Marijuana Health Article

MARIJUANA

Marijuana is a dried mixture of the leaves and flowers of Cannabis sativa, or hemp plant. Slang words for marijuana include "pot," "weed," "grass," and "dope." The term "cannabis" refers to different psychoactive preparations of the plant, including marijuana, hashish, and hashish oil. Hashish is the resin produced by the flowering tops of the plants; hashish oil is a concentrated form of cannabis extracted from the plant or resin using a solvent. Unpollinated female plants are called sinsemilla (sen-suh-mee-ah) and the flowering tops of these plants produce potent "buds" that do not contain seeds.

The major psychoactive ingredient in cannabis is delta-9-tetrahydrocannabinol (THC), but there are more than sixty related chemicals in marijuana, which are called "cannabinoids." Cannabis also contains other unrelated compounds that have similar psychoactive effects. The World Health Organization reported in 1997 that THC content in marijuana ranges from 0.5 to 4 percent, while concentrations in cannabis oil, hashish, and sinsemilla generally range from 7 to 14 percent, but may be as high as 20 percent. THC concentration depends on the variety, sex, and growing conditions of the plant, and it has increased over the years due to hydroponic cultivation techniques and selective breeding.

Marijuana and other cannabis products are usually smoked as a cigarette (a "joint") or in pipes, but may also be ingested orally. In the 1990s, the use of "blunts" to smoke marijuana became more common. A blunt is made by removing the tobacco from a cigar wrapper and filling it with marijuana, or a mixture of marijuana and some other drug like cocaine.

PSYCHOACTIVE AND PHYSIOLOGICAL EFFECTS

THC is absorbed more quickly into the bloodstream when smoked than when eaten. Effects are felt almost immediately and peak within thirty minutes of smoking. The marijuana "high" results when the THC binds with cannabinoid receptors in the brain. This process slows down regular nerve transmission, interfering with normal function. The cannabinoid receptors are located in the areas of the brain involved in muscle control, sexual functioning, vision and hearing, reasoning, hormone release, and memory.

Short-term effects include a temporary increase in heart rate, blood pressure, and blood flow to parts of the brain. Users generally feel a sense of euphoria, relaxation, hilarity, and heightened sensory perception. Negative psychological reactions may include anxiety, hallucinations, and panic attacks. Many smokers report that they feel unmotivated when they are high. Cannabis intoxication alters perceptions of time and space and impairs reaction time—affecting the performance of psychomotor tasks such as driving, which increases the risk of motor vehicle accidents. Cannabis increases food intake, impairs learning capabilities, and affects short-term memory. Many cannabis effects are subjective and influenced by the social circumstances, but the extent of impairment mainly depends on the potency and dose of the drug, the individual's tolerance to and experience using cannabis, and the difficulty and complexity of the task at hand.

LONG-TERM HEALTH CONSEQUENCES

Many of the studies done on the health consequences of marijuana have been inconclusive, although a picture is emerging of some worrisome long-term health effects. Smoking marijuana affects the respiratory system in much the same way as cigarette smoking. Cannabis smoke contains many of the same toxic chemicals and carcinogens as tobacco, as well as cannabinoids, all of which are respiratory irritants. Frequent marijuana smokers often report laryngitis, hoarseness, and coughing, and they are more likely than infrequent or nonusers to get acute and chronic bronchitis.

In a comprehensive analysis of the health effects of cannabis, the World Health Organization reports that cannabis is known to have adverse effects on the immune system, reproductive system, adrenal hormones, growth hormone, and cognitive function, particularly related to attention and memory processes. The long-term consequences of these effects, however, are not fully known, and further research is warranted. Smoking marijuana during pregnancy reduces oxygen flow to the fetus, which may interfere with growth and result in low birth weight, premature birth, and deficits in verbal ability and memory during childhood.

Preliminary research has demonstrated some positive health benefits of marijuana, including control of nausea and vomiting in people suffering from advanced cancer and AIDS (acquired immunodeficiency syndrome), appetite stimulation for those with wasting diseases, treatment of glaucoma by reducing intraoculer pressure, and control of convulsions and muscle spasms. More research in these areas is needed.