What is the defining feature of dissociative amnesia?

The defining feature of dissociative amnesia is the sudden loss of important personal information. This condition typically occurs in response to traumatic or stressful events, where an individual is unable to recall significant autobiographical information, which can include personal history and memories related to the trauma itself. This amnesia is not due to a medical condition or substance, and it is differentiated from other types of amnesia because it directly involves a psychological response to stressors.

In contrast, the other options relate to different psychological phenomena or disorders. Sudden loss of identity may suggest dissociative identity disorder, where an individual may have multiple distinct identities. Prolonged mood swings are more indicative of mood disorders, such as bipolar disorder, rather than dissociative disorders. Lastly, uncontrolled behavioral outbursts can be associated with a variety of conditions, including impulse control disorders or intermittent explosive disorder, but they do not define dissociative amnesia. Therefore, the most accurate description of dissociative amnesia is indeed the sudden loss of critical personal information.