Dissociative Disorders

 In psychiatry, dissociation is an unconscious defense mechanism involving the segregation of any group of mental or behavioral processes from the rest of the person’s psychic activity. Dissociative disorders involve this mechanism so that there is a disruption in one or more mental functions, such as memory, identity, perception, consciousness, or motor behavior. The disturbance may be sudden or gradual, transient or chronic, and psychological trauma is often the cause.


Dissociative Amnesia

The main feature of dissociative amnesia is the inability to recall important personal information, usually related to a significant trauma or stressor, that is too extensive to be explained by ordinary forgetfulness. The disorder cannot result from the direct physiologic effects of a substance or a neurologic or other general medical condition.

Table 11-1 lists the different types of dissociative amnesia.

A 45-year-old, divorced, left-handed, male bus dispatcher was seen in psychiatric consultation on a medical unit. He had been admitted with an episode of chest discomfort, light-headedness, and left-arm weakness. He had a history of hypertension and had a medical admission in the past year for ischemic chest pain, although he had not suffered a myocardial infarction. Psychiatric consultation was called, because the patient complained of memory loss for the previous 12 years, behaving and responding to the environment as if it were 12 years previously (e.g., he did not recognize his 8-year-old son, insisted that he was unmarried, and denied recollection of current events, such as the name of the current president). Physical and laboratory findings were unchanged from the patient’s usual baseline. Brain computed tomography (CT) scan was normal.

On mental status examination, the patient displayed intact intellectual function but insisted that the date was 12 years earlier, denying recall of his entire subsequent personal history and of current events for the past 12 years. He was perplexed by the contradiction between his memory and current circumstances. The patient described a family history of brutal beatings and physical discipline. He was a decorated combat veteran, although he described amnestic episodes for some of his combat experiences. In the military, he had been a champion golden glove boxer noted for his powerful left hand.

He was educated about his disorder and given the suggestion that his memory could return as he could tolerate it, perhaps overnight during sleep or perhaps over a longer time. If this strategy was unsuccessful, hypnosis or an amobarbital interview was proposed. (Adapted from a case of Richard J. Loewenstein, M.D., and Frank W. Putnam, M.D.)

Classic Presentation. The classic disorder is an overt, florid, dramatic clinical disturbance that quickly presents for medical attention. A history of extreme acute trauma is typical. It also commonly develops, however, in the context of profound intrapsychic conflict or emotional stress. Patients may present with physical symptoms, alterations in consciousness, depersonalization, derealization, trance states, spontaneous age regression, and even ongoing anterograde dissociative amnesia. There is a significant risk of depression and suicidal ideation. No single personality profile or antecedent history is consistently reported in these patients, although a prior personal or family history of somatoform or dissociative symptoms can predispose individuals to develop acute amnesia during traumatic circumstances. Many of these patients have histories of prior adult or childhood abuse or trauma. In wartime cases, as in other forms of combat-related posttraumatic disorders, the most crucial variable in the development

of dissociative symptoms, however, appears to be the intensity of combat.

Table 11-2 presents the mental status evaluation of dissociative amnesia.

Nonclassic Presentation. These patients frequently come to treatment for a variety of symptoms, such as depression or mood swings, substance abuse, sleep disturbances, somatoform symptoms, anxiety and panic, suicidal or self-mutilating impulses and acts, violent outbursts, eating problems, and interpersonal problems. Self-mutilation and violent behavior in these patients may also occur. Amnesia may also occur for flashbacks or behavioral reexperiencing episodes related to trauma.

Dissociative Fugue. DSM-5 treats dissociative fugue as a subtype of dissociative amnesia, whereas it is a separate diagnosis in ICD-10. It can occur in patients with both dissociative amnesia and dissociative identity disorder.

Dissociative fugue is as sudden, unexpected travel away from home or one’s customary place of daily activities. Also, the person cannot recall some or all of one’s past. Along with the amnesia, the person is confused about their identity or may even assume a new identity. The disturbance is not due to the direct physiologic effects of a substance or a general medical condition.

Dissociative fugues have been described to last from minutes to months. Some patients report multiple fugues. In some extreme cases of posttraumatic stress disorder (PTSD), a person may awaken from a nightmare in a fugue state. Children or adolescents may be more limited than adults in their ability to travel. Thus, fugues in this population may be brief and involve only short distances.

A teenage girl was continually sexually abused by her alcoholic father and another family friend. She was threatened with perpetration of sexual abuse on her younger siblings if she told anyone about the abuse. The girl became suicidal but felt that she had to stay alive to protect her siblings. She ran away from home after being raped by her father and several of his friends. She traveled to a part of the city where she had lived previously with the idea of finding her grandmother with whom she had lived before the abuse began. She traveled by public transportation and walked the streets, apparently without attracting attention. After approximately 8 hours, she was stopped by the police in a curfew check. When questioned, she could not recall recent events or give her current address, insisting that she lived with her grandmother. On initial psychiatric examination, she was aware of her identity, but she believed that it was 2 years earlier, giving her age as 2 years younger and insisting that none of the events of recent years had occurred. (Courtesy of Richard J. Loewenstein, M.D., and Frank W. Putnam, M.D.)

Table 11-1 Types of Dissociative Amnesia

Localized amnesia: Inability to recall events related to a

circumscribed period of time

Selective amnesia: Ability to remember some, but not all, of the

events occurring during a circumscribed period of time Generalized amnesia: Failure to recall one’s entire life Continuous amnesia: Failure to recall successive events as they


Systematized amnesia: Failure to remember a category of information, such as all memories relating to one’s family or to a particular person

Table 11-2 Mental Status Examination Questions for Dissociative Amnesia

If answers are positive, ask the patient to describe the event. Make

 sure to specify that the symptom does not occur during an episode of intoxication.

1. Do you ever have blackouts? Blank spells? Memory lapses?

2. Do you lose time? Have gaps in your experience of time?

3. Have you ever traveled a considerable distance without recollection of how you did this or where you went exactly?

4. Do people tell you of things you have said and done that you do not recall?

5. Do you find objects in your possession (such as clothes, personal items, groceries in your grocery cart, books, tools, equipment, jewelry, vehicles, weapons, and so on) that you do not remember acquiring? Out-of-character items? Items that a child might have?Toys? Stuffed animals?

6. Have you ever been told or found evidence that you have talents and abilities that you did not know that you had? For example, musical, artistic, mechanical, literary, athletic, or other talents?Do your tastes seem to fluctuate a lot? For example, food preference, personal habits, taste in music or clothes, and so forth.

7. Do you have gaps in your memory of your life? Are you missing parts of your memory for your life history? Are you missing memories of some important events in your life? For example, weddings, birthdays, graduations, pregnancies, birth of children, and so on.

8. Do you lose track of or tune out conversations or therapy sessions as they are occurring? Do you find that, while you are listening to someone talk, you did not hear all or part of what was just said?

9. What is the longest period of time that you have lost? Minutes?Hours? Days? Weeks? Months? Years? Describe.

Adapted from Loewenstein RJ. An office mental status examination for chronic complex dissociative symptoms and multiple personality disorder. Psychiatr Clin North Am.


After the termination of a fugue, the patient may experience perplexity, confusion, trance-like behaviors, depersonalization, derealization, and conversion symptoms, in addition to amnesia. Some patients may terminate a fugue with an episode of generalized dissociative amnesia.

As the patient with dissociative fugue begins to become less dissociated, he or she may display mood disorder symptoms, intense suicidal ideation, and PTSD or anxiety disorder symptoms. In classic cases, the person has an alter identity under whose auspices the patient lives for a period. Many of these latter cases are better classified as dissociative identity disorder or, if

using DSM-5, as other specified dissociative disorder with features of dissociative identity disorder.

Differential Diagnosis

Table 11-3 lists the differential diagnosis of dissociative amnesia.

Ordinary Forgetfulness and Nonpathologic Amnesia. Ordinary forgetfulness is benign and unrelated to stressful events. In dissociative amnesia, memory loss is more extensive than in nonpathologic amnesia. There are other types of nonpathologic amnesia as well, including infantile and childhood amnesia, amnesia for sleep and dreaming, and hypnotic amnesia.

Dementia, Delirium, and Amnestic Disorders due to Medical Conditions. In patients with dementia, delirium, and amnestic disorders due to medical conditions, memory loss is part of a more extensive set of cognitive, language, attentional, behavioral, and memory problems. Loss of memory for personal identity is usually not found without evidence of a marked disturbance in many domains of cognitive function. Causes of organic amnestic disorders include Korsakoff psychosis, cerebral vascular accident (CVA), postoperative amnesia, postinfectious amnesia, anoxic amnesia, and transient global amnesia (see below). Electroconvulsive therapy (ECT) may also cause marked temporary amnesia, as well as persistent memory problems in some cases. Here, however, memory loss for autobiographical experience is unrelated to traumatic or overwhelming experiences and seems to involve many different types of personal experiences, most commonly those occurring just before or during the ECT treatments.

Posttraumatic Amnesia. In posttraumatic amnesia caused by brain injury, we usually find a history of a clear-cut physical trauma, a period of unconsciousness or amnesia, or both. Also, there is objective clinical evidence of brain injury.

Seizure Disorders. In most seizure cases, the clinical presentation differs significantly from that of dissociative amnesia, with clear-cut ictal events and sequelae. In complex–partial seizures, patients may wander or show semipurposeful behavior, or both, during seizures or in postictal states, for which subsequent amnesia occurs. Rarely, patients with recurrent, complex–partial seizures present with ongoing bizarre behavior, memory problems, irritability, or violence, leading to a differential diagnostic puzzle. Seizure patients in an epileptic fugue often exhibit abnormal behavior, however, including confusion, perseveration, and abnormal or repetitive movements. Patients with pseudoepileptic seizures may also have dissociative symptoms, such as amnesia and an antecedent history of psychological trauma. In some of these cases, the diagnosis can be clarified only by telemetry or ambulatory electroencephalographic (EEG) monitoring.

Dissociative Disorders Dissociative Disorders Reviewed by Web of Psychiatry on December 07, 2021 Rating: 5

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