^^ i've lived in mount pleasant for over 6 years. never heard of any halfway houses or addiction centres in the area. I could be wrong though.
you get the occasional homeless people going through your recycling bin in the alleys... but that's about it. I see the same black guy with a wheel barrow rolling through my alley every week. he doesn't cause any problems, and minds his own business.
great neighbourhood, lots of new families moving into the community. close to downtown, and confederation park.
I would try to stay a couple blocks away from 16 ave, 4st and 20ave... as those are the busiest streets in the area.