I am not talking about legalization of cannabis in professional medical research and treatment, when I ask the question above.
This is a very hot topic in discussion-boards in Norway now. I guess it will be here too. So please behave and be a professional.
Cannabis (Cannabis sativa L.) is plants of different varieties, about 4-6 metres in height, found mostly in central and western Asia. The presents of delta-1-THC makes it the worlds third most consumed drug after tobacco and alcohol. THC is affecting the CB1 og CB2 receptors in the nervecells, which is receptors for the natural endo-cannaboid anandamide. Anandamide is regulating the activity in the synaptic cleft.
THC is psychoactive and users is getting heightened awareness and perceptions, euphoria, sedation, and sometimes hallucinations. The most effective way of administering cannabis is by smoking it.
Now, many people say that cannabis is not harmful in any way. But reports states that Cannabis smoking is more dangerous than smoking tobacco . The risk is lowered by use of a vaporizer . Many people say alcohol is more dangerous than cannabis, and a recent report  that take into account both social and health factors clearly states the same. But will this picture change if cannabis is legalized?
But THC's LD50
dose is 5.5 times higher then ethanol. We can reason this that our ancestors might have found rotten fruit with a high ethanol-content more often then THC and cannabis. And so we have adapted our metabolism to make ethanol less harmful. The THC content in hashish is 4-10% THC, and 0.1 - 2.7% in marijuana. So a user dose is way below the lethal dose 50 of 1.2*103
mg/kg for adult male rate.
So, what do you think? Is cannabis harmful? And would you like to legalize it in your country? Why or why not?
I was unable to find other references on the go, but I will check into this later.
 David Nut, Leslie A King, William Saulsbury og Colin Blakemore; Development of a rational scale to assess the harm of drugs of potential misuse; The Lancet, Volume 369, Nummer 9566, 24. mars 2007; DOI:10.1016/S0140-6736(07)60464-4.