Overview:
Cannabis, or Marijuana, is a genus of flowering plant that includes one or more species. The plant is believed to be indigenous to Central Asia, China, and the north-west Himalayas. The common name for Cannabis is hemp, although this term is sometimes used to refer only to strains cultivated for "industrial" (non-drug) use. Cannabis plants produce a unique family of compounds called cannabinoids, several of which produce mental and/or physiological effects when consumed. The crude drug usually comes in the form of dried flowers and leaves, resin (hashish), or various extracts. more...
The reason cannabis is not as addictive as other drugs is
simply because the discontinuation of use results in only
mild withdrawal symptoms, if any at all. The THC in cannabis is eliminated from the body very slowly, lingering for days after the psychoactive effects have passed. This prevents brain cells from experiencing a sudden THC withdrawal, and prevents them from going "cold-turkey". It is believed that the slow release of THC may account for the mild-to-null withdrawal symptoms, and the low incidence of addiction.
Cannabis & Short Term Memory Loss:
Cannabis is linked to short term memory loss because of the concentration of cannabinoid receptors in the hippocampus. Studies have consistently demonstrated significant impairment of short-term memory for number sequences or verbal recall, although not for major events or factual elements of narratives. The effects of cannabis are usually subtle, and although statistically significant, the magnitude of any impairment tends to be dose-related. It is also subject to the tolerance of the it's effects on the personal characteristics of the user and on the circumstances in which the it is taken.
Cannabis may increase the likelihood of minor errors of time perception, verbal recall and similar factors, but not affect recall of important actions observed or experiences undertaken. In a regular user of cannabis, acute intoxication by the drug would have little effect on performance. Cannabinoids appear to disrupt short-term memory by interfering with the filtering of information, such that a greater volume of information reaches consciousness, overwhelming the ability to store, or prioritize such information for storage in memory.
Cannabis and Your Lungs:
There is conflicting research on whether smoking cannabis can increase the risk of lung cancer. A study from the Canadian government found that cannabis smoke has more harmful toxins than tobacco smoke. They found that it has twenty times as much ammonia (a chemical linked to cancer) and five times as much hydrogen cyanide and nitrogen oxides (which are linked to heart and lung damage respectively). Research has also shown that cannabis smoke is more harmful to lungs than tobacco as it is inhaled more deeply and held in the lungs for a longer period. However, it has also been acknowledged that the average tobacco user smokes more than a cannabis user.
With that said, a study at UCLA found that people who smoke marijuana, even heavy, long-term marijuana users, do not appear to be at increased risk of developing lung cancer. It also did not appear to increase the risk of head and neck cancers, such as cancer of the tongue, mouth, throat, or esophagus. These findings surprised researchers because smoking a marijuana cigarette deposits four times more tar in the lungs than smoking an equivalent amount of tobacco. This is because marijuana is packed more loosely than tobacco, so there's less filtration through the rod of the cigarette, and more particles will be inhaled. And marijuana smokers typically smoke differently than tobacco smokers; they hold their breath about four times longer, allowing more time for extra fine particles to deposit in the lung. So far, researchers cannot explain why there is not an increased risk of lung cancer; more research is needed.
As an alternative to smoking, cannabis can be consumed orally. THC is often extracted from cannabis by cooking the plant material in butter. The time to the onset of effects is usually about an hour and may continue for a considerable length of time, whereas the effects of smoking cannabis are almost immediate. This makes it more difficult to titrate to the desired effect than through smoking.
Research:
The Medical Marijuana Problem
Cannabis and Addiction: the false vs. the facts
Cannabis and the Brain
Effects of Cannabis on Memory and Cognitive Function
Study Finds No Link Between Marijuana Use And Lung Cancer
