Memory loss (amnesia) can be due to brain damage and can also be caused by psychological reasons. Amnesia due to brain damage is called organic amnesia. Examples of causes for brain damage include trauma (concussion, contusionâ¦) or illness (all types of dementia, brain insultâ¦). Amnesia due to psychological reasons is called psychic amnesia. This kind of amnesia is present during some types of hysteria â a kind of neurotic disorder. You can consult a neurologist and a psychiatrist about your motherâs condition in order to diagnose her experience of memory loss.