yes it's a complex matter but only because so many symptoms aren't classified as PTSD, they call them DES-NOS symptoms, they are always associated with PTSD and together they are called Complex PTSD
it's just because the regular treatments for "normal" PTSD didn't work for this group
it all started with "soldiers heart" and it’s evolving ever since
like in the article of map9 the metaphor about finding more and more pieces of the elephant ;-)
I started a thread about this subject