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 Chemical Dependency
Marijuana: Addiction, Effects of Use, and Other Issues
by Michael M. Miller, M.D., Meriter Hospital NewStart
Medical Director
© 2004 Meriter Hospital
(Permission is granted to reprint this publication
without alterations for general patient use: You must
cite Meriter Hospital as the copyright holder, along
with the title and year of publication, followed with
the words "Reprinted with permission.")
Introduction |
Key Issues | The Addiction Question |
Tolerance and Withdrawal |
Effects of Use
Effects of Chronic Use |
Health Benefits |
A Final Comment
Marijuana has an interesting history in the United
States. Though used within minority groups (e.g., urban
Blacks, including musicians, artists, and the general
population) in the first half of the 20th Century, it
wasn't until majority youth (white college students,
then high schoolers, from suburban and even rural areas)
began smoking "pot" in the 1960s and after, that
marijuana gained the attention of medical researchers,
parents, government officials, and the media.
By 1979,
more than 60 percent of 12th graders had tried marijuana
at least once in their lives. From this peak, the
percentage of 12th graders who had ever used marijuana
decreased for more than a decade, dropping to a low of
33 percent in 1992. However, by 1993, first-time
marijuana use by 12th graders was again on the upswing,
reaching 50 percent by 1997. Marijuana is America's most
commonly used illegal drug—more than 1/3 of the U.S.
population ages 12 and older have tried marijuana at
least once. According to the 2001 Monitoring the Future
Study, an annual survey of drug use among the nation's
middle- and high-school students, 22 percent of 12th
graders—kids who had not dropped out of school—were
current users.
Marijuana has always been a "politicized" subject—as are
all "controlled substances" that are regulated by the
government. It is common knowledge that marijuana is a
plant that grows wild in many parts of the country, but
to possess it or distribute is a crime. There is a
current public debate about decriminalization of drugs,
especially marijuana. A frequently used argument in such
debates is that marijuana is relatively harmless, so
prohibition of its use is illogical.
One thing that
distinguishes marijuana from other illegal drugs is that
there are significant advocacy groups whose sole purpose
is to legalize this substance: cocaine and heroin never
had their version of NORML (the National Organization
for the Reform of Marijuana Laws). Some of the appeal of
such advocacy positions has come via their reaction to
government scare tactics used to discourage marijuana
use (in fact, the film "Tell Your Children" from 1938,
later renamed "Reefer Madness" was actually purchased
by the founder of NORML and shown to college kids as a
mockery of propagandized positions opposing marijuana
smoking). Because marijuana use has been so widespread
in the cohort of Americans who are now ages 35-55, and
because is was the experience of the vast majority that
one can smoke marijuana, even frequently, and not suffer
long-lasting harm, it is counter-intuitive even for
parents and civic leaders to believe that marijuana can
be harmful.
Marijuana was originally placed in the same drug class
as hallucinogens by medical researchers, since heavy use
is able to produce some of the same effects as LSD and
peyote. Researchers have been studying the behavioral
effects of THC, the active chemical in marijuana, for
decades, as well as the health effects on various organ
systems of chronic smoking of marijuana. More recently,
pharmacologists have been studying potential health
benefits of THC. With this has come a movement to
legalize marijuana for use by 'patients' to relieve
various medical conditions or symptoms.
Key issues about THC and marijuana are as follows:
1. There are indeed several documented health benefits
to pharmaceutical THC, taken orally by patients, in
capsule form, under a physician's prescription.
2. Smoked marijuana is not identical to THC, and health
benefits from smoking marijuana leaf have not been
demonstrated to date in clinical research.
3. For any agent to be approved as a "medicine," it must
undergo review (e.g., by the Food and Drug
Administration) to confirm that it is both safe and
effective—and though it is fair to assume that since the
active ingredient (THC) is effective in relieving some
symptoms of illness, then the biological product that
contains that ingredient (marijuana leaf) will also be
effective, the issue of safety is of critical
importance. How safe is it to smoke marijuana leaf? What
toxicities can occur?
4. To what extent is marijuana truly addictive? Does the
syndrome of chemical dependency develop in some persons
who smoke marijuana regularly? And would this occur in
patients using marijuana leaf for "treatment" of an
approved medical condition or symptom?
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Marijuana:
Health Effects
Immediate/short-term effects of use/intoxication
• Produces state of
relaxation, happiness, euphoria (a drug "high")
• Can intensify perceptions (sounds, colors seem
more intense, enjoyment of music or art may seem
intensified)
• Increases appetite and thirst
• Produces dry mouth
• Dilates blood vessels, including in the eye
• Reduces intra-ocular pressure
• Can decrease nausea
• Impairs time perception
• Impairs attention, judgment, and other
cognitive functions
• Impairs ability to store and retrieve learned
information—thus, it impairs memory (by
affecting the hippocampus)
• Impairs coordination and balance (by affecting
the cerebellum and basal ganglia)
• Increases heart rate (by affecting the
hypothalamus and brainstem)
• Can cause anxiety and panic attacks (by
affecting the amygdala)
• Slows reaction time
• Impairs ability to focus attention and shift
attention
• Impairs ability to track objects moving into
or across one’s visual field
• Impairs perception of velocity and
acceleration of other vehicles on the road
• May affect implantation of a fertilized embryo
in the womb
• Can impair erections
Persistent (lasting longer than intoxication,
but may not be permanent)
• Produces tolerance
• Produces withdrawal
• Impairs memory and learning skills
• Can lead to depression and decreased
motivation/interest
• Can affect work/school attendance/performance
• Can interfere with adolescent emotional and
cognitive development
Long-term (cumulative, potentially permanent
effects of chronic abuse)
• Can lead to addiction
• Increases risk of chronic cough, bronchitis,
and emphysema
• Can interfere with immune system
• Increases risk of cancer of the head, neck,
and lungs
• Decreases testosterone levels, sperm counts,
and sperm motility |
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"The Addiction Question" is one of the most intriguing
issues. The majority of marijuana users do not develop
addiction: they do not experience "loss of control." They use when they choose to, in the amounts they choose
to, getting the results—in general—that they intend to
get. Parents of today certainly recall many
acquaintances from college in the 1960s or 70s, or from
high school in the 1980s or 90s, who smoked marijuana
regularly, without long-term negative consequences.
Similarly, the vast majority of alcohol users do not
develop alcoholism: only 10 percent of regular drinkers
develop "loss of control" and other features of
addiction. Even regular cocaine use can proceed in a
phase of a person's life and then fade away without
life-long addiction taking hold of the user. But just
because addiction doesn't occur to all users, or even
most users, doesn't mean that addiction doesn't
happen—to any user.
Addiction to marijuana has the same features as
addiction to other substances: after a period of regular
but controlled use, users gradually develop an inability
to consistently use within the limits that they have set
for themselves. Use won't just result in "fun" or
"getting high"; it will lead to problems with job
performance, school performance, interpersonal
relationships, or even health.
Others will comment that
there is a change in the user—and the user will at first
deny or rebut such concerns. Use will continue despite
the problems caused by use. Larger and larger amounts of
the substance are used, consuming money that could go to
other purposes, and the person may spend more and more
of the day or the week either using, or thinking about
using, or conniving to get more supplies of the drug, or
planning on how to connive. The substance use takes on a
central place in the person's life, with other
activities—including major life responsibilities—falling
by the wayside. Despite the pleas of friends or family
to examine one's behavior, or to change the behavior,
substance use continues on, causing distress to others
before the addict experiences the distress himself. This
is the cycle of addiction, and it does happen to many
pot smokers. Eventually, the person may seek help, or at
least agree to a professional assessment at the behest
of family, school or employer.
The fact is that for persons under age 18, the
number-one substance use disorder for which persons seek
the help of NewStart is a marijuana problem. Cannabis
Abuse is just as common as Cannabis Dependence among
patients in the NewStart Adolescent Program.
"Dependence" is a term equivalent to "addiction" in this
context, and involves preoccupation, inability to
consistently control the amounts used, and unsuccessful
efforts to cut down or persistently eliminate use, as
described in earlier paragraphs.
"Abuse," as defined by
the DSM Criteria, involves recurrent use despite legal,
occupational or academic problems (e.g., recurrent use
after an arrest for impaired driving or a work
suspension because of a positive urine drug test), or
recurrent use after complaints from others (parents,
school personnel) that they have observed an impairment
of functioning associated with persistent marijuana use.
This relatively less-severe syndrome, Cannabis Abuse,
certainly creates distress for loved ones (family) and
interested parties (teachers, social workers, co-workers
or supervisors), and by definition involves an
observable downturn in the user’s performance of some
important life task. NewStart offers individual and
group treatment for persons with Cannabis Abuse,
including a Chemical Awareness Program for adolescents
that has a health-education focus. But, when indicated,
we also refer youth with a diagnosis of Cannabis Abuse
into our Intensive Outpatient Program.
Two decades ago, addiction medicine doctors and
counselors believed that the difference between the
syndrome of "substance abuse" and the syndrome of
"substance dependence" was whether tolerance and
withdrawal were present. Now it is known, as reflected
in the DSM-IV criteria, that tolerance or withdrawal may
occur in individuals with "dependence" or "addiction,"
but that the condition of addiction can exist without
there being any sign or tolerance or withdrawal. Still,
a common question of interest is, does marijuana produce
"physical dependence," that is, tolerance or withdrawal.
By the 21st Century, the answers to these questions are
clear. Tolerance does develop to THC, and the
neurochemical details of how this occurs, and to which
cannabinoid receptors, is well known. Tolerance is due
to cannabinoid receptors becoming less sensitive to
THC’s effects over time. Tolerance to marijuana is not
due to changes in THC metabolism over time.
Interestingly, there is some cross-tolerance between
cannabinoids and opioids. Moreover, withdrawal
definitely occurs in some users. The effects are
generally the opposite of the effects of intoxication:
- Anxiety and insomnia instead of relaxation
- Loss of
appetite rather than hunger
- Excess salivation instead
of dry mouth
- Decreased pulse
- Irritability
- Even
tremor
Much has been written on the relationship
between anger and marijuana use. It is likely that in
some individuals, THC decreases the experience and the
expression of anger, and that after cessation of
marijuana use, the person can not only be irritable, but
also can have an increase in mood swings and anger and
even an increase in aggressive behavior.
The human body contains receptors for the active
chemical in marijuana. Yes, human beings have evolved
with natural receptors on the membranes of certain cells
that react if chemicals called cannabinoids, including
5-delta-tetrahydrocannabinol (THC), come into contact
with them. Once a receptor has interacted with its
activating chemical, the cell begins to undergo changes.
These include the way it lets ions such as sodium or
calcium enter or leave the cell, or changes in the way
it makes proteins that code for the manufacture of
chemicals by the cell (such as hormones or
neurotransmitters).
Many subtypes of cannabinoid receptors have been
identified by neurochemists, and so-called endogenous
cannabinoids – chemicals naturally manufactured in the
body which act on cannabinoid receptors – have been
identified as well. Many cannabinoid receptors are found
in the parts of the brain that influence pleasure,
memory, thought, concentration, sensory and time
perception, and coordinated movement. Within a few
minutes after marijuana smoke is inhaled:
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THC moves from the lungs into the bloodstream and to
the brain, where it interacts with centers that regulate
vital signs.
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The heart begins beating more rapidly, the airways of
the lungs relax and become enlarged, and blood vessels
in the eyes expand, making the eyes look 'blood-shot' or
red. Heart rate can increase by 25-50 percent, or even
double.
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If the person has used another drug that increases
heart rate (such as Ecstasy, speed, or cocaine), pulse
increases can be even more dramatic.
Because of marijuana's actions on the brain, users may
experience:
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Pleasant sensations as well as colors and sounds of
high intensity, and time appears to pass very slowly.
The euphoric 'high' is the reason people choose to smoke
pot or hashish.
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A sensation of dry mouth and sudden thirst.
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Hunger.
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Measurable interference with short-term memory in
novice as well as regular users. THC interacts with
receptors in the hippocampus, the area of the brain
responsible for memory formation. Recalling what you
have learned isn't possible when memories aren't stored
well in the first place. In fact, researchers have found
that the ability to perform tasks requiring short-term
memory is reduced in laboratory rats treated with THC at
the same degree as it is in rats who have had the nerve
cells in their hippocampus destroyed.
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Loss of the ability to focus or shift attention.
Information on the National Institute on Drug Abuse
website (www.nida.nih.gov) describes how:
"Marijuana's adverse impact on memory and learning can
last for days or weeks after the acute effects of the drug wear off. For
example, a study of 129 college students found that among heavy users of
marijuana, those who smoked the drug at least 27 of the preceding 30 days,
critical skills related to attention, memory, and learning were
significantly impaired, even after they had not used the drug for at least
24 hours. The heavy marijuana users in the study had more trouble
sustaining and shifting their attention and in registering, organizing, and
using information than did the study participants who had used marijuana no
more than 3 of the previous 30 days. As a result, someone who smokes
marijuana once daily may be functioning at a reduced intellectual level all
of the time."
It is well-known that THC alters time perception: things
seem to be moving slower when one is 'high' on
marijuana. What is less well known is that the chemical
acts on cannabinoid receptors in the cerebellum and
basal ganglia of the brain, regions that control
coordination, movement, posture and balance.
THC also affects perception, including the ability to
track moving objects crossing one's visual field (for
example, a car entering an intersection and moving from
right to left). Driving ability is certainly impaired by
the combination of effects on the nervous system (time
perception, spatial perception, visual tracking,
reaction time, coordination, rapidly shifting the focus
of one's attention, the ability to accurately estimate
changes in velocity of other vehicles). This is a
consistent finding in research studies on immediate
effects of THC on complex motor and mental tasks; the
results are more predictable than accidental: in 5 to 10
percent of fatal car crashes, the deceased tests
positive for THC. And as highlighted by NIDA, studies by
the National Highway Traffic Safety Administration show
that the effects of even low doses of marijuana,
especially when combined with alcohol, impair driving,
with impairments far greater from the combination than
from either drug alone.
When used in a positive social context (e.g., around
friends, especially those who are experienced marijuana
users), the emotional effects of THC are usually
pleasurable. But THC can also produce anxiety, a sense
of distrust, and even full-blown panic attacks.
Other emotional effects can include a sense of
depersonalization or de-realization, in which the person
feels dissociated from the physical and interpersonal
environment. Thus, the person may have a feeling of,
"I'm not really myself," or experience other unpleasant
perceptions. High-dose use can result in perceptual
distortions including auditory and visual
hallucinations, even hallucinated odors.
When these experiences come together, especially in a
social context that feels unsafe (the user doesn't grasp
what's happening, there are no friends or experienced
users around to explain what's happening or to provide
reassurance, the effects are unexpected because the drug
exposure took place unwittingly, such as through
brownies, etc.), the result can be a 'bad trip' as
severe as one resulting from LSD or 'magic mushroom'
intoxication.
Occasionally, an individual who is predisposed to a
psychotic mental illness, such as schizophrenia or
psychotic bipolar disorder, will experience psychosis
for the first time when high on marijuana. The diagnosis
of the mental illness can be delayed if the person is a
regular pot smoker: the symptoms can be mistakenly
attributed to drug use rather than to a new-onset
serious mental illness.
One of the most predictable effects of marijuana is its
effect on THC receptors in the nucleus accumbens,
resulting in the overall phenomenon of 'reward.' All
potentially addictive drugs act directly or indirectly
on this compact brain region, often called 'the reward
center.' Because of their actions on this brain area,
the few drugs that are self-rewarding – cocaine,
nicotine, alcohol, heroin, THC – are self-administered
by lab animals that have been exposed to them regularly.
Humans and lesser creatures certainly find these drugs
not only pleasurable but 'rewarding.' When addiction
develops, the drugs are used in preference to other
behaviors that might be pursued.
The development of addiction in humans is a complex
process involving social/cultural variables as well as
genetic variables. The drug alone doesn't produce
addiction. Instead, addiction happens due to
interactions among the drug’s chemical effects, the
genetic make-up of the user, and the stresses, supports,
and interpersonal context in which the drug use occurs.
Again, the vast majority of drug users can use their
drug to produce the desired effects – on mood, on
appetite, on perceptions.
But certain users do not have this luxury. When they use
drugs, including marijuana for some individuals, they
develop problems in their performance of life tasks,
problems with relationships, and even difficulty shaping
their drug use to retain the pleasure they desire and
avoid the problems they know they can experience from
their use. Yes, for some persons, even teenagers, true
addiction to THC can occur.
What about other problems from long-term marijuana use?
Without question, smoking marijuana irritates the
airways and delivers carbon monoxide and cancer-causing
'tars' to the lungs – in amounts over 50 percent higher
than in tobacco smoking. Typically pot smoking involves
deeper 'drags' and holding in the hot, poisonous smoke
longer and deeper in the lungs. As NIDA points out, in
one study of 450 individuals, it was found that "people
who smoke marijuana frequently, but do not smoke tobacco, have more health
problems and miss more days of work than nonsmokers do. Many of the extra
sick days used by the marijuana smokers in the study were for respiratory
illnesses."
Not only are there more cases of acute bronchitis and
asthma in pot smokers; there are also longer-term
effects that include chronic bronchitis and emphysema.
And, marijuana use is linked to lung cancer and other
cancers. One study showed that regular marijuana smoking
doubles or triples the risk of head and neck cancers: to
the vocal cords, trachea, lymph nodes in the neck and
even mouth cancer.
Cancer of the respiratory tract and lungs may also be
promoted by marijuana smoke. A study comparing 173
cancer patients and 176 healthy individuals produced
strong evidence that smoking marijuana increases the
likelihood of developing cancer of the head or neck, and
that the more marijuana smoked, the greater the risk. A
statistical analysis of the data suggested that
marijuana smoking doubled or even tripled the risk of
these cancers.
Marijuana has the potential to promote cancer of the
lungs and other parts of the respiratory tract because
it contains irritants and carcinogens. Compared to
tobacco smoke, marijuana smoke contains 50 to 70 percent
more carcinogenic hydrocarbons. It also produces high
levels of an enzyme that converts certain hydrocarbons
into their carcinogenic form. For more details, one can
access the Research Report on Marijuana by the National
Institute on Drug Abuse:
www.drugabuse.gov/ResearchReports/Marijuana/Marijuana2.html#scope
This report contains one more interesting fact: the Drug
Abuse Warning Network (DAWN), a system for monitoring
the health impact of drugs, estimated that, in 2001,
marijuana was a contributing factor in more than 110,000
hospital emergency department visits in the United
States. This total includes people who decided on their
own that they needed emergency care as well as those who
were conveyed by police or EMTs, where it was determined
that marijuana use wasn’t just an incidental finding,
but significantly contributed to the person’s need for
emergency services.
Additionally, the number one reason youths seek
addiction treatment from specialty treatment centers
like NewStart has been (for over 20 years) – and still
is – a cannabis use disorder.
"Drugs Kill." It's a phrase we've heard many times.
Alcohol and other "rewarding" drugs certainly have the potential to produce
health problems, even death, due to effects of intoxication, overdose or
chronic use. Marijuana is not a lethal drug, however, and marijuana
addiction—while it can lead to significant impairments in functioning—does
not result in mortality like many other "drugs of abuse."
"Drugs Heal." That's a sign that could hang outside of pharmacies.
Many kinds of medications act on the body to change functioning or to abort
or reverse the course of illness. Significant debate in popular, even
political circles—not just in scientific and medical circles—centers on
whether, and to what extent, marijuana or active ingredients in the
marijuana plant (or chemicals synthesized in a lab that are similar to the
chemicals in marijuana) have effects that are beneficial to human health.
Marijuana's effects are well known: relaxation, euphoria, blood pressure
and pulse changes, changes in blood vessels and appetite, changes in
perception (especially time perception), etc. However, some effects of
marijuana may prove to be so beneficial that chemicals from marijuana may
be useful as medications some day. In fact, there are already some benefits
so well established that the active ingredient in cannabis (the marijuana
plant), delta-9-THC, is available in an oral capsule form, called
dronabinol (the trade name is Marinol).
Many health claims have been made about marijuana or chemicals similar to
THC called cannabinoids. But scientific research has confirmed safety and
efficacy only to the extent that the Federal Food and Drug Administration
has approved Marinol for two indications. One, to treat nausea in cancer
chemotherapy patients who have not responded to other medications used to
control nausea and vomiting. And two, to stimulate appetite in patients who
have been wasting away from AIDS, to help them regain weight. There are
many other indications for which delta-9-THC has been alleged to be
beneficial– to treat spasticity in patients with multiple sclerosis, to
lower intraocular pressure in patients with glaucoma, etc. However, the FDA
has not found convincing evidence from research studies to grant the
manufacturer of Marinol the authority to state that these conditions are an
approved indication for this medication. In England, there is no
pharmaceutical THC available, but drug companies are licensed to market
nabilone, a synthetic cannabinoid.
What has been discovered the last 25 years is that the reason delta-9-THC
has an effect on the brain is that there are brain cell receptors that
respond to THC. Thus, when THC comes into contact with these specialized
regions on nerve cell membranes, the cell changes its functioning,
resulting in changes in emotional, motor, perceptual, cognitive or overall
behavioral functioning. There are three well-known cannabinoid receptors:
CB1, CB2, and CB3. What is also known is that there are naturally occurring
chemicals in the human body that attach to these cannabinoid receptors.
Anandamide is the name of one of the endogenous chemicals, made by the
human body, that acts on cannabinoid receptors.
What is the role of endogenous cannabinoids? The best available knowledge
is that they affect inflammation and the ability of other naturally
occurring chemicals, called prostaglandins, to produce an anti-inflammatory
response in general. CB1 receptors are located in regions of the brain that
control mood, motor control, memory formation, regulation of food intake
and central control of cardiovascular and reproductive functioning. CB1
receptors are also present in areas that control processing of pain
information. CB2 receptors seem concentrated in areas that influence the
immune response, and in reproductive glands. Another identified receptor is
the CB3 receptor. It is thought that pharmaceutical companies have, in
their development “pipelines,” synthetic products that serve as both
agonists and antagonists to CB1, CB2 and CB3 receptors. Current research
will determine what happens when you agonize (turn on) or antagonize (turn
off) one or a combination of these CB receptors.
So there are legitimate medical questions about the use of cannabinoids as
analgesics, as they have the ability to directly affect the body’s ability
to produce and interpret information about pain. It is also known that
cannabinoids can potentate the pain relieving actions of opioid analgesics
Here is what research has shown so far. Five milligrams of medicinal THC is
equivalent to 30 milligrams of codeine as a pain reliever. Ten milligrams
of medicinal THC is equivalent to 60 milligrams of codeine. Twenty
milligrams of medicinal THC has the potency of 120 milligrams of codeine.
However, even when given in this oral, medicinal form, patients experience
side effects to the higher doses of pharmaceutical THC, including sedation,
confusion, dizziness, uncoordination, slurred speech, disorientation,
disconnected thoughts, impaired memory, blurred vision and dry mouth. The
20-milligram dose of oral THC is tolerated by few patients in clinical
trials. The 10-milligram dose is somewhat better tolerated, but has clearly
more adverse effects than when people take a 60-milligram dose of codeine.
The five-milligram dose of THC is well tolerated, and does not change
consciousness or behavior in ways patients find uncomfortable. Note,
however, that five milligrams of THC has a pain-killing potency equal to
only 30 milligrams of codeine. Most patients with significant pain
conditions certainly need a higher dose of opiate analgesic than that.
There are several groups of patients for whom it was hoped that
cannabinoids might prove to be effective analgesics: individuals with
neuropathic pain (peripheral nerves themselves are injured), patients with
cancer pain and patients with pain from AIDS. The problem is that it has
not been shown that pharmaceutical cannabinoid has the power to block pain
in these patients effectively without producing undesirable side effects.
The medical question is, are there conditions for which pharmaceutical
cannabinoids will be beneficial? Researchers are looking into alternative
delivery systems for cannabinoids–such as nasal sprays and inhalers–which
might offer better ways to deliver the drug to the bloodstream and the
brain. Still, there’s the question of side effects.
The political question, however, is whether smoked marijuana has medicinal
benefits to the extent it should be approved as a medicine, thus made legal
for “patients.” The political debate, well publicized in the media, is
whether medical marijuana should be legalized in various states. What has
happened is that when the question is put to referendums, citizens almost
always vote in significant majorities in favor of “legalizing medical
marijuana.”
The reason people vote this way is fairly obvious. The question is posed
as, "if something isn't really harmful (the assumption is that marijuana is
a benign agent), and there are patients who are really suffering (such as
AIDS patients), would you want to make it okay for them to smoke this
benign product and get benefits, rather than being thrown in jail?" Of
course, the compassionate side of voters says "yes" to such issues.
Physician organizations don’t agree, because they look to the medical
evidence. The American Medical Association and the American Society of
Addiction Medicine positions on this question are explicit. These
organizations support that well-supervised biomedical research–clinical
trials–be conducted to answer questions about the benefit/risk ratio of
using smoked marijuana to treat various medical conditions. To date, no
published study shows that smoked marijuana provides clear-cut benefits for
any of the conditions for which Marinol is currently approved.
Of course, in calculating a benefit/risk ratio, one has to factor in the
negative health effects of delivering marijuana to the body via smoking. On
one hand, delivering a predictable dose via the smoked route is
challenging. On the other hand, smoke itself contains harmful chemicals,
including carbon monoxide and carcinogens. Use of smoked marijuana has
limitations that include acute adverse effects (bothersome dry mouth,
blurry vision, palpitations and anxiety or other psychiatric phenomenon)
and the potential chronic effects of smoking. Finally, research is pretty
clear now that the amount of analgesic effect one can get from smoked
marijuana does not exceed the analgesic potency of 30 milligrams of
codeine. So there is not much true benefit to be derived, despite the acute
and potential chronic adverse effects.
This sort of medical information rarely enters the public (“media”) or
political debate. In Wisconsin, the chairman of the Assembly Health
Committee has introduced a medical marijuana bill. This bill, like most
around the country, is well intended. The problem is that there is no
medical evidence to show that smoked marijuana has benefits to a sufficient
degree to warrant its use given its side effects and the potential for
harmful outcomes from long-term use–not the least of which is the fact that
probably 10% of marijuana users do develop addiction with long-term use.
The question of whether drugs should be legalized in America is a complex
one. Compared to other countries, the United States has stringent laws and
harsh penalties with respect to euphoria-producing chemicals. In some
countries, such as Mexico, opioid analgesics are available over the
counter, without a prescription.
"Medical marijuana" proponents are leading the debate about whether using
and possessing marijuana should be decriminalized. Some proponents of
"medical marijuana," such as National Organization for the Reform of
Marijuana Laws (NORML) clearly believe that this is a health issue, but
many "medical marijuana" proponents have broader political agendas, and are
using efforts to decriminalize marijuana for "medical use” as a
subterfuge—a way to get the public gradually comfortable with the idea of
overall decriminalization. Legalization arguments should be analyzed on
their own merits–but current biomedical evidence does not support the
"medical argument" as a compelling one for legislative action to
decriminalize marijuana.
Even though marijuana use has been common in many
segments of the American population for two generations,
and many adults and teenagers know marijuana users who
have not developed addiction to even prolonged use, the
potential for the development of addiction is almost
certainly greater today than in the 1960s or 70s,
because the marijuana of today is different. It's not
just that it's much more expensive; it's that the THC
content of today's "pot" is several times higher than
even strong "weed" from the original Flower Power era.
This makes it more rewarding, but also more likely to
induce tolerance and true addiction.
5/18/2005
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