Neither my previous therapists nor my current one required any sort of contract. Then again, my previous two t's, I didn't trust enough to tell them I was considering sui or that I SI. My current t knows that I've considered sui and that I SI, but she has never suggested any sort of contract, for which I am eternally grateful. I think she knows that doing so would absolutely destroy the trust I've built with her because I would feel like she's trying to control me (which is a huge, huge issue for me). We talk about these things, and I tell her when I've felt sui urges or when I've SI'd, and we talk through the feelings around that. The ONLY way I'm willing to discuss these things is if I have control of the conversation and if I feel that it's not being forced on me, and if I feel that my t trusts me to bring my concerns to her. So far, it works for me and my t.