My ex-therapist had a "specialty" of "trauma-PTSD". He'd taken additional courses/classes/seminars, etc. regarding PTSD-trauma as well as did his internship working with trauma survivors (VA hospitals, etc).

I think my main concern in seeking a therapist with a specialty would be asking them how many clients they've treated with this specific issue, have they studied it, have a good understanding on the effects in our lives, etc. You could ask those things over the phone, then interview them further in an initial meeting.

Good luck and let us know?

KD