Marijuana Abuse
What is marijuana?
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. To make blunts, users slice open cigars and replace the tobacco with marijuana, often combined with another drug, such as crack cocaine.
Marijuana also is used to brew tea and is sometimes mixed into foods. The major active chemical in marijuana is delta-9-tetrahydrocannabinol (THC), which causes the mind-altering effects of marijuana intoxication. The amount of THC (which is also the psychoactive ingredient in hashish) determines the potency and, therefore, the effects of marijuana. Between 1980 and 1997, the amount of THC in marijuana available in the United States rose dramatically.
How does marijuana affect the brain?
Scientists have learned a great deal about how THC acts in the brain to produce its many effects. When 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 thereby influences the activity of those cells. Some brain areas have many cannabinoid receptors; others have few or none. Many cannabinoid receptors are found in the parts of the brain that influence pleasure, memory, thought, concentration, sensory and time perception, and coordinated movement.
Can marijuana use during pregnancy harm the baby?
Research has shown that some 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 the preschool years, marijuana-exposed children have been observed to perform tasks involving sustained attention and memory more poorly than nonexposed children do. In the school years, these children are more likely to exhibit deficits in problem-solving skills, memory, and the ability to remain attentive.
Is marijuana use addictive?
Long-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. According to the 2003 National Survey on Drug Use and Health (NSDUH), an estimated 21.6 million Americans aged 12 or older were classified with substance dependence or abuse (9.1 percent of the total population). Of the estimated 6.9 million Americans classified with dependence on or abuse of illicit drugs, 4.2 million were dependent on or abused marijuana.In 2002, 15 percent of people entering drug abuse treatment programs reported that marijuana was their primary drug of abuse.
Along with craving, withdrawal symptoms can make it hard for long-term marijuana smokers to stop using the drug.People trying to quit report irritability, difficulty sleeping, and anxiety.
In addition to its addictive liability, research indicates that early exposure to marijuana can increase the likelihood of a lifetime of subsequent drug problems. A recent study of over 300 fraternal and identical twin pairs, who differed on whether or not they used marijuana before the age of 17, found that those who had used marijuana early had elevated rates of other drug use and drug problems later on, compared with their twins, who did not use marijuana before age 17. This study re-emphasizes the importance of primary prevention by showing that early drug initiation is associated with increased risk of later drug problems, and it provides more evidence for why preventing marijuana experimentation during adolescence could have an impact on preventing addiction.
What treatments are available for marijuana abusers?
Treatment programs directed solely at marijuana abuse are rare, partly because many who use marijuana do so in combination with other drugs, such as cocaine and alcohol. However, with more people seeking help to control marijuana abuse, research has focused on ways to overcome problems with abuse of this drug. One study of adult marijuana users found comparable benefits from a 14-session cognitive-behavioral group treatment and a 2-session individual treatment that included motivational interviewing and advice on ways to reduce marijuana use.Participants were mostly men in their early thirties who had smoked marijuana daily for over 10 years. By increasing patients' awareness of what triggers their marijuana use, both treatments sought to help them devise avoidance strategies. Use, dependence symptoms, and psychosocial problems decreased for at least 1 year after both treatments. About 30 percent of users were abstinent during the last 3-month followup period. Another study suggests that giving patients vouchers for abstaining from marijuana can improve outcomes.
No medications are now available to treat marijuana abuse. However, recent discoveries about the workings of THC receptors have raised the possibility that scientists may eventually develop a medication that will block THC's intoxicating effects. Such a medication might be used to prevent relapse to marijuana abuse by reducing or eliminating its appeal.
Credit: National Institute of Health.