Dissociative Disorders

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. 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, post-traumatic 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) was careful to avoid any etiological hypotheses when describing dissociative behavior, and although there have been changes in the terminology and diagnostic entities in DSM-5, there remains a purely descriptive approach to these conditions in the most recent descriptions of these syndromes. Indeed, case reports persist 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-5 that have undergone re-classifications. These changes include the inclusion of dissociative fugue as a specifier for dissociative amnesia, as well as derealization being added as both a feature of, and part of, the name for the newly coined depersonalization/derealization disorder. Finally, as one might expect given the controversies surrounding dissociative identity disorder, this particular syndrome has undergone the most fundamental changes.

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

Causes of Dissociation

Virtually all explorations of dissociation involve trauma. Thus, although the DSM-5 specifically avoids etiologic explorations, in research settings the study of trauma and the study of dissociation go hand-in-hand. 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, re-experiencing, and numbing that are central to the diagnosis of PTSD. There exists as well increased interest in differentiating PTSD from dissociative disorders using newly discovered differences in proposed neurobiological etiologies for each syndrome.

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.

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). These findings suggest irregular serotonin activity as playing some role in dissociative phenomena. Additionally, many patients with brain injuries, and especially patients with complex partial seizures, have displayed dissociative behavior. 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.

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.

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.