keller [Susie Bruce] University of Virginia."— Presentation transcript:


2 Teaching about Marijuana & the Brain VACALC Workshop 3-6-2012 Adrienne Keller [Susie Bruce] University of Virginia

3 Primary Goals  Share some of what we teach our ADAPT students  Share some of the best web resources we’ve found – watch for the mice!  Caveat: We take several 75 minute long classes to cover this material.

4 THE BRAIN! Before the classes on marijuana, we have already covered

5 hyperlink

6 Brain stem Limbic system Cortex

7 Brain Functioning: It’s all about communication

8 Dense Pathways in the Brain hyperlink



11 Neurotransmitters  natural chemicals associated with emotions  Over 100 chemicals in combinations  Some important ones for response to drugs  Endorphins/ Enkephalins  Serotonin  Norepinephrine  Dopamine  Acetylcholine

12 Neurotransmitters can be… Excitatory Inhibitory hyperlink

13 How neurons excite and inhibit each other… hyperlink

14 Effect of “Exogenous” Drugs on Neurons  Neurons stop production of the natural neurotransmitter  As the body breaks down chemicals from drug, there are no natural chemicals to replace them  Crash/Craving

15 What is drug addiction?  a chronic, relapsing brain disease that affects:  Brain structure  How the brain works  characterized by:  compulsive drug seeking  use, despite harmful consequences  harmful behaviors

16 What do mice know? hyperlink

17 For more specifics in words: http://science- Illustration of cocaine’s effect on dopamine transport:

18 Pathways to the Brain hyperlink


20 "Drug addiction is a brain disease that can be treated." Nora D. Volkow, M.D., Director National Institute on Drug Abuse

21 MARIJUANA & THE BRAIN With that background, we’re then ready to tackle


23 Early Prevention Efforts


25 Marijuana History  One of the oldest cultivated plants  In the U.S. since 1720 for: rope, twine, sail cloth, oil for soap & paint  1937 Marijuana Tax Act  1950s & 60s “Beatnik” &“hippie” cultures  1970 Controlled Substances Act:  Marijuana is Schedule 1 drug  1972 Isolated psychoactive chemical  1978 Science: cannabis is addictive


27 Marijuana:  Cannibas sativa  Genus is cannibas; species is sativa  Native to Asia  Used for centuries for fiber (hemp), herbal remedies and for their psychoactive properties.  Psychoactive substance is a cannabinoid: tetra/hydro/canna/binol (THC)tetrahydrocannabinol

28 Courtesy of Linda Hancock, VCU & NIDA Research Report  61 Cannabinoids  Aldehydes  Phenols  Carcinogens  Carbon monoxide  50-70% more carcinogenic hydrocarbons than tobacco What’s in marijuana smoke?

29 Courtesy of Linda Hancock, VCU Comparison of RISK CIGARETTES MARIJUANA  More consumed Less consumed  Usually filtered Often unfiltered  Less tar More Tar (more oil) 3-4 joints per day are as damaging as 15-20 cigarettes per day.

30 Potency Monitoring Project, Report 104, 2009: Pot Potency Increasing  Due to selective breeding  1975 - 0.74% THC  2009 - 13.01% THC  >10 fold increase  Higher risk for tolerance & addiction


32 A CLOSER LOOK AT THC Remember tetrahydrocannabinol?


34 THC penetrates every cell in the body.

35 THC

36 THC accumulates

37 THC accumulates in cell membranes

38 THC accumulates in cell membranes with regular use

39 Our bodies make natural cannabinoids:  Most important is anandamide  Affects many mental & physical processes  Memory and perception  Fine motor coordination  Pain sensation  Immunity to disease  Reproduction

40 Source:


42  Does marijuana cause short term impairment?  Does marijuana cause lingering impairment?  Are there long term effects from using marijuana?  Is marijuana addictive?  Can I beat the pee test? Common student questions:

43 Courtesy of Linda Hancock, VCU CAUTIONS about the Research  Mainly animal studies. (Huge doses are used compared to doses used in young adults.)  Human studies primarily focus on healthy youth and short term effects.  Very few long term effect studies exist.  Research subjects often used other drugs in addition to marijuana.  This is a topic laden with emotion and political agendas.

44  Time distortion  Trouble shifting attention  Impaired short-term memory  Lower verbal IQ  Impaired executive functioning

45 Similar to Brain Damage to Prefrontal Lobe

46 Short-term typical impairment is roughly equal to a.08 BAC In roadside sobriety tests  90 min. after smoking, 94% failed  2.5 hrs. after smoking, 60% failed

47 Airline pilots using flight simulators…  Skills needed to fly safely remained seriously impaired 24 hours later  But only 1 in 7 recognized the continued impairment.

48 Marijuana and Car Crashes Cannabis use is associated with a 3X greater risk of being responsible for a fatal crash. As # of joints smoked goes up, likelihood of causing a fatal crash increases

49 Cognitive impairment can last at least 28 days after stopping use  Very heavy users:  impairment than light users  Average use = 4.8 years  Average age = 22 years  Cognitive deficits after 28 days abstinence:  verbal and visual memory,  visual perception  psychomotor speed,  manual dexterity  executive functioning Jill Schlabig Williams, NIDA Notes, Vol. 18, #5

50 NIDA Research Report Long-term Effects  A study of 450 people found that people who smoke marijuana frequently but do not smoke tobacco  have more health problems  miss more days of work than nonsmokers  marijuana smoking doubles or triples the risk of developing cancer of the head or neck

51 Does marijuana affect brain structure? An expert opinion hyperlink

52 Marijuana and Other Serious Health Risks  Exposure in the womb associated with:  developmental problems  increased rate of childhood leukemia.  With family history of psychosis, can trigger psychotic episodes.

53 TOLERANCE  Haney 1998  21 day residential study in which participants were alternately given several days’ worth of active doses and placebos.  “During THC administration, there was a progressive decline in subjective effects.”  Georgotas 1979  gave 210 mg of THC for 4 weeks  patients complained that the marijuana was “much weaker”

54 Withdrawal  Nervousness  Anxiety and tension  Restlessness  Sleep disturbances  Release of a stress- related chemical

55 Addictive Potential compared to Other Drugs, including Alcohol

56 Marijuana use is high risk  The trigger level for addiction is low  No real research base for identifying a low- risk quantity/frequency of use  Unpredictable strength and purity  Typical use is to the point of impairment  May trigger underlying psychological issues

57 “I can beat the pee test!”  Many myths…  Water  Clorox  Vaseline  Vinegar  Visine

58 THC Urine tests >97% sensitive 50 nanograms AMOUNT of USE TIME to CLEAR “Infrequent Users” <1-2 joints in a week 3-4 days “Frequent Users” 4 to 5 times a week 1 to 2 weeks “Heavy Users” once daily and/or multiple times daily 4 to 6 weeks (up to 100 days)

59 Low risk choices protect what we value PRIme for Life Curriculum, Prevention Research Institute, Lexington KY

60 hyperlink

61 There’s a lot more…  Like facts about the medical use of marijuana  And more about neurons and synapses and neurotransmitters  And lots of statistics on use: longitudinal, national, local  And more on impairment and addiction…

62 So email us if you want more… Susie: Adrienne:

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