Just FYI for those who may not know ...
Dissociation and disassociation are two things that mean similar things but one is specific to psychological medicine and the other is a more general term for disconnecting from anything. A lot of people interchange these but you shouldn't.
There are 4 stages of dissociation. Each exists to help someone regulate their response to situations or tolerate/adapt to difficult stimulus. Psychological dissociation is a triggered response not a conscious one.
I think now the DSM refers to 5 stages instead of 4 ... It used to just be amnesia, depersonalisation, derealisation and identity confusion ... but now identity alteration is a component to the stages.
Identity confusion is defined by Steinberg as “thoughts and feelings of uncertainty and conflict a person has related to [their] identity” (Steinberg, 2001, p. 101), whereas identity alteration describes the behavioral acting out of this uncertainty and conflict (Bernstein & Putnam, 1986).