This is a great list of things to say to a person with depression, which is a prominent feature of PTSD.
I would add a couple more to address anxiety:
1.) What would help you to feel safer, less vulnerable?
2.) What can I (we) do to help you calm your fears?
Ultimately, whatever is said to a person struggling with PTSD should encourage a sense of safety, support and caring. Remember that each person is unique and carries their own unique emotions, perspective and triggers.