Not an expert. This thread may help, some.
What Is Complex Trauma?
Although it will make it a lot less confusing to read to know in advance that there's
Trauma (single or repeated)
Complex Trauma
PTSD
CPTSD (New, coming out in the ICD but already outlined)
Just like trauma doesn't automatically equal PTSD, complex trauma doesn't automatically equal CPTSD. (& vice versa). Also, just because something has longevity, doesn't automatically make it complex trauma. Repeated rape is still rape. It's a single trauma, with the same sorts of side effects. DV is still DV. Child abuse is still child abuse. A car accident is still a car accident. To oversimplify, things start getting complex when layering different traumas on top of each other. So, say child abuse at home, and then raped at school, and a major car accident, and an abusive marriage. The car accident may seem like "Which of these things is not like the other?" but when the helplessness & dependence of being in hospital is inextricably linked to the helplessness & dependence of being abused as a child? Shit starts getting complicated, fast. And even if there was no CSA, because of the links between rape & child abuse... Now the car accident is also pulling rape issues. Which also links to the DV which links to the child abuse which links to the... So one can't just isolate one
type of trauma, because it all becomes this incredibly tangled web, where you pull on one string, and 40 other things are affected. But that's just complex trauma. A person can have crazy complex trauma, but still have fairly straightforward PTSD. (Or cPTSD or neither).
Notice how I still haven't answered your question about how the symptoms differ between cPTSD & PTSD? That's because I don't really know / understand what the differences are. Complex trauma I grok, as much as one can I think, but cPTSD is too new (it's not even technically a diagnosis, yet, although it will be in 20 minutes when the ICD comes out, thank god, an agreed upon definition! Finally!)... And I'm still wrapping my head around it. I gave up trying before the ICD agreed on a definition as a bad job, because everyone just made up their own definition and ran with it. (Birds have wings, no birds have gills, no birds are inanimate minerals... OMFG. Everyone at least agrees birds are alive!... No we don't! >.<) LOL. So now that we have an agreed upon definition I'm still shaping my understanding of what that definition is.