Occasionally everyone has minor problems integrating their memories, perceptions, identity, and consciousness. For example, people may drive somewhere and then realize that they do not remember the drive. They may not remember it because they are absorbed—with personal concerns, a program on the radio, or a conversation with a passenger—or are just daydreaming. Such problems, referred to as normal dissociation, typically do not disrupt everyday activities.

In contrast, people with a dissociative disorder may totally forget a series of their activities that occurred over minutes, hours, or sometimes much longer. They may sense they are missing a period of time. Dissociation thus disrupts the continuity of self and the recollection of life events. Dissociative disorders involve the following:

Did You Know... A minor blow to the head cannot cause people to suddenly forget who they are and everything they know.

• Poorly integrated memory (dissociative amnesia)
• Fragmentation of identity and memory (dissociative fugue or dissociative identity disorder)
• Disruption of the experience and perception of self (depersonalization disorder)

Dissociative disorders are usually triggered by overwhelming stress or trauma. For example, people may have been abused or mistreated during childhood. They may have experienced or witnessed traumatic events, such as accidents or disasters. Or they may experience inner conflict so intolerable that their mind is forced to separate incompatible or unacceptable information and feelings from conscious thought.

Last full review/revision June 2008 by Daphne Simeon, MD