using mj just once a month is not an addiction.  but when one continues to increase usage because of the euphoria one gets from its use is bad which leads to addiction (a gateway drug), and leads to use of harder drugs.  also smoking anything is bad for one's health.  casual use of most anything is not bad, no matter what mj is addictive and this is a proven fact.  mj in-it-self is not dangerous, like eating, but over eating is bad for one's health.   that is my point, excessive use of anything can be destructive.