Legal status of these chemicals is not going to prevent your neighbor from getting them and becoming addicted.

Legal status (along with stigma associated with it) does prevent them from getting help before completely crashing out. It has the additional side effect of whatever portion of their lives they come out of it with being completely destroyed by the legal process. You know, because chronic illness obviously deserves punishment.

So I guess the real question is: what is the goal? Help chronic illness, or punish people that do things we don't like?

Also, don't we already have laws for literally all the bad things someone can do while addicted? If not, then why is it bad just because they are suffering from a chronic illness?