[ryoshoe]

At the core of this is that your friend came to the realization that he wanted to change his life. He can credit his time in jail for this. However that doesn't mean it will be the same for everyone, or that there's only a single potential trigger to get someone to recover from drug addiction

[cameldrv]

If the jail is properly run (and I will admit that this is a big if), there aren't any drugs in the jail. Some people, if they get clean for a little while, are in a position to reflect on what they're doing. The indignity of being locked up also puts a very fine point on it.

Now I don't think that this would necessarily work for everyone, but it worked for my friend, and I've heard a number of other similar stories. Sometimes you need to get a very clear message from society/the system that your behavior is unacceptable, and you need to get that message sober or it may not get through.

[y0eswddl]

what a naive position... "if a jail is properly run"

no cage can ever be a healthy environment.