This guy, Johann Hari, wrote an excellent, comprehensive and very readable book called Chasing The Scream, about the almost unimaginable horrors of the misguided century-long WAR ON DRUGS.  His book lays out what he learned about the nature of drug addiction and the best policies to help addicts.  He contrasts these successful programs with the endless War on Drugs which winds up killing addicts, and many others.   Here he delivers a talk that distills the book (which I highly recommend) into a smart 14:42.