Yep Jen, it is permanent. You have to think of PTSD uniquely from the trauma that caused it, because that is what it is, a unique entity once formed.
Trauma causes PTSD. Trauma can be healed, thus just leaving PTSD. If stress and exposures are not managed, PTSD returns not from existing trauma's or stressors, but the current one's. What defines recovery though is one's eagerness and management techniques. Once you heal from trauma, you must then manage PTSD.