Marijuana (Cannabis, grass, pot, weed) is the common name for a drug made from the plant Cannabis sativa (this also includes Hashish and Hashish Oil). Each form of the drug is psychoactive or mind-altering.
Some immediate physical effects of marijuana include a faster heartbeat, bloodshot eyes, and a dry mouth and throat. No scientific evidence indicates that marijuana improves hearing, eyesight, and skin sensitivity. Studies of marijuana's mental effects show that the drug can impair or reduce short-term memory, alter sense of time, and reduce the ability to do things which require concentration, swift reactions, and coordination, such as driving a car or operating machinery.
A common bad reaction to marijuana is the "acute panic anxiety reaction." People describe this reaction as an extreme fear of "losing control," which causes panic. The symptoms usually disappear in a few hours
Marijuana is highly fat soluble, and thus it is absorbed readily and will accumulate in the brain, liver, lungs and reproductive organs. These parts of the body are covered by fatty membranes.
Long-term regular users of marijuana may become psychologically dependent. This can lead to coping difficulties, represented by stress, mood swings and anxiety without consumption of the drug. Naturally this can lead to difficulties maintaining employment and personal relationships.
One major concern about marijuana is its possible effects on young people as they grow up. Research shows that the earlier people start using drugs, the more likely they are to go on to experiment with other drugs. In addition, when young people start using marijuana regularly, they often lose interest and are not motivated to do their schoolwork. The effects of marijuana can interfere with learning by impairing thinking, reading comprehension, and verbal and mathematical skills. Research shows that students do not remember what they have learned when they are "high".
The Gateway Hypothesis refers to the potential that the consumption of one drug might lead to the uptake of other drugs.
Agrawal, Neale, Prescott & Kendler ( 2004), concluded that "early cannabis use is strongly associated with other illicit drug use and abuse/dependence. The relationship arises largely due to correlated genetic and environmental influences with persisting evidence for some causal influences".
The conclusion of another recent 25 year longitudinal study in New Zealand in 2009 by Fergusson, Boden and Horwood found that "regular or heavy marijuana use was associated with an increased risk of using other illicit drugs, abusing or becoming dependent upon other illicit drugs, and using a wider variety of other illicit drugs". Naturally, despite the above evidence, many individuals will cite themselves or their friends as being the exception to the above. Studies like those above seek to establish if a hypothesis is statistically significant (more likely than not), rather than attempt to assert that it will occur in every case.
Agrawal A, Neale MC, Prescott CA, Kendler KS., A twin study of early cannabis use and subsequent use and abuse/dependence of other illicit drugs., Psychological Medication, October; 2004 34(7) pp 1227-1237
Fergusson DM, Boden JM, Horwood LJ. Cannabis use and other illicit drug use: testing the cannabis gateway hypothesis. Addiction, April 2009 101 (4) pp 556-69
Driving experiments show that marijuana affects a wide range of skills needed for safe driving -- thinking and reflexes are slowed, making it hard for drivers to respond to sudden, unexpected events. Also, a driver's ability to "track" (stay in lane) through curves, to brake quickly, and to maintain speed and the proper distance between cars is affected. Research shows that these skills are impaired for at least 4-6 hours after smoking a single marijuana cigarette (and even as long as 24 hours in one study), long after the "high" is gone. If a person drinks alcohol, along with using marijuana, the risk of an accident greatly increases. Marijuana presents a definite danger on the road.
Marijuana use increases the heart rate as much as 50 percent, depending on the amount of THC. It can cause chest pain in people who have a poor blood supply to the heart - and it produces these effects more rapidly than tobacco smoke does.
Wan Tan presented a study at the American Thoracic Society 2007 International Conference showing that smoking marijuana and tobacco together more than tripled the risk of developing Chronic obstructive pulmonary disease (COPD) over just smoking tobacco alone. ( American Thoracic Society (May 21, 2007). "Marijuana Worsens COPD Symptoms in Current Cigarette Smokers". Press release. Retrieved August 11, 2009
The effects of marijuana on the lungs has received considerable attention over the years. With respect to lung cancer; Fligiel (1988) asserted the potential for Marijuana to develop precancerous bronchial cell changes in marijuana-only smokers.
However, Roth et al (2001) cited that Marijuana has been found to contain a greater amount of cancer causing CYP1A1 messenger RNA (mRNA) than tobacco, however found that ∆9 -THC actually inhibited the CYP1A1 enzyme.
Fligiel, S.E.G. et al, "Bronchial Pathology in Chronic Marijuana Smokers: A Light Electron Microscope Study," Journal of Psychoactive Drugs 20:33-42 (1988)
Michael D. Roth, Jose A. Marques-Magallanes, Michael Yuan, Weimin Sun, Donald P. Tashkin, and Oliver Hankinson, "Induction and Regulation of the Carcinogen-Metabolizing Enzyme CYP1A1 by Marijuana Smoke and 9-Tetrahydrocannabinol", American Journal of Respiratory Cell Molecular Biology, Volume 24, Number 3, March 2001 339-344)
"Burnout" is a term first used by marijuana smokers themselves to describe the effect of prolonged use. People who smoke marijuana heavily over long periods of time can become dull, slow moving, and inattentive. These "burned-out" users are sometimes so unaware of their surroundings that they do not respond when friends speak to them, and they do not realise they have a problem.
When marijuana is smoked, THC, its active ingredient, is absorbed by most tissues and organs in the body; however, it is primarily found in fat tissues. The body, in its attempt to rid itself of the foreign chemical, chemically transforms the THC into metabolites. Urine tests can detect THC metabolites for up to a week after people have smoked marijuana (light/ casual use [i.e. a small amount, once per month in an average, young healthy & fit person] may result in a positive result for a day or two.
Heavy use (smoking more than 3 times per week) could present a positive result for a month. It is important to note that there are many factors that affect the amount of time for a negative result to be presented so the above information should be taken only as a very rough approximation
- Increased heartbeat, bloodshot eyes and dry mouth
- No evidence of improved hearing, eyesight.
- Impairs short term memory, ability to perform safety sensitive tasks.
- Panic attacks are a common reaction from marijuana, however the effects are normally short term.
- Can be addictive particularly in long-term regular users.
- Marijuana use can compromise the ability of young people to comprehend and remember information.
- Marijuana has been found to be a common Gateway Drug to other drugs.
- It is extremely dangerous to drive after taking marijuana.
- Not surprisingly, the likelihood of having an accident after smoking marijuana is greatly increased.
- Marijuana increases the heart rate, potentially causing chest pain.
- Marijuana use is harmful to lungs and has been found to cause emphysema and cancer
- "Burnout" is a condition resulting from prolonged use of marijuana where users become dull, slow moving and inattentive.
- THC is stored in fat tissues.
- THC will present a positive test result for a day or two in the urine of a light/casual user but as long as a month in the urine of a frequent user (3 times per week or more often).