I was confused about this too - ego states but not DID, and also this - DDNOS or complex PTSD and not DID - from another post in this thread so I talked to my therapist this morning about them.

She said the difference between ego states and alters of DID is that

everyone has ego states even people who are not DID. Ego states are feelings like the inner child concept where you feel like the parent of yourself - always having to remind yourself to eat, go to bed on time stuff a parent would, or feeling like an adult feeling and being responsible making dfecisions from logic not emotional side of things, or feeling like a child where you feel like you can't do anything, want others to take care of you and fix you, tell you what to do, make your decisions for you so you have some one else to blame. Theres no lose of awareness just feelings.

Alters of DID can be traced back to abuse and trauma memories and once the trauma and abuse memories are taken care of the person no longer switches into the alters because the memories have been integrated into the conscious awareness. With Alters there is usually some sort of time loss spanning anywhere between seconds to days.

and the diagnosis questions that I wanted to know about whaat are DDNOS, Complex PTSD but not DID -

DDNOS means the person has some symptoms of each of the dissociative disorders in the DSM IV TR but not enough of any set diagnosis to fit in to one specific dissociative disorder, kind of a pot luck stew of Dissociative amnesia, Dissociative Fugue, Depersonalization, DID, ect.. But not all of the criteria for any one of them.

Complex PTSD thats having a mental disorder plus having PTSD. Like I have the diagnosis of DID plus I have the diagnosis of PTSD. Because I fit all the criteria for both PTSD and DID my file can at any point be wrote up as saying I have Complex PTSD.

I asked her if someone can be Complex PTSD and not be DID, She said not if the catagory they fit is the one that has the DID criteria for it. My being called Complex PTSD doesnt mean I don't have DID. It means I still have DID but I also have PTSD, like atwo for one sale - one lable for two disorders lumped together.

She said theres a few different types of complex PTSD but for each one the person must be diagnosed as having both the disorders in that catagory. and then they are considered to have Complex PTSD. Like theres having both Borderline Personality Disorder and PTSD so a person is called Complex PTSD,