How can you trust someone not to try to cut themselves again?

Question

How can you trust someone not to try to cut themselves again?

Answer 1

Keep hanging out with them casually. Do some spy work and drop some secret glances at areas where you know they have cut before. (Unless its socially considered to be a private area) Also cutting is a form of replacing an emotional pain for a physical one. He/She might want their cuts to be visible to let others know that their hurting. Talk with them and earn their trust. Maybe they will learn to trust you and you may be able to figure out why their cutting and talk with them.  

Answer 2

You can't.  There is no way to know for sure what another person will do in the future.  

Cutting is very difficult to quit because it works so well.  Cutting relieves stress and makes the cutter feel better.

If you care about a cutter try offering an alternative to them.  Very strenuous exercise is a good substitution especially ones like wrestling, boxing or martial arts.  Offer to participate in these or other activities with the cutter.  Strenuous exercise (and cutting) releases endorphins which make people feel better.  Perhaps this is why girls more than boys are cutters - they get fewer chances to really push their bodies to the limit and get that endorphin release.