Dissociative Amnesia is codified 300.12 in DSM-IV. The disorder used to be called Psychogenic Amnesia.
According to DSM-IV, the following criteria must be met in order for a diagnosis of dissociative amnesia to be arrived at:
Criterion A: an inability to recall information of a very personal nature. The inability may be the outcome of an underlying trauma or stress. The inability to recollect cannot be attributed to normal forgetfulness.
Criterion B: memory is reversibly impaired. Memories of personal nature cannot be recalled in verbal form. Even if it is temporarily retrieved, the memory cannot be retained wholly in one’s consciousness. The impairment does not occur exclusively during the course of other dissociative disorders (such as dissociative identity disorder, dissociative fugue, etc), PTSD, acute stress disorder, or somatization disorder. The impairment is also not a result of substance abuse, and it is not due to any neurological or general medical condition.
Criterion C: the symptoms of the disorder are such as to cause clinical stress which is significant in nature, and which can impair the subject’s social, occupational, or other areas of functioning.
The individual afflicted with dissociative amnesia reports gaps in recall for aspects of their personal history. There are chunks of time in their past which they are unable to recall. Some traumatic or stressful event or events are associated with the loss of memory. An acute form of dissociative amnesia is a sudden onset caused due to an elaborate episode, such as finding oneself in the midst of a natural calamity or during wartime.
Types of Dissociative Amnesia
The following types of dissociative amnesia have been identified:
- Localized Amnesia: Here, the individual fails to recall events during a specific stretch of time, and only later manage to remember details of the event. For instance, the survivor of a violent attack who also happens to witness one of their close family members succumbing to the attack might “forget” all about the episode for up to 2-4 days after the event.
- Selective Amnesia: Here, the individual is not able to recall all that happened in an event, just a select few tidbits. For instance, a rape victim might be able to recall just parts of the event of rape and not the full event in its entirety.
- Generalized Amnesia: This is a less common dissociative amnesia disorder. The individual here is unable to recall their entire past history. Such cases usually present themselves to the police, to emergency wards, or to general hospital consultation services.
- Continuous Amnesia: This is a less common dissociative amnesia disorder. The individual here is unable to recall events subsequent to a specific time up to and including the present.
- Systematized Amnesia: This is a less common dissociative amnesia disorder. The individual here is unable to recall specific categories of information. Examples include memory about one’s spouse or about all visits to a place of worship.
Amongst the above types of dissociative amnesia, the last three types – generalized, continuous and systematized – may ultimately be diagnosed as having a more complex form of dissociative disorder, such as dissociative identity disorder.
Associated Features And Disorders
Individuals suffering from dissociative amnesia also tend to report symptoms of depression, anxiety, depersonalization, trance states, analgesia, and spontaneous age regression. They may also provide inaccurate answers to relatively simple questions – such as the sum of 3 and 4 is 8.
The disorder usually also co-occurs with sexual dysfunction, impairment in relationships, self-harm and suicidal impulse, as also aggressive impulse. Individuals with this disorder may also have symptoms that meet the criteria for Conversion Disorder, a mood disorder, substance-related disorder or a Personality Disorder.
Such individuals have also been found to be prone to be hypnotized more than the normal population sample.
The disorder can present in any age group. The main presenting condition is retrospective gap in memory. The duration of the condition may last from a few minutes to years. Individuals who have already had one episode of dissociative amnesia are prone to develop the condition for any future traumatic circumstance.