To your 2nd point: in pretty much all drug abuse/addiction, men are more likely to abuse or become dependent, and they tend to use higher amounts on average.
Well, that's not great. Do we know why? If it's the higher amounts part (and I suspect it is), just knowing that would maybe curb some from not taking so much. That seems like something that should be more well known. I guess it could be chemical make up too, there's got to be studies.