I think that psychiatrists, and for that matter therapists, really treat symptoms, not disorders. So if you are experiencing depression the psychiatrist might prescribe the same antidepressant, regardless if she thinks that depression is part of C-PTSD, schizoaffective disorder, major depressive disorder, dysthymia, bipolar disorder, or whatever other disorders have depressed mood as a criteria. And a therapist might work on self-esteem or increasing activity or challenging thoughts if depression is the primary symptom right now. The treatment might be different if anxiety seemed more prevalent.

That said, words and labels matter to most people. I've seen many therapists and I always ask what they have diagnosed me with. Most of the time I have been ok with it if they label me with something close to what I think I have: major depressive disorder vs. dysthymia for example. I'll own that. But I threw a five alarm fit once when a therapist diagnosed me with personality disorder, NOS. That seemed like a lazy catch all diagnosis. Pretty sure I changed therapists soon after that.