TL:DR Most of the anti-Cannabis arguments used by the flood have been debunked by further research as recently as 2012. While the arguments they are using are from 2009-2010 at best. To put it simply Cannabis has far less negatives, if really any, compared to Alcohol and cigarettes, yet it is still illegal regardless of the fact that almost every main argument against it has been recently disproved. [quote] Cannabis has about 118 carcinogens when smoked, nicotine cigarettes have 70 carcinogens when smoked. [/quote] The pharmacological effects of tobacco and cannabis smoke differ in many ways, mainly because tobacco smoke contains nicotine while cannabis smoke contains tetrahydrocannabinol (THC). The cancer-promoting effects of smoke are increased by nicotine, while they are reduced by THC. Tobacco and cannabis smoke contain the same carcinogenic compounds -- and depending on which part of the plant is smoked, cannabis smoke can contain more of them -- but, whereas nicotine activates these carcinogenic compounds, THC has been shown to inhibit them in mice cells. THC is very likely to have protective effects against the carcinogens present in smoke in humans too, but cannabis smoke remains nonetheless carcinogenic. While nicotine and THC can act on related cellular pathways, they bind to different receptors to activate these pathways. The cells of lungs and the respiratory passages are lined with nicotine receptors, but do not appear to carry THC receptors. This explains why cannabis smoking has not been associated with lung cancer, a main cause of death from cigarette smoking. [quote] A study of 1000-2000+ people in the National British Lung and Cancer foundation found that 9 percent of people who smoked 1-2 cannabis joints succumbed to lung cancer whereas 8 percent of people who smoked 20-30 tobacco cigarettes succumbed to lung cancer. [/quote] http://www.clear-uk.org/british-lung-foundation-fails-to-back-up-its-cannabis-and-lung-cancer-scare/ It was launched with a massive PR campaign with Dame Helena Shovelton, the chief executive, claiming that smoking cannabis was “20 times” more likely to cause cancer than smoking cigarettes. Very swiftly the report was widely.condemned. Professor David Nutt accused the BLF of scaremongering and countless well-researched articles were published exposing the monstrous deception that Dame Helena and her team were trying to achieve. [quote] THC mimics a natural neurotransmitter found in the human brain known as cannabanoids, meaning it has direct access to wreak havoc on various networks of neurons in the brain. Due to THC being a foreign substance and yet being able to bind to cannabanoid receptors in the brain, it can induce foreign effects on the brain that evolution did not want our brain to experience. An example of this is when THC binds to cannabanoid receptors, it induces a foreign biochemical response that decreases the amount of protein kinase A, which has been linked to increased inhibition among neurons, meaning less synaptic transmission in important areas like gray matter (one of the main parts of the brain that has been atrributed to intellectual capabalities). Since weed inhibits neurons in these regions, it creates a dampening effect, which suppresses neural activity, even showing emperically observed decrease in intellectual capabilities of particapants in published studies. [/quote] learning and memory impairments of heavy marijuana users typically vanish within 28 days of “smoking cessation.” (The slight impairments still existed, however, one week after smoking.) While several days might sound like a long hippocampal hangover, heavy alcohol users typically experience deficits that persist for several months, if not years. In other words, heavy marijuana use appears to be a lot less damaging than alcoholism. Taken together, these studies demonstrate that popular stereotypes of marijuana users are unfair and untrue. While it’s definitely not a good idea to perform a cognitively demanding task (such as driving!) while stoned, smoking a joint probably also won’t lead to any measurable long-term deficits. The Dude, in other words, wasn’t dumb because he inhaled. He was dumb because he was The Dude. (All those White Russians probably didn’t help, either.) Furthermore, there’s some intriguing evidence that marijuana can actually improve performance on some mental tests. A recent paper by scientists at University College, London looked at a phenomenon called semantic priming. This occurs when the activation of one word allows us to react more quickly to related words. For instance, the word “dog” might lead to decreased reaction times for “cat,” “pet” and “Lassie,” but won’t alter how quickly we react to “chair.” [quote] Because THC naturally mimics cannabanoids, the brain actually responds by releasing burts of dopamine, because the brain likes foreign substances that produce a "new pattern" of neural activity (or less activity in this case). Smoke too much constantly, enough dopamine (which is a very powerful neuromodulator that creates new neural networks or modifies pre existing ones), that new neural networks that respond to the cannabis, and when they don't get their fix of cannabis, they create havoc (this is known as an addiction). A few years ago, people didn't believe cannabis wans't a powerful enough drug to create this phenomena, but with new research proceeding, evidence suggests otherwise. [/quote] This one i can easily handle on my own. The addiction to which you refer is easily overcome by anyone with a little force of will. The only time something is "addictive" is when it becomes, or appears to be to the user, necessary for survival. While weed causes a positive association and can be "wanted" the sense of "NEED" that is felt by typical addicts is present in a very low percentage in the heavy level of smokers. [quote] Since the THC in cannabis can influence neuron activity, it's been suggested psychological studies (with emperical date backing it) that weed takes a part in causing schizophrenia in people who are predisposed to the condition. [/quote] This happens for the obvious reason stated in the sentence. This is because they are predisposed. Anything can trigger a person with a predisposition to schizophrenia to snap. Everything from seemingly being followed one day to hearing something bad on Tv. The actual science behind the disease itself is iffy at best. I see no need to address this beyond a simple "No duh" response. [quote] Now, it's known as an addictive substance, and the DSM IV, the BIBLE of psychiatrists and psychologists worldwide, often looked as the ultimate authority of psychological disorders, is including cannabis withdrawal and addiction as an official psychological/psychiatric phenomena in its next edition coming out in the fall. [/quote] Any branch of science that pretends to have the ability to gauge human emotion and mental response in the vast majority of the population when so many variables are possible ( psychology for example ) does a disservice to the rest of actual science. We know, in perspective of where what is stored, very little about the human brain. Psychology pretends to make rules about human response through pure observation of tiny groups ( sample groups ) then think they can apply it to all other humans. Humanity is far to diverse and the brain to unknown to make such wide scope claims. The "bible of psychology" is only slightly more trustworthy than the Christian one.