Cannabis does not open the mind. Rather, it harms it. Many researchers have concluded that cannabis impairs short-term memory, cognition and motivation. It has also proven to be highly addictive for some users and has damaged people's mental capabilities and abilities to function in society1. 2 Mabry, C. D. (2001, October). Physicians and the war on drugs: the case against legalization. Retrieved July 20, 2011, from Qualified Surgeons: