Section Learning Objectives

• Describe how dissociative identity disorder presents itself.
• Describe the prevalence of dissociative identity disorder.
• Indicate which disorders are commonly comorbid with dissociative identity disorder.
• Describe factors that may contribute to the etiology of dissociative identity disorder.
• Describe the treatment of dissociative identity disorder.

7.3.1 Clinical Description

Dissociative Identity Disorder (DID) is what people commonly refer to as multiple personality disorder, as it was labeled as such in the DSM III. The key diagnostic criteria for DID is the presence of two or more distinct personality states or expressions. The identities are distinct in that they may have their own tone of voice, engage in different physical gestures (including different gait), and have their own behaviors – ranging anywhere from cooperative and sweet to defiant and aggressive. Additionally, the identities can be of varying ages and genders.

While personalities can present at any time, there is generally a dominant or primary personality that is present the majority of the time. From there, an individual may have several alternate personality states or alters. Although it is hard to identify how many alters an individual may have at one time, it is believed that there are on average 15 alters for women and 8 for men (APA, 2000).

The presentation of switching between alternate personality states varies among individuals and can be as simple as the individual appearing to fall asleep to very dramatic, involving excessive bodily movements. While often sudden and unexpected, switching is generally precipitated by a significant stressor, as the alter is best equipped to handle the current stressor will present. The relationship between alters varies between individuals – with some individuals reporting knowledge of other alters while others have a one-way amnesic relationship with alters, meaning they are not aware of other personality states (Barlow & Chu, 2014). These individuals will experience episodes of “amnesia” when the primary personality is not present.

7.3.2 Epidemiology

Dissociative disorders were once believed to be extremely rare; however, more recent research suggests that they may be more present in the general population than once believed. Estimates for the one-year prevalence rate of DID is 1.5% (APA, 2022), with more women than men experiencing the disorder. Due to the high comorbidity between childhood abuse and DID, it is believed that symptoms begin in early childhood following repeated exposure to abuse; however, the full onset of the disorder may not be observed (or noticed by others) until adolescence (Sar et al., 2014) or later in life. Over 70% of people with DID have attempted suicide and other self-injurious behaviors are common (APA, 2022).

7.3.3 Comorbidity

People with DID commonly experience a large number of comorbid disorders including PTSD , depressive disorders, somatic symptom disorders (e.g., conversion disorder), eating disorders, substance use disorders, obsessive-compulsive disorder, sleep disturbances, as well as antisocial personality disorder.

7.3.4 Etiology

7.3.4.1 Biological

Once again,  heritability rates for dissociation are approximately 50% (APA, 2022; Pieper, Out, Bakermans-Kranenburg, Van Ijzendoorn, 2011). However, it is suggested that the combination of genetic and environmental factors may play a larger role in the development of dissociative disorders than genetics alone (APA, 2022; Pieper, Out, Bakermans-Kranenburg, Van Ijzendoorn, 2011).

7.3.4.2 Cognitive

Neuroimaging studies have revealed differences in hippocampus activation between alters (Tsai, Condie, Wu & Chang, 1999). The hippocampus is involved in memory consolidation (storing information from short-term to long-term memory). It is hypothesized that this brain region is responsible for the generation of dissociative states and amnesia (Staniloiu & Markowitsch, 2010).

7.3.4.3 Sociocultural

The sociocultural model of dissociative disorders has largely been influenced by Lilienfeld and colleagues (1999) who argue that the influence of mass media and its publications of dissociative disorders, provide a model for individuals to not only learn about dissociative disorders but also engage in similar dissociative behaviors. This theory has been supported by the significant increase in DID cases after the publication of Sybil, a documentation of a woman’s 16 personalities (Goff & Simms, 1993).

These mass media productions are not just suggestive to patients; mass media also influences the way clinicians gather information regarding the dissociative symptoms of clients. For example, therapists may unconsciously use questions or techniques in sessions that evoke dissociative types of problems in their patients following exposure to a media source discussing dissociative disorders.

7.3.4.4 Psychodynamic

Once again, the psychodynamic theory of dissociative disorders assumes that dissociative disorders are caused by an individual’s repressed thoughts and feelings related to an unpleasant or traumatic event (Richardson, 1998). In blocking these thoughts and feelings, the individual is subconsciously protecting themself from painful memories.

While dissociative amnesia may be explained by the repression of a single memory, psychodynamic theorists believe that DID results from repeated exposure to traumatic experiences, such as severe childhood abuse, neglect, or abandonment (Dalenberg et al., 2012). According to the psychodynamic perspective, children who experience repeated traumatic events such as physical abuse or parental neglect lack the support and resources to cope with these experiences. In efforts to escape from their current situations, children develop different personalities to essentially flee the dangerous situation they are experiencing. While there is limited scientific evidence to support this theory, the nature of severe childhood psychological trauma is consistent with this theory, as individuals with DID have the highest rate of childhood psychological trauma compared to all other psychiatric disorders (Sar, 2011). Indeed, about 90% of the individuals with DID report multiple types of early neglect and childhood abuse, often extending into late adolescence (APA, 2022).

7.3.5 Treatment

The ultimate treatment goal for DID is the integration of alternate personalities to a point of final fusion (Chu et al., 2011). Integration refers to the ongoing process of merging alters into one coherent personality. Psychoeducation is paramount for integration, as the individual must have an understanding of their disorder, as well as acknowledge their alters. As mentioned above, many individuals have a one-way amnesic relationship with their alters, meaning they are not aware of one another. Therefore, the clinician must first make the individual aware of the various alters that present across different situations.

Achieving integration requires several steps. First, the clinician needs to build a relationship and strong rapport with the primary personality. From there, the clinician can begin to encourage gradual communication and coordination between the alters. Making the alters aware of one another, as well as addressing their conflicts, is an essential component of integration, and the core of DID treatment (Chu et al., 2011).

Once the individual is aware of their alters, treatment can continue with the goal of fusion. Fusion occurs when two or more alternate identities join together (Chu et al., 2011). When this happens, there is a complete loss of separateness. Depending on the number of alters, this process can take quite a while. Once all alternate identities are fused together and the individual identifies themselves as one unified self, it is believed the patient has reached final fusion.

It should be noted that final fusion is difficult to obtain. As you can imagine, some clients do not find final fusion as a desirable outcome, particularly those with extremely painful histories; chronic, serious stressors; advanced age; and comorbid medical and psychiatric disorders to name a few. For individuals where final fusion is not the treatment goal, the clinician may work toward resolution or sufficient integration and coordination of alternate identities that allow the individual to function independently (Chu et al., 2011). Unfortunately, individuals that do not achieve final fusion are at greater risk for relapse of symptoms. Once an individual reaches final fusion, ongoing treatment is essential to maintain this status. In general, treatment focuses on social and positive coping skills. These skills are particularly helpful for individuals with a history of traumatic events, as they can help them process these events, as well as help prevent future relapses.

Chapter Recap

In this chapter, we discussed Depersonalization/Derealization Disorder, Dissociative Amnesia, and Dissociative Identity Disorder, in terms of their clinical presentation, diagnostic criteria, epidemiology, comorbidity, etiology, and treatment approaches.