New article on high potency marijuana as causing significant brain damage:
http://www.hngn.com/articles/154730/20151127/skunk-cannabis-associated-brain-damage-study-finds.htm
Is there a developing parallel to “Lead was to Romans as marijuana is to Western Culture?”. No doubt there are a multiplicity of such parallels.
Heavy drinking isn't good for the brain either ... but banning a drug, be it alcohol or pot, only encourages the making and use of more concentrated forms (in order to make concealment easier, and the act of getting a buzz quicker so less detectable).