goldberg chapter 12

Albia Dugger • Miami Dade College

Chapter 12 Marijuana

History of Marijuana

• Marijuana (cannabis) is one of the world’s oldest known drugs

• Early settlers in Jamestown, Virginia, planted marijuana (hemp) for its fiber, which also was used during World War II

• People started smoking it for its euphoric effect during the 1920s, coinciding with alcohol prohibition

• Marijuana use was banned after the Marijuana Tax Act was enacted in 1937

Cannabis sativa

Characteristics of Marijuana

• The primary mood-altering, psychoactive agent in marijuana is delta-9-tetrahydrocannabinol, or THC

• Several factors influence THC levels: • The plant’s sex• Soil and climate conditions• The part of the plant that is used • How the plant is harvested, prepared, and stored

• Female plants produce more resin and flowers, which contain higher THC concentrations

Characteristics of Marijuana

• Marijuana contains more than 500 chemicals – 60 are unique to the cannabis plant (cannabinoids)

• Marijuana smoke contains 70% more carcinogenic benzopyrene and 50% more tar than tobacco smoke

• Marijuana releases five times as much tar into the lungs as cigarettes

Species and Forms of Marijuana

• Cannabis sativa• Most widespread; used primarily to make rope• Has a tall, woody stem and can reach a height of 20 feet

• Cannabis indica• Grown for its psychoactive properties• Grows to a height of 3 to 4 feet

• Cannabis ruderalis• Found mainly in northern Europe and Asia• Has a short growing season and low potency

Species and Forms of Marijuana

• Ganja, consisting of the top leaves and flowers of the female cannabis plant, is considered the best quality marijuana

• Bhang consists of the lower leaves, stems, and seeds of the cannabis plant and is regarded as poor quality marijuana

• Sinsemilla (“without seeds”) is derived from the unfertilized female cannabis plant, and has higher THC levels

Species and Forms of Marijuana

• Two other forms are hashish (charas) and hash oil

• These forms of marijuana have a higher THC content than Cannabis sativa

• Hashish, taken from the resin of the cannabis plant, is usually smoked in a pipe

• Hash oil is made by boiling resin in alcohol, and has a THC content of 60% – it is mixed with tobacco and smoked

Marijuana Paraphernalia

Points of Origin

• The cannabis plant can be grown almost anywhere

• Production is especially high in Colombia and Mexico

• Other countries in Latin America, and in Asia and the Caribbean, also produce marijuana

• Lebanon, Morocco, Pakistan, and Thailand are particularly known for producing much marijuana

Indoor Cultivation

• Indoor cultivation of marijuana makes it easier to avoid federal, state, and local law enforcement

• Indoor cultivation has allowed for production of marijuana with a higher THC content

• The profits of indoor cultivation are higher because marijuana plants can be harvested four to six times per year

Indoor Cultivation

Extent of Use

• Worldwide, marijuana is the fourth most commonly used drug, after nicotine, caffeine, and alcohol

• Marijuana is the most common illegal drug in the US, with an annual prevalence of 13.7%

• The most important reasons that students significantly increased use of marijuana relate to reduced perception of risk and less disapproval of its use

Age at First Use of Marijuana

Trends in Marijuana and HashishUse by High School Seniors

Methods of Administration

• Marijuana can be smoked or ingested

• Smoked THC is three times more potent than ingested THC

• If ingested, marijuana’s actions last longer

• Most smokers roll marijuana into a cigarette – an alternative is to roll it into a blunt, a type of cigar in which some of the tobacco is removed and replaced with marijuana

Absorption

• When marijuana is smoked, THC reaches the brain within a few seconds – peak effects are felt in about 30 minutes

• When smoked, about half of the THC is absorbed by way of the lungs into the bloodstream

• If ingested, the effects may not be felt for a couple of hours because less THC is absorbed

• Marijuana is fat soluble, and its metabolites can remain in the fatty tissue of heavy users for two to three weeks after use

Tolerance

• In studies, pharmacological tolerance was more likely to develop among daily users

• One indication of tolerance is that heavy users are still capable of doing cognitive tasks

• Many users claim they get high from decreasing doses, though no evidence of reverse tolerance exists

• Frequent users also experience less loss of memory, coordination, and concentration

Physical Dependence

• Although most experts agree that physical dependence on marijuana does not occur – it might depend on how dependency is defined

• One-fourth of adolescents who use marijuana frequently meet the criteria for marijuana abuse or dependency

• 60% of regular marijuana smokers experienced significant withdrawal symptoms, including irritability, nausea, vomiting, diarrhea, sweating, anxiety, and insomnia

Psychological Dependence

• Marijuana can result in psychological dependence

• If dependency develops, it is more likely to be motivated by psychosocial than by physiological factors

• The perceived need for the drug is believed to be responsible for compulsive use and dependency

Effects of Marijuana Use

• In a study of first-year college students, over 9% had a cannabis use disorder that resulted in concentration problems or missing a number of classes

• Adolescents who smoked at least once a week had increased thoughts of suicide, felt more lonely and unloved, and were more likely to run away from home, cut classes, or steal

• Marijuana impairs perceptual and motor skills and the ability to stay awake – skills necessary for driving

Psychological Effects

• Marijuana increases the release of dopamine, a neurotransmitter involved in the experience of euphoria

• Numerous studies support the connection between marijuana use and mental illness

• Detrimental psychological reactions to marijuana are unusual, although high doses can induce anxiety, delusions, disorientation, hallucinations, and paranoia

Perceptual Effects

• Marijuana alters perceptions of time and space

• Mood changes are marked by anxiety, sadness, laughter, and paranoia

• Some people experience panic reactions, which tend to be temporary and triggered by a feeling of not being in control

Cognitive Effects

• One reported cognitive effect of marijuana is impairment of short-term memory

• Learning and remembering new information become more arduous when using marijuana

• Heavy users were impaired in skills involving expression but not in vocabulary, mathematics, and reading comprehension

• Cognitive deficits persist up to 28 days after a person last smoked marijuana

Amotivational Syndrome

• Heavy marijuana users reportedly are unable to concentrate and are unmotivated, apathetic, lacking ambition, and not achievement-oriented (amotivational syndrome)

• Amotivational syndrome is more likely to develop in adolescents than in older people

• However, people who smoke a great deal might also be predisposed to these problems initially

Physical Effects

• Appetite• Marijuana users consistently report increase in appetite

• The Respiratory System• THC acts as a bronchodilator• Smoke contains many respiratory irritants and

carcinogens• One marijuana cigarette equals 20 regular cigarettes in

terms of bronchial damage• Marijuana contains 20 times as much ammonia and 5

times as much hydrogen cyanide as tobacco smoke

Physical Effects

• The Immune System• Studies with animals demonstrate that marijuana affects

the immune system adversely

• The Reproductive System• In males, marijuana decreases testosterone levels, sperm

count, and libido• In women, it may inhibit ovulation

Physical Effects

• The Brain• Chronic marijuana users experience cognitive deficits• Marijuana reduces acetylcholine in the hippocampus, the

portion of the brain that affects memory• Marijuana affects the activity of the neurotransmitters

norepinephrine and dopamine• Anticholinergic drugs such as marijuana are related to

schizophrenia

Factors Influencing Effects of Marijuana

• Factors influencing effects of marijuana:• Whether it is smoked or ingested• Dosage• THC content• Interval between puffs• Depth of inhalation• Length of time in one’s lungs• Set and setting• Previous experiences

Medical Applications

• In the late 1800s, marijuana was used medically to treat convulsions, chronic cough, sleeplessness, gastrointestinal disorders, gonorrhea, and pain

• Recently, marijuana has been used for treating glaucoma, asthma, nausea and vomiting during cancer chemotherapy, and pain associated with multiple sclerosis

• It also has been used to alleviate withdrawal symptoms related to barbiturates, narcotics, and alcohol

Medical Applications

• Glaucoma• Marijuana reduces pressure behind the eye

• Nausea and Vomiting• Marijuana is an effective anti-emetic to counteract nausea

and vomiting associated with chemotherapy for cancer• Marinol (THC formulated in sesame oil) • Cesamet (a synthetic cannabinoid)• More than 40% of oncologists recommended marijuana to

their cancer patients to control nausea and vomiting

Medical Applications

• Asthma• THC dilates the bronchial tubes

• Additional Medical Uses• Appetite stimulant• Pain relief• Muscle relaxant• Recommended for epilepsy, insomnia, rheumatoid

arthritis, chronic pain conditions, premenstrual syndrome and menstrual cramps

Decriminalization and Legalization

• In 1972, the Presidential Commission on Marijuana and Drug Abuse recommended the decriminalization of marijuana

• 11 states decriminalized marijuana, making possession a minor offense punishable by a $100 fine

• In 2008, Michigan became the 13th state to approve the medical use of marijuana

Decriminalization and Legalization

• An argument against marijuana is that it is a gateway drug, leading to the use of more dangerous drugs

• However, most marijuana smokers do not proceed to use other drugs

• Steppingstone theory• Hypothesis that use of soft drugs such as marijuana and

alcohol leads to use of harder drugs such as heroin and cocaine

Decriminalization and Legalization

• Which is the greater problem—marijuana or laws against marijuana?

• The National Organization for the Reform of Marijuana Laws (NORML) contends that the quality of marijuana would be controlled more effectively if it were legal

• Legalization of marijuana is compared to tobacco and alcohol, which have known medical and social consequences

Decriminalization and Legalization

• In 2011, the Dutch government reversed its tolerance policies and reclassified marijuana so that it is now comparable to cocaine and Ecstasy

• The Dutch government believe that better control over marijuana use reduces the risks

• It is estimated that 13% of Dutch high school students have used marijuana, compared to 28% of American students

Legalization for Medical Uses

• Marijuana has a long history of medical use and is reasonably safe

• Opponents believe that if marijuana were available for medical use, its nonmedical use would increase dramatically

• In states that legalized medical marijuana, rates of marijuana use, abuse, and dependence are higher

• One concern is that medical marijuana may be illegally diverted for substance abuse

Legalization for Medical Uses

• In November 1996, California voters eliminated state penalties for medical uses of marijuana

• Fifteen states, including the District of Columbia, have now passed medical marijuana laws

• The Institute of Medicine (IOM) found that marijuana has “potential for therapeutic use”

• In 2006, the FDA reaffirmed that marijuana should remain a Schedule I drug, and has no currently accepted medical use

Cost

• Drug reform advocates:• Treating drug offenders is much cheaper than

incarcerating them• Legalizing marijuana and other drugs would stem the rise

in violence and criminal activity

• Opponents of drug reform:• Marijuana is unhealthy and the only viable option is

elimination of its use• Advertising and marketing would increase drug problems

dramatically

Crime and Violence

• Hassan, an Arabian politico who lived during the Middle Ages, and his cult, purportedly used hashish in preparation for aggressive acts against others

• Legalization might reduce criminal and violent behavior, but interpersonal and intrapersonal problems might escalate

• When alcohol was prohibited, organized crime increased – legalization would remove much of the profit motive