amnesia, [Gr.,=forgetfulness], condition characterized by loss of memory for long or short intervals of time. It may be caused by injury, shock, senility, severe illness, or mental disease. Some cases of amnesia involve the unconscious suppression of a painful experience and everything remindful of it including the individual's identity (see defense mechanism). Retrograde amnesia is loss of memory of events just preceding temporary loss of consciousness, as from head injury; it is evidence that memory proceeds in two stages, short term and long term. One form of the condition known as tropic amnesia, or coast memory, affecting white men in the tropics, is probably a variety of hysteria. Aphasia of the amnesic variety is caused by an organic brain condition and is not to be confused with other forms of amnesia. To cure amnesia, attempts are made to establish associations with the past by suggestion, and hypnotism is sometimes employed.