Cannabis is addictive. Cannabis causes road accidents. Not so, according to the most recent report from the TRRL, which says cannabis users are so cautious that a tired driver is more dangerous. Similar reports have come from Canada and Australia. Saying cannabis is found in the blood of crash victims is also a false illustration as cannabis indicators stay in the blood for up too eight weeks but it has no effect on brain function after about four hours.
Cannabis causes memory loss.
No it does not. This is an urban legend. The New Scientist has published several articles debunking this myth. Alcohol use is far worse for memory loss. Cannabis causes lack of motivation.