Rehabilitation at St. Mungo's?
I was wondering if it would be plausible if St. Mungo's had a sort of rehab center or ward, for people with addictions, such as alcohol or something.
Well you could have it on the 3rd floor for potion and plant poisoning if you had them get alcoholic poisoning.
There doesn't appear to be one in the main hospital but that doesn't mean anything. It could be set up separately.
However, there doesn't seem to be a great deal of addiction going on in the HP universe, and I don't think that's the type of thing that Jo would be likely to suppress, especially given that she broaches the topic of indulgence at the Tri-Wizard cup. You know, we see Hagrid drunk on more than one occasion but there's never any mention of it being an *addiction*, so I'd caution you on the use of this.
I agree with cmwinters, because as wizards seem to be resistant to injury, they might also be resistant to addictions.
Not to say that it isn't possible, though.