Cannabis is a genus of dioecious, annual herbs belonging to the family Cannabaceae, which was formerly placed with the nettles in the order Urticales, but is now in the order Rosales. There is phylogenetic controversy as to whether the cultivated varieties of the plant are of a single species (Cannabis sativa) or represent distinct species (such as those called Cannabis indica, Cannabis ruderalis, or Cannabis americana).
Varieties of the plant grow in most climates. The tough fiber of the plant is known as hemp and has numerous textile uses. Its seeds, used in bird feed, are a valuable source of protein, energy, and long-chain fatty acids. Containing mildly hallucinogenic and other psychoactive and physiologically active chemicals known as cannabinoids, the buds and leaves of the plant are used recreationally and medicinally; such a preparation is often referred to as marijuana (archaic: marihuana; see street names below) and, today, is usually consumed orally or by inhalation in smoking or vaporization.
Concentrated preparations derived from THC-laden resin secreted from the plant are known as hashish. Historically, tinctures, teas, and ointments were also common preparations, especially medicinally.
|Table of contents|
3.1 Largely mental
3.2 Largely physical
3.3 Lethal dose
3.4 Tolerance and Withdrawal
3.5 Long-term effects on the mind and brain
3.6 Long-term effects of smoking
Cannabis reproduces sexually. The female plant forms buds which can produce hundreds of seeds. Males reach sexual maturity several weeks prior to females. Although a gene disposes a plant to become male, environmental factors, including the diurnal light cycle, can alter the sex. Natural hermaphrodytes, with both male and female parts, are usually sterile but artificially induced hermaphrodytes can have fully functional reproductive organs. 'Feminized' seed sold by many commercial seed suppliers are derived from artificially hermaphodytic females that lack the male gene or by treating the seeds with hormones.
Cannabis uses C4 photosynthesis, so is not dependent upon a night cycle for carbon dioxide absorption. A cannabis plant in the vegetative growth phase of its life cycle can thrive under twenty-four hour daylight conditions, although some growers advocate a small rest period to avoid overstressing the plant. Flowering usually occurs when darkness exceeds eleven hours per day and can take up to six weeks.
In soil, the optimum pH for the plant is 5.8 to 6.5. In hydroponic growing, the nutrient solution is best at 5.5 to 6.1, making cannabis well-suited to hydroponics because most bacteria and fungii have difficulty growing in this pH range.
The main psychoactive substance in cannabis is Δ-9-tetrahydrocannabinol (also known as D-9-THC or THC), but the plant contains about 60 cannabinoids in total, including two others of particularly high concentration, cannabinol (CBN) and cannabidiol (CBD). Differences in the chemical composition of cannabis varieties can produce very different human reactions, and the complexity of the composition of the plant is one reason why its effects can differ from that of the synthetic version of THC, dronabinol.
Although the potency of most cannabis varieties is uncertain, most cannabis contains below 8% THC. Selective breeding and modern cultivation techniques, such as hydroponics have produced varieties of up to 25% THC content. With varieties containing below 2-3% THC, such as those specifically cultivated for usage as hemp, smoking produces lightheadedness or mild headache. The THC content is also affected by the sex of the plant, with female plants generating more resin than their male counterparts. Seedless varieties derived from unpollinated female plants, with high THC content, are sometimes described as sinsemilla (Spanish: "without seed").
High relative concentrations of these chemicals significantly modifies the effects of the plant. THC is associated with an energetic, cerebral high, while CBD is associated with a relaxed, more drowsy high. CBN is not fully understood at this point, but high concentrations usually have hallucinogenic effects.
Because THC breaks down into CBD and other cannabinoids as buds mature, the time of harvest can significantly modify the effects of the plant. Because many commercial process growers often wait until the buds fully mature to ensure maximum weight, low-grade cannabis is usually high in CBD with relatively low THC content.
Acute effects of marijuana consumption vary greatly by individual and by the qualities of particular varieties, but generally include some or all of the following:
The effects of the cannabis plant vary according to the individual, the environment, the variety of plant, and the method of use. Smoking, especially, may pose the greatest risk to physical health. A safe environment among friendly companions is traditionally recommended to first-time users.
THC has an effect on the modulation of the immune system which may have an effect on malignant cells, but it is unknown whether this might promote or limit cancer. Mild allergies to cannabis may be possible in some members of the population.
No fatal overdose due to cannabis use has ever been recorded in humans. According to the Merck Index, 12th edition, the LD50, the lethal dose for 50% of tested rats, was 42 milligrams per kilogram of body weight when inhaled. As for oral consumption, the LD50 for rats was 1270 mg/kg and 730 mg/kg for males and females, respectively. It would be impossible for THC in blood plasma to reach such a level in human cannabis smokers. With other methods of administration, such a level may be feasible, though highly unlikely. Moreover, some evidence suggests that toxic levels may be higher for humans than for rats.
Although it can be habit-forming, the use of cannabis does not result in physical dependence. Depending on the level of use, tolerance vanishes with a few days of abstinence, and there is no physical withdrawal. There is some evidence that correlates long-term use with depression and aggravation of pre-existing mental conditions. However, the relationship between depression and drug abuse is not fully understood, and heavy drug use may be the result of a mental condition instead of the cause.
There is little decisive scientific evidence about long-term psychological, neurological, and cognitive effects of cannabis use. Cannabis' effects on the mind and brain is a subject of great controversy. Many old studies which purported to demonstrate such effects were deeply flawed, with strong bias and poor methodology.
There is a correlation between cannabis use and mental diseases like psychosis and schizophrenia. However, there is no evidence of causation, and the physiological effects of cannabis indicate the possibility of persons with such diseases using cannabis to alleviate such diseases and symptoms. Also, rather than causing these illnesses, cannabis may trigger latent conditions or be part of a complex coordination of causes. An amotivational syndrome appears in young people who consume cannabis with high frequency and for a long period of time, and may persist for a year.
Some studies indicate that THC is toxic to the brains of rats, but only after administration for a tenth of the life of a rat. Such results have not been replicated in larger animals and in humans would indicate toxicity after many years of nearly daily use. Other studies indicate that THC may be a neuroprotective antioxidant. The relevance of these studies to the human nervous system is unknown.
Cannabis use causes significant medium-term decreases in cognitive performance, but general intelligence and cognition appear to return to normal within a month of abstinence, except in cases of extremely heavy use. However, more subtle changes in cognition may persist, and more scientific study is necessary to decisively determine long-term effects on cognitive performance.
More scientific study is necessary to determine the physical effects of smoking cannabis. Because of higher levels of dangerous chemicals, cannabis smoke may be more dangerous than tobacco smoke. However, cannabis is consumed in far less quantities than tobacco and is free of impurities and radioactivity found in many tobacco products. In addition, the unique constituent of tobacco, nicotine, is known to be particularly damaging to the body whereas the cannabinoids are rather benign. Research indicates that chronic obstructive pulmonary diseases like emphysema are more likely than fatal diseases like cancer.
In most nations, cannabis is rarely prescribed by physicians due to its legal status. When prescribed, it is often prescribed as an appetite stimulant and pain reliever for terminal illnesses including cancer and AIDS. The medical use of cannabis is controversial and is dealt with under the article medical marijuana. See section on History for information on historical and other medical use.
Cannabis is prepared for human consumption to several forms:
It is most commonly smoked, and usually in a pipe or the form of a rolled cigarette.
Other methods of smoking include the use of water pipes, or "bongs", and buckets, which cool the smoke and, in the case of bongs, remove some unwanted impurities. Smoke is generally inhaled in a "hit" by opening an aerating hole called a "carb".
Cannabis may also be orally ingested by blending it with alcohol or fats. The effects are significantly reduced if it is not so blended. The effects of ingested cannabis are usually not recognizable for more than thirty minutes (many times longer), making it harder for users to regulate their dosage. Butter preparations are included in foods, commonly cookies and brownies. A drink popular in India, called bhang, includes milk and flavoring herbs (e.g: cloves or cinnamon). See also hashish and hashish oil.
The seeds of the hemp plant are also eaten and roasted, as well as being used to make hemp seed oil. A few restaurants that specialize in food with hemp seeds have opened, and appeal mostly to a countercultural clientele. Hemp seeds contain little THC.
Another method of consumption is vaporization. Vaporization allows the cannabis resins (THC and other cannabinoids) to be extracted into a vapor by heating without burning the plant material. This is advantageous because most of the toxic chemicals found in cannabis and tobacco smoke are byproducts of the combustion process. When cannabis is heated to about 190°C, its resins are released into an unburnt vapor which can be inhaled.
Cannabis: bud, chronic, dagga (from Afrikaans via South Africa), dak, dank, dope, doobage, dro (derived from hydroponics), electric puha (puha: a plant in New Zealand), frodis (from The Monkees), ganja, grass, green, hashish, herb, indo, instaga, IZM, KB (kind bud/killer bud), kind, leaf, Mary Jane, nugget, nug, pot, reefer, shwag (low quality), skunk, sticky-icky-icky, tea, tree, waccybaccy, whacky tobaccy, weed.
Cigarette: binge, blunt (cigar papers), bomb, bomber, doobie, fatty, grifo, hooter, J, jacob, joint, L (cigar papers), muggle, reefer, rope, spliff.
Reefer was common in the early twentieth century, but is now usually only used humorously, often in reference to the 1930s propaganda film Reefer Madness, which significantly overstated the effects of cannabis.
Intoxication: baked, blasted, blazed, blitzed, buzzed, faded, fucked up, gone, high, keyed, lit up, lifted, mashed, mullered (UK), ripped, smashed, spaced, spaced out, stoned, throwed, wasted, zonked, zooted.
Smoking: blazing, getting high, toking (up).
Early twentieth century: mez, muggles, gage, viper jive.
Potent strains: White widow (light green-white in appearance), Buddha, C99, AK-47 (C. sativa/C. indica cross), Bubblegum (very sticky), JuicyFruit, Orange Bud and Blueberry (plant smells or tastes somewhat like its name); G-13 (developed at the University of Washington); BC Bud (from British Columbia, Canada); Thunderfuck, Northern-lights (these two natives of Alaska), purple haze, kush, Thai or Thai stick (the legitimate product is C. sativa from Thailand or US Grown of Thai seed, the buds being long and treelike in appearance, often with string wrapped in a spiral pattern for the purpose of holding the bud together); Maui Wowie (from Hawai'i); Acapulco Gold. The term Thai stick is also used for imitation marijuana.
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