Dude, you can't just look at any scientific study that points out drawbacks in some social policy you prefer and say "Ah, those scientists must be evil bad guys for arguing against the True Way." In the real world almost every policy has its drawbacks and its ok to still think that marijuana should be legalized even if it has some medical side effects (alcohol has them too!). If you insist that all possible evidence must line up neatly on your side of the scales then you've made the truth your enemy and nothing good can come of that.