If you smoke marijuana or know someone that does, this new study might be something to read.
http://www.foxnews.com/health/2014/04/15/casual-marijuana-use-linked-with-brain-abnormalities-study-finds/
http://www.foxnews.com/health/2014/04/15/casual-marijuana-use-linked-with-brain-abnormalities-study-finds/