Dissociative Identity Disorder is codified 300.14 in DSM IV. The disorder was formerly known as Multiple Personality Disorder.
According to DSM IV, the following criteria must be met in order for the individual to be diagnosed for dissociative identity disorder:
Criterion A: two or more distinct identities or personality states are present in the individual.
Criterion B: these distinct identities take control over the behavior recurrently.
Criterion C: the individual is unable to recall important personal information, and this inability is too severe to be attributed to mere ordinary forgetfulness.
Criterion D: the disturbance is not an outcome of substance abuse or general medical condition.
The individual affected with Dissociative Identity Disorder finds it challenging to integrate the different aspects of their identity, memory and consciousness. The disorder is diagnosed three to nine times more frequently in adult females than in adult males. The number of identities in such an individual is reported to be from 2 to more than 100. Females tend to have more identities than do males, averaging 15 or more, whereas males average approximately 8 identities.
Each of the personality states that the individual experiences has its own distinct personal history, self-image, and identity, including different age, different gender, and also a different name. There usually exists a main, primary identity which carries the individual’s given name. When this primary identity takes over or regains consciousness, the individual is usually passive, dependent, guilty and depressed. On the other hand, the alternate identities have personalities which contrast the primary personality, for example, they may be dominating, hostile, aggressive, etc.
These alternate identities emerge and take over the individual’s consciousness due to some trigger such as psychosocial stress. The time required to switch between two identities may be a few seconds, or may be gradual. Others around may discern that the switch has happened by specific symptoms such as rapid blinking, facial changes, changes in voice or demeanor, or sudden change of track of the individual’s thoughts. The alternate identities take control in sequence, one after another. They may deny knowledge of the existence of the other alternate identities altogether, or may be critical of the others, or there may be open conflict between the alternate identities. At times, the role of allocating time to take control over the individual is abrogated by the alternate identity that emerges as the most powerful.
In terms of memory recall, the individual’s primary identity appears to experience gaps in memory in both recent and remote episodes, including an overall loss of biographic memory for an extended period of childhood, adolescence or even adulthood. Amongst the alternate identities, the passive ones have more constricted memory recall, while the ones with hostile, controlling or protecting personalities have near-complete memory recall. An identity with less controlling power may gain access to consciousness by producing auditory or visual hallucinations – such as in the form of a voice that gives instructions.
Associated Features and Disorders
Individuals with Dissociative Identity Disorder have been found to be highly hypnotizable and especially vulnerable to suggestive influences. These individuals may also concurrently manifest posttraumatic symptoms such as nightmares, flashbacks and startle responses, or also PTSD. In some alternate identities, self-mutilation and suicidal and aggressive behavior, along with impulsivity and sudden changes in relationships have warranted a concurrent diagnosis of borderline personality disorder. In some cases, certain identities have been found to experience conversion symptoms (e.g. pseudoseizures), or to possess the ability to control pain.
In a number of cases, these individuals report having experienced severe physical and sexual abuse, especially during childhood. There may also be a repetitive pattern of relationships involving physical and sexual abuse.
The average time period from first symptom presentation to diagnosis is six to seven years. Episodic and continuous courses have both been described. The disorder may reduce in intensity and frequency after the age of forty. However, any psychosocial stress such as trauma or substance abuse may trigger a fresh episode.