Truth and Myths About Marijuana: History, Signs & Symptoms, Drug Testing, Medicinal Information and More about Marijuana

marijuana leaves, marijuana information

Marijuana is a dry, shredded green, brown or grey mixture of flowers, stems, seeds, and leaves obtained from the hemp plant Cannabis sativa. It comes in over a hundred street names including Herb, Weed, Smoke, Pot, Killer weed, Jane, Greens, Dope, Mary Jane, or Red Dirt, to name a few. The chief active ingredient of the marijuana plant is delta-9-tetrahydrocannabinol (THC) - a chemical property that can change a person's mood. Once THC enters a person's brain, it creates changes in the way an individual behaves and experiences what is commonly referred to as "high."

Effects of Marijuana

Delta-9-tetrahydrocannabinol (THC) is the main active ingredient in marijuana. It is responsible for many of its known effects which can last from 1 to 3 hours. When marijuana is smoked, the THC content rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body, including the brain. Whereas, if marijuana is consumed in foods or beverages, the effects appear later-usually in 30 minutes to 1 hour-but can last up to 4 hours.

According to Tedd Gottfried's The Facts About Marijuana, the way the drug affects each individual vary on many factors, including:

  • User's previous experience with marijuana;
  • How strong the marijuana is;
  • What the user expects to happen;
  • Where the drug is used;
  • How it is taken; and
  • Whether the user is drinking alcohol or using other drugs.

Meanwhile, the 2010 revised edition Research Report published by the National Institute on Drug Abuse provides a wealth of information on how marijuana use affects the user's body and brain. As THC enters the brain, it causes the person to feel euphoric or high. Along with euphoria, relaxation is another frequently reported effect in human studies. Other effects of marijuana, which vary dramatically among different users, include heightened sensory perception (e.g., brighter colors), laughter, altered perception of time, and increased appetite. After a while, the euphoria subsides, and the user may feel sleepy or depressed. Occasionally, marijuana use may produce anxiety, fear, distrust, or panic.

Marijuana use also impairs a person's ability to form new memories and to shift focus. THC disrupts coordination and balance by binding to receptors in the cerebellum and basal ganglia-parts of the brain that regulate balance, posture, coordination, and reaction time. Therefore, learning, doing complicated tasks, participating in athletics, and driving are also affected.

Individuals who have taken large doses of the drug may experience an acute psychosis, which includes hallucinations, delusions, and a loss of the sense of personal identity.

Other Signs and Symptoms of Marijuana Use

Other common signs and symptoms of marijuana use include:

  • Vivid sights
  • Vivid sounds
  • Dry mouth
  • Dry eyes
  • Hunger (commonly called "munchies)
  • Thirst
  • Clumsiness
  • Vomiting
  • Confusion
  • Paranoia
  • Apathy
  • Increased heart rate
  • Sleep impairment
  • Increased risk of chronic cough, bronchitis
  • Increased risk of schizophrenia in vulnerable individuals

Marijuana Myths

Myth1: Marijuana is medicine.
Reality: Smoked marijuana is not medicine.

The scientific and medical communities have determined that smoked marijuana is a health danger, not a cure. Although research has confirmed that the cannabis plant contains active ingredients with therapeutic potential for relieving pain, controlling nausea, stimulating appetite, and decreasing ocular pressure, there is no medical evidence that smoking marijuana helps patients. In fact, the Food and Drug Administration (FDA) has approved no medications that are smoked, primarily because smoking is a poor way to deliver medicine. Morphine, for example, has proven to be a medically valuable drug, but the FDA does not endorse smoking opium or heroin.

Myth2: Legalization of marijuana in other countries has been a success.
Reality: Liberalization of drug laws in other countries has often resulted in higher use of dangerous drugs.

According to an article, Marijuana: The Myths Are Killing Us, which appeared in the March issue of Police Chief Magazine, an official publication of the International Association of Chiefs of Police, drug policy in some foreign countries, particularly those in Europe, has gone through some dramatic changes toward greater liberalization with failed results. Consider the experience of the Netherlands, where the government reconsidered its legalization measures in light of that country's experience.

After marijuana use became legal, consumption nearly tripled among 18- to 20-year-olds. As awareness of the harm of marijuana grew, the number of cannabis coffeehouses in the Netherlands decreased 36 percent in six years. Almost all Dutch towns have a cannabis policy, and 73 percent of them have a no-tolerance policy toward the coffeehouses.

In 1987 Swiss officials permitted drug use and sales in a Zurich park, which was soon dubbed Needle Park, and Switzerland became a magnet for drug users the world over. Within five years, the number of regular drug users at the park had reportedly swelled from a few hundred to 20,000. The area around the park became crime-ridden to the point that the park had to be shut down and the experiment terminated.

Marijuana use by Canadian teenagers is at a 25-year peak in the wake of an aggressive decriminalization movement. While a decriminalization bill was before the House of Commons, the Canadian government released a report showing that marijuana smoking among teens is "at levels that we haven't seen since the late '70s when rates reached their peak." After a large decline in the 1980s, marijuana use among teens increased during the 1990s, as young people apparently became "confused about the state of federal pot laws."

Myth3: Marijuana is harmless.
Reality: Marijuana is dangerous to the user.

Several studies revealed the adverse effects of marijuana use on a person's body. In the United States, marijuana is noted as the most widely used illegal drug which is readily available to kids. Compounding the problem is that the marijuana of today is not the marijuana of the baby boomers 30 years ago. Average THC levels rose from less than 1 percent in the mid-1970s to more than 8 percent in 2004. The potency of B.C. Bud, a popular type of marijuana cultivated in British Columbia, is roughly twice the national average-ranging from 15 percent THC content to 20 percent or even higher.

Smoking marijuana can cause significant health problems. Marijuana contains more than 400 chemicals, of which 60 are cannabinoids. Smoking a marijuana cigarette deposits about three to five times more tar into the lungs than one filtered tobacco cigarette. Consequently, regular marijuana smokers suffer from many of the same health problems as tobacco smokers, such as chronic coughing and wheezing, chest colds, and chronic bronchitis. In addition, smoking marijuana can lead to increased anxiety, panic attacks, depression, social withdrawal, and other mental health problems, particularly for teens. Research shows that kids aged 12 to 17 who smoke marijuana weekly are three times more likely than nonusers to have suicidal thoughts. Other short-term effects of marijuana use include distorted perception, memory loss, trouble with concentration and impaired problem-solving skills.

Myth4: Smoking marijuana harms only the smokers.
Reality: Marijuana use harms nonusers.

Secondhand smoke is a well-known problem, one that Americans are becoming more unwilling to bear. Secondhand smoke from marijuana kills other innocents as well. Several years ago, two Philadelphia firefighters were killed when they responded to a residential fire stemming from an indoor marijuana grow. In New York City, an eight-year-old boy, Desean Hill, was killed by a stray bullet just steps from his Brooklyn home after a drug dealer sold a dime bag of marijuana on another dealer's turf.

Marijuana smoking can also impair a person's driving skill. According to the estimates released in September 2003 by the Office of National Drug Control Policy (ONDCP), one in six (or 600,000) high school students drive under the influence of marijuana, almost as many as those who drive under the influence of alcohol. For those of you who patrol streets and highways, you know that the consequences of marijuana-impaired driving can be tragic. For example, four children and their van driver-nicknamed Smokey by the children for his regular marijuana smoking-died in April 2002 when a Tippy Toes Learning Academy van veered off a freeway and hit a concrete bridge abutment. He was found at the crash scene with marijuana in his pocket.

Detection of Marijuana Use

In all, there are up to 60 cannabinoids found in marijuana with delta-9-tetrahydrocannabinol (THC) being the primary psychoactive ingredient. Most users smoke marijuana in hand-rolled cigarettes called joints; whereas, some use pipes or water pipes called bongs. Marijuana is also used to brew tea and sometimes is mixed into foods.

When marijuana is smoked, THC rapidly travels from the lungs into the bloodstream, which carries the chemical to organs throughout the body, including the brain. The effects of smoked marijuana can last from 1 to 3 hours. If marijuana is consumed in foods or beverages, the effects appear later-usually in 30 minutes to 1 hour-but can last up to 4 hours.

There are several different ways to detect marijuana metabolites in the person's body, including urine drug test, saliva drug test, hair follicle drug test, and blood test. A urine test is the most popular type of drug testing widely used in schools, government agencies, private institutions, hospitals, law enforcement, and so on. Urine drug testing is capable of detecting the THC component in the individual's system for days or weeks after use - depending on the usage/dosage.

Urine Drug Test

Urine is derived from the blood, as the kidneys eliminate chemicals of all kinds, including alcohol, from the blood. Because the kidneys concentrate chemicals, including drug chemicals, the drug detection window for urine is a bit longer than for the blood.

Cut-Off Level EIA Screen Cutoff Level GC/MS Confirmation Cutoff Level Approximate Detection Time in Urine
Amphetamine (AMP) 1000 ng/mL 1000 ng/mL 500 ng/mL 2-4 Days
Amphetamine (AMP300) 300 ng/mL 1000 ng/mL 500 ng/mL 2-4 Days
Methamphetamine (MET) 1000 ng/mL 1000 ng/mL 500 ng/mL 3-5 Days
Methamphetamine (MET500) 500 ng/mL 1000 ng/mL 500 ng/mL 3-5 Days
Cocaine (COC) 300 ng/mL 300 ng/mL 150 ng/mL 2-4 Days
Cocaine (COC150) 150 ng/mL 300 ng/mL 150 ng/mL 2-4 Days
THC (THC) 50 ng/mL 50 ng/mL 15 ng/mL 15-30 Days
Opiates (OPI) 2000 ng/mL 2000 ng/mL 2000 ng/mL 2-4 Days
Opiates (MOR) 300 ng/mL 2000 ng/mL 2000 ng/mL 2-4 Days
Phencyclidine (PCP) 25 ng/mL 25 ng/mL 25 ng/mL 7-14 Days
Barbiturates (BAR) 300 ng/mL 300 ng/mL 150 ng/mL 4-7 Days
Benzodiazepines (BZO) 300 ng/mL 300 ng/mL 150 ng/mL 3-7 Days
Methadone (MTD) 300 ng/mL 300 ng/mL 150 ng/mL 3-5 Days
Propxyphene (PPX) 300 ng/mL 300 ng/mL 150 ng/mL 1-2 Days
Ecstasy (MDMA) 500 ng/mL - - 1-3 Days
Tricyclic Antidepressants (TCA) 1000 ng/mL - - 7-10 Days
Hydrocodone 300 ng/mL - 300 ng/mL 2-4 Days
Hydromorphone 300 ng/mL - 300 ng/mL 2-4 Days
Oxycodone (OXY) 100 ng/mL - 100 ng/mL 2-4 Days
Oxymorphone 100 ng/mL - 100 ng/mL 2-4 Days


The urinary concentrations of THC are very difficult to interpret due to variables such as dosage of THC ingested, the frequency of use, the timing of urine collection relative to last exposure to marijuana, the rate of release of stored cannabinoids in adipose tissue, and an individual's hydration state. Therefore, it is important to understand that the detection of THC metabolites in the urine is only an indication of past marijuana uses and is not related to the degree of intoxication or impairment.

One of the major controversies surrounding urine drug testing is that it's easier to adulterate. Adulteration usually starts at what is normally termed as "bathroom problem." Unfortunately, there are a variety of strategies used to cheat on urine samples; hence, it is advised by employers and other institutions performing urine drug testing to conduct sample collection under direct supervision. In some cases, urine collection for a drug test is done in bathrooms that blue dye added to the water or that have had all water supplies cut off to discourage the dilution of urine samples and substitution of someone else's urine.

Below are the advantages and disadvantages of urine drug test as proposed by The Hazelden Betty Ford Foundation and from other existing literature.

Advantages of Urine Drug Testing:

  • Urine is the most widely used sample for drug testing; therefore, urine testing has the largest body of experience and has been subject to the greatest legal review.
  • The per-test cost for urine is the lowest among all other sample types.
  • When using urine testing, the school has the largest number of potential suppliers of test for on-site and laboratory drug testing.
  • Urine drug tests are easier to store and are safe for environmental disposal.
  • Gloves and sterile cups are usually included; thus there's no need for any additional tools.
  • They deliver fast and accurate results.

Disadvantages of Urine Drug Testing:

  • Urine is the sample that is most easily cheated on.
  • Urine has a short drug detection window, typically one to three days after drug use, although some urine tests are negative 12 hours after the last drug use.
  • Urine must be handled with gloves to prevent the spread of infectious disease.
  • Bathroom facilities are required to conduct the test, which may not be always monitored.
  • Urine drug testing kits are somewhat invasive.

Hair Follicle Drug Test

Hair follicle drug testing is regarded as a revolutionary method of testing for drugs using hair strand analysis. It is currently used by companies in various sectors for highly safety-critical positions where there is zero tolerance for drug usage including forensics, maritime, insurance, schools, and law enforcement.

Screen Cut-Off GC / MS Cut-Off L.O.D. Level
Amphetamine, Methamphetamine & Ecstasy
300 - 500pg/mg * 200- 500pg/mg * 100 pg/mg
Cocaine & Benzoylecgonine
300 - 500pg/mg * Cocaine: 200 - 500pg/mg *
Benzoylecgonine:50 pg/mg
100 pg/mg
300pg/mg 100 - 300pg/mg * 100 pg/mg
Codeine, Morphine & 6-MAM(Heroin metabolite)
200 - 500pg/mg * 200 - 300 pg/mg * 100 pg/mg
THC, Carboxy-THC
0.1 - 1 pg/mg * THC: 0.3 - 50 pg/mg *
Carboxy-THC: 1 pg/mg
0.1 pg/mg
Barbiturates 500 pg/mg 200 pg/mg -
Benzodiazepines 500 pg/mg 200 pg/mg -
Propoxyphene 500 pg/mg Propoxyphene: 200 pg/mg
Norpropoxyphene: 200 pg/mg
Methadone 500 pg/mg Methadone: 200 pg/mg
EDDP: 200 pg/mg
Oxycotin, Percodan/Percocet
300 pg/mg 300 pg/mg -
Vicodin, Lortab/Lorcet
300 pg/mg 300 pg/mg -
300 pg/mg 300 pg/mg -

 The biology of hair is far different from the biology of urine. Nevertheless, hair follicle testing is just as reliable as a urine test. Hair contains drugs that were in the blood, including illicit substances, when each tiny bit of hair was built. Since head hair grows at a fairly steady rate of about half an inch a month, the hair extending about one and one-half inches from the head contains a virtual tape recording of what was in the blood during the ninety days before the hair sample is taken.

Hair analysis tests can detect a longer period of drug use compared to more traditional forms of random drug testing. A standard hair follicle drug test covers a period of 30 to 90 days of donor's drug use. Using a small sample of hair cut near the scalp, hair analysis evaluates the level of drug metabolites embedded inside the hair shaft. If no head hair is available, body hair can be used. This provides a longer window of detection of approximately 365 days. Bleaches, shampoos and external contaminants have no known impact on the results.

Hair drug tests are more likely to detect regular versus occasional marijuana use. The 2006 publication "Cannabinoid concentrations in Hair from Documented Cannabis Users," revealed that ingested cannabis was less likely to be detected than smoked marijuana.

Advantages of Hair Drug Test:

  • The marijuana detection period is longer - usually up to 90 days.
  • Specimen collection is easier, with no bathroom problems.
  • The specimens are not messy to handle or ship, and there are no infectious disease problems when handling hair samples.
  • In the case of disputed results, it's easy to retest within about 2 weeks of the initial test.
  • Hair samples are easy to store and collection is non-invasive.

Disadvantages of Hair Drug Test:

  • Hair drug testing kits cost more than urine or saliva drug testing.
  • Fewer companies provide hair test.
  • For marijuana, the tests detect only repeated, regular use.

Saliva Drug Test

Saliva drug testing is a fairly new technique, wherein a swab or a piece of absorbent material is placed in the donor's mouth for about one minute and then removed and placed in a collection container. The results are read within a few minutes, and if the donor tested positive, the positive result is sent to a laboratory for confirmation testing. However, despite being effective in identifying the recent use of commonly studied drug, saliva drug testing is relatively insensitive to marijuana.

Cut-Off Level EIA Screen Cutoff Level GC/MS Confirmation Cutoff Level Approximate Detection Time in Saliva
Amphetamine (AMP) 1000 ng/mL 1000 ng/mL 500 ng/mL 1-3 Days
Methamphetamine (MET) 1000 ng/mL 1000 ng/mL 500 ng/mL 1-3 Days
Cocaine (COC) 300 ng/mL 300 ng/mL 150 ng/mL 1-3 Days
THC (THC) 50 ng/mL 50 ng/mL 15 ng/mL 6 -12 Hours
Opiates (OPI) 2000 ng/mL 2000 ng/mL 2000 ng/mL 1-3 Days
Phencyclidine (PCP) 25 ng/mL 25 ng/mL 25 ng/mL 1-3 Days


Many health experts and researchers continue to conduct studies to establish solid theories about saliva drug test's reliability. In general, the use of saliva as a sample specimen is limited in scope because of its shorter detection time.

Advantages of Saliva Drug Test:

  • Saliva/Oral Drug Testing can be collected and tested on site with no intrusion of privacy.
  • They are difficult to adulterate.
  • Samples can be collected easily in virtually any environment.
  • Results can be read in minutes without the need for lab analysis.
  • They can detect a wide range of drug substances like ethanol, amphetamines, barbiturates, benzodiazepines, caffeine, cocaine, THC, opiates, and phencyclidine.
  • They are able to indicate recent drug use for non-smoked drugs.
  • They are suitable for workplace, compliance and forensic testing.

Disadvantages of Saliva/Oral Drug Testing:

  • Saliva drug test is not sensitive to marijuana.
  • It offers small detection window - usually 12 to 24 hours.
  • Drug concentrations may be low and subsequently difficult to analyze.
  • Confirmatory analysis requires sensitive analytical facilities.
  • The sample size is limited.

Detection Period and Methods of Analysis

According to American Society of Addiction Medicine's Principles of Addiction Medicine, the average elimination half-life of THC is between 20 and 30 hours. THC has a highly lipophilic nature and is stored in fatty tissues, where it is slowly released back into the circulation.

Urine screening tests for marijuana typically use cutoffs of 20, 50 or 100 ng/mL. The current federally mandated cutoff for workplace drug testing is 50 ng/mL. Most laboratories measure the inactive metabolite THC-COOH which can be quantitated in blood, urine, hair, oral fluid or sweat using chromatographic techniques as part of a drug use testing program or a forensic investigation of a traffic or other criminal offense.

The chart below indicates the approximate detection periods of marijuana in urine drug test based on usage:

Marijuana Detection Time Based on Usage
Usage at 1 time only 5-8 days
Usage at 2-4 times per month 11-18 days
Usage at 2-4 times per week 23-35 days
Usage at 5-6 times per week 33-48 days
Daily Usage 2000 ng/mL


The most common analytical methods used to detect cannabinoids in urine include immunoassays (EIA, RIA, and FPIA), gas chromatography (GC), gas chromatography/mass spectrometry (GC/MS), high-pressure liquid chromatography (HPLC), and thin layer chromatography (TLC).

At present, there are also drug test kits that detect the presence of synthetic cannabinoids like JWH-018 and JWH-073, which possess biological activities similar to 9-tetrahydrocannabinol (THC) - the primary component of marijuana. In this synthetic marijuana urine laboratory test, the compounds are identified down to levels of approximately 0.1 ng/mL for most of the diagnostic metabolites. JWH-018 and JWH-073 metabolites can be detected in urine up to 72 hours.

Beating Marijuana Drug Tests

The adulteration of a drug test refers to the manipulation of the collected specimens intended for drug testing in order to provide false-negative, or less commonly, false-positive results. This is very common among teenagers, employees or individuals who want to conceal their illegal drug use for various reasons.

At the American Association for Clinical Chemistry's annual meeting in Washington, D.C., toxicologist Amitava Dasgupta of University of Texas-Houston medical school discussed the different ways that employees try to beat workplace drug tests-and how experts uncovered these schemes in the laboratory. The same tricks are likely to be adopted by teenagers who want to cheat on their drug test.

  • Tampering urine specimen. Dasgupta says that household substances like vinegar, bleach, detergent, or drain cleaner are all too often easily sneaked into the bathroom and used to alter the composition of urine samples, making the presence of some illegal substances undetectable. These and other household additives will cloud or discolor urine, easily casting suspicion on the specimen, but others leave the sample looking normal. To catch adulterated specimens, laboratory toxicologists employ simple tests like using a few drops of hydrogen peroxide which could turn the urine sample to brown if it's been mixed with pyridinium chlorochromate, an otherwise-imperceptible chemical designed to foil drug tests.
  • Gulping fluids before specimen collection. By drinking a large volume of water, the urine is diluted. As a result, many diluted urine drug tests fall below the cut off levels, producing a negative urine drug test result even for individuals who have recently used illegal drugs like marijuana. Sharon Levy, a pediatrician and director of the Adolescent Substance Abuse Program at Children's Hospital Boston, shares that gulping fluids before providing urine, a long-standing tactic, is still the most common way that teens try to beat tests.
  • Substituting urine samples. This is another very common tactic used by people to cheat on their urine drug test. However, the biggest warning sign here is the temperature. If the temperature is not close to the normal body temperature-98.6 degrees Fahrenheit-most likely the sample was not coming from the person giving the specimen, or that water had been added to dilute the sample.

As substance abuse continues to evolve, so do the emerging tactics used by people to cheat on their drug screening. However, what these individuals are missing is that they are facing a more serious problem if they are caught adulterating their drug test samples. In Will County, Illinois, if the test is a condition of probation and you are caught cheating, you are looking at a petition to revoke. Depending on other factors, community service or jail are certainly options. In the State of Illinois, a person found to be defrauding a drug and alcohol screening can be charged with a Class 4 felony.

The penalty for cheating on a drug testing differs from one state to another. Hence, to save yourself from further legal complications, it is better to dismiss any attempt of adulterating your specimen samples for your drug test.

Moreover, because of the various devices, adulterants, and masking agents that abound, state officials and law enforcers have already become aware of the tactics. Early this year, U.S. Congressman Eliot Engel (D-New York) introduced a bill that would prohibit the manufacture, marketing, sale, or shipment in interstate commerce of products designed to assist in defrauding a drug test. The bill is co-sponsored by Reps. Jean Schmidt, R-Ohio, and Lee Terry, R-Neb. The legislation was referred to the House Energy and Commerce Committee.

In Salem County, New Jersey, a 38-year old man was arrested for "defrauding a drug test" with a bail of $10,000. In South Carolina, drug screening organizations that are found guilty of altering or defrauding drug tests can receive a fine up to $5,000. They can also receive a court order to serve up to three years in prison. And in North Carolina, there is the General Statutes § 14-401.20 Defrauding drug and alcohol screening tests that makes it unlawful for a person to attempt to foil or defeat a drug or alcohol screening test by the substitution or spiking of a sample or the advertisement of a sample substitution or other spiking device or measure.

So, save yourself the further trouble and comply with the drug testing procedures, whether it's done for the purpose of pre-employment, random workplace testing, or applying for insurance.

History of Marijuana

The history of marijuana dates back from the ancient times. In China, marijuana is used as a remedy for gout, rheumatism, malaria, beriberi, constipation, and absentmindedness. Chinese doctors like Hua T'o allegedly used cannabis to perform a painless operation in the second century A.D. Eastern Indian documents in the Atharveda, dating from before the first millennium BC, also refer to the medicinal use of cannabis.

In the late Middle Ages, Europeans learned marijuana's painkilling properties from traders who traveled from the Middle East and Asia. By the 19th century, William B. O'Shaughnessy, an Irish physician, brought knowledge of the medical properties of cannabis to Europe in 1839. After observing marijuana use in India, he experimented with alcohol-based tinctures to treat rheumatism, rabies, cholera, tetanus, and convulsions. Around the same period, marijuana preparations were sold legally in many countries. Cannabis became popular in the treatment of painful menstruation and childbirth, asthma, migraines, neuralgia, and senile insomnia.

However, as stronger and more conventional medicines became available by the late 19th century, marijuana's medicinal use started to wane, and finally ended as it was embattled with political misfortunes.

Chronological Evolution of Marijuana

Marijuana is known as one of the most widely used illicit substances worldwide. Interestingly, its origin began many centuries ago. Below is the detailed chronology of marijuana documented in W. Scott Ingram's Junior Drug Awareness: Marijuana:

10,000 B.C.

The earliest evidence of cannabis being used for fiber is found in Taiwan.

4,000 B.C.

Textiles made of hemp are used in China.

2727 B.C.

Use of cannabis as medicine in China is first recorded.

1200-800 B.C.

Bhang (dried cannabis leaves, seeds, and stems) is mentioned in Hindu texts as one of the five sacred plants of India. It is used medicinally and in religious ceremonies.

500 B.C.

Hemp is introduced into northern Europe by the Scythians. An urn containing leaves and seeds of the cannabis plant is unearthed in Germany and dated to about this time.

500-100 B.C.

Hemp spreads throughout northern Europe.

A.D. 70

Dioscorides mentions the use of cannabis as a Roman medicine.


Hashish use spreads through Arabian Peninsula.


Cannabis is introduced in Egypt.


Marco Polo's journeys bring the first reports of cannabis as an intoxicant in Asia to the attention of Europe.


The British cultivate cannabis in their American colonies.


Soldiers returning to France from wars in Egypt bring cannabis and hashish with them.


In the United States, medicines containing cannabis are widely used.


The Pure Food and Drug Act is passed in the United States, regulating the labeling of products containing alcohol, opiates, and cocaine, among other substances.


Marijuana begins to be prohibited by states, including California (1915), Texas (1919), Louisiana (1924), and New York (1927).


Cannabis is made illegal nationwide in the United States with the passage of the Marihuana Tax Act.


The Shafer Commission, a federally sponsored group, urges legalization of cannabis in a similar manner to tobacco and alcohol. The recommendation is ignored.


The U.S. Food and Drug Administration establishes a program for medical marijuana.


A Drug Enforcement Administration judge finds that marijuana has medical uses and should be reclassified as a prescriptive drug. His recommendation is ignored. In June 2003, Canada is the first country in the world to offer medical marijuana to its patients.

February 2006

Studies show that marijuana is the largest cash crop in the United States.

Statistics on Marijuana Abuse

According to the 2010 World Drug Report, marijuana remains the most widely used illicit substance in the world. Globally, the number of people who had used cannabis at least once in 2008 is estimated between 129 and 191 million, or 2.9% to 4.3% of the world population aged 15 to 64.

North America

In North America, there are an estimated 29.5 million people who had used cannabis at least once in 2008, a decrease from the 31.2 million estimated in 2007. This decrease reflects the availability of new data for Canada, which in 2008 showed a considerably lower number of cannabis users compared to their previous 2004 survey estimates.

However, despite the declining or stabilizing state of cannabis use in the United States and Canada, a slight increase was observed in the United States in 2008 - from 12.3% of the population aged 15-64 in 2007 to 12.5% in 2008).

In the United States - between 2002-2007 - there was a significant decrease in the annual prevalence of cannabis use within the population aged 12 and older, from 11% to 10.1%. In 2008, the annual prevalence of cannabis use increased for the first time after 2002, reaching the level observed in 2006 (10.3% of the population aged 12 and older). A similar trend has been observed among secondary school students.

South America

Although the annual prevalence of cannabis use in South America remains considerably lower than in North America, a perceived increase in cannabis use has been reported from almost all national experts, wherein 3%, or an estimated 7.3 -7.5 million people among the population aged 15 to 64, had used cannabis at least once in the past year in 2008, which is a decrease from the 8.5 million estimated for 2007. The highest prevalence of cannabis use is found in Argentina (7.2%), Chile (6.7%) and Uruguay (6%). However, compared to the general population, the highest cannabis use prevalence among school students was reported among those in Chile (15.6%), Uruguay (14.8%) and Colombia (8.4%).

Most of the countries in the Caribbean also have higher than world average prevalence of cannabis use, with rates such as 11.7% in Saint Kitts and Nevis and 10.8% in Dominica and Grenada. Haiti (1.4%) and the Dominican Republic (0.3%) are the two countries with low prevalence of cannabis use.

An increasing trend in prevalence of cannabis use among the general population is registered in the Bahamas (from 4.7% in 2003 to 5.5% in 2008), Grenada (from 6.7% in 2003 to 10.8% in 2005), Saint Vincent and the Grenadines (from 6.2% in 2002 to 7.1% in 2006), Trinidad and Tobago (from 3.7% in 2002 to 4.7% in 2006).


In Europe, an estimated 29.5 million people, or around 5.4% of the general population aged 15 to 64, used cannabis in the previous year. Cannabis use is largely concentrated among young people (15 - 34 years old).

Cannabis use is largely concentrated among young people (15 - 34 years old). Within Europe, cannabis use differs considerably among the general population, with higher prevalence (7.7%) reported in West and Central Europe, compared to East and South-East Europe (3%). The Czech Republic (15.2% - 2008), Italy (14.6% - 2008) and Spain (10.1% - 2007) are the three countries with the highest cannabis use prevalence rates, accounting for about one-third of all cannabis users in Europe (5 million only in Italy).

England and Wales (the third largest European market of cannabis users after Italy and the Russian Federation) had shown a strong decline between 2003 and 2008 (from 10.8% to 7.4% of the general population), however, in 2009, the prevalence increased to 7.9%. New data for Scotland, Finland, Romania and Bosnia and Herzegovina show a decrease. However, the majority of countries with new data in 2008 reported an increase in cannabis use from previous estimates. These are Bulgaria, the Czech Republic, Denmark, Estonia and Lithuania.


In the Oceania region, between 2.1 and 3.4 million people are estimated to have used cannabis in the past year (9.3% - 14.8% of the general population aged 15 - 64). Except for Australia, Fiji and New Zealand, there are no recent or reliable estimates available of cannabis use in the remaining parts of the region.

In Australia, the annual prevalence of cannabis use has been declining since 1998, with an almost one-fifth decline between 2004 and 2007. The major decline in cannabis use has been observed in the younger population (aged 14 to 19) from a prevalence of 34.6% in 1998 to 12.9% in 2007. In New Zealand, the annual prevalence of cannabis use fell from 20.4% in 2003 to 13.3% in 2006, to increase again in 2008 to 14.6%.

    Marijuana Effects on Pregnancy

    In the book Medical Use of Marijuana: Policy, Regulatory, and Legal Issues, author Tatiana Shohov noted that according to research babies born to women who used marijuana during their pregnancies display altered responses to visual stimuli, increased tremulousness, and a high-pitched cry, which may indicate problems with neurological development. During infancy and preschool years, marijuana-exposed children have been observed to have behavioral problems and poorer performance on tasks of visual perception, language comprehension, sustained attention, and memory. In school, these children are more likely to exhibit deficits in decision-making skills, memory, and the ability to remain attentive.

    Marijuana and Your Teenagers

    According to the National Survey on Drug Use and Health, in 2009, there are 16.7 million Americans aged 12 or older who used marijuana at least once in the month prior to being surveyed. The figure is significantly higher than the rates reported in all years between 2002 and 2008. There was also an increase among youth aged 12-17, with current use up from 6.7% in 2008 to 7.3% in 2009, although this rate is lower than what was reported in 2002 (8.2 percent). Past-month use also increased among those 18-25, from 16.5% in 2008 to 18.1% in 2009.

    Meanwhile, the result from a 2009 Monitoring the Future survey revealed that as in the past few years, a stall in the decline of marijuana use that began in the late 1990s among our Nation's youth. In 2009, 11.8% of 8th-graders, 26.7% of 10th-graders, and 32.8% of 12th-graders reported past-year use. In addition, perceived risk of marijuana use declined among 8th- and 10th-graders and disapproval of marijuana use declined among 10th-graders.

    In the case of children and teenagers, peer pressure is seen as one of the major reasons why they use marijuana. Some young people smoke marijuana because they see their brothers, sisters, friends, or worst, their older family member using it. Others think smoking pot is cool as portrayed by the media on TV and in movies. There are also teenagers who use marijuana as a way to escape from problems at home, at school, or with friends.

    Marijuana: Facts for Teens is a published booklet by the National Institute on Drug Abuse (NIDA) which clearly summarizes the ill effects of marijuana use on teenagers, as well as how it can affect your teens' school performance and activities. Since marijuana affects memory, judgment and perception, the drug can mess up in school, in sports or clubs, or with your teenagers' friends.

    Marijuana also negatively impacts on the skills required to drive safely: alertness, concentration, coordination, and reaction time. Marijuana use can make it difficult to judge distances and react to signals and sounds on the road.

    In one study conducted in Memphis, TN, researchers found that, of the 150 reckless drivers who were tested for drugs at the arrest scene, 33% tested positive for marijuana, and 12% tested positive for both marijuana and cocaine.

    Celebrities Busted for Marijuana

    Celebrities are idolized for a varied number of reasons. However, for some of them, fame is the main culprit for them to get entangled with drug misuse. For celebrities, marijuana is also a widely abused substance that somehow landed them on the news pages.

    American jazz trumpeter and singer Louis Armstrong was arrested in 1930 along with drummer Vic Berton, outside the Cotton Club in Culver City, California for marijuana use. Both were kept overnight after the arrest, because "they were still high," and a judge gave them each six-month jail sentences (which were later suspended) and a $1,000 fine.

    On March 12, 1969, officers raided the London home of Harrison and Patti Boyd and arrested them for marijuana possession. Both pleaded guilty and were fined 250 pounds each.

    In the spring of 1977, while living in London, Marley was arrested and fined by British police for marijuana possession.

    In 1980, while on tour with the band Wings, McCartney was detained at Tokyo's Narita Airport after customs officials found half a pound of marijuana in his luggage. He spent 10 nights in jail before being released and deported. He later admitted, according to the BBC, that "it was the daftest thing I've done in my entire life."

    In 2000, soulful diva Whitney Houston was detained at an airport in Hawaii after authorities searched her handbag and found 15.2 grams of marijuana. Security reportedly tried to hold the singer, but she walked away and got on her flight to San Francisco, which left before police could arrive. She later pleaded no contest and the marijuana possession charge was dropped.

    Child star sensation Macauley Culkin was the passenger in a car pulled over for speeding in Oklahoma City in 2004, and when police searched the car and found marijuana, Xanax and clonazepam, he was charged with possession of marijuana and possession of a controlled substance without a prescription. He was given a one-year deferred sentence on each charge and had to pay a $540 fine.

    The O.C. star Mischa Barton was arrested in 2007 for driving under the influence of alcohol, driving without a license, possessing a controlled substance and possessing marijuana. The actress pleaded no contest to misdemeanor driving under the influence and driving without a license and was given three years probation.

    Marijuana Medical Use and Legal Issues

    For years, the potential medical effects of marijuana have been the subject of substantive research and political debates. Although this hemp plant derivative has been widely used in the ancient times to remedy various ailments like rheumatism, malaria, as well as aches and pains, marijuana's medicinal use remains unacknowledged in many countries today.

    Scientists have confirmed that the cannabis plant contains active ingredients with therapeutic potential for relieving pain, controlling nausea, stimulating appetite, and decreasing ocular pressure. Consequently, it is sometimes used to treat the symptoms of AIDS, cancer, multiple sclerosis, epilepsy, glaucoma, and other serious conditions. Yet despite these marijuana facts, only a few countries have allowed the use of marijuana for clinical and medicinal purposes.

    In 2001, Canada became the first country to regulate and legalize marijuana for medical use - published under the Marijuana Medical Access Regulations. The policy authorized people suffering from terminal illnesses or severe conditions such as epilepsy, AIDS, multiple sclerosis and cancer to use the drug if it eased their symptoms. Furthermore, it allows some people to be able to grow marijuana themselves under strict guidelines. Others would be allowed to buy it from companies licensed by the government. Ottawa awarded the first (and so far, the only) federal license to supply marijuana to a Saskatoon-based company, Prairie Plant Systems. The pot is grown in an underground mine in Flin Flon, Man.

    In the United States, marijuana remains a controlled substance under the federal law; yet, some states have passed laws that create a medical use exception to otherwise applicable state marijuana sanctions. In 1996, California was the first to pass such a law when Californian voters passed a ballot initiative, Proposition 215 (The Compassionate Use Act of 1996) that removed certain state criminal penalties for the medicinal use of marijuana. Voters in Oregon, Alaska, Colorado, Maine, Washington and Nevada have followed suit in passing medical marijuana initiatives. To date, more than half of the 50 states in the US have passed and enacted laws to legalize medical marijuana, including:

    • Delaware (2011)
    • Arizona (2010)
    • DC (2010)
    • New Jersey (2010)
    • Michigan (2008)
    • New Mexico (2007)
    • Rhode Island (2006)
    • Montana (2004)
    • Vermont (2004)
    • Colorado (2000)
    • Hawaii (2000)
    • Nevada (2000)
    • Maine (1999)
    • Alaska (1998)
    • Oregon (1998)
    • Washington (1998)
    • California (1996)

    The 13 states with failed legislation to legalize medical marijuana are:

    • Indiana
    • Iowa
    • Kansas
    • Kentucky
    • Mississippi
    • Missouri
    • Nebraska
    • Oklahoma
    • South Carolina
    • Tennessee
    • Texas
    • Utah
    • Virginia

    Marijuana will continue to be a controversial substance for years to come, and much focus will shift towards the legalization of cannabis throughout the United States and the remainder of the world. 

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