that marijuana, pot, grass, whatever you want to call it, is probably the most dangerous drug in the united states. >> but what if that long-held notion isn't true? >> there's really no evidence that cannabis is the gateway to hard drugs. ten years of clinical experience i have never seen it. >> gateway sure. gateway to recovery. gateway to feeling better. gateway to getting my life back. >> cannabis is opposed to being a gateway, it can be a terminus. it can stop drug use. >> these are the researchers who write the books, advance the science, grow our knowledge and they are seeing an increasing body of research suggesting marijuana can actually stop addiction and help offset the opioid epidemic. a rand corporation study funded by the national institute on drug abuse showed something few initially expected. between 1999 and 2010, states with legal functioning medical