Overview of Dissociative Disorders

ByDavid Spiegel, MD, Stanford University School of Medicine
Reviewed/Revised May 2023
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    Many people occasionally experience minor problems with a gap in 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 were absorbed—with personal concerns, a program on the radio, or a conversation with a passenger—or 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 activities that occurred over minutes, hours, or sometimes much longer. They may sense they are missing a period of time. In addition, they may feel detached (dissociated) from themselves—that is, from their memories, perceptions, identity, thoughts, emotions, body, and behavior. Or they may feel detached from the world around them. Thus, their sense of identity, memory, and/or consciousness is fragmented.

    Dissociative disorders involve the following:

    Did You Know...

    • Major stress or trauma may cause gaps in memory, but a minor blow to the head cannot cause people to suddenly forget who they are and everything they know.

    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.

    Dissociative disorders are related to trauma and stress-related disorders (acute stress disorder and posttraumatic stress disorder). People with stress-related disorders may have dissociative symptoms, such as amnesia, flashbacks, numbing, and depersonalization/derealization. Some people with posttraumatic stress disorder (PTSD) also experience depersonalization, derealization, or both, and this is classified as a dissociative subtype of PTSD.

    Research in animals and humans shows that certain underlying brain structures and functions appear to be associated with dissociative disorders. Scientists do not yet understand how these abnormalities in these structures and functions cause dissociative disorders or how this knowledge could guide treatment, but they appear to be promising leads that would benefit from further research.

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