Marijuana – often-called pot, grass, reefer, weed, herb, Mary Jane, or mj – is a greenish-gray mixture of the dried, shredded leaves, stems, seeds, and flowers of Cannabis sativa, the hemp plant.
Most users smoke marijuana in hand-rolled cigarettes called joints, among other names; some use pipes or water pipes called bongs. Marijuana cigars called blunts have also become popular. Marijuana is produced in all 50 states, and the primary foreign sources for marijuana found in the United States are Mexico, Canada, Colombia, and Jamaica.The marijuana plant grows quickly in many environments and can reach a height of 20 feet. The leaves consist of five or more narrow leaflets, each radiating from a slender stem attached to a thick and hallow stalk.In ancient times cannabis or hemp plant, also called “Marijuana”, produced fibers used to make pipe, cloth, roofing materials and floor covering.The major active chemical in marijuana is delta-9-tetrahydrocannabinol (THC), which causes the mind-altering effects of marijuana intoxication.
The amount of THC determines the potency and, therefore, the effects of marijuana. EffectsMarijuana’s effects begin immediately after the drug enters the brain and last from 1 to 3 hours. If marijuana is consumed in food or drink, the short-term effects begin more slowly, usually in to 1 hour, and last longer, for as long as 4 hours. Smoking marijuana deposits several times more THC into the blood than does eating or drinking the drug.
Within a few minutes after inhaling marijuana smoke, an individual’s heart begins beating more rapidly, the bronchial passages relax and enlarge, and blood vessels in the eyes expand, making the eyes look red. The heart rate, normally 70 to 80 beats per minute, may increase by 20 to 50 beats per minute or, in some cases, even double. This effect can be greater if other drugs are taken with marijuana. As THC enters the brain, it causes a user to feel euphoric – or “high” – by acting in the brain’s reward system, areas of the brain that respond to stimuli such as food and drink as well as most drugs of abuse. THC activates the reward system in the same way that nearly all drugs of abuse do, by stimulating brain cells to release the chemical dopamine.A marijuana user may experience pleasant sensations, colors and sounds may seem more intense, and time appears to pass very slowly. The user’s mouth feels dry, and he or she may suddenly become very hungry and thirsty.
His or her hands may tremble and grow cold. The euphoria passes after awhile, and then the user may feel sleepy or depressed. Occasionally, marijuana use produces anxiety, fear, distrust, or panic. Marijuana use impairs a person’s ability to form memories, recall events, and shift attention from one thing to another. THC also disrupts coordination and balance by binding parts of the brain that regulate balance, posture, coordination of movement, and reaction time.Effects on the BrainWhen someone smokes marijuana, THC rapidly passes from the lungs into the bloodstream, which carries the chemical to organs throughout the body, including the brain.
In the brain, THC connects to specific sites called cannabinoid receptors on nerve cells and influences the activity of those cells. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement.Effects on the Heart One study has indicated that a user’s risk of heart attack more than quadruples in the first hour after smoking marijuana. The researchers suggest that such an effect might occur from marijuana’s effects on blood pressure and heart rate and reduced oxygen-carrying capacity of blood.Effects on the Lungs. Someone who smokes marijuana regularly may have many of the same respiratory problems that tobacco smokers do, such as daily cough and phlegm production, more frequent acute chest illness, a heightened risk of lung infections, and a greater tendency to obstructed airways.Cancer of the respiratory tract and lungs may also be promoted by marijuana smoke.
Marijuana use has the potential to promote cancer of the lungs and other parts of the respiratory tract because it contains irritants and carcinogens. In fact, marijuana smoke contains 50 to 70 percent more carcinogenic hydrocarbons than does tobacco smoke and produces high levels of an enzyme that converts certain hydrocarbons into their carcinogenic formlevels that may accelerate the changes that ultimately produce malignant cells. Other Health EffectsSome of marijuana’s adverse health effects may occur because THC impairs the immune system’s ability to fight off infectious diseases and cancer. Effects of Heavy Marijuana Use on Learning and Social BehaviorDepression, anxiety, and personality disturbances are all associated with marijuana use. . Because marijuana compromises the ability to learn and remember information, the more a person uses marijuana the more he or she is likely to fall behind in accumulating intellectual, job, or social skills.
Students who smoke marijuana get lower grades and are less likely to graduate from high school, compared to their non-smoking peers.Short-term effectsImpairs short-term memory Impairs attention, judgment, and other cognitive functions Impairs coordination and balance Increases heart rate Increases pleasureLong-term effectsCan lead to addiction Increases risk of chronic cough, bronchitis, and emphysemaIncreases risk of cancer of the head, neck, and lungsAddictive PotentialLong-term marijuana use can lead to addiction for some people; that is, they use the drug compulsively even though it often interferes with family, school, work, and recreational activities. Drug craving and withdrawal symptoms can make it hard to stop using the drug. People trying to quit may experience irritability, sleeplessness, and anxiety. Latest ResearchMarijuana is the Nation’s most commonly used illicit drug. More than 83 million Americans (37 percent) age 12 and older have tried marijuana at least once in 2001. Marijuana was a contributing factor in more than 110,000 emergency department (ED) visits in the United States, with about 15 percent of the patients between the ages of 12 and 17, and almost two-thirds male.
With 14.6 million current users (6.2 percent of the population). About one third of these marijuana users (4.8 million persons) In 2002, most users (56.7 percent) got the drug for free.
Almost 40 percent of marijuana users bought it. Most marijuana users obtained the drug from a friend; 79.0 percent, who bought their marijuana and 81.8 percent who obtained the drug for free. The percentage of youths aged 12 to 17 who had ever used marijuana declined slightly from 2001 to 2002 (21.
9 to 20.6 percent). Among young adults aged 18 to 25, the rate increased slightly from 53.
0 percent in 2001 to 53.8 percent in 2002.There were an estimated 2.6 million new marijuana users in 2001. An estimated 974,000 persons received treatment for marijuana.
Treatment Treatment programs directed at marijuana abuse are rare, but treatment that includes cognitive behavioral therapy, twelve-step facilitation, and motivational interviewing assist in maintaining abstinence. The number of admissions to drug and alcohol treatment in the United States increased from 1,527,930 in 1992 to 1,739,796 in 2001.The number of admissions for primary marijuana abuse (255,394 admissions) accounted for 14.7% of the total admissions in 2001. This was up from 1992 when there were 92,414 marijuana admissions, or 6% of the years admissions.About 40% of those treated for primary marijuana abuse during 2001 were between ages 15 and 19 at admission. For all admissions to treatment (all illicit drugs and alcohol), this age group.
More than half of the drug-related treatment admissionsinvolving individuals under the age of 15 (55.0%) and more than half of those ages 15 to 19 (54.1%) were treated for primary marijuana abuse. Among the marijuana/hashish admissions with data available (255,394), more than 25% of those admitted began using marijuana at age 12 or younger. Some 56.8% of the marijuana admissions to treatment in 2001 were referred through the Criminal justice system.
Other sources for referral treatment included individual referred self (17.5%), substance abuse provider (5.9%), other health care provider (4.9%), school (4.2%), employer/employee assistance program (1.
2%), and other community referrals (9.5%). SourcesBlock,R.I., and M.M.
Ghoneim, “Effects of Chronic Mariuana Use on Human Cognition,”Psychopharmacology 100(1-2): 219-228, 1993Gilman, A.G.; T.W. Rall; A.
S Nies; and P. Taylor(eds.), Goodman and Gilman’s The Pharmacological Basis of Therapuetics, 8th Edition, New York: Pergamon Press, 1998Results from the 2002 National Survey on Drug Use and Health: National Findings, September 2003.www.samhsa.gov/oas/nhsda/2k2nsduh/2k2soFW.pdf