Dissociative amnesia, also known as psychogenic amnesia, is characterized by a sudden loss of memory in an individual, and can last for a period of time ranging from a few hours to a period of years. An episode of dissociative amnesia is also often accompanied by personality changes in the afflicted individual, most notably increased impulsivity or uncharacteristic hostility or aggression (Staniliou and Markowitsch, 2010). A subset of dissociative amnesia is colloquially known as a “memory blackout,” and often involves the sudden disappearance of a specific episode or period of time in an individual’s autobiographic memory. Dissociative amnesia is one of the more mysterious disorders in the realm of abnormal psychology, and is often a disorder invoked in criminal trials involving child sexual abuse, with both prosecutors and defense attorneys alike taking advantage of the fact that memory blackouts are common to survivors of early childhood trauma (Staniliou and Markowitsch, 2010).
Dissociative amnesia is estimated to affect 1.8 percent of the overall general population, and it afflicts women at a greater rate than men (Staniliou and Markowitsch, 2010). Admittedly, the gender disparity in diagnosis can likely be attributed to the fact that women are much more statistically likely than men to self-report dissociative episodes, as well as past childhood sexual traumas. Dissociative amnesia appears to afflict individuals under the age of 50 at a greater rate than older individuals; again, this disparity can also simply be due to the lessened stigma of psychiatric treatment among younger generations (Sandberg and Lynn, 1992). There is no available data on ethnic, racial or socio-economic differences in the overall diagnosis of this disorder, however, it might be surmised that individuals from a more affluent background would be diagnosed at a higher rate, simply because they have greater access to psychiatric care services. The only outstanding definitive characteristic of individuals diagnosed with dissociative amnesia is that they have disproportionately suffered from early childhood trauma, particularly trauma related to sexual abuse (Sandberg and Lynn, 1992).
As far as the etiology of dissociative amnesia, there are two major schools of thought regarding the underlying origins of this psychological disorder. One is that episodic, autobiographical memory loss is the result of physical changes in the brain. A 2010 study by Staniliou and Markowitsch found that individuals diagnosed with dissociative amnesia presented clear “reductions in brain metabolism or alterations primarily in the right temporo-frontal cortices” of the brain. Other studies, remarkably that of Sandberg and Lynn (1992), contend that the causes of dissociative amnesia are environmental and extraneous, and can usually be attributed to sexual trauma inflicted upon an individual in early childhood. Of course, the most likely answer is that trauma has a very real and tangible impact on a young child’s neurochemistry, with devastating impacts on memory formation.
As of this writing, there is no known “cure” for dissociative amnesia; this is not surprising, as there remains controversy among the psychiatric community as regards the veracity of this disorder (Staniliou and Markowitsch, 2010). Although various inroads have been made in recent years with regards to understanding the neurochemistry behind memory blackouts and dissociative episodes, there are no recommended psychotropic medications that are specified for dissociative amnesia. As individuals who suffer from this disorder also often experience comorbid depression and anxiety, antidepressant and anti-anxiety drugs are often prescribed to these patients (Staniliou and Markowitsch, 2010). Since the likeliest source of dissociative amnesia is childhood sexual trauma, interpersonal therapy is often indicated as a treatment for this disorder. However, this approach raises some ethical concerns. Traumatic memories are often suppressed by the brain as a survival mechanism, and to attempt to resurrect such horrible experiences might do more harm than good to the patient.
- Sandberg, D.A., and Lynn, S.J. (1992). “Dissociative experiences, psychopathology and adjustment and child and adolescent maltreatment in female college students.” Journal of Abnormal Psychology 101 (4), 717-723.
- Staniliou, A., and Markowitsch, H.J. (2010). “Searching for the anatomy of dissociative amnesia.” Journal of Psychology 218 (2), 96-108.