Honestly, I believe that SI is like any other addiction. It is very rare that the urges go away completely but in time we can usually get better at coping with them and managing situations without feeling a strong urge to SI.

SI is a coping strategy for most people who do it. Something we have learned to do to cope when everything else in our coping toolbox fails. If we get to points in our lives when all of our coping mechanisms fail again then the urges can return and be stronger.

But in time they get easier to manage and much less frequent as you can build up other coping mechanisms.