Marijuana
(See: Drugs in American Society,
5th, 6th, and 7theditions, Erich Goode, McGraw-Hill, 1999/2005, 2008. Chapter
9 and Drugs, Society, and Human Behavior (7th ed),
Ray and Ksir, Mosby, 1996. Chapter 16)


Basic Facts
- A Vegetal
Substance
- Parts used (ASC):
Leaves,
Flowering
Tops- (Buds), Resin
- Parts
Used (Other): Fibers (rope), Seeds (oil--diesel
fuel, cosmetics and food),
Entire plant (paper, clothing, etc.)
- Psychoactivity: Plant
genetics and environment
- Three Species: Named
in 1793 by Linneaus
- Cannabis
Sativa (Asia- fibers, up to 18 ft., Specified in Law)
- Cannabis
Indica (Grown specifically for resin, 2-3 ft.)
- Cannabis Ruderalis
(Russian)
- Varieties
- Hemp
(local)
versus Marijuana

WWW Links
- DrugText
Information on Cannabis
- Marijuana
Links
- PDX
NORMAL Article Links
- William
Novak's "High Culture"
1980.
- The
Lycaeum
- The
Vaults of Erowid: Exposing
Marijuana Myths
- Yahooka
- Cannabis
Research Library
- Drug
Policy Alliance Library (Lindesmith Center) (Medical
Marijuana)
- Safety
First Fact Sheet on Marijuana
- Marijauna-Info.org
(NIDA)
- Cannabis
Facts and Information
- http://www.drugscience.org
Cannabis Rescheduling
- "Busted:
America's War on Marijuana" (PBS)
- YouTube
Marijuana Videos
- Google
Marijuana Videos
- A
cannabis reader: global issues and local experiences, EMCDDA, Lisbon,
June 2008 (local
copy in .pdf)
- Ancient
Marijuana
- Why
is Marijuana Illegal? (local
copy) A nicely done "blog" by Peter Guither

Active Ingredients
- About 400 Chemicals
in the smoke of marijuana
- 61==> Cannabinoids
(found only in marijuana)
- Primary Active Ingredient:
Delta-9-Tetrahydrocannabinol (THC)
Marijuana contains
between 1-20% THC
- Mexican marijuana
(1960-1970's): ~2-6% THC
- Columbian marijuana:
4-8% THC
- Sinsemilla: 6-20%
(Female
versus Male plant)
- Domestically cultivated
marijuana today can contain up to 20% THC but this is rare (about 10% of confiscated
samples have THC content above 15%
- Marijuana
potency in Europe, 2005
- Street
level content today: 1-20%; typical 4-10% !!! No Significant Change. More potent forms more easily
available, but no dramatic (20-30 times) increase in potency as reported by
press and governmental agencies. See also: http://stopthedrugwar.org/chronicle/373/marijuanapotency.shtml,
and http://www.maps.org/news-letters/v09n3/09320gie.html
- Reports from
the DEA Marijuana Potency Monitoring Project indicate perhaps
a doubling of average potency over past 10 years
Traditional Indian
Preparations
Charas (pure
resin)
Ganja (Top
and pistillate flowers) from the female plant (Sinsemilla)
Bhang: All
the rest
Red Oil of
Cannabis
- Boil plant substance
in ETOH
- Filter
- Evaporate=> (Hash
Oil): up to 50% THC
- Long known and utilized
for a variety of recreational and medicinal purposes.
Street
level content today: 1-20%; typical 4-10% !!! No Significant Change. More potent forms more easily
available, but no dramatic (20-30 times) increase in potency as reported by
press and governmental agencies. See also: http://stopthedrugwar.org/chronicle/373/marijuanapotency.shtml,
and http://www.maps.org/news-letters/v09n3/09320gie.html
- Reports from
the DEA Marijuana Potency Monitoring Project indicate perhaps
a doubling of average potency over past 10 years

Other Psycho-Active Agents

Metabolism of THC
- Marijuana is distinctively
different from other drugs
- When
smoked: rapidly absorbed into blood stream=> first to brain.
- Within 30 minutes=>
redistributed throughout body
- Effects set in within
5-10 minutes
- THC half-life in blood:
19 hours
- Metabolites (45 formed
in liver): Half-lives up to 50 hours
- After 1 week, 25-30%
of THC and Metabolites remain
- High dose==> 2-3 weeks
for complete elimination
- Oral ingestion: slower
absorption, more metabolized
- THC and Metabolites:
Lipid (fat) soluble=> stored in fatty tissue and released slowly (primarily
in feces.
- Used regularly: Stored
and accumulates
- NO easy test for
acute intoxication
- Questions as to the
impact of long term exposure to metabolites
- Dosage varies: Marijuana
(common in USA) vs. Hashish (Europe and 19th Century)

Marijuana and the Brain
- 1988-90- Researchers
at St. Louis University identified specific receptor site for cannabinoids
in the brains of laboratory rats.
- 1992- the chemical substance
(neurotransmitter) anandamide is identified- a endogenous cannabinoid produced
by the body which is tied to the above receptor sites.
- Jon Gettman's 1995
article reviewing this discovery in "High Times" magazine: Part
1 and Part 2. Also available
through PDX NORML
- FAQs
on marijuana

History of Marijuana
Use
- American Colonial Use:
- Legend--Earliest
reference: 2737 B.C.- Chinese Emperor Shen Nung=> "Liberator of Sin"
(euphoria) and medicinal uses=> "female weakness, gout, absent mindedness
(Goode-page 214, 5th edition-suggests current research indicates this actually
comes from a text of the first or second century!)
- BUT--here's
some interesting evidence of ancient use of marijuana
- There are accounts
that demonstrate marijuana fibers being used in pottery that dates back 10,000
years in China (p. 213, from Ernst Abel: Marijuana the First Twelve Thousand
years, 1982, p.4)
- Other
References
- By 1000 A.D.--
social use spread to Moslem world; North Africa. Legend of the "cult"-
Hashishiyya (assassin).
Story spread by Marco Polo (1259), Topic in literature (Arabian Nights, etc.),
circulated widely in Europe.
Americas
- 1619-Jamestown;
1631-Massachusetts Law requiring every household to cultivate=> important
resource for a maritime society: Hemp fibers-> Rope vital to military
development, military uniforms, sails, and varnish from oil (as well as
for lamps)
- 1763-1767 Virginia:
imprisonment for not growing
- George
Washington grew plant (as many others did); once commenting in a diary
his neglectfulness in separating out the male plants
- Thomas Jefferson
(Tobacco vs. Hemp):
"It is impolitic. The fact is well established in
the system of agriculture that the best hemp and the best tobacco grow on
the same kind of soil. The former article is of first necessity to the commerce
and marine, in other words to the wealth and protection of the country.
The latter, never useful...derives its value from taxes." (Jefferson's
Farm Journal (16 March 1791), see Robert Nelson's, A
History of Hemp)
- Widely used medicinally
- 1850 (Post-colonial):
8,327 hemp plantations of 2,000 acres or more. Hemp
and industry.
- Hash smoking was spread
to Europe during the 1800's: Napoleonic war veterans returning from Egypt
- Use fairly widespread
by 1830-40's
- Le Club de Hachischins:
artists and writers (Dumas told of its effects and pleasures in "The
Count of Monti Cristo," Bauldedaire extolled its virtues in "Artificial
Paradise"
"At first, a certain
absurd, irresistible hilarity overcomes you. The most ordinary words, the
simplest ideas assume a new and
bizzare aspect. This mirth is intolerable to you; but it is useless to resist.
The demon has invaded you...The slightest ambiguities, the most inexplicable
transpositions of ideas take place. In sounds there is color; in colors
there is a music... You are sitting and smoking; you believe that you are
sitting in your pipe, and that *your pipe* is smoking *you*; you are exhaling
*yourself* in bluish clouds."
- By end of 19th Century-
other drugs introduced (barbiturates and narcotics common) and use declined.
Hashish never really significant in "middle" America.
- American psychologist
William James: introduced idea of using psychoactive substance in the study
of psychological processes. One psychologist is recorded as saying:
"To the psychologist
it (Cannabis) was as useful as the microscope to the naturalist; it magnifies
psychological states and in this way is an aid to its study"

20th Century USA
- Early--little discussed
or used recreationally
- But, significant commercial
use: Paints, varnishes, and other industrial applications
- 1935: 116 million pounds
of hempseed oil used-- "The Billion Dollar
Crop" (Total DEA seizures 1988 -all parts of plants- 130,200 pounds)
- Use by Mexicans started
surfacing in the 1920's- associated with deviant behavior, Newspaper series
in 1926 from New Orleans linked marijuana and crime and stimulated national
interest
- Bureau of
Narcotics file on marijuana was less than 2 inches thick in 1931: Treasury
Department memo- "No cause for alarm"
See
Also: Clifford Schaffer's History of Drugs and Why
is Marijuana Illegal? (local
copy) A nicely done "blog" by Peter Guither.

Moral and Economic Entrepreneurs:
Harry Anslinger, William R. Hearst, DuPont chemical, and Andrew Mellon
(source: Oregon NORML)
(careful about conspiracies)
- Technological improvements
in cultivation and harvesting=> equivalent of the cotton gin.
- Supreme court ruling:
Enabled the legislation of taxes as a means of prohibiting things.
- DuPont: 1937 patented
a process to make plastics/nylon: direct competitor to hemp. Also a process
to make paper from wood pulp. These processes used chemicals to which DuPont
owned the rights
- Prior to the Marijuana
Tax Act passage, a report to DuPont shareholders indicated:
"radical changes
(were coming) from the revolution raising government into an instrument for
forcing new ideas of industry and social reorganization"
- DuPont's financial backer==>
Andrew Mellon. Mellon served as President Hoover's Secretary of the Treasury.
Mellon appointed Harry Anslinger (a relative) to be the head of the Bureau
of Narcotics (1931).
- Anslinger viewed marijuana
and its"spreading use" as a cause for the "greatest national
concern."
- Federal hearings are
held.
- 1936 "Scientific
American" article: marijuana makes smokers vicious- fight and kill. "Popular
Science Monthly"-- "a horrible crime: look first at the marijuana
smokers"
- One contrary report in
the "Literary Digest" linked criminal violence to alcohol-- largely
ignored.
- Anslinger's
"Pyramid of Prejudice":
- Anslinger's agents
testify at hearing: presenting hearsay evidence
- Medical journal
cites testimony: often in letter to editor
- Anslinger writes
article citing JAMA as source of information
- Hearst's newspapers,
dominating the American market, provided further "documentation"
that minorities such as "mexicans, niggars, and chinamen" were responsible
for most of the crimes in American society
- This association with
"deviant" minorities, coupled with the depression which led to a
distrust of "foreign influences" helped steamroll the act through
congress.
- Marijuana: Assassin
of Youth (1937) (still off-line, looking for a new source)
- Reefer
Madness (1938) (part
1, too)
- Ads and media focus:
Reefer Madness, too.
- 1935-1940: 95% of
popular magazine characterize marijauan as dangerous, with use leading to
violence. Moderate use was discounted, and the "marijuana addict"
became a public menance. (Himmelstein, in Goode, 2005, page 123)
- Bill was introduced
to the Ways and Means Committee, bypassing other appropriate committees (Ways
and Means is only committee which can send its bills directly to House floor
without debate within other committees).
- Testimony from the
AMA representative urging not to pass the bill was covered up: When asked
if the AMA had been consulted, Committeeman Vinson answered "Yes, they
are in complete agreement."
- Tax Act passed on
Oct. 1, 1937: Taxed growers, distributors, sellers, and buyers- making it
impossible to legitimately engage in production or use
- Bureau of Narcotics
writes uniform law (been pushed since 1934)- specifically naming C. Sativa,
for adoption by the 48 states, making production, sale and consumption illegal.
- After passage: reports
of criminal behavior decline rapidly
- Price of marijuana
on the streets goes up by a factor of 6.
- Concern over "violence"
and marijuana use wanes, by the 1970s, it's the "drop-out drug."

Post 1937 to Today
See
Also Clifford Schaffer's Collection of Major Studies
Portland
NORML's Article collection
- Ned Polsky (1960s research):
Use spreads from Mexican-Americans in S.W. USA to working class Blacks- especially
linked to New Orleans. From there, use spreads to urban north, working
class and jazz musicians (1920s). From there recreational use
spreads to other entertainment subcultures to the "beats" and finally
the college scene. By the 1970s!!! (p. 213, see: Polsky, Hustlers,
Beats, and Others, 1969)
- Hemp
for Victory--cultivation during WWII
(see
it)
- Henry Ford's
Hemp Bodied Car.
- LaGuardia (Mayor NYC)
becomes aware of the 1930 Panama study linking troubles to alcohol rather
than marijuana. Orders own study by the New York Academy of Medicine.
- Report issued in 1944:
Agrees with the 1890 Indian Hemp Commission Report, and the Panama Canal Zone
Report of the 1930's==> Slight impairment of intellectual functioning when
under the influence, no impact on basic personality structure, no overt increase
in behavioral activity, no long term mental or physical deterioration.
- 1950-1960's: No research
- Studies in New Zealand,
Canada, Great Britain, and the USA during the 1970's support.
- 1970: Comprehensive Drug
Abuse Prevention and Control Act: Marijuana-- Schedule I
- 1972: National Commission
on Marijuana and Drug Abuse: Allow private use and possession. AMA favors.
ABA: Decriminalize.
- Even William F. Buckley
agrees
- 1973: Oregon decriminalizes--
$100 fine
- 1977: President Carter
suggested decriminalization.
- During 1970's: Defacto
decriminalization
| |
Ever
Used |
Current
Use |
| 1974 |
18% |
9% |
| 1977 |
25% |
10% |
- This was at the time
of nationwide peak in use.
- Eleven other states follow
suit (through October 2006): Maine, Colorado, California (est. $95 million
saved between 1976-1985), Minnesota, Mississippi, New York, North Carolina,
and Ohio (possession up to 100 grams: $100 fine), Alaska (legal for personal/home
use), Nevada. (Explore
the list)
- World Health Organization
1981, and U.S. National Academy of Science 1982 Report to the Congress of
the United States: Both agree that there is no evidence of marijuana being
a dangerous drug.
- Alaska legalized private
use and possession- up to 4 oz., but in 1990 recriminalized.
- 1980's: President Reagan:
Get Tough- focus on domestic cultivation, international interdiction, seizure
of private property.
- 1988: Anti-Drug Abuse
Act=> $2.7 billion for enforcement
- 1990: $6.5 billion
- In 1991 Oregon raised
the fine for possession to $500, currently a debate to recriminalize is being
held.
- FY 1996: $9.3 billion
($5.3 for demand reduction)
- New Strategy for 1996:
Marijuana targeted as "The
Gateway Drug"
(see also, Denise B.
Kandel, Does Marijuana Use Cause the Use of Other Drugs?, JAMA 289:4, January
2003, 482-483).
21st Century

Use of Marijuana
- Pervasive, relatively
universal- all who have desired have had experience:

- Current (2000 NHSDA):
Marijuana is the most commonly used illicit drug. It is used by 76 percent
of current illicit drug users. Approximately 59 percent of current illicit
drug users consumed only marijuana, 17 percent used marijuana and another
illicit drug, and the remaining 24 percent used an illicit drug but not marijuana
in the past month. Therefore, about 41 percent of current illicit drug users
in 2000 (an estimated 5.7 million Americans) use illicit drugs other than
marijuana and hashish, with or without using marijuana as well.

For 2004
(NHSDUH, 2005)

- 40% of the population
reports lifetime use, and 6% report use in the past month.
(NHSDUH,
2005)
- Use common among High
School students. 48.8% 12th graders report lifetime use, 21.6% report use
in past 30 days (down slightly from 1999) (MTF
2000 )
- Among persons
aged 12 or older, the overall rate of past month marijuana use was about the
same in 2004 (6.1 percent) as it was in 2003 (6.2 percent) and 2002 (6.2 percent).
(NHSDUH,
2004)
- 3x as many current
(past year) users than have ever used cocaine, 6x current users than current
cocaine users. 9x past month users than past month cocaine users.
- Used much more frequently,
probably more frequently than all other illicit drugs combined.

Effects
Mechanism of Action (THC)
- Impacts electrical properties
of nerve membranes=> Alters turnover rate of serotonin (deep sleep and
hallucinations) and dopamine (reward centers)- New research on cannabinoid
receptors challenges this idea of THC's impact on dopamine- , and
effects prostaglandin synthesis (without prostaglandin experience of pain
is reduced).
- Whether and which of
these is the central effect--? They may be byproducts of another effect.
- Psychopharmacology depends
on which effect of marijuana one wants to study.
Acute
Objective Effects
- Main:
- Increase pulse rate
and Blood pressure
- Reddening of the
eyes
- Dryness of the mouth
and throat
- Broncodilation
- Impact on brain:
promotes brain cell growth and maintains cognitive
abilities
- Other:
- Motor coordination:
complex, unfamiliar tasks; tracking. Especially for inexperienced (Cannabis
and Driving)
- Tolerance: Paradoxical-
Experienced users report greater subjective impact at lower doses=>
Placebo effect (table below, from Ray and Ksir, 1996, 414--415) or reverse
tolerance?
| intoxication
level (100 highest) |
Marijuana
(# reporting) |
Placebo
(# reporting) |
| 0-19
|
15
|
35 |
| 20-39
|
11
|
28 |
| 40-59
|
20
|
21 |
| 60-79
|
32
|
12 |
| 80-100
|
22
|
4 |
| average
|
61
|
34 |
| physiological
change |
|
|
| pulse
rate |
+24
|
-4 |
| salivary
flow |
-1.6
|
+.8 |
| redness
of eyes |
+1.92
|
+.04 |
When THC containing cigarettes
were smoked, infrequent users report more significant effect, than regular users.
(Tolerance? See Jon Gettman's 1995 article reviewing this discovery in "High
Times" magazine: Part 2 for discussion of
dynamic tolerance.)
| |
Infrequent
user |
Regular
(<7x/month) |
| A. Marijuana
|
67 |
52 |
| A. Placebo
|
22 |
48 |
| B.
Marijuana |
62
|
56 |
| B.
Oral extract |
72
|
32 |
| B.
Placebo cigarette |
26
|
51 |
| B.
Placebo oral extract |
2
|
5 |
| Physiological
Changes |
|
|
| Pulse rate
|
+31* |
+17 |
| Salivary flow
|
-1.8* |
-.9 |
| Redness of eyes
|
2.1 |
+1.5 |
- STML: learning and remembering
new information and/or directions while intoxicated==> related to sense
of time distortion (subject effect). A. Wikler (in Ray and Ksir,8th, p. 413):
"The drunkard
staggers only when he walks, The pothead forgets- only when he talks"
Subjective Effects
- Goode:
- Peaceful, relaxed
- heightened sensory
awareness
- deeper thoughts
- cosmic
- comical
- time distortion
- appetite stimulated
- Favorable
- Little paranoia (social
context)
- Recreational use (associated
with other pleasurable activities)
- Used to intensify other
experiences
- Avoid use with serious
activities
- Few panic reactions (inexperienced,
setting)
Chronic-objective
effects
- 1970's scares: Chromosomal
distortion, sterility
- Research problems:
Impact of poly-drug use (esp. Alcohol), laboratory studies vs. Reality of
use
- Cerebral atrophy and
other brain
damage (very questionable research; current research-- some changes in
brain structure; not permanent.
- Immune
system: yes. but caused by exposure to high doses unlikely for typical
user to experience through smoking
- Reproduction:
lowering of sperm count in males, yet still within normal range. Some, although
insignificant impact on fetus: But, don't do drugs when pregnant (goes for
the man who got the woman pregnant , too!)
- Lungs
and cancer: Maybe not, actually, No.
Less frequency of use and THC appears to "kill aging cells and keep them
from becoming cancerous."
- Marijuana
use during pregnancy harms the fetus.
- Marijuana
is an addictive drug.
- AMS:
sure. When people are high, they sit around and avoid hard work.
- Are users high most
of the time
- Is there a long
lasting effect?
- Role of metabolites?
(Heavy users tend to excrete them faster)
- Use highly correlated
with certain indicators: school performance, etc.
- But, Reality of
a Non-Achieving Sub-Culture
- And, direction of
influence? Could lose motivation and turn to drugs

Medical
Use???
- Long history
here, see: A
cannabis reader: global issues and local experiences,
EMCDDA, Lisbon, June 2008 (local
copy in .pdf). Chapter
1: Cannabis and Mediciine in 19th Century Europe
- 200 A.D.: China- mixed
with wine as anesthetic
- Extensively used in
India
- Widely used in Europe
during the 1800's
- 1839: Reviewed by
British doctor in India: nontoxic, anticonvulsant, muscle relaxant, relieves
pain of rheumatism
- 1860: Ohio Medical
Association (C. Indica): Stomach pain, chronic cough, gonorrhea
- Problems: Variability
- 1902: Parke, Davis
and Co.: new standardization- chocolate covered tablet, 1/4 grain.
Also, fluid extract
of cannabis,
- 1937: all 28 legal
preparations dropped from the market
- 1941: removed from
the National Formulary and U.S. Pharmacopeia (wasn't much in use)
- 1949: Compare to dilantin
as an anticonvulsant, perhaps useful for treatment of tension and migraines
- 1972: Interoccular
Pressure. 1975 Glaucoma patient arrested, charges dropped, doctor certifies
use and government supplies: FDA "compassionate use" protocol
- 1975: THC seen as
effective in reducing the nausea associated with chemo-therapy
- 1982: National Academy
of Science: Marijuana holds promise for-
- glaucoma
- chemotherapy
- seizures
- spasticity
- 1985: FDA approves
Donabinol (Marinol) (Marinol
image) for appetite stimulation in the treatment of cancer patients and
AIDS
- NORML:
Pushes for approval of marijuana
- DEA Chief Legal Counsel:
Recommends Schedule II
- 1992: DEA==> NO!
Since "pure" THC is now available, no need.
- FDA silently stopped
reviewing "compassionate use" proposals for the plant substance
- 36 states had approved
marijuana use under physician's prescription; only13 patients had received
FDA approval over the 17 years of the program.
- Marijuana
as Medicine:A Plea for Reconsideration. From the Department of Psychiatry,
Harvard Medical School, and the Massachusetts Mental Health Center, Boston.
(Dr Grinspoon). JAMA, June 21, 1995 -- Vol. 273, No. 23 1875.
- Marijuana
Policy Project Page of State Laws Concerning Medicinal Use of Marijuana
- 1999: Institute
of Medicine (prepublication release)--Marijuana is Medicine
- Summary
of Active State Medical Marijuana Programs
- Overview
of medical marijuana use form NORML
- Is
Pot Good for You? (Time Magazine, 11/4/02)(alternative
site: http://www.mapinc.org/drugnews/v02/n1998/a09.html)
- Cannabis
Neuroprotective?
- Cannabis
and brain cell growth.
- November 2004:
Montana becomes the ninth state to legalize marijuana for medicinal purposes
(other states: Alaska, Arizona, California, Colorado, Maine, Nevada, Oregon
and Washington. Vermont and Hawaii have legislation protecting patients from
prosecution. Maryland protects patients using marijuana from the threat of
jail, but not arrest.
- Supreme
Court rules that federal authorities can prosecute individuals using marijuana
on doctors' orders (June 2005).
- Cannabinoids
and medicine (9/05)
- Australian Survey
on Cannabis for Medical Purposes (2005)
- Cannabinoids
and Pain
- Marijuana a "wonder
drug?"
- States
with medicianl marijuana laws (NORML)
- Marijuana
Vending Machines 2008
- THC
induces autophagy in human brain cancer cells (destroying
brain cancer cells), 2009
- Search the International
Association for Cannabis as Medicine database.
- April 20, 2009:
The American Academy of Cannabinoid Medicine
is founded. "The members of the AACM have the medical training, clinical
experience and familiarity with the scientific literature to speak knowledgeably
about the current medical utility and future therapeutic potential for cannabis
and cannabinoids."

Who Uses Marijuana?
Radosevich (1980): Selective Interaction/Socialization
Structural Factors
- Age: peaks for 18-25
year olds: growing independence and freedom
- Gender: Men slightly
more than women (58% vs. 48%). Once 2x as likely. Still higher rates of heavy
use. Pattern typical for all drug use, except young cigarette use (no difference)
and prescription drug use (females higher)
- Class, race, and residence
Socio-interactional Factors
- Peer influence: Reciprocity,
Selective Socialization.
- Social context
- Friends legitimate
- Friends define experience
- Friends provide access
to the drug
Attitudinal Variables
- Unconventionality
- Tolerance for deviance
- Risk-taking
- Less authoritarian
- Low religiosity

Use in International Setting: The
Netherlands
(A
Menu from the Wallstreet Cafe in Maastricht) (a
newer menu)

The
Gateway Drug?
- Drug itself
- Tolerance
- Desensitizes
- Leads to the need
of a stronger substance
- Hardin Jones: Gross
tolerance to marijuana leads to heroin use
- O'Donnell and Clayton:
relationship exists, marijuana use precedes heroin use, "no other intervening
variables" (??)
- Involvement: Activity
of use vs. Experience of the drug effect
- Friends use of other
drugs
- Access and exposure
to other drugs
- Relationship is not
spurious, the intrinsic explanation IS.
(2003 AMA Study: http://jama.ama-assn.org/cgi/content/abstract/289/4/427)

