" Helping the identities to be aware of one another as legitimate parts of the self and to negotiate and resolve their conflicts is at the very core of the therapeutic process. It is countertherapeutic for the therapist to treat any alternate identity as if it were more “real” or more important than any other.
The therapist should not “play favorites” among the alternate identities or exclude apparently unlikable or disruptive ones from the therapy (although such steps may be necessary for a limited period of time at some stages in the treatment of some patients to provide for the safety and stability of the patient or the safety of others).
The therapist should foster the idea that all alternate identities represent adaptive attempts to cope or to master problems that the patient has faced. Thus, it is countertherapeutic to tell patients to ignore or “get rid” of identities (although it is acceptable to provide strategies for the patient to resist the influence of destructive identities, or to help control the emergence of certain identities at inappropriate circumstances or times).
It is countertherapeutic to suggest that the patient create additional alternate identities, to name identities when they have no names (although the patient may choose names if he or she wishes), or to suggest that identities function in a more elaborated and autonomous way than they already are functioning.
A desirable treatment outcome is a workable form of integration or harmony among alternate identities."
Guidelines for Treating Dissociative Identity Disorder in Adults, Third Revision, Journal of Trauma & Dissociation, 12:2, 115-187 (2011)
DOI 10.1080/15299732.2011.537247 "

― International Society for the Study of Trauma and Dissociation