Reckless Driving Overview

Amotivational syndrome is not the only social problem attributed to marijuana. The drug's potential role in auto accidents has also generated considerable concern. In 1997, traffic accidents in the United States numbered 16 million and caused 43,000 deaths. Comparable numbers of crashes and fatalities have likely occurred in more recent years (Bureau of Census, 1999). These statistics raise an understandable concern about impaired driving. Many drugs can increase highway mishaps. Alcohol is...

Marijuanas Health Effects

Concerns about marijuana's potential impact on health have generated volumes of research, numerous conferences, and considerable controversy. This chapter addresses marijuana's toxicity, as well as its impact on mental illness, the brain, the pulmonary system, reproduction, pregnancy, and immune function. In general, the drug is incapable of creating an overdose. It can exacerbate the symptoms of some mental disorders but does not appear to cause them. Data fail to show any marijuana-induced...

Toxicity

Media reports highlight tales of increased THC content in new strains of cannabis, leading some to worry about the potential of a fatal overdose. Yet cannabis is essentially nontoxic. No one has ever died of THC poisoning (Iversen, 2000). Extrapolations from animal research suggest a lethal dose of THC would require 125 mg of the drug per kilogram of body weight (Nahas, 1986). A 160-pound (73-kilogram) person would require 9,125 mg of THC to receive a fatal dose. Most marijuana cigarettes weigh...

The Bodys Own Cannabinoids

It seems unlikely that so many animals would develop receptors simply to respond to some green weed. The identification of the cannabinoid receptors inspired the search for the body's own substances that might activate them. Studies of the functions of these endogenous cannabinoids could reveal a lot about how marijuana works, as well as how the brain works. Several endogenous chemicals appear to interact with the cannabinoid receptor. The two studied most are arachidonylethanolamine...

Overview of Critiques of Studies That Reveal Few or No Deficits

Many researchers report no differences between people who never use drugs and unintoxicated, chronic users of cannabis. These results suggest that chronic marijuana exposure has little permanent impact on thought and memory. Critics of these studies emphasize that genuine differences may exist, but they failed to appear for several reasons. These reasons relate to both the participants studied and the tests employed. The issues related to participants concern samples that are too small to...

Involuntary Movement

Several disorders show unintentional muscle contractions comparable to spasticity, but these diseases lead to more dramatic, debilitating motion. They can create some of the same problems associated with spasticity, including difficulty sleeping and trouble with fine motor tasks. Given the large number of cannabinoid receptors in the brain's motor areas, a few studies have examined the potential therapeutic effects of cannabinoids in movement disorders, including Tourette's, Huntington's...

Studies That Found Few Marijuana Related Deficits

One of the first studies to support no marijuana-induced cognitive deficits examined 30 using and 24 nonusing Jamaican men (Bowman & Pihl, 1973). Testing occurred in many environments, including homes, huts, and public areas. This mobile approach to testing helped ensure that even the most impaired individuals could participate. Chronic users had smoked an average of 20 joints a day for at least 10 years. Thus, the sampling does not appear particularly biased toward unimpaired users. The...

Few Differences Deemed Anomalous

Some researchers found a few small differences but concluded that they were spurious for methodological reasons. A study of 60 Jamaican men (30 smokers and 30 controls) used 47 measures of IQ, memory, and motor speed only 4 showed significant results. Two or three could be expected by chance, as explained below in the discussion of multiple tests performed in studies that reveal differences. Oddly enough, one of these tests suggested better memory functioning in the smokers. Users smoked daily...

Studies Showing Marijuana Related Differences

Accurate interpretations of studies that reveal deficits must consider differences prior to use, polydrug consumption, intoxication during testing, multiple tests employed, and reporting of small or inconsequential differences. Any study that reveals deficits associated with chronic marijuana consumption must address these critiques. Generally, these studies suggest that long-term use of cannabis does not lead to overt signs of gross intellectual impairment. Nevertheless, subtle problems on...

Headache

One recurring painful condition that may benefit from cannabis treatment is headache. Migraine, a form of headache that often includes severe throbbing accompanied by disturbed vision, chills, sweating, nausea, and vomiting, can be extremely debilitating. Bright lights, loud sounds, or pungent odors can initiate the pain. Symptoms often begin with visual disturbances like seeing flashes or auras. Then sufferers feel extreme tension and fatigue (Grinspoon & Bakalar, 1997 Russo, 1998)....

School Performance

Parents and educators express understandable concern about marijuana, amotivational syndrome, and schoolwork. Research has focused on academic achievement in college and high school students. Contrary to popular belief, over half a dozen studies reveal that marijuana smokers and nonsmokers have comparable grades in college. One typical report surveyed 1,400 undergraduates, revealing no differences between users and nonusers on grades, changes in their majors, or number of colleges attended....

Addiction

Marijuana addiction proves difficult to define. Some researchers claim that marijuana is not particularly addictive. Experts assert that cannabis's addictive power parallels caffeine's (Franklin, 1990 Hilts, 1994). Hilts asked two prominent drug researchers to rank features of six common drugs nicotine, caffeine, heroin, cocaine, alcohol, and marijuana. Both experts ranked marijuana last in its ability to produce withdrawal, tolerance, and dependence. Another study had experts rank 18 drugs on...

Immune Function

The impact of smoked marijuana on immune function remains a controversial topic, particularly given recent medicinal use of the drug. Many people employ cannabis in the battle against AIDS-related wasting and the anorexia associated with cancer chemotherapy. Physicians and patients show an understandable concern about any treatment that might impair the ability to ward off illness. People with AIDS and cancer need all their immune cells to function as well as possible. Research on THC and...

Cannabis Use and Misuse

This chapter describes the use and misuse of cannabis. Estimating the number of marijuana smokers proves difficult. Many people show an understandable reluctance to confess to illegal behavior. This reluctance may also bias estimates of the amount of cannabis consumed. Marijuana lacks the standard dosage common to many other drugs, such as a pack of cigarettes or a shot of whiskey. In addition, people can misremember, exaggerate, or minimize their use. Many different terms have developed to...

The Prevalence Of Problems

The frequency of marijuana problems may prove difficult to estimate. Just as people are unwilling to confess to using the drug, they may also be reluctant to admit to related troubles. Thus, any studies of self-reported marijuana problems may underestimate their number. One of the most comprehensive studies of abuse and dependence began with interviews of over 42,000 people. This research focused on people who had used cannabis in the previous year and revealed that 23 qualified for a diagnosis...

Marijuanas Impact on Thought and Memory

People think and remember differently during cannabis intoxication. Chronic consumption of the drug might change aspects of cognition, too. The deficits associated with intoxication are relatively specific. People who are high show obvious problems concentrating, attending to details, focusing on goals, performing two actions simultaneously, and learning new, complex information. These problems grow worse with higher doses of the drug and more complicated tasks. In some studies, marijuana...

Drug Testing at the Workplace

Employers have an understandable interest in maximizing the performance of employees. Many are concerned that drug users may work less efficiently, have more accidents, or use more medical benefits. Other employers may favor hiring abstainers because of moral objections to drug use. Over 80 of major U.S. firms test for drugs, spending millions of dollars in the process. Opponents of employee drug testing view it as a degrading experience that qualifies as an illegal search and seizure. They...

Potential Improvements for Treatment of Cannabis Problems

Therapists and researchers have suggested several changes that might improve treatments for marijuana problems. These include using individual therapy, adding an inpatient stay in the hospital, increasing the number of sessions, and providing medications to help abstinence. Data suggest that some of these changes may provide more help than others. Many drug programs have focused on individual rather than group treatment. At first glance, the group format may seem less promising. Time spent...

Gateways and Causality

The lack of evidence for an obvious, biological stepping-stone inspired theorists to formulate ideas about marijuana as a gateway drug. A gateway usually serves as a passage to a region. Proponents of gateway theory show that people who use drugs like heroin and cocaine often used alcohol, tobacco, and marijuana first (Kandel, Yamaguchi, & Chen, 1992 Miller, 1994). Confusion about these theories has led to the idea that gateway drugs cause users to consume other substances. The prominent...

Subjective Effects

Perceptions change during marijuana intoxication. Time and space appear distorted. The senses seem more sensitive. Higher functions like thought, memory, and spirituality can alter, too. Some of these changes stem from the pharmacological properties of the cannabinoids. Others arise from the expectations of the user, the demands of the environment, or the attitudes of the culture where the drug is ingested. These factors can combine in unpredictable ways to create odd experiences. This chapter...

Brain Function

Although advanced techniques in brain imaging reveal that those who start cannabis use in adulthood show no marijuana-induced changes in brain structure, chronic cannabis consumption might alter brain function. New measures of function include brain imaging techniques that measure blood flow and metabolism. Other approaches use the electroencephalogram to assess brain waves, which relate to the way that people process information. These measures are more sensitive to changes in the brain that...

Differences Prior To Marijuana

Critics of studies that reveal disparities between chronic users and nonusers emphasize a key point about participants. People who choose to smoke marijuana daily for years may be different from those who do not. These differences may have been present long before they started using the drug. Under these circumstances, lower scores found in smokers might not stem from marijuana use. The differences may arise because the groups were unequal for some reason that preceded marijuana use. The best...

Elevated Intraocular Pressure

Glaucoma, the name depicting a group of problems characterized by raised pressure within the eye, affects over 67 million people worldwide. Approximately 300 people out of every 100,000 suffer from the disorder. More than 2 million Americans have glaucoma, 80,000 of whom cannot see. The heightened pressure within the eye eventually damages the optic disk, hindering vision dramatically. It is the leading preventable cause of visual impairments. Only cataracts, a currently unpreventable...

Brief History

Medicinal uses for cannabis date back to 2737 B.C., when the Chinese emperor and pharmacologist Shen Neng prescribed the drug for gout, malaria, beriberi, rheumatism, and memory problems. News of the medication spread throughout the world. The drug helped reduce symptoms in India, Africa, Greece, and Rome. Many authors assert that medical marijuana treatments would not have reached other countries unless they had meaningful efficacy. Dr. William O'Shaughnessy introduced the medication to Europe...

Potency

Cannabis preparations vary dramatically in their effects. The most common indicator of potency is the percentage of delta-9 tetrahydrocannabinol (THC). Although THC is not the only source of psychoactive effects in the plant, it is the most abundant chemical that clearly alters subjective experience. Hashish typically contains 20 THC, with some estimates as high as 50 . Hash oil can contain up to 70 THC. Yet each of these products can vary dramatically in potency. Some samples of hash oil and...

Final Thoughts

A great deal of the available information on marijuana appears in this book. But the marijuana literature is extensive. It does not lend itself to easy summaries or interpretations. As mentioned in the preface, any attempt to explain this research may say more about the explainer than the explained. People who claim to be rational often gather information before forming opinions and making decisions. Others form opinions, make decisions, and then go in search of reasons afterward. A selective...

History of Cannabis the Intoxicant

The story of cannabis as a medicine is separate from its role as a recreational drug. The consumption of cannabis solely for psychoactive, mindaltering effects differs from other forms of use. Industrial hemp alters consciousness only in those who find fashion a source of ecstasy. Ailing patients who use medical marijuana report altered thoughts and feelings, but the alleviation of symptoms seems the primary goal. Some individuals use cannabis as part of religious ritual, with varying emphasis...

Pulmonary Harm Reduction

Drug lore suggests that certain strategies may minimize marijuana's potential harm to the lungs. These include ingesting the drug orally, using water pipes or vaporizers, refraining from holding smoke down in the lungs for extended periods, and smoking stronger cannabis. Research suggests that results for some of these strategies are mixed. Obviously, eating marijuana or hashish will have no impact on the respiratory system. Water pipes that cool the smoke will decrease the negative effects of...

Temporal Antecedence

If marijuana actually caused the consumption of other intoxicants, cannabis consumption must precede the use of hard drugs. Many studies show that hard drug users smoke marijuana first. The stereotyped progression of the use of drugs probably begins with caffeine, but no data address this drug's potential as a gateway. Most research suggests that adolescents first use alcohol or nicotine. Some authors argue that cigarettes serve as the actual gateway to drug problems (Kandel et al., 1992...

Association

Hume's first criterion for establishing a cause concerns association. Despite popular stereotypes, the association between marijuana and harder drugs is not particularly strong. Many people who abuse hard drugs used marijuana first, but few people who smoke marijuana go on to consume other intoxicants. One study found that 75 of men who used marijuana between 10 and 99 times never used any other illicit drug (Kandel & Davies, 1992). Part of the absence of an association stems from the small...

Diminished Appetite and Weight Loss

In an era where some of the most famous icons of popular culture look emaciated, loss of appetite and body mass may not seem like important medical problems. Yet decreased hunger, a symptom of many illnesses and a side effect of many treatments, can lead to an inappropriate loss of weight, lowering survival rates for those with serious diseases. This loss of appetite, or anorexia, differs markedly from the psychological disorder anorexia nervosa. Anorexia nervosa typically includes a distorted...

Crim e

A more scientific way to investigate marijuana's link to violence appeared in studies of crime rates. Researchers have looked for an association between violent crime and cannabis consumption for at least 70 years. This association does not prove that marijuana causes aggression, but any theory linking cannabis and violence would suggest that the two should covary. Early studies of military personnel, arrestees, and patients in mental hospitals revealed no relationship between cannabis and...

History of Medical Marijuana

The cannabis plant's history as the source of hemp is separate from its story in medicine. Cannabis's use as a treatment for a variety of illnesses helped it spread from ancient Asia throughout the world. The plant consistently appeared in pharmacopoeia and folk medicine as a treatment for pain, seizure, muscle spasm, poor appetite, nausea, insomnia, asthma, and depression. Its potential to alleviate labor pains, premenstrual symptoms, and menstrual cramps also received attention in multiple...

Undesirable Effects

Negative feelings associated with marijuana intoxication often receive less attention than the stereotypical euphoria. Cannabis can create aversive reactions, particularly after extremely large doses or during the first exposure to the drug. Literature has not neglected the distressing impact hashish may have. Gautier, Ludlow, and Baudelaire all detail frightening effects associated with overdose. One of Louisa May Alcott's (1869) characters in a rePerilous Playa * describes the aversive...

Defining Amotivation

Vague definitions and varied measurements of amotivational syndrome have led to compelling critiques of the idea. Some investigators have examined employment history and educational achievement others look at performance on laboratory tasks. Yet all claim to measure motivation or amotivational syndrome. Nearly all measurement strategies reflect stereotypically Western values about productivity. Many researchers tacitly assume that motivated people perform well in school, work hard for their...

The Stages of Change Model

This empathy, warmth, and genuineness lay the foundation for any productive, therapeutic interaction. Many therapies rely on these aspects of the relationship to help support growth. Motivational interviewing combines these qualities with the stages of change model to help inspire a shift away from problem drug use. The stages of change model describes particular steps that individuals appear to take any time they alter a problem behavior Prochaska amp DiClemente, 1983 . Researchers identified...

THC Metabolism

The amount of time required to metabolize THC has shown considerable variation from person to person and study to study. The period required to eliminate THC from the body should not be confused with the duration of the drug's psychoactive effects. People stop feeling high long before THC has left their bodies. Intoxication rarely last more than a few hours, with orally administered doses lasting longer than smoked cannabis. After an intravenous injection of THC, blood levels peak almost...