Download Drugs, Behavior, and Modern Society FIFTH EDITION Charles F

Chapter 7 - Marijuana
CANNABIS PRODUCTS AND
CONCENTRATION LEVELS OF THC
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Marijuana --- serrated cannabis leaves, 6-8 percent THC
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Sinsemilla --- seedless portion of the cannabis plant,
8-15 percent THC
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Hashish --- resin from cannabis plant, 8-14 percent THC
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Hashish oil, hashish oil crystals --- hashish that is
boiled in alcohol then filtered, 15-60 percent THC
A movie poster of this 1942 film, which
followed the infamous Reefer Madness
Such films were linked
to the anti-marijuana
campaign led by the
FBN.
HIGHLIGHTS FROM THE HISTORY OF
MARIJUANA
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2737 B.C. --- First reference to a cannabis plant
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1920s --- Recreational use of marijuana limited to jazz
musicians and people in show business
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1937 --- Marijuana Tax Act virtually illegalizes marijuana
in the U.S.
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1960s --- Marijuana smoking becomes widespread
among American youth.
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1990s-present --- Medical applications of marijuana draw
increasing attention and controversy.
How THC Moves Through The
Body
Rapidly absorbed from the lungs
 Much gone in a few hours-but
accumulates in liver, kidneys, spleen, and
testes
 Joint-10-20% of THC in the joint is
transferred to body; pipe-40-50%; bongmost efficient
 About 50% still in body 24 hrs. after
smoking

Liver converts THC to other compoundsmay remain for several days
 Effects on mental & physical functioning
can last for days
 Very lipid soluble-remains in body
 Eaten-effects occur slower and last longer

Effects on the Brain
Cannabinoid receptors
 Anadamide-binds with cannabinoid
receptors
 2-AG-also activates THC receptors-170
more 2-AG than anadamide
 Hippocampus-formation of new memorieshigh concentration of cannabinoid
receptors

Most well-established adverse effect on
mental function
 Animals-THC-perform as poorly as those
with a damaged hippocampus
 THC-eliminated from their bodies-return to
normal
 2-AG also effects hippocampus
 New studies-adolescents are more likely to
have problems with learning and memory

Also-fewer unpleasant side effects in
adolescents-more likely to continue using
 Does marijuana kill brain cells? “At present
the weight of scientific evidence suggests
that it does”. But not for most people
 Rats-extremely high doses of THC for
several months-cell damage in
hippocampus

Other studies-realistic amounts of THChippocampal cells didn’t survive (in a
culture)
 Also, decreased ability of hippocampal
cells to make connections w/other cells in
the culture
 Rhesus monkeys-exposed to reasonable
amount of smoke-1 year-no evidence of
neuronal death

May be worse effects if brain is still
maturing
 Effects last after marijuana use is stopped
 Cerebellum and basal ganglia-rich in
cannabinoid receptors
 Brain stem-no receptors-virtually
impossible to OD on marijuana

No evidence it causes heart disease or
heart attack
 Lungs: Dies chronic marijuana use impair
lung function? Yes-many studies
 Also, abnormal appearance and cell
organization
 Is marijuana smoke 100x more toxic than
tobacco smoke?

Tar, carbon monoxide, cyanidecomparable in both
 Benzopyrene-greater in marijuana smoke
 Does marijuana smoking cause lung
cancer?
 Most believe a link will be established
 One study-DNA damage in cells-precursor
to lung cancer

3-4 joints a day-chronic bronchitis as often
as cigarette smokers who smoke 1 pack a
day
 Reproductive system: doesn’t make you
sterile
 Decreases probability of conception
 Men: reduces testosterone levels & sperm
count; increases abnormally formed sperm
 Women: irregular periods; reduction in
leutenizing hormone (LH)-necessary for

MARIJUANA EFFECTS ON DRIVING
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•
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Driving ability is impaired while under the
influence of marijuana.
Not a matter of reaction time
Difficulty lies in the ability to attend to
peripheral information and in making an
appropriate response while driving.
Copyright (c) Pearson Education 2010
Psychological Effects
High-intellectually interesting and
emotionally pleasing
 Improvement in sense perceptions
 Sense of euphoria and well-being
 Sharpened sense of sight and sound
 May feel creativity is increased
 Time passes slowly
 Sometimes sleepy and dreamy

Tolerance, Dependence, and
Withdrawal
Tolerance: less a feeling of being high;
placebos; significant learning effect;
reverse tolerance? No-efficient smoking
and buildup of THC in system
 Psychological Dependence: not many
experience loss of control
 Physical Dependence: marijuana
withdrawal is usually mild

Copyright (c) Pearson Education 2010
One study: 10 or 30 mg oral doses every
3-4 hrs for 21 days-irritability,
restlessness, insomnia, sweating, mild
nausea; symptoms went away when THC
was readministered
 Nucleus accumbens

Copyright (c) Pearson Education 2010
Effects on Memory
Long term memory and cognitive
functioning?
 Appears to have effects for 48 hrs after
smoking
 Study-day after last use, daily smokers
had significant impairment on memory for
words and pictures

Also-more errors on problem-solving tasks
requiring mental flexibility
 Other studies – p. 160

Other Reported Problems
Psychoses? : most smokers, modest risk
 Some predisposed; genetics
 Using during adolescence-relatively high
risk of developing psychological disorders
 Another reason why adolescents shouldn’t
use
 Aggression?

Motor Performance and Driving
Impairs ability to concentrate and make
corrections; not necessarily reaction time
 Lose ability to attend to peripheral
information

Acute Physiological Effects
Increased heart rate
 Blood pressure-may increase, decrease, or
stay the same (standing, sitting, lying
down)
 Bloodshot eyes
 Dry mouth
 “munchies”-true of North Americans; not
Jamaicans

Enhanced sexual response; Indiaconsidered a sexual depressant
 2006-291,000 ED visits involved
marijuana; 2nd only to coke; most had
other drugs in system

Medical Uses
Nausea, glaucoma, MS, seizures, chronic
pain, migraine headaches
 Since 1996 – 13 states passes medical
marijuana initiatives or legislation favoring
medical use

STATEMENT FROM THE INSTITUTE OF
MEDICINE REPORT ON MARIJUANA
(1999)
“Until a nonsmoked, rapid-onset
cannabinoid drug delivery system
becomes available, we acknowledge that
there is no clear alternative for people
suffering from chronic conditions that
might be relieved by smoking marijuana,
such as pain and AIDS wasting.”
STATUS OF MEDICAL MARIJAUANA
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Eleven U.S. states (Alaska, Arizona, California,
Colorado, Hawaii, Maine, Montana, Nevada,
Oregon, Washington, and Vermont) as well as
the District of Columbia allow marijuana smoking
for relief of pain and discomfort, when
prescribed by a physician
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Canada permits patients to grow and smoke
marijuana if their symptoms have been certified
by a physician as warranting this treatment
U.S. SUPREME COURT 2005
GONZALES v. RAICH
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Overturned 2003 ruling by a federal
appeals court that shield California’s
Compassionate Use Act from federal drug
enforcement
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Upheld “Congress’s power to regulate
purely local activities that are part of an
economic ‘class of activities’ that have a
substantial effect on interstate commerce”
CONSEQUENCES OF
GONZALES v. RAICH (2005)
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A restriction of medical marijuana to intrastate
(within a state) commerce could not be
guaranteed.
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Therefore, federal jurisdiction takes over.
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The federal prohibition of possession and use of
marijuana for medical purposes remains in force,
even in those states that permit it.
Legalization/Decriminalization
Pharmacological, social, and economic
viewpoints
 2 principal factors that change attitudes
and laws=culture and time
 1930s-marijuana led to violent behavior
 1940s-studies indicated marijuana was
relatively harmless; didn’t change
personality of user

1950s & 1960s-few scientific studies
 1970s-AMA and ABA-suggested reducing
or even eliminating criminal penalties for
possession of small amount
 1980s (Reagan)-”War on Drugs”
 1990s-marijuana use increased; between
1992-1994, used by 12-17 yr olds doubled
 Future?
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