Dissociative Identity Disorder - Definitions

Definitions

Dissociation, the term that underlies the dissociative disorders including DID, lacks a precise, empirical and generally agreed upon definition. A large number of diverse experiences have been termed dissociative, ranging from normal failures in attention to the breakdowns in memory processes characterized by the dissociative disorders. Thus it is unknown if there is a common root underlying all dissociative experiences, or if the range of mild to severe symptoms are a result of different etiologies and biological structures. Other terms used in the literature, including personality, personality state, identity, ego state and amnesia, also have no agreed upon definitions. Multiple competing models exist that incorporate some non-dissociative symptoms while excluding dissociative ones. The most widely used model of dissociation conceptualizes DID as at one extreme of a continuum of dissociation, with flow at the other end, though this model is being challenged.

Some terms have been proposed regarding dissociation. Psychiatrist Paulette Gillig draws a distinction between an "ego state" (behaviors and experiences possessing permeable boundaries with other such states but united by a common sense of self) and the term "alters" (each of which may have a separate autobiographical memory, independent initiative and a sense of ownership over individual behavior) commonly used in discussions of DID. Ellert Nijenhuis and colleagues suggest a distinction between personalities responsible for day-to-day functioning (associated with blunted physiological responses and reduced emotional reactivity, referred to as the "apparently normal part of the personality" or ANP) and those emerging in survival situations (involving fight-or-flight responses, vivid traumatic memories and strong, painful emotions, the "emotional part of the personality" or EP). "Structural dissociation of the personality" is used by van der Hart and colleagues to distinguish dissociation they attribute to traumatic or pathological causes, which in turn is divided into primary, secondary and tertiary dissociation. According to this hypothesis, primary dissociation involves one ANP and one EP, while secondary dissociation involves one ANP and several EPs and tertiary dissociation, which is unique to DID, is described as having several of each. Others have suggested dissociation can be separated into two distinct forms, detachment and compartmentalization, the latter of which, involving a failure to control normally controllable processes or actions, is most evident in DID. Efforts to psychometrically distinguish between normal and pathological dissociation have been made, but they have not been universally accepted.