These alterations can include: a sense that self or the world is unreal (depersonalization and derealization), a loss of memory (amnesia), forgetting identity or assuming a new self (fugue), and separate streams of consciousness, identity and self (dissociative identity disorder, formerly termed multiple personality disorder) and complex post-traumatic stress disorder. Although some dissociative disruptions involve amnesia, other dissociative events do not. Dissociative disorders are typically experienced as startling, autonomous intrusions into the persons usual ways of responding or functioning. Due to their unexpected and largely inexplicable nature, they tend to be quite unsettling. Dissociative disorders are sometimes triggered by trauma, but may be preceded only by stress, psychoactive substances, or no identifiable trigger at all. The ICD-10 classifies conversion disorder as a dissociative disorder. The Diagnostic and Statistical Manual of Mental Disorders groups all dissociative disorders into a single category and recognizes dissociation as a symptom of acute stress disorder, posttraumatic stress disorder, and borderline personality disorder.Misdiagnosis is common among people who display symptoms of dissociative disorders, with an average of seven years to receive proper diagnosis and treatment. Research is ongoing into etiologies, symptomology, and valid and reliable diagnostic tools. In the general population, dissociative experiences that are not clinically significant are highly prevalent with 60% to 65% of the respondents indicating that they have had some dissociative experiences. Diagnostic and Statistical Manual of Mental Disorders
Diagnoses listed under the DSM-5 are dissociative identity disorder, dissociative amnesia, depersonalization/derealization disorder, other specified dissociative disorder and unspecified dissociative disorder.
Dissociation, as a concept that has been developed over time, is any of a wide array of experiences, ranging from a mild emotional detachment from the immediate surroundings, to a more severe disconnection from physical and emotional experiences. The major characteristic of all dissociative phenomena involves a detachment from reality, rather than a loss of reality as in psychosis.The phenomena are diagnosable under the DSM-5 as a group of disorders as well as a symptom of other disorders through various diagnostic tools. Its cause is believed to be related to neurobiological mechanisms, trauma, anxiety, and psychoactive drugs. Research has further related it to suggestibility and hypnosis, and it is inversely related to mindfulness, which is a potential treatment. History
French philosopher and psychologist Pierre Janet (1859–1947) is considered to be the author of the concept of dissociation. Contrary to some conceptions of dissociation, Janet did not believe that dissociation was a psychological defense.Psychological defense mechanisms belong to Sigmund Freuds theory of psychoanalysis, not to Janetian psychology. Janet claimed that dissociation occurred only in persons who had a constitutional weakness of mental functioning that led to hysteria when they were stressed. Although it is true that many of Janets case histories described traumatic experiences, he never considered dissociation to be a defense against those experiences. Quite the opposite: Janet insisted that dissociation was a mental or cognitive deficit.