Cannabis sativa, the source of marijuana is a hardy weed. Whether it is hot or cold, wet or
dry, cannabis will grow abundantly from seeds that are unbelievably prolific.
Considering a category for marijuana as a drug is difficult for it has many unconnected
properties. Marijuana produces some excitatory effects, but it is not generally regarded as
a stimulant. It produces some sedative effects, but it carries no danger of slipping into a
coma or dying (like barbiturates). It produces mild analgesic effects, but it is not related
pharmacologically to opiates or opiate-like drugs. There is no cross tolerance with LSD or
any other drug formally categorized as a hallicinogen.
Few other drugs have been so politicized in recent history as marijuana. It is frequently
praised by one side or condemned by the other, on the basis of emotional issues rather
than an objective view of research.
Marijuana is frequently referred to as a synonum for cannabis, but the two terms are
seperate. Cannabis is the botanical term for the hemp plant. Cannabis grows to about 8
feet, has sturdy stalks and has been commercially valuable for thousands of years in the
production of rope, twine, shoes, sailcloth and containers. Archaeological digs in China
have discovered hemp pots which dated back to the Stone Age. It is arguably the oldest
cultivated plant not used for food.
In 1545 it was brought to the New World by the Spanish. The English introduced it in
Jamestown in 1611 where it became a major commercial crop alongside tobacco.
Marijuana is obtained from the serrated leaves of the plant, not the stalks. The key
psychoactive factor is contained in a sticky substance, or resin, that accumulates on the
leaves. As many as 80 separate chemical compounds, called cannabinoids, can be
extracted from the resin. The chief psychoactive compound and active ingredient is
delta-9-tetrahydrocannabinol, or THC.
The first direct reference to a cannabis product as a psychoactive agent dates from 2737
BC, in the writings of the Chinese emperor Shen Nung. The focus was on its powers as a
medication for rheumatism, gout, malaria, and oddly enough, absent-mindedness. Mention
was made of the intoxicating properties, but the medicinal value was considered more
important. In India though it was clearly used recreationally. The Muslims too used it
recreationally for alcohol consumption was banned by the Koran. It was the Muslims who
introduced hashish, whose popularity spread quickly throughout 12th century Persia (Iran)
and North Africa.
Chances are that anyone living in the United States at the beginning of the 20th century
would not have heard of marijuana, much less hashish. By 1890, hemp had been replaced
by cotton as a major cash crop in southern states. Some patent medicines during this era
contained marijuana, but it was a small percentage compared to the number containing
opium or cocaine. It was in the 1920's that marijuana began to catch on. Some historians
say its emergance was brought about by Prohibition. Its recreational use was restricted to
jazz musicians and peple in show business. "Reefer songs" became the rage of the jazz
world. Marijuana clubs, called tea pads, sprang up in every major city. These marijuana
establishments were tolerated by the authorities because marijuana was not illegal and
patrons showed no evidence of making a nuisance of themselves or disturbing the
community. Marijuana was not considered a social threat.
To understand how marijuana went from a localized, negligible phenomenon to a national
social issue, the changes in American society during the 1920's and 1930's must be
examined. As Mexican immigrants began filtering into American society they were looked
upon with great hostility and prejudice. Their casual everyday use of marijuana did not
help. Rumors about Mexicans violent behavior after smoking spread throughout America,
largely unchallenged by objective data. By 1933, 32 states had made marijuana illegal. By
1936, the rest of the states followed.
During the 1940's and 1950's marijuana research was at a stand still. The theory that
marijuana was connected with violence slowly faded away, only to be replaced by the
gateway theory. This was the idea that marijuana was dangerous because it would lead to
the abuse of heroin, cocaine and other illicit drugs. As research declined, penalties for
involvement steadily increased.
In 1960 arrests and seizures for possession of marijuana were relatively rare and attracted
little or no public attention. Up until 1960 the consensus was held that marijuana
involvement was a deviant act, and there was little tolerance for personal deviance. By the
mid-1960's the consensus had changed. Marijuana smoking was an attraction on the
campuses of US colleges and universities, affecting a wide cross-section of the nation. At
the same time, the experimental use of drugs, particularly marijuana, by young people set
the stage for a wholesale questioning of what it meant to respect authority, on an individual
level as well as governmental level.
Immediate physiological effects after smoking marijuana are minor. It is estimated that a
human would need to ingest a dose of marijuana that was from 20,000 to 40,000 times the
effective dose before death would occur. There are no documented cases of a human
death from marijuana. There are dose-related increase in the heart-rate during the early
stages of ingestion, up to 160 beats per minute when dose levels are high. Blood pressure
either increases, decreases or stays the same depending on whether an individual is
standing, sitting or lying down. Dilation of blood vessels on the cornea result in bloodshot
eyes about an hour after first smoking. Frequently there is drying of the mouth and an urge
to drink. Other physiological reactions are inconsistent. While North Americans observe
hunger and the craving of sweet things, Jamaicans consider marijuana an appetite
suppressant.
With marijuana, it is likely that first-time smokers will feel no effects of any kind at all. It
takes practice to be able to inhale deeply and keep the smoke in the lungs long enough for
a minimal level of THC to take effect. The marijuana high is a feeling of euphoria,
well-being and peacefulness. There is a sharpened sense of sight and sound, most things
become very funny, and usually mundane ideas can be filled with profound implications. At
the same time there is significant deficits in behavior. The major one being the decline in the
ability to carry out tasks involving attention and memory. Speech will be increasingly
fragmented and individuals usually forget what they just said or what others have just said.
Emotional problems from smoking weed are rare.
In 1990 the mechanism in the brain which THC affects was discovered. It turns out that
just like morphine, special receptors exist in the brain that are stimulated specifically by
THC. They are concentrated in areas of the brain that are important for short-term
memory and motor control. Researchers have now isolated a natural substance, dubbed
anandamide, that turns on these receptors and appears to produce the same effects as
THC in the brain. The question remains, why would the brain be producing a THC-like
substance in the first place?
Medical uses for marijuana include the treatment of glaucoma, the treatment of asthma, and
the treatment of nausea resulting from chemotherapy. Marijuana significantly reduces the
intraocular pressure of the eye, so for glaucoma patients it used to keep the pressure down
where it would normally rise so high to cause damage to the optic nerve and cause
blindness. Marijuana is initially a bronchodilator, followed by bronchoconstriction. For
asthma, this would be not advised, except that when orally administered THC results in
bronchodilation without the expected constriction later on. The beneficial effects of THC
as an antiemetic drug is an important application as medical treatment for nausea, lack of
appetite and loss of body weight.
In sheer numbers, marijuana is the dominant illicit drug in US society. From the
house-to-house survey conducted by the National Institute of Drug Abuse in 1992, it is
estimated that 67 million Americans, roughly 1/3 of the population, have smoked marijuana
at least once in their lives. Between the ages of 26 and 34, roughly 6 of every 10 have
smoked marijuana at least once. More than 17 million Americans are estimated to have
smoked in the last year, almost 9 million have smoked during the last month.
The 1960's emergence of marijuana initiated a slow but steady reassessment of myths that
had been attached to it for decades. By 1972, liberalization of laws regarding the
possession of marijuana were being proposed. Since then, 11 states including, CA, NY,
CO, MN and NC have adopted some form of decriminalization laws with respect to
possession in small amounts. Small possession is considered a civil offense rather than a
criminal one. Statistics drawn from states that either have or have not decriminalized show
little or no difference in its use or non-use.
Chronic marijuana use produces mild tolerance effects, but their is no evidence of
withdrawal symptoms nor that it is habit forming. The lethal dose rate for marijuana is
20-40,000 times the normal intake of one joint, so there is no overdose potential for weed.
THC produces significant increases in heart rate, but there is no evidence of adverse
effects in the cardiovascular functioning in young, healthy people. When THC is
administered to animals there is a suppression of the immune system. In humans the
evidence is inconclusive. Because marijuana smoking has not been associated with a higher
incidence of any major disease, we can tentatively conclude that marijuana smoking does
not have a major impact on the immune system. The hypothesis that there exists an
amotivational syndrome attributed to the pharmacological effects of marijuana have been
largely discredited. Also discredited is the idea that weed sets the stage for future drug
abuse.
Studies of Rastafarians, Costa Ricans and Greeks whose daily life included the chronic
heavy use of marijuana yeilded interesting results. Studies found almost no adverse effects.
There was a small decrease in pulmonary functions, but no evidence of deterioration. No
evidence of amotivation, neurological differences, or brain abnormalities either.
from: Drugs, Behavior and Modern Society by Charles F. Levinthal
