Defining Dissociation

Figure 1. People often think of dissociation as multiple personality disorder. While multiple personality disorder, called dissociative identity disorder, is an example of identity confusion and alteration consistent with dissociation, dissociation also includes amnesia, fugue, depersonalization, and derealization.

The DSM-5 defines dissociation as “a disruption and/or discontinuity in the normal integration of consciousness, memory, identity, emotion, perception, body representation, motor control and behavior” (American Psychiatric Association, 2013, p. 291). A distinction is often made between dissociative states and dissociative traits (e.g., Bremner, 2010; Bremner & Brett, 1997). State dissociation is viewed as a transient symptom, which lasts for a few minutes or hours (e.g., dissociation during a traumatic event). Trait dissociation is viewed as an integral aspect of personality. Dissociative symptoms occur in patients but also in the general population, like you and me. Therefore, dissociation has commonly been conceptualized as ranging on a continuum, from nonsevere manifestations of daydreaming to more severe disturbances typical of dissociative disorders (Bernstein & Putnam, 1986). The dissociative disorders include the following:

• dissociative amnesia: extensive forgetting typically associated with highly aversive events
  • dissociative fugue: short-lived reversible amnesia for personal identity, involving unplanned travel or “bewildered wandering.” Dissociative fugue is not viewed as a separate disorder but is a feature of some, but not all, cases of dissociative amnesia.
• depersonalization/derealization disorder: feeling as though one is an outside observer of one’s body
• dissociative identity disorder (DID): experiencing two or more distinct identities that recurrently take control over one’s behavior (American Psychiatric Association, 2000)

Although the concept of dissociation lacks a generally accepted definition, the Structural Clinical Interview for DSM-4 Dissociative Disorders (SCID-D) (Steinberg, 2001) assesses five symptom clusters that encompass key features of the dissociative disorders. These clusters (also found in the DSM-5) are

• depersonalization,
• derealization,
• dissociative amnesia,
• identity confusion, and
• identity alteration.

Depersonalization refers to a “feeling of detachment or estrangement from one’s self.” Imagine that you are outside of your own body, looking at yourself from a distance as though you were looking at somebody else. Maybe you can also imagine what it would be like if you felt like a robot, deprived of all feelings. These are examples of depersonalization. Derealization is defined as “an alteration in the perception of one’s surroundings so that a sense of reality of the external world is lost” (Steinberg, 2001, p. 101). Imagine that the world around you seems as if you are living in a movie or looking through a fog. These are examples of derealization. Dissociative amnesia does not refer to permanent memory loss, similar to the erasure of a computer disk, but rather to the hypothetical disconnection of memories from conscious inspection (Steinberg, 2001). Thus, the memory is still there somewhere, but you cannot reach it. 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).

Dissociative disorders are not as uncommon as you would expect. Several studies in a variety of patient groups show that dissociative disorders are prevalent in a four to 29% range (Ross, Anderson, Fleischer, & Norton, 1991; Sar, Tutkun, Alyanak, Bakim, & Baral, 2000; Tutkun et al., 1998. For reviews see: Foote, Smolin, Kaplan, Legatt, & Lipschitz, 2006; Spiegel et al., 2011). Studies generally find a much lower prevalence in the general population, with rates in the order of 1%-3% (Lee, Kwok, Hunter, Richards, & David, 2010; Rauschenberger & Lynn, 1995; Sandberg & Lynn, 1992). Importantly, dissociative symptoms are not limited to the dissociative disorders. Certain diagnostic groups, notably patients with borderline personality disorder, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder  (OCD) (Rufer, Fricke, Held, Cremer, & Hand, 2006), and schizophrenia (Allen & Coyne, 1995; Merckelbach, à Campo, Hardy, & Giesbrecht, 2005; Yu et al., 2010) also display heightened levels of dissociation.

Measuring Dissociation

The Dissociative Experiences Scale (DES) (Bernstein & Putnam, 1986; Carlson & Putnam, 2000; Wright & Loftus, 1999) is the most widely used self-report measure of dissociation. A self-report measure is a type of psychological test in which a person completes a survey or questionnaire with or without the help of an investigator. The DES measures dissociation with items such as (a) “Some people sometimes have the experience of feeling as though they are standing next to themselves or watching themselves do something, and they actually see themselves as if they were looking at another person” and (b) “Some people find that sometimes they are listening to someone talk, and they suddenly realize that they did not hear part or all of what was said.”

The DES is suitable only as a screening tool. When somebody scores a high level of dissociation on this scale, this does not necessarily mean that they are suffering from a dissociative disorder. It does, however, give an indication to investigate the symptoms more extensively. This is usually done with a structured clinical interview, called the Structured Clinical Interview for DSM-4 Dissociative Disorders (Steinberg, 1994), which is performed by an experienced clinician. With the publication of the new DSM-5 there has been an updated version of this instrument.

Figure 2. As with many disorders, it is widely thought that childhood neglect and/or abuse is partly to blame as an underlying cause of dissociative disorders.

Etiology

People with this disorder tend to report a history of childhood trauma, some cases having been corroborated through medical or legal records (Cardeña & Gleaves, 2006).

Research by Ross et al. (1990) suggests that in one study about 95% of people with DID were physically and/or sexually abused as children. Of course, not all reports of childhood abuse can be expected to be valid or accurate. However, there is strong evidence that traumatic experiences can cause people to experience states of dissociation, suggesting that dissociative states—including the adoption of multiple personalities—may serve as a psychologically important coping mechanism for threat and danger (Dalenberg et al., 2012).