Dissociative amnesia is also known as functional or psychogenic amnesia. It is a psychiatric disorder in which the memory of the individual is affected adversely without any clinical cause such as trauma, diseases of the central nervous system or brain injury. Severe cases of this disorder are extremely rare. This type of amnesia is restricted to a failure to recall previous events. In this disorder, the information that has been forgotten by the individual exists in the consciousness and comes to light under the effect of hypnosis or neurosis where the amnesia suddenly vanishes. There are four types of psychogenic amnesia:

Localized amnesia: In this type of amnesia the person completes forgets about the happenings and experiences during a specific time period, particularly, the immediate hours prior to a traumatic event.

Selective amnesia: In this type of amnesia the individual forgets only some of the events and experiences in a specific time period.

Generalized amnesia: In this disorder the individual forgets the whole life history.

Continuous amnesia: In this type of amnesia forgets everything after a certain period of time in life.

In Dissociative amnesia, the individual usually forgets the events associated with unbearably shocking incidents such as destruction of property due to a natural calamity, events occurring immediately after a catastrophe, period of war, being held hostage etc. In some cases, the amnesia also develops as a defense mechanism against unpleasant stressful situations with which most individuals tend to deal in a more effective manner.

Symptoms of Dissociative Amnesia:

In some cases, the affected person is unable to recall his/her name, identity or address.

They are unable to recognize their parents, spouses, relatives or friends and colleagues.

Their general habits such as the ability to talk, read or perform certain tasks are unaffected but are unable to retrieve certain information.

Only the episodic memory is affected in dissociative amnesia.

Dissociative amnesia can be a debilitating disorder and the patient might suffer on account of being unable to recall his/her identity, whereabouts and relatives. There is no genetic or clinical linkage that can be established for this disorder and it develops purely in response to extremely distressful life situations.