My therapist has asked whether they can write about me and our work together in a book. They already have a publisher. I’m torn. What should I ask before making a decision?

I think if my therapist were to make this request, I would want to know a bit about the book they are writing, what it’s goal/purpose is, and how my work with them fit in. I would want to know exactly what it is/was about our work together that they were hoping to highlight in the book and how it would be presented. Of course there is the obvious anonymity, but in addition, how would more subtle details be protected and are you comfortable with the level of protection they are offering. Personally, I might be ok with some level of our transference, our relationship, etc being used in a book, but I wouldn’t want my personal traumas being described because that feels triggering to me. I would feel like they were somehow profiting off of me/my trauma. But if was about our relationship/us, then I would feel better about it, because it is part of their work also.