Transcript It can’t happen to me…..

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.
Before the classes on marijuana, we have already covered
THE BRAIN!
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Cortex
Limbic system
Brain stem
Brain Functioning:
It’s all about communication
Dense Pathways in the Brain
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Neurotransmitters
 natural chemicals associated with emotions
 Over 100 chemicals in combinations
 Some important ones for response to drugs
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Endorphins/ Enkephalins
Serotonin
Norepinephrine
Dopamine
Acetylcholine
Neurotransmitters can be…
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Excitatory
Inhibitory
How neurons excite and inhibit each
other…
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Effect of “Exogenous” Drugs on
Neurons
 Neurons stop production of the natural
neurotransmitter
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As the body breaks down chemicals from
drug, there are no natural chemicals to
replace them
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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
What do mice know?
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For more specifics in words:
http://scienceeducation.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
Pathways to the Brain
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"Drug addiction is a brain disease that
can be treated."
Nora D. Volkow, M.D., Director
National Institute on Drug Abuse
With that background, we’re then ready to tackle
MARIJUANA & THE BRAIN
Early
Prevention
Efforts
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
What’s in marijuana smoke?
 61 Cannabinoids
 Aldehydes
 Phenols
 Carcinogens
 Carbon monoxide
 50-70% more carcinogenic hydrocarbons than
tobacco
Courtesy of Linda Hancock, VCU
& NIDA Research Report
Comparison of RISK
CIGARETTES
 More consumed
 Usually filtered
 Less tar
MARIJUANA
Less consumed
Often unfiltered
More Tar (more oil)
3-4 joints
per day
are as damaging
as 15-20
cigarettes
per day.
Courtesy of Linda Hancock, VCU
Pot Potency Increasing
 Due to selective breeding
 1975 - 0.74% THC
 2009 - 13.01% THC
 >10 fold increase
 Higher risk for
tolerance & addiction
Potency Monitoring Project, Report 104, 2009:
http://www.whitehousedrugpolicy.gov/publications/pdf/mpmp_report_104.pdf
Remember tetrahydrocannabinol?
A CLOSER LOOK AT THC
THC IS FAT SOLUBLE…
So what?
THC
penetrates
every cell
in the
body.
THC
THC level
Days
THC accumulates
THC level
Days
THC accumulates in cell
membranes
THC level
Days
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
Source: http://cannagraphic.com/cannabis/effects-of-marijuana-on-the-brain-infographic/
Common student questions:
 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?
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.
Courtesy of Linda Hancock, VCU
 Time distortion
 Trouble shifting attention
 Impaired short-term memory
 Lower verbal IQ
 Impaired executive functioning
Similar to Brain Damage
to Prefrontal Lobe
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
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Very heavy users:  impairment than light users
Average use = 4.8 years
Average age = 22 years
Cognitive deficits after 28 days abstinence:
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verbal and visual memory,
visual perception
psychomotor speed,
manual dexterity
executive functioning
Jill Schlabig Williams, NIDA Notes, Vol. 18, #5
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
NIDA Research Report
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Does marijuana affect brain
structure? An expert opinion
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
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Nervousness
Anxiety and tension
Restlessness
Sleep disturbances
Release of a stressrelated 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 lowrisk 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…
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Water
Clorox
Vaseline
Vinegar
Visine
THC Urine tests
>97% sensitive
50 nanograms
AMOUNT of USE
“Infrequent Users”
<1-2 joints in a week
“Frequent Users”
4 to 5 times a week
“Heavy Users”
once daily and/or
multiple times daily
TIME to CLEAR
3-4 days
1 to 2 weeks
4 to 6 weeks
(up to 100 days)
Low risk choices
protect
what we value
PRIme for Life Curriculum, Prevention Research Institute, Lexington KY
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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: [email protected]
Adrienne: [email protected]