Teaching about Marijuana & the Brain VACALC Workshop 3-6-2012 Adrienne Keller [Susie Bruce] University of Virginia
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.
THE BRAIN! Before the classes on marijuana, we have already covered
Neurotransmitters natural chemicals associated with emotions Over 100 chemicals in combinations Some important ones for response to drugs Endorphins/ Enkephalins Serotonin Norepinephrine Dopamine Acetylcholine
Neurotransmitters can be… Excitatory Inhibitory hyperlink
How neurons excite and inhibit each other… hyperlink
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
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
For more specifics in words: http://science- education.nih.gov/supplements/nih2/addiction/guide/lesson3-1.htm Illustration of cocaine’s effect on dopamine transport: http://science-education.nih.gov/supplements/nih2/addiction/activities/lesson3_cocaine.htm
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
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
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?
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.
Potency Monitoring Project, Report 104, 2009: http://www.whitehousedrugpolicy.gov/publications/pdf/mpmp_report_104.pdf Pot Potency Increasing Due to selective breeding 1975 - 0.74% THC 2009 - 13.01% THC >10 fold increase Higher risk for tolerance & addiction
THC accumulates in cell membranes with regular use
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
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:
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.
Time distortion Trouble shifting attention Impaired short-term memory Lower verbal IQ Impaired executive functioning
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
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.
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
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
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
Does marijuana affect brain structure? An expert opinion hyperlink
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.
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”
Withdrawal Nervousness Anxiety and tension Restlessness Sleep disturbances Release of a stress- related chemical
Addictive Potential compared to Other Drugs, including Alcohol
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
“I can beat the pee test!” Many myths… Water Clorox Vaseline Vinegar Visine
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)
Low risk choices protect what we value PRIme for Life Curriculum, Prevention Research Institute, Lexington KY
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…
So email us if you want more… Susie: firstname.lastname@example.org@virginia.edu Adrienne: email@example.com@virginia.edu