Exposing Marijuana
Myths:
A Review of the
Scientific Evidence
Lynn
Zimmer
Associate Professor of
Sociology,
John P.
Morgan
Professor of
Pharmacology,
© October 1995 Open
Society Institute/The
INTRODUCTION
Since
the 1920s, supporters of marijuana prohibition have exaggerated the drug's
dangers. In different eras, different claims have gained prominence, but few
have ever been abandoned. Indeed, many of the "reefer madness" tales that were
used to generate
support
for early anti-marijuana laws continue to appear in government and media reports
today.
For
a while in the 1970s, it seemed as if scientific inquiries were beginning to
influence the government's marijuana policies. Following thorough reviews of the
existing evidence by scholars 1
and
official commissions, 2 criminal
penalties for marijuana offenses were lessened and a number of states moved in
the direction of decriminalization. 3 However,
in response to lingering concerns about marijuana's potential toxicity, the
government expanded its funding of scientific research, mostly through the
newly-created National Institute on Drug Abuse (NIDA). Probably the most important studies of
the 1970s were three large "field studies" in
than
previously thought. But in nearly all such cases, the methodologies were
seriously flawed and the findings could not be replicated by other
researchers. Especially since the
1980s, when the federal government's renewed war on cannabis began, both the
funding of marijuana research and the dissemination of its findings have been highly politicized. Indeed, NIDA's role seems to have become one of service to the War
on Drugs. Dozens of claims of toxicity appear in its documents, despite the
existence of scores of scientific studies refuting their validity. At the same
time, studies that fail to
find
serious toxicity are ignored. In
the following pages, we review the scientific evidence surrounding the most
prominent
of
the anti-marijuana claims.
CLAIM No. 1: MARIJUANA USE IS INCREASING AT AN
ALARMING RATE
CLAIM No. 2: MARIJUANA POTENCY HAS INCREASED
SUBSTANTIALLY
CLAIM No. 3: MARIJUANA IS A DRUG WITHOUT THERAPEUTIC
VALUE
CLAIM No. 4: MARIJUANA CAUSES LUNG
DISEASE
CLAIM No. 5: MARIJUANA IMPAIRS IMMUNE SYSTEM
FUNCTIONING
CLAIM No. 6: MARIJUANA HARMS SEXUAL MATURATION AND
REPRODUCTION
CLAIM No. 7: MARIJUANA USE DURING PREGNANCY HARMS
THE FETUS
CLAIM No. 8: MARIJUANA CAUSES BRAIN
DAMAGE
CLAIM No. 9: MARIJUANA IS AN ADDICTIVE
DRUG
CLAIM No.10: MARIJUANA-RELATED MEDICAL EMERGENCIES
ARE INCREASING
CLAIM No.11: MARIJUANA PRODUCES AN AMOTIVATIONAL
SYNDROME
CLAIM No.12: MARIJUANA IS A MAJOR CAUSE OF HIGHWAY
ACCIDENTS
CLAIM No.13: MARIJUANA IS A "GATEWAY" TO THE USE OF
OTHER DRUGS
CLAIM No.14: DUTCH MARIJUANA POLICY HAS BEEN A
FAILURE
Footnotes:
CLAIM
#1:
MARIJUANA
USE IS INCREASING AT AN ALARMING RATE
Reports
of a recent slight increase in marijuana use, especially among youth, are being
used to convince Americans that a renewed campaign about the drug's dangers is
necessary to avert an impending epidemic.
THE
FACTS
According
to government surveys of the general population, marijuana use began decreasing
in 1980, after more than a decade of steady increase. By 1990, the downward
trend showed signs of slowing, but use-rates remained substantially lower than
those recorded in the 1970s. For
example, among 12-17 year olds, past year marijuana use was about 8% in 1992,
compared to 24.1% in 1979. Among 18-25 year olds, past year use was 23 % in
1992, compared to 46.9 % in 1979. 5
A
separate survey of high school students shows similar trends, with use-rates in
the 1990s well below those reported in the 1970s. However, after reaching an
all-time low in 1992, they increased slightly during the next two
years.
Lifetime
Prevalence of Marijuana:
High
School Seniors, 1976-1994 6
1976 1978 1980 1982 1984 1986 1988 1990 1992 1994
52.8 59.2 60.3 58.7 54.9 50.9 47.2 40.7 32.6 38.2
The
High School Survey was originally conceived by the National Institute on Drug
Abuse (NIDA) as a measure of non-pathological drug use. This is still what it
measures. Adolescence is a time of
experimentation, with drug use as well as other activities. Most adolescent drug
users do not go on to become "drug abusers." Indeed, most adolescent drug users,
after a few years of experimentation, cease using illegal drugs altogether. We will probably never know why
marijuana use-rates go up and down over time. However, it is worth noting that the
recent increase occurred among the same population of young people who had been
exposed to a decade-long anti-marijuana campaign in the schools and the media.
That campaign, based on exaggerations of marijuana's harms and a "just say no"
ideology, has clearly failed. 7 Young
people, and Americans generally, need to know the scientific evidence about
marijuana if they are to make informed decisions about both their own
drug
use
and the future of American drug policy.
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Claim]
CLAIM
#2:
MARIJUANA
POTENCY HAS INCREASED SUBSTANTIALLY
The
claim that there has been a 10-, 20- or 30-fold increase in marijuana potency
since the 1970s is used to discredit previous studies that showed minimal harm
caused by the drug and convince users from earlier eras that today's marijuana
is much more dangerous.
THE
FACTS
For
more than 20 years the government-funded Potency Monitoring Project (PMP) at the
During
the 1970s, the PMP regularly reported potency averages of under 1%, with a low of 0.4% in 1974.
Quite
clearly, these averages underestimate the THC content of marijuana smoked during
this period.
Marijuana
of under 0.5% potency has almost no psychoactivity.
While it is possible that people sometimes obtained marijuana of such low
potency, for the drug to have become popular in the 1960s and 1970s, most people
must have regularly obtained marijuana with higher THC
content.
Until
the late 1970s, PMP samples included none of the traditionally higher-potency
cannabis products, such as buds and sinsemilla, even
though these products were available on the retail market. When changes in
police practices resulted in their seizure, PMP potency averages
increased.
Every
independent analysis of potency in the 1970s found higher THC averages than the
PMP.
For
example, the 59 samples submitted to PharmChem
Laboratories in 1973 averaged 1.62%; only 16 (27%) contained less than 1% THC,
more than half were over 2% and about one-fifth (1/5) were over 4%. In 1975,
PharmChem samples ranged from 2 to 5%, with some as
high as 14% - nearly 30 times the .71 average reported by the PMP 9
After
1980, both the number and variety of official seizures increased dramatically,
improving the validity
of
the PMP's reported averages, although they continue to
be based on "convenience" rather than "representative"
samples.
As
shown below, average potency has remained essentially unchanged since the early
1980s:
Mean
Percentage THC of Seized Marijuana, 1981-1993
1981
1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992
1993
2.28 3.05 3.23 2.39 2.82 2.30 2.93 3.29 3.06 3.36 3.36 3.32 3.00
Even
if potency had increased slightly since the 1970s, it would not mean that
smoking marijuana had become more dangerous. In fact, since the primary health
risk of marijuana comes from smoking, higher potency products can be less
dangerous because they allow people to achieve the desired effect by inhaling
less.
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Claim]
CLAIM
#3:
MARIJUANA
IS A DRUG WITHOUT THERAPEUTIC VALUE
Proposals
to make marijuana legally available as a medicine are countered with claims that
safer, more effective drugs are available, including a synthetic version of
delta-9-THC, marijuana's primary active ingredient.
THE
FACTS
For
thousands of years, throughout the world, people have used marijuana to treat a
variety of medical conditions. 10
Today,
in the
A
number of studies have shown that marijuana is effective in reducing nausea and
vomiting, 11
lowering
intraocular pressure associated with glaucoma 12,
and decreasing muscle spasm and spasticity.
13
Today,
many
people use marijuana for these and other medical purposes, despite its illegal
status. 14
People
undergoing cancer chemotherapy have found smoked marijuana to be an effective
anti-nauseant –
often
more effective than available pharmaceutical medications. 15
Indeed,
44 % of oncologists responding to a questionnaire said they had recommended
marijuana to their cancer
patients;
others said they would recommend it if it were legal. 16
Marijuana
is also smoked by thousands of AIDS patients to treat the nausea and vomiting
associated with both the disease and AZT drug therapy. Because it stimulates
appetite, marijuana also counters HIV-related "wasting,"
allowing
AIDS patients to gain weight and prolong their lives. In 1986, a synthetic
delta-9-THC capsule (Marinol) was marketed in the
Because
THC delivered in oral capsules enters the bloodstream slowly, it yields lower
scrum concentrations per
dose. Oral THC circulates in the body longer
at effective concentrations, and more of it is metabolized to an active
compound; thus, it more frequently yields unpleasant psychoactive effects. In patients suffering from nausea, the
swallowing of capsules may itself provoke vomiting. In short, the smoking of crude marijuana
is more efficient in delivering THC and, in some cases, it may be more
effective. The continuing
illegality of medical marijuana is based more on political than scientific
considerations. Although during the 1970s the government
supported
exploration into marijuana's therapeutic potential, 18
its
role has become one of blocking new research l9
and
opposing any change in marijuana's legal status. 20
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Claim]
CLAIM
#4:
MARIJUANA
CAUSES LUNG DISEASE
It
is frequently claimed that marijuana smoke contains such high concentrations of
irritants that marijuana users' risk of developing lung disease is equal to or
greater than that of tobacco users.
THE
FACTS
Except
for their psychoactive ingredients, marijuana and tobacco smoke are nearly
identical. 21
Because
most marijuana smokers inhale more deeply and hold the smoke in their lungs,
more dangerous material may be consumed per cigarette. However, it is the total
volume of irritant inhalation - not the amount in each cigarette - that
matters. Most tobacco smokers
consume more than 10 cigarettes per day and some consume 40 or more. Regular
marijuana smokers seldom consume more than three to five cigarettes per day and
most consume far fewer. Thus, the amount of irritant material inhaled almost
never approaches that of tobacco users.
Frequent marijuana smokers experience adverse respiratory symptoms from
smoking, including chronic cough, chronic phlegm, and wheezing. However, the only prospective clinical
study shows no increased risk of crippling pulmonary disease (chronic bronchitis
and emphysema).
Since
1982, UCLA researchers have evaluated pulmonary function and bronchial cell
characteristics in marijuana-only smokers, tobacco-only smokers, smokers of
both, and nonsmokers. Although they
have found changes in marijuana only smokers, the changes are much less
pronounced than those found in tobacco smokers.
The
nature of the marijuana-induced changes was also different, occurring primarily
in the lung's large airways – not the small peripheral airways affected by
tobacco smoke. Since it is
small-airway inflammation that causes chronic bronchitis and emphysema,
marijuana smokers may not develop these diseases. 22
In
an epidemiological survey, approximately 1200 subjects gave information on
smoking and pulmonary function at two-year intervals. A large percentage of the
subjects underwent pulmonary function testing. Although a small group who reported
previous marijuana smoking had significant pulmonary abnormalities, current
marijuana smokers had no significant reduction in any pulmonary functions.
23
There
are no epidemiological or aggregate clinical data suggesting that marijuana-only
smokers develop lung cancer. However, since some bronchial cell changes appear
to be pre-cancerous, an increased risk of cancer among frequent marijuana
smokers is possible. 24 Since
the pulmonary risks associated with marijuana are related to smoking, the danger
is eliminated with other routes of administration. For committed smokers,
pulmonary risk might be reduced with higher potency products, which produce
desired psychoactive effects with less inhalation of irritants. Smokers could
also be encouraged to abandon deep inhalation and breath-holding, which increase
drug delivery only slightly.
Finally, pulmonary risk might be reduced if marijuana were smoked
in
water
pipes rather than cigarettes. 25
[Next
Claim]
CLAIM
#5:
MARIJUANA
IMPAIRS IMMUNE SYSTEM FUNCTIONING
It
has been widely claimed that marijuana substantially increases users' risk of
contracting various infectious diseases. First emerging in the 1970s, this claim
took on new significance in the 1980s, following reports
of
marijuana use by people suffering from AIDS.
THE
FACTS
The
principal study fueling the original claim of immune impairment involved
preparations created with white blood cells that had been removed from marijuana
smokers and controls. After exposing the cells to known immune activators,
researchers reported a lower rate of "transformation" in those taken from
marijuana smokers. 26 However,
numerous groups of scientists, using similar techniques, have failed to confirm
this original study. 27 In
fact, a 1988 study demonstrated an increase in responsiveness when white blood
cells from marijuana smokers were exposed to immunological activators.
28 Studies
involving laboratory animals have shown immune impairment following administration of THC, but
only with the use of extremely high doses.
For
example, one study demonstrated an increase in herpes infection in rodents given
doses of 100 mg/kg/day - a dose approximately 1000 times the dose necessary to
produce a psychoactive effect in humans. 29
There
have been no clinical or epidemiological studies showing an increase in
bacterial, viral, or parasitic infection among human marijuana users. In three
large field studies conducted in the 1970s, in
use
in HIV-wasting syndrome relied upon the absence of any immuno-pathology due to THC. 32 Today,
thousands of people with AIDS are smoking marijuana daily to combat nausea and
increase appetite. There is no scientific basis for claims that this practice
compromises their immune responses. Indeed, the recent discovery of a peripheral
cannabinoid receptor associated with lymphatic tissue
should encourage aggressive exploration of THC's potential use as an
immune-system stimulant. 33
[Next
Claim]
CLAIM
#6:
MARIJUANA
HARMS SEXUAL MATURATION AND REPRODUCTION
Marijuana
has been said to interfere with the production of hormones associated with
reproduction, causing possible infertility among adult users and delayed sexual
development among adolescents.
THE
FACTS
There
is no evidence that marijuana impairs male reproductive functioning. The Jamaican and Costa Rican field
studies detected no differences in hormone levels between marijuana users and
non-users. In epidemiological
surveys of marijuana users, no problems with fertility have emerged as
important. In 1974, researchers
reported diminished testosterone, reduced sexual function and abnormal sperm
cells in males identified as chronic marijuana users. 34 In
a laboratory study, the same researchers reported an acute decrease in
testosterone, but no chronic effect after nine weeks of smoking; they did not
evaluate sperm volume or quality. 35 In
other laboratory studies, researchers have been generally unable to replicate
these findings, 36 although
by
administering
very high THC doses - up to 20 cigarettes per day for 30 days - one study found
a slight decrease in sperm concentrations. 37
In
all studies, test results remained within normal ranges and probably would not
have affected actual fertility.
Severe adverse consequences have also been produced in male laboratory
animals, although only with extremely high daily THC doses. 38 More
importantly, in both the human and animal laboratory studies, all observed
changes were reversed once THC administration was halted. The claim that marijuana impairs female
reproductive functioning in humans has no support in the scientific
literature. There have been no
epidemiological studies indicating diminished fertility in female users of
marijuana, and a recent
survey
found no impact of chronic marijuana use on female sex hormones. 39 Animal
studies show hormonal changes and depressed ovulation following extremely high
daily doses of THC. As occurs with males, these changes disappear once the
experiment is completed. 40
In
addition, when THC was administered to female monkeys for an entire year, they
developed tolerance to its hormonal effects and normal cycles were
reestablished. 41 Almost
immediately following publication of the few studies showing a marijuana impact
on reproductive hormones, warnings about marijuana's potential impact on
adolescent sexual development began to appear. Other than one case report of a 16-year
old marijuana smoker who had failed to progress to puberty, 42
there
has been nothing to indicate that such a potential exists. In whatever other
ways one might consider
marijuana
to be bad for adolescents, it does not retard their sexual
development.
[Next
Claim]
CLAIM
#7:
MARIJUANA
USE DURING PREGNANCY HARMS THE FETUS
A
powerful accusation in anti-drug campaigns is that children are permanently
harmed by their mothers' use
of
drugs during pregnancy. Today, it
is commonly claimed that marijuana is a cause of birth defects
and
development deficits.
THE
FACTS
A
number of studies claimed reported low birth weight and physical abnormalities
among babies exposed to marijuana in uterus. 43 However,
when other factors known to affect pregnancy outcomes were
controlled
for
- for example, maternal age, socioeconomic class, and alcohol and tobacco use -
the association between marijuana use and adverse fetal effects disappeared.
44 Numerous
other studies have failed to find negative impacts from marijuana exposure.
45
However,
when negative outcomes are found, they tend to be widely publicized, regardless
of the quality of the study. It is
now often claimed that marijuana use during pregnancy
causes
childhood leukemia. The basis for this claim is one study, in which. 5% of the
mothers of leukemic children admitted to using
marijuana prior to or during pregnancy. A "control group" of mothers with normal
children was then created and questioned by telephone about previous drug use.
Their reported .5 % marijuana use-rate was used to calculate a 10-fold greater
risk of leukemia for children born to marijuana users. 46
Given
national surveys showing marijuana prevalence rates of at least 10%, these
"control group" mothers almost certainly under-reported their drug use to
strangers on the telephone. Also
used as evidence of marijuana-induced fetal harm are two longitudinal studies,
in which the children of marijuana users were examined repeatedly. However, on
closer examination, the effects of marijuana appear to be quite minimal, if
existent at all. After finding a
slight deficit in visual responsiveness among marijuana-exposed newborns, no
differences were found at six months, 12 months, 18 months, or 24 months.
47 At
age 3, the only difference (after controlling for confounding variables) was
that children of "moderate" smokers had superior psycho-motor skills. At age 4,
children of "heavy" marijuana users (averaging 18.7
joints/week) had lower scores on one subscale of one standardized test of
verbal development. 48 At
age 6, these same children scored lower on one computerized task - that
measuring "vigilance." On dozens of others scales and subscales, no differences
were ever found. 49 In
another study, standardized IQ tests were administered to marijuana-exposed and
unexposed three year-olds.
Researchers found no differences in the overall scores. However, by dividing the sample by race,
they found - among African-American children only - lower scores on one subscale
for those exposed during the first trimester and lower scores on a different
subscale for those exposed during the second trimester. 50 Although
it is sensible to advise pregnant women to abstain from using most drugs -
including marijuana - the weight of scientific evidence indicates that marijuana
has few adverse consequences for the developing human
fetus.
[Next
Claim]
CLAIM
#8:
MARIJUANA
CAUSES BRAIN DAMAGE
Critics’
state that marijuana has been shown to damage brain cells and that this damage,
in turn, causes
memory
loss, cognitive impairment, and difficulties in learning.
THE
FACTS
The
original basis of this claim was a report that, upon postmortem examinations,
structural changes in several brain regions were found in two rhesus monkeys
exposed to THC. 51 Because
these changes primarily
involved
the hippocampus, a cortical brain region known to play an important role in
learning and memory, this finding suggested possible negative consequences for
human marijuana users. Additional
studies, employing rodents, reported similar brain changes. However, to achieve these results,
massive doses of THC – up to 200 times the psychoactive dose in humans - had to
be given . In fact, studies employing 100 times the
human dose
have
failed to reveal any damage. 52 In
the most recently published study, rhesus monkeys were
exposed
through
face-mask inhalation to the smoke equivalent of four to five joints per day for
one year. When sacrificed seven months later, there was no observed alteration
of hippocampal architecture, cell size, cell number,
or
synaptic
configuration. The authors conclude:
"while behavioral and neuroendocrinal effects
are observed
during
marijuana smoke exposure in the monkey, residual neuropathological and neurochemical effects of marijuana exposure were not
observed seven months after the year long marijuana smoke regimen." 53
Thus,
20 years after the first report of brain damage in two marijuana exposed
monkeys, the claim of damage to brain cells has been effectively disproven. No
postmortem examinations of the brains of human marijuana
users
have
ever been conducted. However, numerous studies have explored marijuana effect on
brain-related cognitive functions. Many employ an experimental design - in which
subjects are given marijuana in a laboratory setting, and then compared to
controls on a variety of measures involving attention, learning and memory. In a number of studies, no significant
differences were detected. 54
In
fact, there is substantial research demonstrating that that marijuana
intoxication does not impair the retrieval of information learned previously.
55 However,
there is evidence that marijuana, particularly in high doses, may interfere with
users' ability to transfer new
information
into longterm memory. 56 While
there is general agreement that, while under the influence
of
marijuana,
learning is less efficient, 57
there
is no evidence that marijuana users - even long term users - suffer permanent
impairment. Indeed, numerous
studies comparing chronic marijuana users with non-user controls have found no
significant differences in learning, memory recall or other cognitive functions.
58
[Next
Claim]
CLAIM
#9:
MARIJUANA
IS AN ADDICTIVE DRUG
It
is now frequently stated that marijuana is profoundly addicting and that any
increase in prevalence of use
will
lead inevitably to increases in addiction.
THE
FACTS
Essentially
all drugs are used in "an addictive fashion" by some people. However, for any drug to be identified
as highly addictive there should be evidence that substantial numbers of users
repeatedly fail in their attempts to discontinue use and develop use-patterns
that interfere with other life activities.
National epidemiological surveys show that the large majority of people
who have had experience with marijuana do not become regular users. In 1993, among Americans age 12 and
over, about 34% had used marijuana sometime in their life, but only 9% had used
it in the past year, 4.3% in the past month, and 2.8% in the past week.
59 A
longitudinal study of young adults who had first been surveyed in high school
also found a high "discontinuation rate" for marijuana. While 77% had used the
drug, 74% of those had not used in the past year and 84% had not used
in
the
past month. 60 Of
course, even people who continue using marijuana for several years or more are
not necessarily "addicted" to it.
Many regular users - including many daily users – consume marijuana in a
way that does not interfere with other life activities, and may in some cases
enhance them. There is only scant
evidence that marijuana produces physical dependence and withdrawal in
humans. When human subjects were
administered daily oral doses of 180-210 mg of THC - the equivalent of 15-20
joints per day - abrupt cessation produced adverse symptoms, including disturbed
sleep, restlessness, nausea, decreased appetite, and sweating. The authors
interpreted these symptoms as evidence of physical dependence. However, they
noted the syndrome's relatively mild nature and remained skeptical of its
occurrence when marijuana is consumed in usual doses and situations.
61 Indeed,
when humans are allowed to control consumption, even high doses are not followed
by adverse withdrawal symptoms. 62 Signs
of withdrawal have been created in laboratory animals following the
administration of very high doses. 63 Recently,
at a NIDA-sponsored conference, a researcher described unpublished observations
involving rats pretreated with THC and then dosed with a cannabinoid receptor-blocker. 64
Not
surprisingly, this provoked sudden withdrawal, by stripping receptors of the
drug. This finding has no relevance to human users who, upon ceasing use,
experience a very gradual removal of THC from receptors. The most avid publicizes of marijuana's
addictive nature are treatment providers who, in recent years, have increasingly
admitted insured marijuana users to their programs. 65
The
increasing use of drug detection
technologies
in the workplace, schools and elsewhere has also produced a group of marijuana
users who identify themselves as "addicts" in order to receive treatment instead
of punishment. 66
[Next
Claim]
CLAIM
#10:
MARIJUANA-RELATED
MEDICAL EMERGENCIES ARE INCREASING
As
evidence of its harmful effects, prohibition advocates point to dramatic
increases in emergency room episodes related to marijuana
ingestion.
THE
FACTS
Data
gathered by the Drug Abuse Warning Network (DAWN) show a recent increase in
"marijuana mentions" by people seeking treatment in hospital emergency rooms.
Using a one-page form, emergency-room personnel record "drug abuse episodes,"
note the presence or absence of alcohol as a contributing factor, and list up to
four other drugs recently consumed by the patient. Although DAWN began compiling data in
the 1970s, recent
changes
in recording procedures, the hospital selection, and methods of statistical
estimation prevent comparisons of data gathered prior to 1988 with those
gathered recently. Thus, discussion of emergency-room trends is limited to the
years 1988 to 1993. 67 The
lowest number of marijuana-mentions, recorded in 1990, was 15,706 (7.1 mentions
per 100,000 population). The highest was 29,166 (12.7 per 100,000 population),
recorded in 1993. Using these
figures, an increase of 86% has been reported. However, if 1988 is used as the "base
year" instead - a year in which there were 19,962 marijuana mentions – the
increase is reduced immediately by more than half, to 42%. Despite marijuana being the most
frequently used illicit drug, in emergency rooms, it remains the least often
mentioned illicit drug. In 1993,
marijuana accounted for 6.25% of mentions,
compared
to 15.3% for cocaine and 9.8% for heroin. Even over-the-counter pain medications
were mentioned more often than marijuana - comprising 9% of the total. For youth aged six to 17, there were
more mentions of
marijuana
than of heroin and cocaine - not because marijuana is more harmful to them but
because these latter
drugs
are used so infrequently by young people. In this age group, mentions of
over-the-counter pain medications were substantially higher than those for
marijuana. While marijuana accounted for 6.48% of drug mentions by youth,
over-the-counter pain medications accounted for 47%. For the total population, not only is
marijuana mentioned less frequently than other recreational drugs, it is seldom
mentioned alone. In 1992, in
more
than 80% of the drug-abuse episodes involving marijuana, at least one other drug
was mentioned; and, in more than 40%, two or more additional drugs were
mentioned. Of 24,000 marijuana
mentions in 1992, more than 13,000 involved alcohol and nearly
10,000 involved cocaine.
Despite recent increases in marijuana mentions, hospital emergency rooms
are not flooded with marijuana users seeking medical attention. In
1992,
of
433,493 total drug mentions, only 4,464 - about 1% - involved the use of
marijuana alone.
[Next
Claim]
CLAIM
#11:
MARIJUANA
PRODUCES AN AMOTIVATIONAL SYNDROME
Marijuana
is said to have a deleterious effect on society by making users passive,
apathetic, unproductive, and unable or unwilling to fulfill their
responsibilities.
THE
FACTS
The
concept of an amotivational syndrome first appeared in
the late 1960s, 68
as
marijuana use was increasing among American youth. In
the years since, despite the absence of an agreed-upon definition of the
concept, numerous researchers have attempted to verify its occurrence. Large-scale studies of high school
students have generally found no difference in grade-point averages between
marijuana users and non-users. 69
One
study found lower grades among students reported to be daily users of marijuana,
but the authors failed to identify a causal relationship and concluded that both
phenomena were part of a complex of inter-related social and emotional problems.
70 In
one longitudinal study of college students, after controlling for other factors,
marijuana users were found to have higher grades than non-users 7l
and
to be equally as likely to successfully complete their educations. 72 Another
study found that marijuana users in college scored higher than
nonusers
on
standardized "achievement values" scales. 73 Field
studies conducted in
The
results of laboratory studies have been nearly as consistent. In one study lasting 94 days, marijuana
had no significant impact on learning, performance or motivation. 74 In
another 31-day study, subjects given marijuana worked more hours than controls
and turned in an equal number of tokens for cash at the study's completion.
75
However,
in a Canadian study that required subjects in the marijuana group to consume
unusually high doses, some reduction in work efficiency was noted in the days
following intoxication. 76 Undoubtedly,
when marijuana is used in a way that produces near constant intoxication, other
activities are 1ikely to be neglected.
However,
the weight of scientific evidence suggests that there is nothing in the
pharmacological properties of cannabis that alter people's attitudes, values, or
abilities regarding work.
[Next
Claim]
CLAIM
#12:
MARIJUANA
IS A MAJOR CAUSE OF HIGHWAY ACCIDENTS
The
detrimental impact of alcohol on highway safety has been well documented.
Marijuana's opponents claim that it, too, causes
significant impairment and that any increase in use will lead to increased
highway
accidents
and fatalities.
THE
FACTS
In
high doses, marijuana probably produces driving impairment in most people.
However, there is no evidence that marijuana, in current consumption patterns,
contributes substantially to the rate of vehicular accidents in
those,
alcohol was present and may have been the primary contributor to the fatal
outcome. 78 To
accurately assess marijuana's contribution to fatal crashes, the positive rate
among deceased drivers would have to be compared to the positive rate from a
random sample of drivers not involved in fatal accidents. Since the rate of past-month marijuana
use for Americans above the legal driving age is about 12%, on any given day a
substantial proportion of all drivers would test positive, particularly since
marijuanas’ metabolites remain in blood and urine long
after its psychoactive effects are finished. A recent study found that one-third of
those stopped for "bad driving" between the hours of
[Next
Claim]
CLAIM
#13:
MARIJUANA
IS A "GATEWAY" TO THE USE OF OTHER DRUGS
Advocates
of marijuana prohibition claim that even if marijuana itself causes minimal
harm, it is a dangerous substance because it leads to the use of "harder drugs"
such as heroin, LSD, and cocaine.
THE
FACTS
Most
users of heroin, LSD and cocaine have used marijuana. However, most marijuana
users never use another illegal drug.
Over time, there has been no consistent relationship between the use
patterns of various drugs. 83
As
marijuana use increased in the 1960s and 1970s, heroin use declined. And, when
marijuana use declined in the 1980s, heroin use remained fairly stable. For the past 20 years, as marijuana
use-rates fluctuated, the
use
of LSD hardly changed at all.
Cocaine use increased in the early 1980s as marijuana use was declining.
During the late 1980s, both marijuana and cocaine declined. During the last few
years, cocaine use has
continued
to decline as marijuana use has increased slightly. In 1994, less than 16% of high school
seniors who had ever tried marijuana had ever tried cocaine - the lowest
percentage ever recorded. In fact,
as shown below, the proportion of marijuana users trying cocaine has declined
steadily since 1986, when a high of more than 33% was
recorded.
Proportion
of Marijuana Users Ever Trying Cocaine
High
School Seniors, 1975-1994 84
1975:
19% 1980: 27% 1985: 31% 1990:
22%
1976:
19% 1981: 28% 1986: 33% 1991:
22%
1977:
20% 1982: 27% 1987: 30% 1992:
18%
1978:
22% 1983: 28% 1988: 26% 1993:
17%
1979:
25% 1984: 29% 1989: 23% 1994:
16%
In
short, there is no inevitable relationship between the use of marijuana and
other drugs. This fact is supported by data from other countries. In the
[Next
Claim]
CLAIM
#14:
DUTCH
MARIJUANA POLICY HAS BEEN A FAILURE
While
American critics of marijuana prohibition often point to the
including
escalating rates of drug use among youth.
THE
FACTS
In
1976, following the recommendations of two national commissions, the Dutch
government revised many aspects of its drug policy. While not legalizing
marijuana, it adopted an "expediency principle," which
directed
police
and prosecutors to ignore retail sale to adults as long as the circumstances of
the sale do not constitute a public nuisance. This change in policy was based on
several factors, including: A
principle of tolerance toward alternative lifestyles finding that, compared to
other illegal drugs, marijuana poses little risk to users desire to protect
marijuana users from the marginalization that accompanies arrest and prosecution
belief that separating the retail markets for "soft" and "hard" drugs decreases
the likelihood that marijuana users will experiment with cocaine or heroin. Following the policy change, marijuana
sales emerged openly in coffee shops, which were required to follow a set of
regulations, including a ban on advertising, sale of no more than 5 grams (Was
30 grams thanks Mathieu) at a time, and a minimum purchase age of 18. The
sale of other drugs on the premises is strictly prohibited, and constitutes
grounds for immediate closure by the police. Local officials were also
authorized to create additional regulations to protect the interests of the
community - for example, limiting the number of coffee shops concentrated in any
one area. 87 Since
liberalization, marijuana use has increased in the
MARIJUANA
USE AMONG DUTCH YOUTH (ages
12-18) 88
ever
used past month
1984
4.8% 2.3%
1988
8.0 3.1
1992
13.6 6.5
MARIJUANA
USE AMONG AMERICAN YOUTH (ages
12-17) 89
ever
used past month
1985
23.6% 12.0%
1988
17.4 6.4
1993
11.7 4.9
MARIJUANA
USE AMONG AMERICAN YOUTH (high
school seniors) 90
ever
used past month
1985
54.2% 25.7%
1988
47.2 18.0
1993
35.3 15.5
While
marijuana use-rates have increased in the
about
1.5% of 12 to 18 year-olds had ever tried cocaine and only .3% had used it in
the past month. 91
Although
there are some Dutch critics of that country's liberalized marijuana policy, the
government's official position remains steadfastly supportive of the 1976
initiative that decriminalized possession and retail. 92
[Endnotes]
THE
Footnotes
From
Exposing
Marijuana Myths - A Review of the Scientific Evidence
1.
Grinspoon,
L., Marihuana Reconsidered,
2.
3.
Himmelstein,
J., The Strange Career of Marijuana: Politics
and Ideology of Decriminalization in
Journal
of Public Health Policy 10:456-66
(1989).
4.
Carter,
W.E. (ed), Cannabis in Costa Rica: A Study of
Chronic Marijuana Use,
5.
Preliminary
Estimates From the 1993 National Household Survey on
Drug Abuse,
6.
7.
Ennett,
S.T, et al, "How Effective is Drug Abuse Resistance Education? A Meta-Analysis of Project DARE Outcome
Evaluations," American Journal of Public Health 84:1394-1401
(1994).
8.
ElSohly,
M.A. et al, "Constituents of Cannabis Sativa L XXIV: The Potency of Confiscated
Marijuana, Hashish, and Hash Oil Over a Ten-year Period," Journal of Forensic
Sciences 29:500-14 (1984).
9.
Perry,
D., "Street Drug Analysis and Drug Use Trends, Part II, 1969-1976," PharmChem Newsletter 6
(1977).
10.
Rubin,
V., "Cross-Cultural Perspectives on Therapeutic Uses of Cannabis," pp 1-18 in S.
Cohen and R.C. Stillman (eds), The Therapeutic Potential of Marijuana,
11.
Chang,
A.E. et al, "Delta-Nine-Tetrahydrocannabinol as an
Antiemetic in Cancer Patients Receiving High-Dose
Methotrexate: A Prospective Randomized Evaluation,
Annals of Internal Medicine 91: 819-24 (1979).
12.Hepler,
R.S. and Frank, I.R., "Marijuana Smoking and Intracular Pressure," Journal of the American Medical
Association 217: 1392 (1971).
13.
Petro,
D.J., "Marijuana as a Therapeutic Agent for Muscle Spasm or Spasticity," Psychosomatics 21: 81-85
(1980).
14.
Grinspoon,
L. and Bakalar, J.B, Marihuana: The Forbidden
Medicine,
15.
Vinciguerra,
V. et al, "Inhalation Marijuana as an Antiemetic for
Cancer Chemotherapy," New York State Journal of Medicine 85:525-27
(1988); Dansac, D., "In the Matter of Marijuana
Rescheduling Petition,"
Affidafit
filed in Drug Enforcement Adminstration Hearings,
Docket 86-22 (1987).
16.
Doblin,
R. and Kleiman, M.A.R., "Marijuana as an Anti-Emetic
Medicine: A Survey of Oncologists' Attitudes and Experiences," Journal of
Clinical Oncology 19: 1275-1290 (1991).
17.
Agurell,
S. et al, "Pharmacokinetics and Metabolism of Delta-1- Tetrahydrocannabinol and Other Cannabinoids with Emphasis on Man," Pharmacological
Reviews 38: 21-43 (1986).
18.
Cohen,
S., "Therapeutic Aspects," pp 194-225 in R.C. Petersen (ed) Marijuana Research Findings: 1976,
Potential
of Marijuana,
19.
"Members
of Congress Voice Support for Marijuana/AIDS Research," Newsletter of the
Multidisciplinary Association for Psychedelic Studies 5,3 (Winter 1995).
20.
Drug
Enforcement Administration, Drug Legalization: Myths and Misconceptions,
21.
Huber,
G.L. et al, "The Effects of Marihuana on the Respiratory and Cardiovascular
Systems," pp 3-18 in G. Chesher et al (eds), Marijuana: an
International Research Report,
Publishing
Service
(1988).
22.
Tashkin,
D.P. et al, "Longitudinal Changes in Respiratory Symptoms and Lung Function in
Non-smokers, Tobacco Smokers, and Heavy, Habitual Smokers of Marijuana With or
Without Tobacco," pp 25-36 in G.
Chesher
et al (eds), Marijuana: an
International Research Report,
23.
Sherrill,
D.L. et al, "Respiratory Effects of Non-Tobacco Cigarettes: A Longitudinal Study
in General Population," International Journal of Epidemiology 20: 132-37
(1991).
24.
Fligiel,
S.E.G. et al, "Bronchial Pathology in Chronic Marijuana Smokers: A Light
Electron Microscope Study," Journal of Psychoactive Drugs
25.
Doblin,
R., "The MAPS/California NORML/Marijuana Waterpipe/
Vaporizer Study," Newsletter of the Multidisciplinary Association for
Psychedelic Studies 5,1 (Summer
1994).
26.
Nahas,
G.G. et al, "Inhibition of Cellular Mediated Immunity in Marijuana Smokers,"
Science 183:419-20 (1974).
27.
Lau,
R.J. et al, "Phytohemagglutinin-Induced Lymphocyte
Transformation in Humans Receiving Delta-9-Tetrahydrocannabinol," Science
192: 805-07 (1976); White, S.C. et al, "Mitogen-Induced Blastogenetic
Responses to Lymphocytes from Marijuana Smokers," Science 188: 71-72
(1975).
28.
Wallace,
J.M. et al, "Peripheral Blood Lymphocyte Subpopulations and Mitogen Responsiveness in Tobacco and Marijuana Smokers,"
Journal of Psychoactive Drugs 20:9-14 (1988).
29.
Mishkin,
E.M. and Cabral, G.A., "Delta-9-Tetrahydrocannabinol Decreases Host Resistance
to Herpes Simplex Virus Type 2 Vaginal Infection in the BGC3F1 Mouse,"
Journal of General Virology 66:2539-49 (1985).
30.
Carter,
W.E. (ed), Cannabis in Costa Rica: A Study of
Chronic Marijuana Use,
31.
Coates,
R.A. et al, "Cofactors of Progression to Acquired Immunodeficiency Syndrome in a
Cohort of Male Sexual Contacts of Men with Immunodeficiency Virus Disease,"
American Journal of Epidemiology 132: 717-22
(1990).
32.
Plasse,
T.F. et al, "Recent Clinical Experience with Dronabinol," Pharmacology Biochemistry and Behavior
40:695-700 (1991).
33.
Modulation
by Cannabinoids, " Journal of Pharmacology and
Experimental Therapeutics 268:
1612-23
(1994).
34.
Kolodny,
R.C. et al, "Depression of Plasma Testosterone Levels After Chronic Intensive
Marijuana Use," New England Journal of Medicine 290:872-74
(1974).
35.
Kolodny,
R.C. et al, "Depression of Plasma Testosterone with Acute Marijuana
Administration," pp 217-25 in M.C. Braude and S. Szara (eds), Pharmacology of Marijuana,
36.
Mendelson,
G.D. et al, "Plasma Testosterone Levels Before, During,
and After Chronic Marijuana Smoking," New England Journal of Medicine
291:1051-55 (1975); Schaefer, C.F. et al, "Normal Plasma
Testosterone
Concentrations
After Marijuana Smoking,"
37.
Hembree,
W.C. et al, "Changes in Human Spermatozoa Associated with High Dose Marijuana
Smoking," pp 429-39 in G.G. Nahas and W.D.M. Paton (eds), Marijuana:
Biological Effects, Oxford: Pergamon Press
(1979).
38.
Fijimoto,
G.I. et al, "Effect of Marijuana Extract Given Orally on Male Rat Reproduction
and Gonads," Proceedings of Sixth Annual Meetings of Endocrinology Society
(1978); Okey, A.B. and Truant, G.S.,
"Cannabis
Demasculinizes
Rats But Is Not Estrogenic," Life Sciences 17:1113-18
(1975).
39.
Block,
R.I. et al, "Effects of Chronic Marijuana Use on Testosterone, Luteinizing Hormone, Follicle Stimulating Hormone, Prolactin and Cortisol in Men and
Women," Drug and Alcohol Dependence 28:121-8
(1991).
40.
Smith,
C.G. and Asch, R.H., "Acute, Short-Term, and Chronic
Effects of Marijuana on the Female Primate Reproductive Function," pp 82-96 in
M.C. Braude and J.P. Ludford
(eds), Marijuana Effects
on the Endocrine
and
Reproductive Systems,
41.
Smith,
C.G. et al, "Tolerance Develops to the Disruptive Effects of Delta 9 Tetrahydrocannabinol on the Primate Menstrual Cycle,"
Science 219:1453-55 (1983).
42.
Copeland,
K.C. et al, "Marijuana Smoking and Pubertal Arrest," Journal of Pediatrics
96:1079-80 (1980).
43.
Tennes,
A., "Effects of Marijuana on Pregnancy and Fetal Development in the Human," pp
115-23 in M.C. Braude and J. P, Ludford (eds), Marijuana Effects on the Endocrine and
Reproductive Systems,
44.
Astley,
S., "Analysis of Facial Shape in Children Gestationally Exposed to Marijuana, Alcohol, and/or
Cocaine," Pediatrics 89:67-77 (1992); Day, N. et al, "Prenatal Marijuana
Use and Neonatal Outcome," Neurotoxicology
and
Teratology 13:329-34
(1992); Linn, S. et al, "The Association of Marijuana Use with Outcome of
Pregnancy," American Journal of Public Health 73:1161-64
(1983).
45.
Hayes,
J. et al, "Newborn Outcomes with Maternal Marijuana Use in Jamaican Women,"
Pediatric Nursing 14(2):107-10 (1988); Streissguth, A. P. et al, "IQ at Age 4 in Relation to
Maternal Alcohol Use and Smoking
During
Pregnancy," Developmental Psychology 25: 3-11 (1989); Richardson, G.A. et
al, "The Effect of Prenatal Alcohol, Marijuana and Tobacco Exposure on Neonatal
Behavior," Infant Behavioral Development 12: 199-209 (1989); O'Connell,
C.M. and Fried, P.A., "Prenatal Exposure to Cannabis: A Preliminary Report of
Postnatal Consequences in School-Age Children," Neurotoxicology and Teratology 13: 631-39
(1991); Fried, P.A. et al, "60- and 72-Month Follow-Up of Children Prenatally Exposed to Marijuana, Cigarettes and Alcohol,"
Journal of Developmental Behavior and Pediatrics 13: 383-91 (1992); Dreher, M.C. et al, "Prenatal Exposure and Neonatal Outcomes
in Jamaica: An Ethnographic Study," Pediatrics 93: 254-60
(1994).
46.
Buckley,
J.D. et al, "Occupational Exposure of Parents of Children with Acute Nonlymphocytic Leukemia: A Report from the Children's Cancer
Study Group," Cancer Research 49:4030-37 (1989).
47.
Fried,
P.A., "Postnatal Consequences of Maternal Marijuana Use," pp 61-72 in T.M. Pinkert (ed), Current Research on the Consequences of
Maternal Drug Abuse, Rockville, MD: National Institute on Drug
Abuse;
Fried,
P.A. and B. Watkinson, "12- and 24-Month Neurobehavioral Follow-Up of Children
Prenatally Exposed to Marijuana, Cigarettes and
Alcohol," Neurotoxicology and Teratology
10: 305-13 (1988)
48.
Fried,
P.A. and B. Watkinson, "36- and 48-Month Neurobehavioral Follow-Up of Children
Prenatally Exposed to Marijuana, Cigarettes, and
Alcohol," Developmental and Behavioral Pediatrics11: 49-58
(1990).
49.
Fried,
P.A. et al, "A Follow-Up Study of Attentional Behavior
in 6-Year-Old Children Exposed Prenatally to
Marijuana, Cigarettes, and Alcohol," Neurotoxicology and Teratology 14: 299-311
(1992).
50.
Day,
N.L. et al, "Effect of Prenatal Marijuana Exposure on the Cognitive Development
of Offspring at Age Three," Neurotoxicology
and Teratology 16: 169-75 (1994).
51.
Heath,
B.C. et al, "Cannabis Sativa: Effects on Brain Function and Ultrastructure in Rhesus Monkeys," Biological Psychiatry
15:657 (1980).
52.
Scallet,
A.C., "Neurotoxicology of Cannabis and THC: A Review
of Chronic Exposure Studies in Animals," Pharmacology Biochemistry and
Behavior 40:671-82 (1991).
53.
Slikker,
W. et al, "Behavioral, Neurochemical, and Neurohistological Effects of Chronic Marijuana Smoke
Exposure in the Nonhuman Primate," pp 219-74 in L. Murphy and A. Bartke (eds), Marijuana/Cannabinoids
Neurobiology
and Neurophysiology,
54.
Weckowicz,
T.E. et al, "Effect of Marijuana on Divergent and Convergent Production
Cognitive Tests," Journal of Abnormal Psychology 84:386-98 (1975);
Hooker, W.D., and Jones, R.T., "Increased Susceptibility to Memory Intrusions
and the Stroop Interference Effect During Acute
Marijuana Intoxication," Psychopharmacology 91: 20-24 (1987); Waskow, I.E. et el, "Psychological Effects of Tetrahydrocannabinol," Archives of General Psychiatry
22: 97-107 (1970); Dornbush, R.L. and Kokkevi, A., "Acute Effects of Cannabis on Cognitive,
Perceptual, and Motor Performance in Chronic Hashish Users," Annals of the
New York Academy of Sciences 282: 213-22 (1976).
55.
Darley,
C.F. et al, "Marijuana Effects on Long-Term Memory Assessment and Retrieval,"
Psychopharmacology 52:239-41 (1977); Abel, E.L., "Retrieval of
Information After Use of Marijuana," pp 121-24 in E.L. Abel (ed) The
Scientific Study of Marijuana, Chicago: Nelson-Hall Publishers (1976); Abel,
E.L., "Marijuana and Memory: Acquisition or Retrieval?" pp 125-32 in E.L. Abel
(ed) The Scientific Study of Marijuana, Chicago: Nelson-Hall Publishers
(1976).
56.
Abel,
E.L., "Marijuana and Memory: Acquisition or Retrieval?" pp 125-32 in E.L. Abel
(ed) The Scientific Study of Marijuana,
Narrative
Material and Stroop Colour-Word Performance," pp 117-20 in E. L. Abel (ed) The
Scientific Study of Marijuana, Chicago: Nelson-Hall Publishers (1976); Dornbush, R.L. et al, "Marijuana, Memory, and Perception,"
pp 133-40 in E.L. Abel (ed) The Scientific Study of Marijuana, Chicago:
Nelson-Hall Publishers (1976).
57.
Ferraro,
D.P., "Acute Effects of Marijuana on Human Memory and Cognition," pp 98-119 in
R.C. Petersen (ed) Marijuana Research
Findings: 1980,
58.
Satz,
P. et al, "Neuropsychologic, Intellectual, and
Personality Correlates of Chronic Marijuana Use in Native Costa Ricans,"
Annals of the New York Academy of Sciences 282: 266-306 (1976); Grant,
"A
Neuropsychological Assessment of the Effects of Moderate Marijuana Use," Journal of Nervous and Mental
Disease 156: 278-80 (1973); Knights, R., "Psychological Test Results," pp 111-20 in V. Rubin and L. Comitas (eds), Ganja in
Jamaica, The Hague: Mouton (1975); Page, J.B., "Psychosociocultural Perspectives on Chronic Cannabis Use:
The Costa Rican Follow-Up," Journal of Psychoactive Drugs 20: 57-65
(1988); Carlin, A.S. and Trupin, E.W., "The Effect of
Long-Term Chronic Marijuana Use on Neuropsychological Functioning,"
International Journal of the Addictions 12:617-24
(1977).
59.
Preliminary
Estimates from the 1993 National Household Survey on Drug Abuse,
60.
Johnston,
L.D. et al, Drug Use Among American High School Seniors, College Students and
Young Adults, 1975-1990,Vol II, Rockville, MD: U.S. Department of Health and
Human Services (1991), p 31.
61.
Jones,
R.T. et al, "Clinical Studies of Cannabis Tolerance and Dependence," Annals
of the New York Academy of Sciences 282:221-39 (1976).
62.
Stefanis.
C. et al, "Experimental Observations of a 3-Day Hashish Abstinence Period and
Reintroduction of Use," Annals of the New York Academy of Sciences
282:113-20 (1976); Cohen, S. et al, "The 94-Day
Study,"
pp 621-26 in M.C. Braude and S. Szara (eds), The Pharmacology of Marijuana,
63.
Deneau,
G.A. and Kaymakcalan, S., "Physiological and
Psychological Dependence to Synthetic Delta-9-Tetrahydrocannabinol (THC) in
Rhesus Monkeys," Pharmacologist13:246 (1971).
64.
Martin,
B.R., "Marijuana: What It Is and What It Does," Presentation at NIDA's National Conference on Marijuana Use Prevention,
Treatment and Research,"
65.
Gold,
M.S., The Good News About Drugs and
Alcohol,
66.
Jacobs,
J.B. and Zimmer, L., "Drug Treatment and Workplace Drug Testing: Politics,
Symbolism and Organizational Dilemmas," Behavioral Sciences and the Law
9:345-60 (1991).
67.
Annual
Emergency Room Data,
1990, National Institute on Drug Abuse Statistical Series, Series I, Number
10-A, Rockville, MD: National Institute on Drug Abuse (1991); Annual
Emergency Room Data, 1992, National Institute on Drug Abuse Statistical
Series, Series I, Number 12-A, Rockville, MD: National Institute on Drug Abuse
(1993); Preliminary Estimates from the Drug Abuse Warning Network,
Advance Report Number 8, Rockville, MD: National Institute on Drug Abuse
(1994).
68.
McGlothlin,
H.W. and West, L.J., "The Marijuana Problem: An Overview," American Journal
of Psychiatry 125:1126-34 (1968); Smith, D. E., "The Acute and Chronic
Toxicity of Marijuana," Journal of Psychedelic
Drugs
2:37-48
(1968).
69.
Brill,
N.O. and Christie, R.L., "Marijuana Use and Psychosocial Adaptation,"
Archives of General Psychiatry 31:713-19 (1974); Kupfer, D. J. et al, "A Comment on the Amotivational Syndrome in Marijuana Smokers," American
Journal of Psychiatry 130:1319-22 (1973).
70.
Kleinman,
P.H. et al, "Daily Marijuana Use and Problem Behaviors Among Adolescents," International Journal of Addictions
23:87-107 (1988).
71.
Mellinger,
G.D. et al, "Drug Use, Academic Performance, and Career Indecision: Longitudinal
Data in Search of a Model," pp 157-77 in D.B. Kandel
(ed), Longitudinal Research on Drug Use: Empirical
Findings and
Methodological
Issues,
72.
Mellinger,
G.D. et al, "The Amotivational Syndrome and the
College Student," Annals of the New York Academy of Sciences 282:37-55
(1976).
73.
Miranne.
H.C., "Marijuana Use and Achievement Orientations of College Students, " Journal of Health and Social Behavior 20:194-99
(1979).
74.
Cohen,
S., "The 94-Day Cannabis Study," Annals of the
75.
Mendelson,
J.H. et al, "The Effects of Marijuana Use on Human Operant Behavior: Individual
Data," pp 643-53 in M.C. Braude and
76.
77.
McBay,
A.J. and Owens, S.M., "Marijuana and Driving," pp 257-63 in L.S. Harris (ed) Problems of Drug Dependence 1980,
Cannabinoids
in Fatally Impaired Drivers: An
Investigation by Radioimmunoassay and High Pressure Liquid Chromatography," Journal of the Forensic Science
Society 17: 177-83 (1978).
78.
Terhune,
K.W. et al, The Incidence and Role of Drugs in Fatally Injured Drivers,
79.
Brookoff,
D. et al, "Testing Reckless Drivers for Cocaine and Marijuana," New England
Journal of Medicine 331:518-22 (1994).
80.
Kv'alseth,
T.O., "Effects of Marijuana on Human Reaction Time and Motor Control,"
Perceptual and Motor Skills 45:935-39 (1977); Hansteen, R.W. et al, "Effects of Cannabis and Alcohol on
Automobile Driving and
Psychomotor
Tracking," Annals of New York Academy of Sciences 282:240-56 (1976);
Moskowitz, H. et al, "Marijuana: Effects on Simulated
Driving Performance," Accident Analysis and Prevention
Moskowitz,
H. et al, "Visual Search Behavior While Viewing Driving Scenes Under the Influence of Alcohol and Marijuana," Human
Factors 18:417-31 (1976).
81.
Stein,
A.C. et al, A Simulator Study of the Combined Effects of Alcohol and
Marijuana on Driving Behavior-Phase II, Washington, DC: U.S. Department of
Transportation (1983).
82.
Robbe,
H. and O'Hanlon, J., Marijuana and Actual Driving Performance,
83.
Preliminary
Estimates from the 1993 National Household Survey on Drug Abuse.
84.
85.
Cohen,
P.D.A., Cannabisgebruikers in
86.
Leuw,
E. and Marshall, I.H. (eds).,
Between Prohibition and Legalization: The Dutch Experiment in Drug
Policy,
87.
Netherlands
Institute for Alcohol and Drugs, "Cannabis Policy Fact Sheet,"
40
in E. Leuw and I.H. Marshall (eds), Between Prohibition and Legalization: The Dutch
Experiment in Drug Policy,
88.
de
Zwart, W.M. et al, Key Data: Smoking, Drinking, Drug Use and Gambling
Among Pupils Aged 10 Years and Older,
National
Institute on Drug Abuse
(1994).
90.
National
Survey Results on Drug Use, from the Monitoring the Future Study,
1975-1993,
Volume I,
91.
de
Zwart, W.M. et al, Key Data: Smoking, Drinking, Drug Use and Gambling
Among Pupils Aged 10 Years and Older,
92.
"The
Drug Policy in the