Диссоциативная амнезия: расстройство памяти и идентичности

Human memory disorder
Dissociative amnesia was previously known as psychogenic amnesia, a memory disorder, which was characterized by sudden retrograde episodic memory loss, said to occur for a period of time ranging from hours to years to decades. The atypical clinical syndrome of the memory disorder (as opposed to organic amnesia) is that a person with psychogenic amnesia is profoundly unable to remember personal information about themselves; there is a lack of conscious self knowledge which affects even simple self knowledge, such as who they are. Psychogenic amnesia is distinguished from organic amnesia in that it is supposed to result from a nonorganic cause: no structural brain damage should be evident but some form of psychological stress should precipitate the amnesia. Psychogenic amnesia as a memory disorder is controversial.

Psychogenic amnesia is the presence of retrograde amnesia (the inability to retrieve stored memories leading up to the onset of amnesia), and an absence of anterograde amnesia (the inability to form new long term memories). Access to episodic memory can be impeded, The most commonly cited examples of global transient psychogenic amnesia are 'fugue states', of which there is a sudden retrograde loss of autobiographical memory resulting in impairment of personal identity and usually accompanied by a period of wandering. There are many clinical anecdotes of psychogenic or dissociative amnesia attributed to stressors ranging from cases of child sexual abuse to soldiers returning from combat.

The neurological cause of psychogenic amnesia is controversial. Failure to find an organic cause may result in the diagnosis that the amnesia is psychological, however it is possible that some organic causes may fall below a threshold of detection, while other neurological ails are thought to be unequivocally organic (such as a migraine) even though no functional damage is evident. Some researchers Psychological triggers are instead considered as preceding psychogenic amnesia,

Brain activity can be assessed functionally for psychogenic amnesia using imaging techniques such as fMRI, PET and EEG, in accordance with clinical data. while self identity deficits have been suggested as attributable to functional changes related to the posterior parietal cortex. to the amnesia as a form of self punishment in a Freudian sense, with the obliteration of personal identity as an alternative to suicide. Treatment attempts often have revolved around trying to discover what traumatic event had caused the amnesia, and drugs such as intravenously administered barbiturates (often thought of as 'truth serum') were popular as treatment for psychogenic amnesia during World War II; benzodiazepines may have been substituted later. Under the influence of these 'truth' drugs the patient would more readily talk about what had occurred to them. If no motive for the amnesia was immediately apparent, deeper motives were usually sought by questioning the patient more intensely, often in conjunction with hypnosis and 'truth' drugs.

Dissociative amnesia is a common fictional plot device in many films, books and other media. Examples include William Shakespeare's King Lear, who experienced amnesia and madness following a betrayal by his daughters; and the title character Nina in Nicolas Dalayrac's 1786 opera.