here in america the term trauma in psychological terms means anything that causes a person emotional/physical or sexual harm....

examples many people are emotionally traumatized when they go through natural disasters (hurricanes, floods, earthquakes) others are emotionally traumatized through abuse....

in general dissociation problems ....do not....depend upon whether someone was traumatized or not. Dissociation in its simplest terms is a reaction to triggers. triggers in its simplest terms is anything that causes a reaction...

think of it like shooting a gun... a gun doesnt fire (react)until something \someone pulls the trigger. once that trigger is hit any number of things can happen.

a person who 's trigger point is reached can have any number of reactions (numbness, spacy\foggy mind, disconnected from one self or others...

from there in general dissociation moves into the dissociative disorders (for america those are listed in my link at the bottom of my post)

for all of the dissociative disorders ....except DID... trauma is not necessary.

here in my own location the demographics\statistics show that people with DID have been extremely traumatized (in otherwards not just once or a few times but many times) before the age of 5. this extreme trauma causes a child's brain to react by dissociating the traumatic events, emotions, memories to the point where alternate personalities are created.

these alternate personalities take control and affect that childs life in every aspect of that childs life and continue to do so until the diagnosis and treatment and integration of those alters (in other words until the alters have all merged back together to become one whole person again.)

for the exact wording and criterion that america goes by for what is DID and alters you can read about that in the link at the bottom of my post.

other locations outside the USA may go by different diagnostics and criterion for what is and isnt dissociation, and recognized dissociative disorders.

for those with PTSD with dissociation. here in america PTSD now includes dissociation in their diagnostics as a "specifier" the specifiers are not DID or OSDD(dissociation to the point of having alters) the specifiers with PTSD are Depersonalization and Derealization.

if you have been diagnosed with PTSD with dissociative features it means your treatment providers have decided you do not have alternate personalities, that your mood switching \feeling like other people in some situations falls into the range of Post traumatic Stress Disorder along with depersonalization\derealization disorder. it is similar to having DID and OSDD but not quite the same and not quite as extreme as DID and OSDD.