Definition
Cannabis, more commonly called marijuana, refers to the several varieties of Cannabis sativa, or Indian hemp plant, that contains the psychoactive drug delta-9-tetrahydrocannabinol (THC). Cannabis-related disorders refer to problems associated with the use of substances derived from this plant.
Description
Cannabis—in the form of marijuana, hashish (a dried resinous material that seeps from cannabis leaves and is more potent than marijuana), or other cannabinoids—is considered the most commonly used illegal substance in the world. Its effects have been known for thousands of years, and were described as early as the fifth century B.C., when the Greek historian Herodotus told of a tribe of nomads who, after inhaling the smoke of roasted hemp seeds, emerged from their tent excited and shouting for joy.
Cannabis is the abbreviation for the Latin name for the hemp plant—Cannabis sativa. All parts of the plant contain psychoactive substances, with THC making up the highest percentage. The most potent parts are the flowering tops and the dried, blackish-brown residue that comes from the leaves known as hashish, or “hash.”
There are more than 200 slang terms for marijuana, including “pot,” “herb,” “weed,” “Mary Jane,” “grass,” “tea,” and “ganja.” It is usually chopped and/or shredded and rolled into a cigarette, or “joint,” or placed in a pipe (sometimes called a “bong”) and smoked. An alternative method of using marijuana involves adding it to foods and eating it, such as baking it into brownies. It can also be brewed as a tea. Marijuana has appeared in the form of “blunts”—cigarettes emptied of their tobacco content and filled with a combination of marijuana and another drug such as crack cocaine.
Between 1840 and 1900, European and American medical journals published numerous articles on the therapeutic uses of marijuana. It was recommended as an appetite stimulant, muscle relaxant, painkiller, sedative, and anticonvulsant. As late as 1913, Sir William Osler recommended it highly for treatment of migraine. Public opinion changed, however, in the early 1900s, as alternative medications such as aspirin, opiates, and barbiturates became available. In 1937, the United States passed the Marijuana Tax Act, which made the drug essentially impossible to obtain for medical purposes.
By the year 2000, the debate over the use of marijuana as a medicine continued. THC is known to successfully treat nausea caused by cancer treatment drugs, stimulate the appetites of persons diagnosed with acquired immune deficiency syndrome (AIDS), and possibly assist in the treatment of glaucoma. Its use as a medicinal agent is still, however, highly controversial. Even although the states of Arizona and California passed laws in 1996 making it legal for physicians to prescribe marijuana in the form of cigarettes for treatment of the diseases listed above, governmental agencies continue to oppose strongly its use as a medicine, and doctors who do prescribe it may find their licenses at risk.
Cannabis-related disorders reflect the problematic use of cannabis products to varying degrees. These dis orders include:
- • Cannabis dependence: The compulsive need to use the drug, coupled with problems associated with chronic drug use.
- • Cannabis abuse: Periodic use that may cause legal problems, problems at work, home, or school, or danger when driving.
- • Cannabis intoxication: The direct effects of acute cannabis use and reactions that accompany it such as feeling “high,” euphoria, sleepiness, lethargy, impairment in short-term memory, stimulated appetite, impaired judgment, distorted sensory perceptions, impaired motor performance, and other symptoms.
Causes and symptoms
Causes
Cannabis-related disorders share many of the same root causes with other addictive substances. The initial desire for a “high,” combined with the widely held perception that cannabis use is not dangerous, often leads to experimentation in the teen years.
Recent research challenges the notion that cannabis use is not physically addictive. According to the National Institute of Drug Abuse (NIDA), daily cannabis users experience withdrawal symptoms including irritability, stomach pain, aggression, and anxiety. Many frequent cannabis users are believed to continue using in order to avoid these unpleasant symptoms. Long-term use may lead to changes in the brain similar to those seen with long-term use of other addictive substances. It is believed that the greater availability, higher potency, and lower price for cannabis in recent years all contribute to the increase in cannabis-related disorders.
Beginning in the 1990s, researchers began to discover that cannabis-like compounds are naturally produced in various parts of the human body. These compounds, called “endocannabinoids,” appear to suppress inflammation and other responses of the immune system. One of these endocannabinoids— anandamide—appears to help regulate the early stages of pregnancy.
Symptoms
CANNABIS DEPENDENCE AND ABUSE. The handbook used by mental health professionals to diagnose mental disorders is the Diagnostic and Statistical Manual of Mental Disorders, also known as the DSM-IV-TR. This manual states that the central features of cannabis dependence are compulsive use, tolerance of its effects, and withdrawal symptoms. Use may interfere with family, school, and work, and may cause legal problems.
Regular cannabis smokers may show many of the same respiratory symptoms as tobacco smokers. These include daily cough and phlegm, chronic bronchitis, and more frequent chest colds. Continued use can lead to abnormal functioning of the lung tissue, which may be injured or destroyed by the cannabis smoke.
Recent research indicates that smoking marijuana has the potential to cause severe increases in heart rate and blood pressure, particularly if combined with cocaine use. Even with marijuana use alone, however, the heart rate of subjects increased an average of 29 beats per minute when smoking marijuana.
A study of heavy marijuana users has shown that critical skills related to attention, memory, and learning can be impaired, even after use is discontinued for at least 24 hours. Heavy users, compared to light users, made more errors on tasks and had more difficulty sustaining attention and shifting attention when required. They also had more difficulty in registering, processing, and using information. These findings suggest that the greater impairment in mental functioning among heavy users is most likely due to an alteration of brain activity directly produced by the marijuana use.
Recent studies have found that babies born to mothers who used marijuana during pregnancy were smaller than those born to nonusing mothers. Smaller babies are more likely to develop health problems. Additionally, nursing mothers who use marijuana pass some of the THC to the baby in their breast milk. Research shows that use of marijuana during the first month of breastfeeding can impair an infant’s motor development.
Cannabis abuse is characterized by less frequent use and less severe problems. However, as with cannabis dependence, abuse can interfere with performance at school or work, cause legal problems, and interfere with motor activities such as driving or operating machinery.
CANNABIS INTOXICATION. Cannabis intoxication refers to the occurrence of problematic behaviors or psychological changes that develop during, or shortly after, cannabis use. Intoxication usually starts with a “high” feeling followed by euphoria, inappropriate laughter, and feelings of grandiosity. Other symptoms include sedation, lethargy, impaired short-term memory, difficulty with motor tasks, impaired judgment, distorted sensory perceptions, and the feeling that time is passing unusually slowly. Sometimes severe anxiety, feelings of depression, or social withdrawal may occur. Along with these symptoms, common signs of cannabis intoxication include reddening of the membranes around the eyes, increased appetite, dry mouth, and increased heart rate.
Demographics
The NIDA conducts an annual nationwide study of twelfth-, tenth-, and eighth-grade students and young adults. This study is known as the Monitoring the Future Study, or MTF. Results show that after a decade of decreased use in the 1980s, marijuana use among students began to rise in the early 1990s. Data show that, between 1998 and 1999, marijuana use continued to increase among twelfth and tenth graders. For twelfth graders, the lifetime rate (use of marijuana at least one or more times) is higher than for any year since 1987. However, these rates remain well below those seen in the late 1970s and early 1980s. Daily marijuana use among students in all three grades also showed a slight increase.
Another method by which the government measures marijuana use is the Community Epidemiology Work Group, or CEWG. This method examines rates of emergency room admissions related to marijuana use in 20 major metropolitan areas. In 1998, use of marijuana showed an upward trend in most of the areas monitored, with the largest increases occurring in Dallas, Boston, Denver, San Diego, and Atlanta. The highest percentage increase in emergency room visits related to marijuana was among 12- to 17-year-olds.
Treatment data for marijuana abuse increased in six of the metropolitan areas surveyed but remained stable elsewhere. Marijuana treatment admissions were highest in Denver, Miami, New Orleans, and Minneapolis/St. Paul. Half of the admissions in Minneapolis/St. Paul were under the age of 18 years.
Marijuana remains the most commonly used illicit drug in the United States. As with most other illicit drugs, cannabis use disorders appear more often in males and is most common among people between the ages of 18 and 30 years.
An estimated 2.1 million people started using marijuana in 1998. According to data from a study released in the late 1990s called the National Household Survey on Drug Abuse, or NHSDA, more than 72 million Americans ages 12 years and older (33%) tried marijuana at least once during their lifetime, while almost 18.7 million (8.6%) used marijuana in the previous year. The reader can compare these figures to the figures from 1985, when 56.5 million Americans (29.4%) had tried marijuana at least once in their life, and 26.1 million (13.6%) had used marijuana within the past year.
Diagnosis
Diagnosis of cannabis-related disorders is made in a number of ways. Intoxication is easiest to diagnose because of clinically observable signs, including reddened eye membranes, increased appetite, dry mouth, and increased heart rate. It is also diagnosed by the presence of problematic behavioral or psychological changes such as impaired motor coordination, judgment, anxiety, euphoria, and social withdrawal. Occasionally, panic attacks may occur, and there may be impairment of short-term memory. Lowered immune system resistance, lowered testosterone levels in males, and chromosomal damage may also occur. Psychologically, chronic use of marijuana has been associated with a loss of ambition known as the “amotivational syndrome.”
Cannabis use is often paired with the use of other addictive substances, especially nicotine, alcohol, and cocaine. Marijuana may be mixed and smoked with opiates, phencyclidine (“PCP” or “angel dust”), or hallucinogenic drugs. Individuals who regularly use cannabis often report physical and mental lethargy and an inability to experience pleasure when not intoxicated (known as “anhedonia”). If taken in sufficiently high dosages, cannabinoids have psychoactive effects similar to hallucinogens such as lysergic acid diethylamide (LSD), and individuals using high doses may experience adverse effects that resemble hallucinogen-induced “bad trips.” Paranoid ideation is another possible effect of heavy use, and, occasionally, hallucinations and delusions occur. Highly intoxicated individuals may feel as if they are out-side their body (“depersonalization”) or as if what they are experiencing isn’t real (“derealization”). Fatal traffic accidents are more common among individuals testing positive for cannabis use.
Urine tests can usually identify metabolites of cannabinoids. Because cannabinoids are fat soluble, they remain in the body for extended periods. Individuals who have used cannabis may show positive urine tests for as long as two to four weeks after using.
Examination of the nasopharynx and bronchial lining may also show clinical changes due to cannabis use. Marijuana smoke is known to contain even larger amounts of carcinogens than tobacco smoke. Sometimes cannabis use is associated with weight gain.
Treatments
Treatment options for individuals with cannabis-related disorders are identical to those available for people with alcohol and other substance abuse disorders. The goal of treatment is abstinence. Treatment approaches range from in-patient hospitalization, drug and alcohol rehabilitation facilities, and various outpatient programs. Twelve-step programs such as Narcotics Anonymous are also treatment options. For heavy users suffering from withdrawal symptoms, treatment with anti-anxiety and/or antidepressant medication may assist in the treatment process.
Prognosis
According to the DSM-IV-TR, cannabis dependence and abuse tend to develop over a period of time. It may, however, develop more rapidly among young people with other emotional problems. Most people who become dependent begin using regularly. Gradually, over time, both frequency and amount increase. With chronic use, there can sometimes be a decrease in or loss of the pleasurable effects of the substance, along with increased feelings of anxiety and/or depression. As with alcohol and nicotine, cannabis use tends to begin early in the course of substance abuse and many people later go on to develop dependence on other illicit substances. Because of this, cannabis has been referred to as a “gateway” drug, although this view remains highly controversial. There is much that remains unknown about the social, psychological, and neurochemical basis of drug use progression, and it is unclear whether marijuana use actually causes individuals to go on to use other illicit substances.
One long-term effect of chronic use has been termed the “amotivational syndrome.” This refers to the observation that many heavy, chronic users seem unambitious in relation to school and/or career.
Prevention
Many drug education programs focus strongly on discouraging marijuana experimentation among young teenagers. Recent research reported by the NIDA indicates that high-sensation-seekers—that is, individuals who seek out new, emotionally intense experiences and are willing to take risks to obtain these experiences— are at greater risk for using marijuana and other drugs, and for using them at an earlier age. As a result, the NIDA developed a series of public service announcements (PSAs) for national television. These PSAs were dramatic and attention getting, and were aired during programs that would appeal to high sensation-seekers, such as action-oriented television shows. These PSAs were aired in a limited television area and the results monitored. Marijuana use declined substantially among teens during the PSA campaigns, and long-term effects were shown for several months afterwards. In one county, marijuana use decreased by 38%, and in another, by 26.7%.