OVERVIEW

Dissociative disorders are among the most controversial, as well as the most intriguing, psychiatric conditions. Central to the conceptualization of dissociation is the understanding that a person’s consciousness may not be fully integrated. Thus, a patient may experience a distinct alteration in personality or experience, in which thoughts, feelings, or actions are not logically integrated with other self-referential experiences.¹ Furthermore, although the concept of dissociation is more than 100 years old, there continues to exist great debate as to the validity of the symptoms of dissociation itself, as to whether the symptoms of dissociative disorders are better accounted for as subsets of different psychiatric conditions (e.g., anxiety disorders, posttraumatic stress disorder [PTSD], brief traumatic reactions, psychotic disorders, and attachment disorders), and as to the extent to which political and even cinematic agendas have contributed to the current conceptualization of dissociative syndromes. Certainly, the most famous of the dissociative conditions, dissociative identity disorder (DID), is featured in more than a half a dozen popular films and is sometimes mentioned in the now somewhat discounted “epidemic” of ritual satanic cults said to spawn new cases of dissociative disorder in the 1980s.

Nevertheless, most clinicians continue to view the concept of dissociation as a rare, albeit possible, response to horrific and traumatic events and experiences. To this extent, dissociative phenomena are often discussed in the setting of trauma studies, and case reports of dissociation detail those who have suffered a single, horrifying event, as well as those who have suffered the repeated neglect and abuse that characterizes early poor attachment. However, it is not the case that trauma is a necessary etiological factor in the development of dissociation. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) is careful to avoid any etiological hypotheses when describing dissociative behavior, and there certainly exist case reports that involve individuals with significant dissociative symptoms that occur in the absence of an identifiable stressor. Given the heterogeneous nature of the syndromes and those who suffer from them, it is no wonder that dissociative disorders are the subject of at times intense controversy.

Finally, there are a number of dissociative conditions described in the DSM-IV. In addition to DID, these include dissociative amnesia, dissociative fugue, depersonalization disorder, and dissociative disorder not otherwise specified (NOS).² Additionally, one must remain vigilant against individuals who feign dissociative symptoms for secondary gain or to assume the sick role. These are best characterized as factitious disorders or malingering and are not true dissociative phenomena. This distinction, however, is made difficult by the possibility that many who feign dissociative symptoms might also have true dissociative disorders. Thus, even the differential diagnosis can be contentious.

This chapter defines the overall concept of dissociation, gives brief summaries of the main dissociative conditions, and discusses etiology and treatment.

HISTORICAL PERSPECTIVE

Dissociative phenomena have been observed and described for hundreds of years. In the late eighteenth century, Franz Mesmer explored the concept of dissociation from the perspective of hypnosis, and indeed was likely the first clinician to document the relationship between those who are easily hypnotized and those who are prone to dissociation.^3,4 Nearly a century later, Pierre Janet, building on the work of Sigmund Freud, suggested that the ego fragments in the setting of traumatic events, leading to dissociative states. Importantly, this theory represents a departure from Freud’s primary notions regarding trauma and dissociation. While Janet felt that it was primarily a fragile ego that collapsed under the weight of horrifying trauma, thus yielding dissociative symptoms, Freud conceptualized dissociation as the work of a powerful ego defense, in which individuals wall off intense emotional pain as something separate from the self and left to be expressed only in dissociative states.⁵ Finally, in the early 1900s, Morton Prince wrote “The Dissociation of a Personality,” a lengthy case study that documented his patient, Sally Beauchamp, as “The Saint, the Devil, the Woman.” This was the first in-depth analysis of what is today known as DID.^6,7

As mentioned, dissociative disorders became a much discussed subject in psychiatry during the 1980s, in which presumed victims of satanic ritual abuse were often diagnosed with DID and discovered their past via hypnosis and the reclamation of lost memories. Much has been written about the huge recent increase in recovered memories that is often tied to dissociative states, with some clinicians feeling that these cases represent a barely touched-on epidemic of dissociation, whereas others feel strongly that these cases were instead the result of suggestible patients being led to express symptoms and memories that had little basis in the suggested etiology of their predicaments. It is clear that controversy still exists regarding these cases.⁸

CAUSES OF DISSOCIATION

Virtually all explorations of dissociation involve trauma. The majority of academic writing that discusses dissociation occurs in the trauma literature, and scholars have even defined trauma itself as a threat to one’s personal integrity. This is in fact one of the main reasons some believe that dissociative behavior is more a subset of PTSD, with the symptoms of disconnection representing the flashbacks, reexperiencing, and numbing that are central to the diagnosis of PTSD.^9,10

Additionally, those who are more easily hypnotized are also more prone to dissociation. As younger people and especially children are also more easily hypnotized, this finding is perhaps tied to the fact that younger individuals are also more likely to dissociate. Finally, to the extent that deficiencies in early attachment have been tied to dissociation, it may be that children are more prone to dissociation simply because they have more recently experienced the challenges to secure attachment that have been suggested as etiological to dissociation.^11,12

From a more biological perspective, dissociative-like states have long been observed in patients who are given dissociative anesthetics (such as midazolam), or who use illicit substances such as lysergic acid diethylamide (LSD).^11,13 These findings suggest irregular serotonin activity as playing some role in dissociative phenomena. Additionally, many patients with brain injury, and especially patients with complex partial seizures, have displayed dissociative behavior.^14–17 These findings suggest that multiple triggers, both biological and psychological in origin, mingle in the formation of dissociation as a pathological state.

However, community samples also document a relatively high degree of dissociation in the general population. Although the reasons for this finding are not clear, dissociation has more recently been characterized as akin to state-dependent learning, in which certain information is more easily retrieved from some individuals in specific states of self. As with many psychiatric phenomena, dissociation may exist along a spectrum, with some expressions of dissociation more closely tied to normal states and other symptoms more obviously representative of significant pathology.¹¹

THE EPIDEMIOLOGY OF DISSOCIATION

Estimates as to the prevalence of dissociation vary widely. The overall rate of dissociative disorders is thought to be approximately 10%, based primarily on standardized assessments (such as the Dissociative Experience Scale [DES] and the Structured Clinical Interview for Dissociative Disorders [SCID-D]). Importantly, these assessments have face validity only; therefore, caution must be exercised in interpreting data that stem from these investigations. Additionally, the prevalence of dissociative experiences in the general population is estimated by some to be as high as 75%. It is not clear how to interpret these findings when drawing conclusions regarding the epidemiology of dissociation.¹¹

Nevertheless, some important demographic features have emerged from these investigations. First, as already noted, younger people and especially children are more likely to suffer both dissociative events and to meet criteria for dissociative disorders. Second, for symptoms of general dissociation, there appear to be equal male-to-female ratios. However, specific dissociative syndromes have different gender profiles. While dissociative fugue is more common in men, DID is found more often in women.

DIFFERENT DISSOCIATIVE DISORDERS

The DSM-IV lists dissociative amnesia (formerly called psychogenic amnesia), dissociative fugue, DID (formerly called multiple personality disorder), depersonalization disorder, and dissociative disorder NOS among the dissociative disorders. Tables 35-1 through 35-5 summarize important findings for each of these syndromes.

Table 35-1 Dissociative Amnesia (DSM-IV Criteria and Exclusions)