Teaching about Marijuana & the Brain

VACALC Workshop3-6-2012

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

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Brain stem

Limbic system

Cortex

Brain Functioning:

It’s all about communication

Dense Pathways in the Brainhyperlink

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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

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How neurons excite and inhibit each other…

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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

What do mice know?hyperlink

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

Pathways to the Brainhyperlink

"Drug addiction is a brain disease that can be treated."

Nora D. Volkow, M.D., DirectorNational Institute on Drug Abuse

MARIJUANA & THE BRAINWith that background, we’re then ready to tackle

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

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

A CLOSER LOOK AT THCRemember tetrahydrocannabinol?

THC IS FAT SOLUBLE…

So what?

THC penetrates every cell

in the body.

THC

Days

THC level

THC accumulates

Days

THC level

THC accumulates in cell membranes

Days

THC level

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/

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

Similar to Brain Damageto 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

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

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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% sensitive50 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

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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: seb7q@virginia.eduAdrienne: akeller@virginia.edu